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Sample records for 193nm immersion lithography

  1. Inorganic immersion fluids for ultrahigh numerical aperture 193 nm lithography

    NASA Astrophysics Data System (ADS)

    Zhou, Jianming; Fan, Yongfa; Bourov, Anatoly; Smith, Bruce W.

    2006-05-01

    Immersion lithography has become attractive since it can reduce critical dimensions by increasing numerical aperture (NA) beyond unity. Among all the candidates for immersion fluids, those with higher refractive indices and low absorbance are desired. Characterization of the refractive indices and absorbance of various inorganic fluid candidates has been performed. To measure the refractive indices of these fluids, a prism deviation angle method was developed. Several candidates have been identified for 193 nm application with refractive indices near 1.55, which is approximately 0.1 higher than that of water at this wavelength. Cauchy parameters of these fluids were generated and approaches were investigated to tailor the fluid absorption edges to be close to 193 nm. The effects of these fluids on photoresist performance were also examined with 193 nm immersion lithography exposure at various NAs. Half-pitch 32 nm lines were obtained with phosphoric acid as the immersion medium at 1.5 NA. These fluids are potential candidates for immersion lithography technology.

  2. Novel high refractive index fluids for 193nm immersion lithography

    NASA Astrophysics Data System (ADS)

    Santillan, Julius; Otoguro, Akihiko; Itani, Toshiro; Fujii, Kiyoshi; Kagayama, Akifumi; Nakano, Takashi; Nakayama, Norio; Tamatani, Hiroaki; Fukuda, Shin

    2006-03-01

    Despite the early skepticism towards the use of 193-nm immersion lithography as the next step in satisfying Moore's law, it continuous to meet expectations on its feasibility in achieving 65-nm nodes and possibly beyond. And with implementation underway, interest in extending its capability for smaller pattern sizes such as the 32-nm node continues to grow. In this paper, we will discuss the optical, physical and lithographic properties of newly developed high index fluids of low absorption coefficient, 'Babylon' and 'Delphi'. As evaluated in a spectroscopic ellipsometer in the 193.39nm wavelength, the 'Babylon' and 'Delphi' high index fluids were evaluated to have a refractive index of 1.64 and 1.63 with an absorption coefficient of 0.05/cm and 0.08/cm, respectively. Lithographic evaluation results using a 193-nm 2-beam interferometric exposure tool show the imaging capability of both high index fluids to be 32-nm half pitch lines and spaces.

  3. Nanocomposite liquids for 193 nm immersion lithography: a progress report

    NASA Astrophysics Data System (ADS)

    Chumanov, George; Evanoff, David D., Jr.; Luzinov, Igor; Klep, Viktor; Zdryko, Bogdan; Conley, Will; Zimmerman, Paul

    2005-05-01

    Immersion lithography is a new promising approach capable of further increasing the resolution of semiconductor devices. This technology requires the development of new immersion media that satisfy the following conditions: the media should have high refractive index, be transparent and photochemically stable in DUV spectral range. They should also be inert towards photoresists and optics and be liquid to permit rapid scanning. Here we propose and explore a novel strategy in which high refractive index medium is made of small solid particles suspended in liquid phases (nanocomposite liquids). The dielectric particles have high refractive index and the refractive index of nanocomposite liquids becomes volume weighted average between refractive indices of nanoparticles and the liquid phase. We investigate aluminum oxide (alumina) nanoparticles suspended in water. Alumina is known to have high (1.95) refractive index and low absorption coefficient at 193 nm. Alumina nanoparticles were prepared by chemical methods followed by removal of organic molecules left after hydrolysis reactions. Measurements of optical and reological properties of the nanocomposite liquid demonstrated potential advantage of this approach for 193 nm immersion lithography.

  4. High-index optical materials for 193nm immersion lithography

    NASA Astrophysics Data System (ADS)

    Burnett, John H.; Kaplan, Simon G.; Shirley, Eric L.; Horowitz, Deane; Clauss, Wilfried; Grenville, Andrew; Van Peski, Chris

    2006-03-01

    We report on our comprehensive survey of high-index UV optical materials that may enable extension of immersion lithography beyond a numerical aperture of 1.45. Band edge, refractive index, and intrinsic birefringence (IBR) at 193 nm determine basic viability. Our measurements of these properties have reduced the list of potential candidates to: ceramic spinel, lutetium aluminum garnet, and a class of germanium garnets. We discuss our measurements of the intrinsic properties of these materials and assess the present status of their material quality relative to requirements. Ceramic spinel has no significant IBR, but transmission and scatter for the best samples remain at least two orders of magnitude from specifications. Improving these would require a major development effort. Presently available lutetium aluminum garnet has material quality much closer to the specifications. However, the IBR is about three times the required value. The germanium garnets offer the possibility of a lower IBR, but a suitable candidate material has yet to be established.

  5. Defectivity reduction by optimization of 193-nm immersion lithography using an interfaced exposure-track system

    NASA Astrophysics Data System (ADS)

    Carcasi, Michael; Hatakeyama, Shinichi; Nafus, Kathleen; Moerman, Richard; van Dommelen, Youri; Huisman, Peter; Hooge, Joshua; Scheer, Steven; Foubert, Philippe

    2006-03-01

    As the integration of semiconductor devices continues, pattern sizes required in lithography get smaller and smaller. To achieve even more scaling down of these patterns without changing the basic infrastructure technology of current cutting-edge 193-nm lithography, 193-nm immersion lithography is being viewed as a powerful technique that can accommodate next-generation mass productions needs. Therefore this technology has been seriously considered and after proof of concept it is currently entering the stage of practical application. In the case of 193-nm immersion lithography, however, because liquid fills the area between the projection optics and the silicon wafer, several causes of concern have been raised - namely, diffusion of moisture into the resist film due to direct resist-water interaction during exposure, dissolution of internal components of the resist into the de-ionized water, and the influence of residual moisture generated during exposure on post-exposure processing. To prevent these unwanted effects, optimization of the three main components of the lithography system: materials, track and scanner, is required. For the materials, 193nm resist formulation improvements specifically for immersion processing have reduced the leaching and the sensitivity to water related defects, further benefits can be seen by the application of protective top coat materials. For the track component, optimization of the processing conditions and immersion specific modules are proven to advance the progress made by the material suppliers. Finally, by optimizing conditions on the 3 rd generation immersion scanner with the latest hardware configuration, defectivity levels comparable to dry processing can be achieved. In this evaluation, we detail the improvements that can be realized with new immersion specific track rinse modules and formulate a hypothesis for the improvements seen with the rinsing process. Additionally, we show the current status of water induced

  6. Study of barrier coats for application in immersion 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Houlihan, Francis; Kim, Wookyu; Sakamuri, Raj; Hamilton, Keino; Dimerli, Alla; Abdallah, David; Romano, Andrew; Dammel, Ralph R.; Pawlowski, Georg; Raub, Alex; Brueck, Steve

    2005-05-01

    We will describe our barrier coat approach for use in immersion 193 nm lithography. These barrier coats may act as either simple barriers providing protection against loss of resist components into water or in the case of one type of these formulations which have a refractive index at 193 nm which is the geometric mean between that of the resist and water provide, also top antireflective properties. Either type of barrier coat can be applied with a simple spinning process compatible with PGMEA based resin employing standard solvents such as alcohols and be removed during the usual resist development process with aqueous 0.26 N TMAH. We will discuss both imaging results with these materials on acrylate type 193 nm resists and also show some fundamental studies we have done to understand the function of the barrier coat and the role of differing spinning solvents and resins. We will show LS (55 nm) and Contact Hole (80 nm) resolved with a 193 nm resist exposed with the interferometric tool at the University of New Mexico (213 nm) with and without the use of a barrier coat.

  7. 193nm immersion lithography for high-performance silicon photonic circuits

    NASA Astrophysics Data System (ADS)

    Selvaraja, Shankar K.; Winroth, Gustaf; Locorotondo, Sabrina; Murdoch, Gayle; Milenin, Alexey; Delvaux, Christie; Ong, Patrick; Pathak, Shibnath; Xie, Weiqiang; Sterckx, Gunther; Lepage, Guy; Van Thourhout, Dries; Bogaerts, Wim; Van Campenhout, Joris; Absil, Philippe

    2014-04-01

    Large-scale photonics integration has been proposed for many years to support the ever increasing requirements for long and short distance communications as well as package-to-package interconnects. Amongst the various technology options, silicon photonics has imposed itself as a promising candidate, relying on CMOS fabrication processes. While silicon photonics can share the technology platform developed for advanced CMOS devices it has specific dimension control requirements. Though the device dimensions are in the order of the wavelength of light used, the tolerance allowed can be less than 1% for certain devices. Achieving this is a challenging task which requires advanced patterning techniques along with process control. Another challenge is identifying an overlapping process window for diverse pattern densities and orientations on a single layer. In this paper, we present key technology challenges faced when using optical lithography for silicon photonics and advantages of using the 193nm immersion lithography system. We report successful demonstration of a modified 28nm- STI-like patterning platform for silicon photonics in 300mm Silicon-On-Insulator wafer technology. By careful process design, within-wafer CD variation (1sigma) of <1% is achieved for both isolated (waveguides) and dense (grating) patterns in silicon. In addition to dimensional control, low sidewall roughness is a crucial to achieve low scattering loss in the waveguides. With this platform, optical propagation loss as low as ~0.7 dB/cm is achieved for high-confinement single mode waveguides (450x220nm). This is an improvement of >20 % from the best propagation loss reported for this cross-section fabricated using e-beam lithography. By using a single-mode low-confinement waveguide geometry the loss is further reduced to ~0.12 dB/cm. Secondly, we present improvement in within-device phase error in wavelength selective devices, a critical parameter which is a direct measure of line

  8. Low leaching and low LWR photoresist development for 193 nm immersion lithography

    NASA Astrophysics Data System (ADS)

    Ando, Nobuo; Lee, Youngjoon; Miyagawa, Takayuki; Edamatsu, Kunishige; Takemoto, Ichiki; Yamamoto, Satoshi; Tsuchida, Yoshinobu; Yamamoto, Keiko; Konishi, Shinji; Nakano, Katsushi; Tomoharu, Fujiwara

    2006-03-01

    receding contact angle become very important issue for not only defectivity but also scanner throughput. Some of our experimental results along this line of study are also included in the report. The last topic covered is LWR (Line Width Roughness) as an essential leverage for performance improvement, especially for the smaller CD that immersion lithography is aiming to define. Our recent effort to find effect and working concept to reduce LWR with low leaching materials is also described.

  9. High-index nanocomposite photoresist for 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Bae, Woo Jin; Trikeriotis, Makros; Rodriguez, Robert; Zettel, Michael F.; Piscani, Emil; Ober, Christopher K.; Giannelis, Emmanuel P.; Zimmerman, Paul

    2009-03-01

    In immersion lithography, high index fluids are used to increase the numerical aperture (NA) of the imaging system and decrease the minimum printable feature size. Water has been used in first generation immersion lithography at 193 nm to reach the 45 nm node, but to reach the 38 and 32 nm nodes, fluids and resists with a higher index than water are needed. A critical issue hindering the implementation of 193i at the 32 nm node is the availability of high refractive index (n > 1.8) and low optical absorption fluids and resists. It is critical to note that high index resists are necessary only when a high refractive index fluid is in use. High index resist improves the depth of focus (DOF) even without high index fluids. In this study, high refractive index nanoparticles have been synthesized and introduced into a resist matrix to increase the overall refractive index. The strategy followed is to synthesize PGMEA-soluble nanoparticles and then disperse them into a 193 nm resist. High index nanoparticles 1-2 nm in diameter were synthesized by a combination of hydrolysis and sol-gel methods. A ligand exchange method was used, allowing the surface of the nanoparticles to be modified with photoresist-friendly moieties to help them disperse uniformly in the resist matrix. The refractive index and ultraviolet absorbance were measured to evaluate the quality of next generation immersion lithography resist materials.

  10. Carbon dioxide gas purification and analytical measurement for leading edge 193nm lithography

    NASA Astrophysics Data System (ADS)

    Riddle Vogt, Sarah; Landoni, Cristian; Applegarth, Chuck; Browning, Matt; Succi, Marco; Pirola, Simona; Macchi, Giorgio

    2015-03-01

    The use of purified carbon dioxide (CO2) has become a reality for leading edge 193 nm immersion lithography scanners. Traditionally, both dry and immersion 193 nm lithographic processes have constantly purged the optics stack with ultrahigh purity compressed dry air (UHPCDA). CO2 has been utilized for a similar purpose as UHPCDA. Airborne molecular contamniation (AMC) purification technologies and analytical measurement methods have been extensively developed to support the Lithography Tool Manufacturers purity requirements. This paper covers the analytical tests and characterizations carried out to assess impurity removal from 3.0 N CO2 (beverage grade) for its final utilization in 193 nm and EUV scanners.

  11. Advanced patterning approaches based on negative-tone development (NTD) process for further extension of 193nm immersion lithography

    NASA Astrophysics Data System (ADS)

    Shirakawa, Michihiro; Inoue, Naoki; Furutani, Hajime; Yamamoto, Kei; Goto, Akiyoshi; Fujita, Mitsuhiro

    2015-03-01

    Two approaches which achieve the further evolution of NTD (Negative Tone Development) process are shown in this article. One is ACCEL (Advanced Chemical Contrast Enhancement Layer) process that can improve the lithography performance and the other is DTD (Dual Tone Development) process that can shrink patterning pitch below the limit of single exposure process. ACCEL is an additionally provided layer which is coated on a surface of NTD resist film before exposure and removed by NTD developer. ACCEL can enhance the acid distribution and dissolution contrast of the NTD resist. In fact, lithography performances such as exposure latitude (EL) and DOF improved dramatically by applying ACCEL compared to the NTD resist without ACCEL. We consider that suppression of excessive acid diffusion and material transfer between the resist layer and the ACCEL layer are the causes of the contrast enhancement. DTD process is one of the simplest pitch shrink method which is achieved by repeating PTD and NTD process. Feasibility study of DTD patterning has been demonstrated so far. However, Exposure latitude margin and CDU performance were not sufficient for applying DTD to HVM. We developed the novel DTD specific resist under a new concept, and 32 nm half pitch (hp) contact hole (CH) pattern was successfully formed with enough margins. DTD line and space (L/S) patterning are also demonstrated and 24 nm hp L/S pattern can be resolved. k1 factors of DTD CH and L/S patterns reach to 0.20 and 0.15, respectively.

  12. Design, synthesis, and characterization of fluorine-free PAGs for 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Liu, Sen; Glodde, Martin; Varanasi, Pushkara R.

    2010-04-01

    Photoacid generators (PAGs) are a key component in chemically amplified resists used in photolithography. Perfluorooctanesulfonates (PFOS) and other perfluoroalkylsulfonates (PFAS) have been well adopted as PAGs in 193 nm photoresist. Recently, concerns have been raised about their environmental impact due to their chemical persistency, bioaccumulation and toxicity. It is a general interest to find environmentally benign PAGs that are free of fluorine atoms. Here we describe the design, synthesis and characterization of a series of novel fluorine-free onium salts as PAGs for 193 nm photoresists. These PAGs demonstrated desirable physical and lithography properties when compared with PFAS-based PAGs for both dry and immersion exposures.

  13. Adamantane based molecular glass resist for 193 nm lithography

    NASA Astrophysics Data System (ADS)

    Tanaka, Shinji; Ober, Christopher K.

    2006-03-01

    As the feature dimensions decreases there are several issues must be addressed to implement the corresponding technology in high volume production. Line width roughness (LWR) and line edge roughness (LER) are the most important technological issue arises as the feature dimension decreases. In order to improve both of LWR and LER, we have developed novel low molecular weight glass resists as high performance resist materials. These molecular glass resists are adamantane derivatives and are highly transparent at 193 nm. We have prepared series of new molecular glass resists based on adamantane core carrying acetal and ester protecting groups. Particularly, adamantane core derivatives of tripod structure were investigated in detail. Several compositions of them showed glass transition temperatures (Tg) above 120 °C. Lithographic evaluation confirmed their high sensitivity at 254 nm and e-beam exposure. It also resolved feature size as small as 200 nm line/space when it evaluated using e-beam lithography. These new molecular glass resists also have high plasma-etch resistance.

  14. Alternatives to chemical amplification for 193nm lithography

    NASA Astrophysics Data System (ADS)

    Baylav, Burak; Zhao, Meng; Yin, Ran; Xie, Peng; Scholz, Chris; Smith, Bruce; Smith, Thomas; Zimmerman, Paul

    2010-04-01

    Research has been conducted to develop alternatives to chemically amplified 193 nm photoresist materials that will be able to achieve the requirements associated with sub-32 nm device technology. New as well as older photoresist design concepts for non-chemically amplified 193 nm photoresists that have the potential to enable improvements in line edge roughness while maintaining adequate sensitivity, base solubility, and dry etch resistance for high volume manufacturing are being explored. The particular platforms that have been explored in this work include dissolution inhibitor photoresist systems, chain scissioning polymers, and photoresist systems based on polymers incorporating formyloxyphenyl functional groups. In studies of two-component acidic polymer/dissolution inhibitor systems, it was found that compositions using ortho-nitrobenzyl cholate (NBC) as the dissolution inhibitor and poly norbornene hexafluoro alcohol (PNBHFA) as the base resin are capable of printing 90 nm dense line/space patterns upon exposure to a 193 nm laser. Studies of chain scission enhancement in methylmethacrylate copolymers showed that incorporating small amounts of absorptive a-cleavage monomers significantly enhanced sensitivity with an acceptable increase in absorbance at 193 nm. Specifically, it was found that adding 3 mol% of α-methyl styrene (α-MS) reduced the dose to clear of PMMA-based resist from 1400 mJ/cm2 to 420 mJ/cm2. Preliminary data are also presented on a direct photoreactive design concept based on the photo-Fries reaction of formyloxyphenyl functional groups in acrylic copolymers.

  15. Modeling chemically amplified resists for 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Croffie, Ebo H.; Cheng, Mosong; Neureuther, Andrew R.; Houlihan, Francis M.; Cirelli, Raymond A.; Sweeney, James R.; Dabbagh, Gary; Watson, Pat G.; Nalamasu, Omkaram; Rushkin, Ilya L.; Dimov, Ognian N.; Gabor, Allen H.

    2000-06-01

    Post exposure bake (PEB) models in the STORM program have been extended to study pattern formation in 193 nm chemically amplified resists. Applications to resists formulated with cycloolefin-maleic anhydride copolymers, cholate based dissolution inhibitor, nonaflate photoacid generator and base quencher are presented. The PEB modeling is based on the chemical and physical mechanisms including the thermally induced deprotection reaction, acid loss due to base neutralization and protected-sites-enhanced acid diffusion. Simplifying assumptions are made to derive analytical expressions for PEB. The model parameters are extracted from the following experiments. UV-visible spectroscopy is used to extract the resist absorbance parameters. The generation of acid is monitored using the method of 'base additions.' The extent of deprotection that occurs during the bake is determined by monitoring the characteristic FTIR absorbance band around 1170 cm-1 over a range of exposure doses and bake temperatures. Diffusion parameters are extracted from line end shortening (LES) measurements. These parameters are optimized using the Method of Feasible Directions algorithm. Application results show good agreement with experimental data for different LES features.

  16. 193-nm immersion photomask image placement in exposure tools

    NASA Astrophysics Data System (ADS)

    Cotte, Eric; Alles, Benjamin; Wandel, Timo; Antesberger, Gunter; Teuber, Silvio; Vorwerk, Manuel; Frangen, Andreas; Katzwinkel, Frank

    2006-03-01

    In case drastic changes need to be made to tool configurations or blank specifications, it is important to know as early as possible under which conditions the tight image placement requirements of future lithography nodes can be achieved. Modeling, such as finite element simulations, can help predict the magnitude of structural and thermal effects before actual manufacturing issues occur, and basic experiments using current tools can readily be conducted to verify the predicted results or perform feasibility tests for future nodes. Using numerical simulations, experimental mask registration, and printing data, the effects on image placement of stressed layer patterning, pellicle attachment, blank dimensional and material tolerances, as well as charging during e-beam writing were investigated for current mask blank specifications. This provides an understanding of the areas that require more work for image placement error budgets to be met and to insure the viability of optical lithography for future nodes.

  17. Extension of 193 nm dry lithography to 45-nm half-pitch node: double exposure and double processing technique

    NASA Astrophysics Data System (ADS)

    Biswas, Abani M.; Li, Jianliang; Hiserote, Jay A.; Melvin, Lawrence S., III

    2006-10-01

    Immersion lithography and multiple exposure techniques are the most promising methods to extend lithography manufacturing to the 45nm node. Although immersion lithography has attracted much attention recently as a promising optical lithography extension, it will not solve all the problems at the 45-nm node. The 'dry' option, (i.e. double exposure/etch) which can be realized with standard processing practice, will extend 193-nm lithography to the end of the current industry roadmap. Double exposure/etch lithography is expensive in terms of cost, throughput time, and overlay registration accuracy. However, it is less challenging compared to other possible alternatives and has the ability to break through the κ I barrier (0.25). This process, in combination with attenuated PSM (att-PSM) mask, is a good imaging solution that can reach, and most likely go beyond, the 45-nm node. Mask making requirements in a double exposure scheme will be reduced significantly. This can be appreciated by the fact that the separation of tightly-pitched mask into two less demanding pitch patterns will reduce the stringent specifications for each mask. In this study, modeling of double exposure lithography (DEL) with att-PSM masks to target 45-nm node is described. In addition, mask separation and implementation issues of optical proximity corrections (OPC) to improve process window are studied. To understand the impact of OPC on the process window, Fourier analysis of the masks has been carried out as well.

  18. Chemical trimming overcoat: an enhancing composition and process for 193nm lithography

    NASA Astrophysics Data System (ADS)

    Liu, Cong; Rowell, Kevin; Joesten, Lori; Baranowski, Paul; Kaur, Irvinder; Huang, Wanyi; Leonard, JoAnne; Jeong, Hae-Mi; Im, Kwang-Hwyi; Estelle, Tom; Cutler, Charlotte; Pohlers, Gerd; Yin, Wenyan; Fallon, Patricia; Li, Mingqi; Jeon, Hyun; Xu, Cheng Bai; Trefonas, Pete

    2016-03-01

    As the critical dimension of devices is approaching the resolution limit of 193nm photo lithography, multiple patterning processes have been developed to print smaller CD and pitch. Multiple patterning and other advanced lithographic processes often require the formation of isolated features such as lines or posts by direct lithographic printing. The formation of isolated features with an acceptable process window, however, can pose a challenge as a result of poor aerial image contrast at defocus. Herein we report a novel Chemical Trimming Overcoat (CTO) as an extra step after lithography that allows us to achieve smaller feature size and better process window.

  19. Front-end-of-line process development using 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Pollentier, Ivan K.; Ercken, Monique; Eliat, Astrid; Delvaux, Christie; Jaenen, Patrick; Ronse, Kurt G.

    2001-04-01

    It is expected that 193nm lithography will be introduced in front-end-of-line processing for all critical layers at the 100nm node, and possibly also for some layers at the 130nm node, where critical layers are required to have the lowest mask cost. These processes are currently being investigated at IMEC for CMOS logic applications. While the lithographic performance of 193 nm resists has improved significantly in the last year, most materials still have important processing issues that need further improvement. On one hand, the resists material itself suffers from for example poor dry etch resistance and SEM CD shrinkage. On the other hand, interaction with other materials such as SiON inorganic ARCs becomes more challenging in terms of footing behavior, adhesion, and line edge roughness. In this paper, the 193nm processing experience gained at IMEC will be outlined, as well as solutions for manufacturability. Front- end-of-line integration results will also be shown, mainly for gate applications. It will be demonstrated that currently several commercial resist are capable of printing 130nm gates within the +/- 10 percent CD tolerance, even after gate etch. The impact of line edge roughness will also be discussed. Finally, the feasibility of printing 100nm logic patterns using only binary masks has been demonstrated, including gate etch.

  20. Radiation sensitive developable bottom anti-reflective coatings (DBARC) for 193nm lithography: first generation

    NASA Astrophysics Data System (ADS)

    Toukhy, Medhat; Oberlander, Joseph; Mullen, Salem; Lu, PingHung; Neisser, Mark

    2007-03-01

    A first generation DBARC applicable for 1 st minimum 193nm lithography is described in this paper. The polymer used in this DBARC is insoluble in the casting solvent of the resist, which is propyleneglycolmonomethyletheracetate (PGMEA). Photo acid generator (PAG) and base extractions from the DBARC coating by the resist casting solvent were examined by the DBARC dissolution rates in the developer, before and after solvent treatments. Although the resist and the DBARC do not appear to intermix, strong interaction between the two is evident by their lithographic performance and dissolution rate study.

  1. Top surface imaging through vapor phase silylation for 193 nm lithography

    NASA Astrophysics Data System (ADS)

    Somervell, Mark Howell

    temperatures were synthesized. Using these alicyclic polymers at 193 nm produces high resolution features with greatly decreased LER. This dissertation describes the synthesis and characterization of these TSI polymers and their application to 193 nm lithography. Also, the fundamental physical mechanisms that control the silylation process are discussed.

  2. Next-generation 193-nm laser for sub-100-nm lithography

    NASA Astrophysics Data System (ADS)

    Duffey, Thomas P.; Blumenstock, Gerry M.; Fleurov, Vladimir B.; Pan, Xiaojiang; Newman, Peter C.; Glatzel, Holger; Watson, Tom A.; Erxmeyer, J.; Kuschnereit, Ralf; Weigl, Bernhard

    2001-09-01

    The next generation 193 nm (ArF) laser has been designed and developed for high-volume production lithography. The NanoLithTM 7000, offering 20 Watts average output power at 4 kHz repetition rates is designed to support the highest exposure tool scan speeds for maximum productivity and wafer throughput. Fundamental design changes made to the laser core technologies are described. These advancements in core technology support the delivery of highly line-narrowed light with lithography, meeting specifications for bandwidth, dose stability (+/- 0.3% in 20 ms window) and wavelength stability (+/- 0.05 pm average line center error in 20 ms window) across 2 - 4 kHz repetition rates. Improvements in optical materials and coatings have led to increased lifetime of optics modules. Optimization of the discharge electrode design has increased chamber lifetime. Early life-testing indicates that the NanoLithTM core technologies have the potential for 400% reduction of cost of consumables as compared to its predecessor, the ELX-5000A and has been discussed elsewhere.

  3. Novel low-reflective index fluoropolymers-based top anti-reflective coatings (TARC) for 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Yamashita, Tsuneo; Hayami, Takashi; Ishikawa, Takuji; Kanemura, Takashi; Aoyama, Hirokazu

    2007-03-01

    Implant lithography, which has up to now utilized 365-nm (i-line) and 248-nm (KrF) light sources, must now turn to 193-nm (ArF) sources. In implant lithography, an anti-reflective material is often used to coat the resist-film. The top anti-reflective coating (abbreviated to TARC) is most often used to reduce CD swing. TARC materials must have low refractive index and water solubility. The TARC materials for used 193-nm use must have very low reflective index and alternatives to perfluorooctylsulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) must be found. We synthesized some novel fluorinated amorphous polymers as 193-nm TARC candidates. Their fundamental properties were characterized, such as transparency and reflective index at 193-nm (wavelength) along with their solubility in water and a standard alkaline developer. High transparency, i.e., k value less than 0.01, and very low reflective index, i.e., lower than n=1.4 at 193-nm wavelength are confirmed. Their dissolution behaviors are studied using the Quartz Crystal Microbalance (QCM) method. In surprise finding, we find that several of the polymers examined, those that have high fluorine content, dissolved in water. Test results show that the proposed polymers can be applied as top anti reflective coatings .

  4. High speed AFM studies of 193 nm immersion photoresists during TMAH development

    NASA Astrophysics Data System (ADS)

    Ngunjiri, Johnpeter; Meyers, Greg; Cameron, Jim; Suzuki, Yasuhiro; Jeon, Hyun; Lee, Dave; Choi, Kwang Mo; Kim, Jung Woo; Im, Kwang-Hwyi; Lim, Hae-Jin

    2016-03-01

    In this paper we report on our studies of the dynamic process of resist development in real time. Using High Speed - Atomic Force Microscopy (HS-AFM) in dilute developer solution, changes in morphology and nanomechanical properties of patterned resist were monitored. The Bruker Dimension FastScan AFMTM was applied to analyze 193 nm acrylic-based immersion resists in developer. HS-AFM operated in Peak Force mapping mode allowed for concurrent measurements of image topography resist stiffness, adhesion to AFM probe and deformation during development. In our studies we focused on HS-AFM topography data as it readily revealed detailed information about initial resist morphology, followed by a resist swelling process and eventual dissolution of the exposed resist areas. HS-AFM showed potential for tracking and understanding development of patterned resist films and can be useful in evaluating the dissolution properties of different resist designs.

  5. Pellicle choice for 193-nm immersion lithography photomasks

    NASA Astrophysics Data System (ADS)

    Cotte, Eric P.; Haessler, Ruediger; Utess, Benno; Antesberger, Gunter; Kromer, Frank; Teuber, Silvio

    2004-12-01

    An assessment of the mechanical performance of pellicles from different vendors was performed. Pellicle-induced distortions were experimentally measured and numerical simulations were run to predict what improvements were desirable. The experiments included mask registration measurements before and after pellicle mounting for three of the major pellicle suppliers, and adhesive gasket material properties characterization for previously untested samples. The finite element numerical simulations were verified via comparison to experimental data for pellicles with known frame bows, measured by the vendor. The models were extended to simulate the effect of the chucking of reticles in an exposure tool, as well as the various magnification correction schemes available in such tools. Results were compared to ITRS requirements to evaluate performances. This study enables the AMTC to give important feedback to pellicle suppliers and make proper recommendations to customers for future pellicle choices.

  6. Resist component leaching in 193-nm immersion lithography

    NASA Astrophysics Data System (ADS)

    Dammel, Ralph R.; Pawlowski, Georg; Romano, Andrew; Houlihan, Frank M.; Kim, Woo-Kyu; Sakamuri, Raj; Abdallah, David

    2005-05-01

    The leaching of ionic PAGs from model resist films into a static water volume is shown to follow first order kinetics. From the saturation concentration and the leaching time constant, the leaching rate at time zero is obtained which is a highly relevant parameter for evaluating lens contamination potential. The levels of leaching seen in the model resists generally exceed both static and rate-based dynamic leaching specifications. The dependence of leaching on anion structure shows that more hydrophobic anions have lower saturation concentration; however, the time constant of leaching increases with anion chain length. Thus in our model system, the initial leaching rates of nonaflate and PFOS anions are identical. Investigation of a water pre-rinse process unexpectedly showed that some PAG can still be leached from the surface although the pre-rinse times greatly exceeded the times required for saturation of the leaching phenomenon, which are expected to correspond to complete depletion of leachable PAG from the surface. A model is proposed to explain this phenomenon through re-organization of the surface as the surface energy changes during the air/water/air contact sequence of the pre-rinse process.

  7. Extremely long life and low-cost 193nm excimer laser chamber technology for 450mm wafer multipatterning lithography

    NASA Astrophysics Data System (ADS)

    Tsushima, Hiroaki; Katsuumi, Hisakazu; Ikeda, Hiroyuki; Asayama, Takeshi; Kumazaki, Takahito; Kurosu, Akihiko; Ohta, Takeshi; Kakizaki, Kouji; Matsunaga, Takashi; Mizoguchi, Hakaru

    2014-04-01

    193nm ArF excimer lasers are widely used as light sources for the lithography process of semiconductor production. 193nm ArF exicmer lasers are expected to continue to be the main solution in photolithography, since advanced lithography technologies such as multiple patterning and Self-Aligned Double Patterning (SADP) are being developed. In order to apply these technologies to high-volume semiconductor manufacturing, the key is to reduce the total operating cost. To reduce the total operating cost, life extension of consumable part and reduction of power consumption are an important factor. The chamber life time and power consumption are a main factor to decide the total operating cost. Therefore, we have developed the new technology for extension of the chamber life time and low electricity consumption. In this paper, we will report the new technology to extend the life time of the laser chamber and to reduce the electricity consumption.

  8. Top-coatless 193nm positive-tone development immersion resist for logic application

    NASA Astrophysics Data System (ADS)

    Liu, Lian Cong; Yeh, Tsung Ju; Lin, Yeh-Sheng; Huang, Yu Chin; Kuo, Chien Wen; Huang, Wen Liang; Lin, Chia Hung; Yu, Chun Chi; Hsu, Ray; Wan, I.-Yuan; Lin, Jeff; Im, Kwang-Hwyi; Lim, Hae Jin; Jeon, Hyun K.; Suzuki, Yasuhiro; Xu, Cheng Bai

    2015-03-01

    In this paper, we summarize our development efforts for a top-coatless 193nm immersion positive tone development (PTD) contact hole (C/H) resist with improved litho and defect performances for logic application specifically with an advance node. The ultimate performance goal was to improve the depth of focus (DoF) margin, mask error enhancement factor (MEEF), critical dimension uniformity (CDU), contact edge roughness (CER), and defect performance. Also, the through pitch CD difference was supposed to be comparable to the previous control resist. Effects of polymer and PAG properties have been evaluated for this purpose. The material properties focused in the evaluation study were polymer activation energy (Ea), polymer solubility differentiated by polymerization process types, and diffusion length (DL) and acidity (pKa) of photoacid generator (PAG). Additionally, the impact of post exposure bake (PEB) temperature was investigated for process condition optimization. As a result of this study, a new resist formulation to satisfy all litho and defect performance was developed and production yield was further improved.

  9. Double-exposure materials for pitch division with 193nm lithography: requirements, results

    NASA Astrophysics Data System (ADS)

    Bristol, Robert; Shykind, David; Kim, Sungwon; Borodovsky, Yan; Schwartz, Evan; Turner, Courtney; Masson, Georgeta; Min, Ke; Esswein, Katherine; Blackwell, James M.; Suetin, Nikolay

    2009-03-01

    We present the results of both theoretical and experimental investigations of materials for application either as a reversible Contrast Enhancement Layer (rCEL) or a Two-Stage PAG. The purpose of these materials is to enable Litho- Litho-Etch (LLE) patterning for Pitch Division (PD) at the 16nm logic node (2013 Manufacturing). For the rCEL, we find from modeling using an E-M solver that such a material must posses a bleaching capability equivalent to a Dill A parameter of greater than 100. This is at least a factor of ten greater than that achieved so far at 193nm by any usable organic material we have tested. In the case of the Two-Stage PAG, analytical and lithographic modeling yields a usable material process window, in terms of reversibility and two-photon vs. one-photon acid production rates (branching ratio). One class of materials, based on the cycloadduct of a tethered pair of anthracenes, has shown promise under testing at 193nm in acetonitrile. Sufficient reversibility without acid production, enabled by near-UV exposure, has been achieved. Acid production as a function of dose shows a clear quadratic component, consistent with a branching ratio greater than 1. The experimental data also supports a acid contrast value of approximately 0.05 that could in principle be obtained with this molecule under a pitch division double-exposure scenario.

  10. High-n immersion lithography

    NASA Astrophysics Data System (ADS)

    Sewell, Harry; Mulkens, Jan; Graeupner, Paul; McCafferty, Diane; Markoya, Louis; Donders, Sjoerd; Cortie, Rogier; Meijers, Ralph; Evangelista, Fabrizio; Samarakone, Nandarisi

    2008-03-01

    A two-year study on the feasibility of High-n Immersion Lithography shows very promising results. This paper reports the findings of the study. The evaluation shows the tremendous progress made in the development of second-generation immersion fluid technology. Candidate fluids from several suppliers have been evaluated. All the commercial fluids evaluated are viable, so there are a number of options. Life tests have been conducted on bench top fluid-handling systems and the results referenced to full-scale systems. Parameters such as Dose per Laser Pulse, Pulse Rate, Fluid Flow Rate, and Fluid Absorbency at 193nm, and Oxygen/Air Contamination Levels were explored. A detailed evaluation of phenomena such as Last Lens Element (LLE) contamination has been conducted. Lens cleaning has been evaluated. A comparison of High-n fluid-based technology and water-based immersion technology shows interesting advantages of High-n fluid in the areas of Defect and Resist Interaction. Droplet Drying tests, Resist Staining evaluations, and Resist Contrast impact studies have all been run. Defect-generating mechanisms have been identified and are being eliminated. The lower evaporation rate of the High-n fluids compared with water shows the advantages of High-n Immersion. The core issue for the technology, the availability of High-n optical material for use as the final lens element, is updated. Samples of LuAG material have been received from development partners and have been evaluated. The latest status of optical materials and the technology timelines are reported. The potential impact of the availability of the technology is discussed. Synergy with technologies such as Double Patterning is discussed. The prospects for <22nm (hp) are evaluated.

  11. High-performance 193nm photoresists based on fluorosulfonamide

    NASA Astrophysics Data System (ADS)

    Li, Wenjie; Chen, Kuang-Jung; Kwong, Ranee; Lawson, Margaret C.; Khojasteh, Mahmoud; Popova, Irene; Varanasi, P. Rao; Shimokawa, Tsutomu; Yamaguchi, Yoshikazu; Kusumoto, Shiro; Sugiura, Makoto; Kawakami, Takanori; Slezak, Mark; Dabbagh, Gary; Liu, Zhi

    2007-03-01

    The combination of immersion lithography and reticle enhancement techniques (RETs) has extended 193nm lithography into the 45nm node and possibly beyond. In order to fulfill the tight pitch and small critical dimension requirements of these future technology nodes, the performance of 193nm resist materials needs to further improve. In this paper, a high performance 193nm photoresist system based on fluorosulfonamide (FSM) is designed and developed. The FSM group has good transparency at 193nm. Compared to the commonly used hexafluoroalcohol (HFA) group, the trifluoromethyl sulfonamide (TFSM) functionality has a lower pKa value and contains less fluorine atoms. Polymers containing the TFSM functionality have exhibited improved dissolution properties and better etch resistance than their HFA counterparts. Resists based on the FSM-containing polymers have shown superior lithographic performance for line, trench and contact hole levels under the 45nm node exposure conditions. In addition, FSM resists have also demonstrated excellent bright field and dark field compatibility and thereby make it possible to use one resist for both bright field and dark field level applications. The structure, property and lithographic performance of the FSM resist system are reported.

  12. Immersion lithography bevel solutions

    NASA Astrophysics Data System (ADS)

    Tedeschi, Len; Tamada, Osamu; Sanada, Masakazu; Yasuda, Shuichi; Asai, Masaya

    2008-03-01

    The introduction of Immersion lithography, combined with the desire to maximize the number of potential yielding devices per wafer, has brought wafer edge engineering to the forefront for advanced semiconductor manufactures. Bevel cleanliness, the position accuracy of the lithography films, and quality of the EBR cut has become more critical. In this paper, the effectiveness of wafer track based solutions to enable state-of-art bevel schemes is explored. This includes an integrated bevel cleaner and new bevel rinse nozzles. The bevel rinse nozzles are used in the coating process to ensure a precise, clean film edge on or near the bevel. The bevel cleaner is used immediately before the wafer is loaded into the scanner after the coating process. The bevel cleaner shows promise in driving down defectivity levels, specifically printing particles, while not damaging films on the bevel.

  13. Designing dual-trench alternating phase-shift masks for 140-nm and smaller features using 248-nm KrF and 193-nm ArF lithography

    NASA Astrophysics Data System (ADS)

    Petersen, John S.; Socha, Robert J.; Naderi, Alex R.; Baker, Catherine A.; Rizvi, Syed A.; Van Den Broeke, Douglas J.; Kachwala, Nishrin; Chen, J. Fung; Laidig, Thomas L.; Wampler, Kurt E.; Caldwell, Roger F.; Takeuchi, Susumu; Yamada, Yoshiro; Senoh, Takashi; McCallum, Martin

    1998-09-01

    One method for making the alternating phase-shift mask involves cutting a trench into the quartz of the mask using an anisotropic dry etch, followed by an isotropic etch to move the corners of the trench underneath the chrome to minimize problems caused by diffraction at the bottom corners of the phase-trench. This manufacturing method makes the addition of subresolution scattering bars and serifs problematic, because the amount of the undercut causes chrome lifting of these small features. Adding an additional anisotropically etched trench to both cut and uncut regions is helpful, but the etch does not move the trench corners under the chrome and result in a loss to intensity and image contrast. At 248 nm illumination and 4X magnification, our work shows that a combination of 240 nm dual-trench and 5 nm to 10 nm undercut produces images with equal intensity between shifted and unshifted regions without loss of image contrasts. This paper demonstrates optical proximity correction for doing 100 nm, 120 nm, 140 nm and 180 nm lines of varying pitch for a simple alternating phase-shift mask, with no dual-trench or undercut. Then the electromagnetic field simulator, TEMPEST, is used to find the best combination of dual-trench depth and amount of undercut for an alternating phase-shift mask. Phase measurement using 248 nm light and depth measurement of thirty-six unique combinations of dual-trench and phase-shift trench are shown. Based on modeling and experimental results, recommendations for making a fine tuned dual-trench 248 nm mask, as well as an extension of the dual-trench alternating phase-shift technique to 193 nm lithography, are made.

  14. Novel spin-coating technology for 248-nm/193-nm DUV lithography and low-k spin on dielectrics of 200-mm/300-mm wafers

    NASA Astrophysics Data System (ADS)

    Gurer, Emir; Zhong, Tom X.; Lewellen, John W.; Lee, Ed C.

    2000-06-01

    An alternative coating technology was developed for 248 nm/193 nm DUV lithography and low-k spin on dielectric (SOD) materials used in the interconnect area. This is a 300 mm enabling technology which overcomes turbulent flow limitations above 2000 rpm and it prevents 40 - 60% reduction on the process latitudes of evaporation-related variables, common to 300 mm conventional coaters. Our new coating technology is fully enclosed and it is capable of controlling the solvent concentration above the resist film dynamically in the gas phase. This feature allows a direct control of the evaporation mass transfer which determines the quality of the final resist profiles. Following process advantages are reported in this paper: (1) Demonstrated that final resist film thickness can be routinely varied by 4000 angstrom at a fixed drying spin speed, thus minimizing the impact of turbulence wall for 300 mm wafers. (2) Evaporation control allows wider range of useful thickness from a fixed viscosity material. (3) Latitudes of evaporation-related process variables is about 40% larger than that of a conventional coater. (4) Highly uniform films of 0.05% were obtained for 8800 angstrom target thickness with tighter wafer-wafer profile control because of the enclosed nature of the technology. (5) Dynamic evaporation control facilitates resist consumption minimization. Preliminary results indicate feasibility of a 0.4 cc process of record (POR) for a 200 mm substrate. (6) Lower COO due to demonstrated relative insensitivity to environmental variables, robust resist consumption minimization and superior process capabilities. (7) Improved planarization and gap fill properties for the new generation photoresist/low-k SOD materials deposited using this enclosed coating technology.

  15. Defectivity reduction studies for ArF immersion lithography

    NASA Astrophysics Data System (ADS)

    Matsunaga, Kentaro; Kondoh, Takehiro; Kato, Hirokazu; Kobayashi, Yuuji; Hayasaki, Kei; Ito, Shinichi; Yoshida, Akira; Shimura, Satoru; Kawasaki, Tetsu; Kyoda, Hideharu

    2007-03-01

    Immersion lithography is widely expected to meet the manufacturing requirements of future device nodes. A critical development in immersion lithography has been the construction of a defect-free process. Two years ago, the authors evaluated the impact of water droplets made experimentally on exposed resist films and /or topcoat. (1) The results showed that the marks of drying water droplet called watermarks became pattern defects with T-top profile. In the case that water droplets were removed by drying them, formation of the defects was prevented. Post-exposure rinse process to remove water droplets also prevented formation of the defects. In the present work, the authors evaluated the effect of pre- and post-exposure rinse processes on hp 55nm line and space pattern with Spin Rinse Process Station (SRS) and Post Immersion Rinse Process Station (PIR) modules on an inline lithography cluster with the Tokyo Electron Ltd. CLEAN TRACK TM LITHIUS TM i+ and ASML TWINSCAN XT:1700Fi , 193nm immersion scanner. It was found that total defectivity is decreased by pre- and post-exposure rinse. In particular, bridge defects and large bridge defects were decreased by pre- and post-exposure rinse. Pre- and post-exposure rinse processes are very effective to reduce the bridge and large bridge defects of immersion lithography.

  16. Negative-tone 193-nm resists

    NASA Astrophysics Data System (ADS)

    Cho, Sungseo; Vander Heyden, Anthony; Byers, Jeff D.; Willson, C. Grant

    2000-06-01

    A great deal of progress has been made in the design of single layer positive tone resists for 193 nm lithography. Commercial samples of such materials are now available from many vendors. The patterning of certain levels of devices profits from the use of negative tone resists. There have been several reports of work directed toward the design of negative tones resists for 193 nm exposure but, none have performed as well as the positive tone systems. Polymers with alicyclic structures in the backbone have emerged as excellent platforms from which to design positive tone resists for 193 nm exposure. We now report the adaptation of this class of polymers to the design of high performance negative tone 193 nm resists. New systems have been prepared that are based on a polarity switch mechanism for modulation of the dissolution rate. The systems are based on a polar, alicyclic polymer backbone that includes a monomer bearing a glycol pendant group that undergoes the acid catalyzed pinacol rearrangement upon exposure and bake to produce the corresponding less polar ketone. This monomer was copolymerized with maleic anhydride and a norbornene bearing a bis-trifluoromethylcarbinol. The rearrangement of the copolymer was monitored by FT-IR as a function of temperature. The synthesis of the norbornene monomers will be presented together with characterization of copolymers of these monomers with maleic anhydride. The lithographic performance of the new resist system will also be presented.

  17. Optical extension at the 193-nm wavelength

    NASA Astrophysics Data System (ADS)

    Zandbergen, Peter; McCallum, Martin; Amblard, Gilles R.; Domke, Wolf-Dieter; Smith, Bruce W.; Zavyalova, Lena; Petersen, John S.

    1999-07-01

    Lithography at 193nm is the first optical lithography technique that will be introduced for manufacturing of technology levels. where the required dimensions are smaller than the actual wavelength. This paper explores several techniques to extend 193nm to low k1 lithography. Most attention is given to binary mask solution in at 130nm dimensions, where k1 is 0.4. Various strong and Gaussian quadrupole illuminators were designed, manufactured and tested for this application. Strong quadrupoles show that largest DOF improvements. The drawback however, is that these strong quadrupoles are very duty cycle and dimensions specific, resulting in large proximity biases between different duty cycles. Due to their design, Gaussian quadrupoles sample much wider frequency ranges, resulting in less duty cycles specific DOF improvements and less proximity basis. At sub-130nm dimensions, strong phase shift masks provide significant latitude improvements, when compared to binary masks with quadrupole illumination. However, differences in dose to size for different duty cycles were up to 25 percent. For definition of contact holes, linewidth biasing through silylation, a key feature of the CARL bi-layer resist approach, demonstrated significant DOF latitude improvements compared to SLR at 140nm and 160nm contact holes.

  18. Material design for immersion lithography with high refractive index fluid (HIF)

    NASA Astrophysics Data System (ADS)

    Miyamatsu, Takashi; Wang, Yong; Shima, Motoyuki; Kusumoto, Shiro; Chiba, Takashi; Nakagawa, Hiroki; Hieda, Katsuhiko; Shimokawa, Tsutomu

    2005-05-01

    ArF immersion lithography is considered as the most promising next generation technology which enables to a 45 nm node device manufacturing and below. Not only depth of focus enlargement, immersion lithography enables to use hyper numerical aperture (NA) larger than 1.0 and achieve higher resolution capability. For 193nm lithography, water is an ideal immersion fluid, providing suitable refractive index and transmission properties. Furthermore the higher refractive index fluid is expected to provide a potential extension of optical lithography to the 32 nm node. This paper describes the material design for immersion lithography with high refractive index fluid. We have developed promising high refractive index fluids which satisfy the requirement for immersion fluid by screening wide variety of organic compounds. The physical and chemical properties of this high refractive index fluid are discussed in detail. Also the topcoat material which has good matching with high refractive index fluid is developed. While this topcoat material is soluble into aqueous TMAH developer, it does not dissolve into water or high refractive index fluid and gives suitable contact angle for immersion scan exposure. Immersion exposure experiments using high refractive index fluid with and w/o topcoat material was carried out and its lithographic performance is presented in this paper.

  19. 193-nm full-field step-and-scan prototype at MIT Lincoln Laboratory

    NASA Astrophysics Data System (ADS)

    Hibbs, Michael S.; Kunz, Roderick R.

    1995-05-01

    Optical lithography at a 193-nm exposure wavelength has been under development at MIT Lincoln Laboratory for several years, supported by ARPA's Advanced Lithography Program. As part of this program, a prototype 193-nm full-field step-and-scan lithographic exposure system was built and installed in the clean-room facilities of MIT Lincoln Laboratory. This exposure system has now been in use for one year, supporting a program of photoresist and lithographic process development at 193 nm. This paper describes the characteristics of the exposure system and some of the advances in 193-nm lithography that have been achieved with the system.

  20. Point-of-use filtration strategy for negative tone developer in extended immersion and extreme-ultraviolet (EUV) lithography

    NASA Astrophysics Data System (ADS)

    D'Urzo, L.; Foubert, P.; Stokes, H.; Thouroude, Y.; Xia, A.; Wu, Aiwen

    2015-03-01

    Negative tone development (NTD) has dramatically gained popularity in 193 nm dry and immersion lithography, due to their superior imaging performance [1, 2 and 3]. Popular negative tone developers are organic solvents such as n- butyl acetate (n-BA), aliphatic ketones, or high-density alcohols such as Methyl Isobutyl Carbinol (MIBC). In this work, a comparative study between ultra-high molecular weight polyethylene (UPE) and polytetrafluoroethylene (PTFE) POU filtration for n-BA based NTD has been carried out. Results correlate with the occurrence or the mitigation of micro bridges in a 45 nm dense line pattern created through immersion lithography as a function of POU membrane.

  1. Polarization aberration compensation method by adjusting illumination partial coherent factors in immersion lithography

    NASA Astrophysics Data System (ADS)

    Jia, Yue; Li, Yanqiu; Liu, Lihui; Han, Chunying; Liu, Xiaolin

    2014-11-01

    As the numerical aperture (NA) increasing and process factor k1 decreasing in 193nm immersion lithography, polarization aberration (PA) of projection optics leads to image quality degradation seriously. Therefore, this work proposes a new scheme for compensating polarization aberration. By simulating we found that adjusting the illumination source partial coherent factors σout is an effective method for decreasing the PA induced pattern critical dimension (CD) error while keeping placement error (PE) within an acceptable range. Our simulation results reveal that the proposed method can effectively compensate large PA in actual optics.

  2. VUV spectrophotometry for photomasks characterization at 193 nm

    NASA Astrophysics Data System (ADS)

    Yang, Minghong; Leiterer, Jork; Gatto, Alexandre; Kaiser, Norbert; Höllein, Ingo; Teuber, Silvio; Bubke, Karsten

    2005-10-01

    This paper intends to develop a measurement system to characterize photomasks for 193 nm lithography applications. Based on the VUV spectrophotometer at the Fraunhofer IOF institute, some modifications have been addressed to fulfil these special measurements. Characterizations on photomasks have been successfully carried out, which show good correlations to simulations.

  3. Binary 193nm photomasks aging phenomenon study

    NASA Astrophysics Data System (ADS)

    Dufaye, Félix; Sartelli, Luca; Pogliani, Carlo; Gough, Stuart; Sundermann, Frank; Miyashita, Hiroyuki; Hidenori, Yoshioka; Charras, Nathalie; Brochard, Christophe; Thivolle, Nicolas

    2011-05-01

    193nm binary photomasks are still used in the semiconductor industry for the lithography of some critical layers for the nodes 90nm and 65nm, with high volumes and over long period. These 193nm binary masks seem to be well-known but recent studies have shown surprising degrading effects, like Electric Field induced chromium Migration (EFM) [1] or chromium migration [2] [3] . Phase shift Masks (PSM) or Opaque MoSi On Glass (OMOG) might not be concerned by these effects [4] [6] under certain conditions. In this paper, we will focus our study on two layers gate and metal lines. We will detail the effects of mask aging, with SEM top view pictures revealing a degraded chromium edge profile and TEM chemical analyses demonstrating the growth of a chromium oxide on the sidewall. SEMCD measurements after volume production indicated a modified CD with respect to initial CD data after manufacture. A regression analysis of these CD measurements shows a radial effect, a die effect and an isolated-dense effect. Mask cleaning effectiveness has also been investigated, with sulphate or ozone cleans, to recover the mask quality in terms of CD. In complement, wafer intrafield CD measurements have been performed on the most sensitive structure to monitor the evolution of the aging effect on mask CD uniformity. Mask CD drift have been correlated with exposure dose drift and isolated-dense bias CD drift on wafers. In the end, we will try to propose a physical explanation of this aging phenomenon and a solution to prevent from it occurring.

  4. Self-segregating materials for immersion lithography

    NASA Astrophysics Data System (ADS)

    Sanders, Daniel P.; Sundberg, Linda K.; Brock, Phillip J.; Ito, Hiroshi; Truong, Hoa D.; Allen, Robert D.; McIntyre, Gregory R.; Goldfarb, Dario L.

    2008-03-01

    In this paper, we employ the self-segregating materials approach used in topcoat-free resists for water immersion lithography to extend the performance of topcoat materials for water immersion and to increase the contact angles of organic fluids on topcoat-free resists for high index immersion lithography. By tailoring polymers that segregate to the air and resist interfaces of the topcoat, high contact angle topcoats with relatively low fluorine content are achieved. While graded topcoats may extend the performance and/or reduce the cost of topcoat materials, the large amount of unprotected acidic groups necessary for TMAH development prevent them from achieving the high contact angles and low hysteresis exhibited by topcoat-free resists. Another application of this self-segregating approach is tailoring resist surfaces for high index immersion. Due to the low surface tension and higher viscosities of organic fluids relative to water and their lower contact angles on most surfaces, film pulling cannot be prevented without dramatically reducing wafer scan rates; however, tuning the surface energy of the resist may be important to control stain morphology and facilitate fluid removal from the wafer. By tailoring fluoropolymer additives for high contact angles with second generation organic high index immersion fluids, we show herein that topcoat-free resists can be developed specifically for high index immersion lithography with good contact angles and lithographic imaging performance.

  5. Cycloolefin-maleic anhydride copolymers for 193-nm resist compositions

    NASA Astrophysics Data System (ADS)

    Rahman, M. D.; Bae, Jun-Bom; Cook, Michelle M.; Durham, Dana L.; Kudo, Takanori; Kim, Woo-Kyu; Padmanaban, Munirathna; Dammel, Ralph R.

    2000-06-01

    Cycloolefin/maleic anhydride systems are a favorable approach to dry etch resistant resists for 193 nm lithography. This paper reports on poly(BNC/HNC/NC/MA) tetrapolymers, from t- butylnorbornene carboxylate (BNC), hydroxyethyl-norbornene carboxylate (HNC), norbornene carboxylic acid (NC) and maleic anhydride (MA). It was found that moisture has to be excluded in the synthesis of these systems if reproducible results are to be obtained. Lithographic evaluation of an optimized, modified polymer has shown linear isolated line resolution down to 100 nm using conventional 193 nm illumination. Possible reactions of the alcohol and anhydride moieties are discussed, and the effect of the anhydride unit on polymer absorbance is discussed using succinnic anhydride as a model compound.

  6. Development of cleaning process for immersion lithography

    NASA Astrophysics Data System (ADS)

    Chang, Ching Yu; Yu, D. C.; Lin, John C.; Lin, Burn J.

    2006-03-01

    In immersion lithography, DI water fills the space between the resist surface and the last lens element. However water is also a good solvent for most of the leaching compounds from resists. The leaching materials from the resist and the original impurities in the water from pipelines pose a significant risk on bottom lens deterioration, wafer surface particles, and facility contamination. If the bottom lens surface deteriorates, it can cause flare and reduce transparency. Particles on the wafer surface can degrade image formation. In addition to contaminating the facility, the impurity inside the water can cause stains or defects after the water is evaporated from the wafer surface. In order to reduce the impact of such contamination, we have evaluated many chemicals for removing organic contamination as well as particles. We have collected and characterized immersion-induced particles from cleaning studies on bare silicon wafers. We have also used oxide wafers to simulate the lens damage caused by the cleaning chemicals. In case, a mega sonic power is not suitable for scanners last lens element in production FABs, the emulsion concept has also been adopted to remove the lens organic contaminants. We have studied many chemical and mechanical methods for tool cleaning, and identified those that possess good organic solubility and particle removal efficiency. These cleaning methods will be used in periodic maintenance procedures to ensure freedom from defects in immersion lithography.

  7. Film stacking architecture for immersion lithography process

    NASA Astrophysics Data System (ADS)

    Goto, Tomohiro; Sanada, Masakazu; Miyagi, Tadashi; Shigemori, Kazuhito; Kanaoka, Masashi; Yasuda, Shuichi; Tamada, Osamu; Asai, Masaya

    2008-03-01

    In immersion lithography process, film stacking architecture will be necessary due to film peeling. However, the architecture will restrict lithographic area within a wafer due to top side EBR accuracy In this paper, we report an effective film stacking architecture that also allows maximum lithographic area. This study used a new bevel rinse system on RF3 for all materials to make suitable film stacking on the top side bevel. This evaluation showed that the new bevel rinse system allows the maximum lithographic area and a clean wafer edge. Patterning defects were improved with suitable film stacking.

  8. 193nm single layer photoresists: defeating tradeoffs with a new class of fluoropolymers

    NASA Astrophysics Data System (ADS)

    Varanasi, Pushkara R.; Kwong, Ranee W.; Khojasteh, Mahmoud; Patel, Kaushal; Chen, Kuang-Jung; Li, Wenjie; Lawson, M. C.; Allen, Robert D.; Sooriyakumaran, Ratnam; Brock, P.; Sundberg, Linda K.; Slezak, Mark; Dabbagh, Gary; Liu, Z.; Nishimura, Yukio; Chiba, Takashi; Shimokawa, Tsutomu

    2005-05-01

    The focus of this paper is to utilize the acidity of hexafluoroalcohol (HFA) in addressing performance deficiencies associated with current 193nm methacrylate resist materials. In this study, we have designed and developed a variety of HFA pendant methacrylate monomers and the corresponding imaging polymers for ArF lithography. It was shown that typical swelling behavior observed in methacrylate resists can be substantially reduced or eliminated by replacing commonly used multicylcic lactone polar functionalities with acidic HFA side chains. The incorporation of aliphatic spacers between HFA and polymer backbone were found to be more effective than cyclic hindered moieties, in achieving linear dissolution characteristics. The typical poor etch stability associated with fluorine atoms in HFA can be substantially minimized by designing side chains with a combination of appropriate cyclic and aliphatic moieties and fine-tuning the corresponding polymer compositions. PEB sensitivity of high activation energy protecting group (e.g., methyladamentyl group) based methacrylate resists can be substantially improved through the incorporation of acidic HFA side chains (6nm/C to <1 nm/C). The key application space for HFA-methacrylate resists appears to be trench level lithography. It was also demonstrated that these HFA materials are compatible with immersion lithography and result in dramatically improved process windows for iso trench features, in addition to other lines/space features.

  9. Understanding the photoresist surface-liquid interface for ArF immersion lithography

    NASA Astrophysics Data System (ADS)

    Conley, Will; LeSuer, Robert J.; Fan, Frank F.; Bard, Allen J.; Taylor, Chris; Tsiartas, Pavlos; Willson, Grant; Romano, Andrew; Dammel, Ralph

    2005-05-01

    Extraction of small molecule components into water from photoresist materials designed for 193 nm immersion lithography has been observed. Leaching of photoacid generator (PAG) has been monitored using three techniques: liquid scintillation counting (LSC); liquid chromatography mass spectrometry (LCMS); and scanning electrochemical microscopy (SECM). LSC was also used to detect leaching of residual casting solvent (RCS) and base. The amount of PAG leaching from the resist films, 30 - 50 ng/cm2, was quantified using LSC. Both LSC and LCMS results suggest that PAG and photoacid leach from the film only upon initial contact with water (within 10 seconds) and minimal leaching occurs thereafter for immersion times up to 30 minutes. Exposed films show an increase in the amount of photoacid anion leaching by upwards of 20% relative to unexposed films. Films pre-rinsed with water for 30 seconds showed no further PAG leaching as determined by LSC. No statistically significant amount of residual casting solvent was extracted after 30 minutes of immersion. Base extraction was quantified at 2 ng/cm2 after 30 seconds. The leaching process is qualitatively described by a model based on the stratigraphy of resist films.

  10. A study on effect of point-of-use filters on defect reduction for advanced 193nm processes

    NASA Astrophysics Data System (ADS)

    Vitorino, Nelson; Wolfer, Elizabeth; Cao, Yi; Lee, DongKwan; Wu, Aiwen

    2009-03-01

    Bottom Anti-Reflective Coatings (BARCs) have been widely used in the lithography process for decades. BARCs play important roles in controlling reflections and therefore improving swing ratios, CD variations, reflective notching, and standing waves. The implementation of BARC processes in 193nm dry and immersion lithography has been accompanied by defect reduction challenges on fine patterns. Point-of-Use filters are well known among the most critical components on a track tool ensuring low wafer defects by providing particle-free coatings on wafers. The filters must have very good particle retention to remove defect-causing particulate and gels while not altering the delicate chemical formulation of photochemical materials. This paper describes a comparative study of the efficiency and performance of various Point-of-Use filters in reducing defects observed in BARC materials. Multiple filter types with a variety of pore sizes, membrane materials, and filter designs were installed on an Entegris Intelligent(R) Mini dispense pump which is integrated in the coating module of a clean track. An AZ(R) 193nm organic BARC material was spin-coated on wafers through various filter media. Lithographic performance of filtered BARCs was examined and wafer defect analysis was performed. By this study, the effect of filter properties on BARC process related defects can be learned and optimum filter media and design can be selected for BARC material to yield the lowest defects on a coated wafer.

  11. Results from a new 193nm die-to-database reticle inspection platform

    NASA Astrophysics Data System (ADS)

    Broadbent, William H.; Alles, David S.; Giusti, Michael T.; Kvamme, Damon F.; Shi, Rui-fang; Sousa, Weston L.; Walsh, Robert; Xiong, Yalin

    2010-05-01

    A new 193nm wavelength high resolution reticle defect inspection platform has been developed for both die-to-database and die-to-die inspection modes. In its initial configuration, this innovative platform has been designed to meet the reticle qualification requirements of the IC industry for the 22nm logic and 3xhp memory generations (and shrinks) with planned extensions to the next generation. The 22nm/3xhp IC generation includes advanced 193nm optical lithography using conventional RET, advanced computational lithography, and double patterning. Further, EUV pilot line lithography is beginning. This advanced 193nm inspection platform has world-class performance and the capability to meet these diverse needs in optical and EUV lithography. The architecture of the new 193nm inspection platform is described. Die-to-database inspection results are shown on a variety of reticles from industry sources; these reticles include standard programmed defect test reticles, as well as advanced optical and EUV product and product-like reticles. Results show high sensitivity and low false and nuisance detections on complex optical reticle designs and small feature size EUV reticles. A direct comparison with the existing industry standard 257nm wavelength inspection system shows measurable sensitivity improvement for small feature sizes

  12. Birefringence issues with uniaxial crystals as last lens elements for high-index immersion lithography

    NASA Astrophysics Data System (ADS)

    Burnett, John H.; Benck, Eric C.; Kaplan, Simon G.; Sirat, Gabriel Y.; Mack, Chris

    2009-03-01

    We discuss the birefringence issues associated with use of crystalline sapphire, with uniaxial crystal structure, as a last lens element for high-index 193 nm immersion lithography. Sapphire is a credible high-index lens material candidate because with appropriate orientation and TE polarization the ordinary ray exhibits the required isotropic optical properties. Also, its material properties may give it higher potential to meet the stringent optical requirements compared to the potential of the principal candidate materials, cubic-symmetry LuAG and ceramic spinel. The TE polarization restriction is required anyway for hyper-NA imaging, due to TM-polarization contrast degradation effects. Further, the high uniaxial-structure birefringence of sapphire may offer the advantage that any residual TM polarization results in a relatively-uniform flare instead of contrast degradation. One issue with this concept is that spatial-dispersion-induced effects should cause some index anisotropy of the ordinary rays, in a way similar to the intrinsic birefringence (IBR) effects in cubic crystals, except that there is no ray splitting. We present the theory of this effect for the trigonal crystal structure of sapphire and discuss its implications for lithography optics. For this material the spatial-dispersion-induced effects are characterized by eight material parameters, of which three contribute to index anisotropy of the ordinary rays. Only one gives rise to azimuthal distortions, and may present challenges for correction. To assess the consequences of using sapphire as a last element, neglecting any IBR effects, we use lithography simulations to characterize the lithographic performance for a 1.7 NA design, and compare to that for LuAG.

  13. A method for compensating the polarization aberration of projection optics in immersion lithography

    NASA Astrophysics Data System (ADS)

    Jia, Yue; Li, Yanqiu; Liu, Lihui; Han, Chunying; Liu, Xiaolin

    2014-08-01

    As the numerical aperture (NA) of 193nm immersion lithography projection optics (PO) increasing, polarization aberration (PA) leads to image quality degradation seriously. PA induced by large incident angle of light, film coatings and intrinsic birefringence of lens materials cannot be ignored. An effective method for PA compensation is to adjust lens position in PO. However, this method is complicated. Therefore, in this paper, an easy and feasible PA compensation method is proposed: for ArF lithographic PO with hyper NA (NA=1.2), which is designed by our laboratory, the PA-induced critical dimension error (CDE) can be effectively reduced by optimizing illumination source partial coherent factor σout. In addition, the basic idea of our method to suppress pattern placement error (PE) is to adopt anti-reflection (AR) multi-layers MgF2/LaF3/MgF2 and calcium fluoride CaF2 of [111] crystal axes. Our simulation results reveal that the proposed method can effectively and quantificationally compensate large PA in the optics. In particular, our method suppresses the dynamic range of CDE from -12.7nm ~ +4.3nm to -1.1nm ~ +1.2nm, while keeping PE at an acceptable level.

  14. Optical lithography for nanotechnology

    NASA Astrophysics Data System (ADS)

    Flagello, Donis G.; Arnold, Bill

    2006-09-01

    Optical lithography is continually evolving to meet the ever demanding requirements of the micro - and nano- technology communities. Since the optical exposure systems used in lithography are some of the most advanced and complex optical instruments ever built, they involve ever more complex illuminator designs, nearly aberration free lenses, and hyper numerical apertures approaching unity and beyond. Fortunately, the lithography community has risen to the challenge by devising many inventive optical systems and various methods to use and optimize exposure systems. The recent advancement of water immersion technology into lithography for 193nm wavelengths has allowed the numerical aperture (NA) of lithographic lenses to exceed 1.0 or a hyper-NA region. This allows resolution limits to extend to the 45nm node and beyond with NA>1.3. At these extreme NAs, the imaging within the photoresist is accomplished by not only using water immersion but also using polarized light lithography. This paper will review the current state-of-the-art in immersion, hyper-NA lithography. We show the latest results and discuss the various phenomena that may arise using these systems. Furthermore, we show some of the advanced image optimization techniques that allow lithographic printing at the physical limits of resolution. In addition, we show that the future of optical lithography is likely to go well beyond the 30nm regime using advancements in 193nm double-patterning technology and/or the use of extreme ultra-violet (EUV) optical systems.

  15. Understanding dissolution behavior of 193nm photoresists in organic solvent developers

    NASA Astrophysics Data System (ADS)

    Lee, Seung-Hyun; Park, Jong Keun; Cardolaccia, Thomas; Sun, Jibin; Andes, Cecily; O'Connell, Kathleen; Barclay, George G.

    2012-03-01

    Herein, we investigate the dissolution behavior of 193-nm chemically amplified resist in different organic solvents at a mechanistic level. We previously reported the effect of solvent developers on the negative tone development (NTD) process in both dry and immersion lithography, and demonstrated various resist performance parameters such as photospeed, critical dimension uniformity, and dissolution rate contrast are strongly affected by chemical nature of the organic developer. We further pursued the investigation by examining the dependence of resist dissolution behavior on their solubility properties using Hansen Solubility Parameter (HSP). The effects of monomer structure, and resist composition, and the effects of different developer chemistry on dissolution behaviors were evaluated by using laser interferometry and quartz crystal microbalance. We have found that dissolution behaviors of methacrylate based resists are significantly different in different organic solvent developers such as OSDTM-1000 Developer* and n-butyl acetate (nBA), affecting their resist performance. This study reveals that understanding the resist dissolution behavior helps to design robust NTD materials for higher resolution imaging.

  16. An anti-reflection coating for use with PMMA at 193 nm

    NASA Technical Reports Server (NTRS)

    Yen, Anthony; Smith, Henry I.; Schattenburg, M. L.; Taylor, Gary N.

    1992-01-01

    An antireflection coating (ARC) for use with poly(methyl methacrylate) (PMMA) resist for ArF excimer laser lithography (193 nm) was formulated. It consists of PMMA and a bis-azide, 4.4-prime-diazidodiphenyl sulfone (DDS) which crosslinks the film after deep UV (260 nm) irradiation and subsequent annealing. The reacted DDS then serves as the absorber for the 193 nm radiation and also prevents mixing of the ARC and PMMA during PMMA spin-coating and development. The effectiveness of the ARC was demonstrated by exposing, in PMMA, using achromatic holographic lithography, gratings of 100 nm period (about 50 nm linewidth) that are almost entirely free of an orthogonal standing wave.

  17. An anti-reflection coating for use with PMMA at 193 nm

    NASA Astrophysics Data System (ADS)

    Yen, Anthony; Smith, Henry I.; Schattenburg, M. L.; Taylor, Gary N.

    1992-02-01

    An antireflection coating (ARC) for use with poly(methyl methacrylate) (PMMA) resist for ArF excimer laser lithography (193 nm) was formulated. It consists of PMMA and a bis-azide, 4.4-prime-diazidodiphenyl sulfone (DDS) which crosslinks the film after deep UV (260 nm) irradiation and subsequent annealing. The reacted DDS then serves as the absorber for the 193 nm radiation and also prevents mixing of the ARC and PMMA during PMMA spin-coating and development. The effectiveness of the ARC was demonstrated by exposing, in PMMA, using achromatic holographic lithography, gratings of 100 nm period (about 50 nm linewidth) that are almost entirely free of an orthogonal standing wave.

  18. Programmed defects study on masks for 45nm immersion lithography using the novel AIMS 45-193i

    NASA Astrophysics Data System (ADS)

    Scherübl, Thomas; Dürr, Arndt C.; Böhm, Klaus; Birkner, Robert; Richter, Rigo; Strößner, Ulrich

    2007-02-01

    Mask manufacturing for the 45nm node for hyper NA lithography requires tight defect and printability control at small features sizes. The AIMS TM1 technology is a well established methodology to analyze printability of mask defects, repairs and critical features by scanner emulation. With the step towards hyper NA imaging by immersion lithography the AIMS TM technology has been faced with new challenges like vector effects, polarized illumination and tighter specs for repeatability and tool stability. These requirements pushed the development of an entirely new AIMS TM generation. The AIMS TM 45-193i has been designed and developed by Carl Zeiss to address these challenges. A new mechanical platform with a thermal and environmental control unit enables high tool stability. Thus a new class of specification becomes available. The 193nm optical beam path together with an improved beam homogenizer is dedicated to emulate scanners up to 1.4 NA. New features like polarized illumination and vector effect emulation make the AIMS TM 45- 193i a powerful tool for defect disposition and scanner emulation for 45nm immersion lithography. In this paper results from one of the first production tools will be presented. Aerial images from phase shifting and binary masks with different immersion relevant settings will be discussed. Also, data from a long term repeatability study performed on masks with programmed defects will be shown. This study demonstrates the tool's ability to perform defect disposition with high repeatability. It is found that the tool will fulfill the 45nm node requirements to perform mask qualification for production use.

  19. Modular Polymer Biosensors by Solvent Immersion Imprint Lithography

    SciTech Connect

    Moore, Jayven S.; Xantheas, Sotiris S.; Grate, Jay W.; Wietsma, Thomas W.; Gratton, Enrico; Vasdekis, Andreas

    2016-01-01

    We recently demonstrated Solvent Immersion Imprint Lithography (SIIL), a rapid benchtop microsystem prototyping technique, including polymer functionalization, imprinting and bonding. Here, we focus on the realization of planar polymer sensors using SIIL through simple solvent immersion without imprinting. We describe SIIL’s impregnation characteristics, including an inherent mechanism that not only achieves practical doping concentrations, but their unexpected 4-fold enhancement compared to the immersion solution. Subsequently, we developed and characterized optical sensors for detecting molecular O2. To this end, a high dynamic range is reported, including its control through the immersion duration, a manifestation of SIIL’s modularity. Overall, SIIL exhibits the potential of improving the operating characteristics of polymer sensors, while significantly accelerating their prototyping, as it requires a few seconds of processing and no need for substrates or dedicated instrumentation. These are critical for O2 sensing as probed by way of example here, as well as any polymer permeable reactant.

  20. Refractive index change during exposure for 193-nm chemically amplified resists

    NASA Astrophysics Data System (ADS)

    Oh, Hye-Keun; Sohn, Young-Soo; Sung, Moon-Gyu; Lee, Young-Mi; Lee, Eun-Mi; Byun, Sung Hwan; An, Ilsin; Lee, Kun-Sang; Park, In-Ho

    1999-06-01

    Some of the important areas to be improved for lithography simulation are getting correct exposure parameters and determining the change of refractive index. It is known that the real and imaginary refractive indices are changed during exposure. We obtained these refractive index changes during exposure for 193 nm chemically amplified resists. The variations of the transmittance as well as the resist thickness were measured during ArF excimer laser exposure. We found that the refractive index change is directly related to the concentration of the photo acid generator and de-protected resin. It is important to know the exact values of acid concentration from the exposure parameters since a small difference in acid concentration magnifies the variation in the amplified de-protection during post exposure bake. We developed and used a method to extract Dill ABC exposure parameters for 193 nm chemically amplified resist from the refractive index change upon exposure.

  1. IBM-JSR 193-nm negative tone resist: polymer design, material properties, and lithographic performance

    NASA Astrophysics Data System (ADS)

    Patel, Kaushal S.; Lawson, Margaret C.; Varanasi, Pushkara Rao; Medeiros, David R.; Wallraff, Gregory M.; Brock, Phillip J.; DiPietro, Richard A.; Nishimura, Yukio; Chiba, Takashi; Slezak, Mark

    2004-05-01

    It has been previously proposed that negative-tone resist process would have an intrinsic advantage for printing narrow trench geometry. To demonstrate this for 193nm lithography, a negative resist with performance comparable to a leading positive resist is required. In this paper we report the joint development of a hexafluoroalcohol containing, 193nm, negative-tone, chemically amplified resist based on the crosslinking approach. Lithographic performance is presented which includes the ability of the negative-tone resist to print 90nm line/space and isolated trenches with standard resist processing. The impact of the fluorinated polymer on etch performance is also quantified. Finally, key resist characteristics and their influence on performance and limiting factors such as microbridging are discussed.

  2. Study of stress birefringence for 193-nm immersion photomasks

    NASA Astrophysics Data System (ADS)

    Cotte, Eric; Selle, Michael; Bubke, Karsten; Teuber, Silvio

    2005-06-01

    The goal of the present study was to investigate and quantify reticle stress birefringence in exposure conditions. Birefringence can arise in fused silica photomask substrates due to their state of stress, and cause optical effects such as phase front distortion, ray bifurcation, and polarization changes. These effects potentially produce image blurring and illumination non-uniformity, leading to lower resolution and CD variations, respectively. The main sources of substrate stress studied were the absorber stack, the mounting of a pellicle, and the impact of initial reticle bow when chucking in an exposure tool. Jones calculus was used to relate birefringence at discrete locations in the reticle, derived from the state of stress, to the net birefringence experienced by light passing through the mask. Experimentally-obtained birefringence data as well as analytical calculations of stress birefringence caused by known states of stress were used to validate the models. These results can then be compared to photomask birefringence specifications or employed in optical simulations to determine the precise impact of this substrate stress birefringence.

  3. Inline detection of Chrome degradation on binary 193nm photomasks

    NASA Astrophysics Data System (ADS)

    Dufaye, Félix; Sippel, Astrid; Wylie, Mark; García-Berríos, Edgardo; Crawford, Charles; Hess, Carl; Sartelli, Luca; Pogliani, Carlo; Miyashita, Hiroyuki; Gough, Stuart; Sundermann, Frank; Brochard, Christophe

    2013-09-01

    193nm binary photomasks are still used in the semiconductor industry for the lithography of some critical layers for the nodes 90nm and 65nm, with high volumes and over long periods. However, these 193nm binary photomasks can be impacted by a phenomenon of chrome oxidation leading to critical dimensions uniformity (CDU) degradation with a pronounced radial signature. If not detected early enough, this CDU degradation may cause defectivity issues and lower yield on wafers. Fortunately, a standard cleaning and repellicle service at the mask shop has been demonstrated as efficient to remove the grown materials and get the photomask CD back on target.Some detection methods have been already described in literature, such as wafer CD intrafield monitoring (ACLV), giving reliable results but also consuming additional SEM time with less precision than direct photomask measurement. In this paper, we propose another approach, by monitoring the CDU directly on the photomask, concurrently with defect inspection for regular requalification to production for wafer fabs. For this study, we focused on a Metal layer in a 90nm technology node. Wafers have been exposed with production conditions and then measured by SEM-CD. Afterwards, this photomask has been measured with a SEM-CD in mask shop and also inspected on a KLA-Tencor X5.2 inspection system, with pixels 125 and 90nm, to evaluate the Intensity based Critical Dimension Uniformity (iCDU) option. iCDU was firstly developed to provide feed-forward CDU maps for scanner intrafield corrections, from arrayed dense structures on memory photomasks. Due to layout complexity and differing feature types, CDU monitoring on logic photomasks used to pose unique challenges.The selection of suitable feature types for CDU monitoring on logic photomasks is no longer an issue, since the transmitted intensity map gives all the needed information, as shown in this paper. In this study, the photomask was heavily degraded after more than 18,000 300

  4. 32 nm logic patterning options with immersion lithography

    NASA Astrophysics Data System (ADS)

    Lai, K.; Burns, S.; Halle, S.; Zhuang, L.; Colburn, M.; Allen, S.; Babcock, C.; Baum, Z.; Burkhardt, M.; Dai, V.; Dunn, D.; Geiss, E.; Haffner, H.; Han, G.; Lawson, P.; Mansfield, S.; Meiring, J.; Morgenfeld, B.; Tabery, C.; Zou, Y.; Sarma, C.; Tsou, L.; Yan, W.; Zhuang, H.; Gil, D.; Medeiros, D.

    2008-03-01

    The semiconductor industry faces a lithographic scaling limit as the industry completes the transition to 1.35 NA immersion lithography. Both high-index immersion lithography and EUV lithography are facing technical challenges and commercial timing issues. Consequently, the industry has focused on enabling double patterning technology (DPT) as a means to circumvent the limitations of Rayleigh scaling. Here, the IBM development alliance demonstrate a series of double patterning solutions that enable scaling of logic constructs by decoupling the pattern spatially through mask design or temporally through innovative processes. These techniques have been successfully employed for early 32nm node development using 45nm generation tooling. Four different double patterning techniques were implemented. The first process illustrates local RET optimization through the use of a split reticle design. In this approach, a layout is decomposed into a series of regions with similar imaging properties and the illumination conditions for each are independently optimized. These regions are then printed separately into the same resist film in a multiple exposure process. The result is a singly developed pattern that could not be printed with a single illumination-mask combination. The second approach addresses 2D imaging with particular focus on both line-end dimension and linewidth control [1]. A double exposure-double etch (DE2) approach is used in conjunction with a pitch-filling sacrificial feature strategy. The third double exposure process, optimized for via patterns also utilizes DE2. In this method, a design is split between two separate masks such that the minimum pitch between any two vias is larger than the minimum metal pitch. This allows for final structures with vias at pitches beyond the capability of a single exposure. In the fourth method,, dark field double dipole lithography (DDL) has been successfully applied to BEOL metal structures and has been shown to be

  5. Faster qualification of 193-nm resists for 100-nm development using photo cell monitoring

    NASA Astrophysics Data System (ADS)

    Jones, Chris M.; Kallingal, Chidam; Zawadzki, Mary T.; Jeewakhan, Nazneen N.; Kaviani, Nazila N.; Krishnan, Prakash; Klaum, Arthur D.; Van Ess, Joel

    2003-05-01

    The development of 100-nm design rule technologies is currently taking place in many R&D facilities across the world. For some critical alyers, the transition to 193-nm resist technology has been required to meet this leading edge design rule. As with previous technology node transitions, the materials and processes available are undergoing changes and improvements as vendors encounter and solve problems. The initial implementation of the 193-nm resits process did not meet the photolithography requirements of some IC manufacturers due to very high Post Exposure Bake temperature sensitivity and consequently high wafer to wafer CD variation. The photoresist vendors have been working to improve the performance of the 193-nm resists to meet their customer's requirements. Characterization of these new resists needs to be carried out prior to implementation in the R&D line. Initial results on the second-generation resists evaluated at Cypress Semicondcutor showed better CD control compared to the aelrier resist with comparable Depth of Focus (DOF), Exposure Latitute, Etch Resistance, etc. In addition to the standard lithography parameters, resist characterization needs to include defect density studies. It was found that the new resists process with the best CD control, resulted in the introduction of orders of magnitude higher yield limiting defects at Gate, Contact adn Local Interconnect. The defect data were shared with the resists vendor and within days of the discovery the resist vendor was able to pinpoint the source of the problem. The fix was confirmed and the new resists were successfully released to production. By including defect monitoring into the resist qualification process, Cypress Semiconductor was able to 1) drive correction actions earlier resulting in faster ramp and 2) eliminate potential yield loss. We will discuss in this paper how to apply the Micro Photo Cell Monitoring methodology for defect monitoring in the photolithogprhay module and the

  6. Using scanning electrochemical microscopy to probe chemistry at the solid-liquid interface in chemically amplified immersion lithography

    NASA Astrophysics Data System (ADS)

    LeSuer, Robert J.; Fan, Fu-Ren F.; Bard, Allen J.; Taylor, J. Christopher; Tsiartas, Pavlos; Willson, Grant; Conley, Willard E.; Feit, Gene; Kunz, Roderick R.

    2004-05-01

    Three modes of scanning electrochemical microscopy (SECM) - voltammetry, pH, and conductivity - have been used to better understand the chemistry at, and diffusion through, the solid/liquid interface formed between a resist film and water in 193 nm immersion lithography. Emphasis has been placed on investigating the photoacid generator (PAG), triphenylsulfonium perfluorobutanesulfonate, and the corresponding photoacid. The reduction of triphenylsulfonium at a hemispherical Hg microelectrode was monitored using square wave voltammetry to detect trace amounts of the PAG leaching from the surface. pH measurements at a 100 μm diameter Sb microelectrode show the formation of acid in the water layer above a resist upon exposure with UV irradiation. Bipolar conductance measurements at a 100 μm Pt tip positioned 100 μm from the surface indicate that the conductivity of the solution during illumination is dependent upon the percentage of PAG in the film. Liquid chromatography mass spectrometric analysis of water samples in contact with resist films has been used to quantify the amounts (< 10 ng/cm2) of PAG leaching from the film in the dark which occurs within the first 30 seconds of contact time. Washing the film removes approximately 80% of the total leachable PAG.

  7. Study of 193-nm resist degradation under various etch chemistries

    NASA Astrophysics Data System (ADS)

    Bazin, Arnaud; May, Michael; Pargon, Erwine; Mortini, Benedicte; Joubert, Olivier

    2007-03-01

    The effectivity of 193nm photoresists as dry etch masks is becoming more and more critical as the size of integrated devices shrinks. 193nm resists are known to be much less resistant to dry etching than 248nm resists based on a poly(hydroxystyrene) polymer backbone. The decrease in the resist film budget implies a better etch resistance to use single layer 193nm photoresists for the 65nm node and beyond. In spite of significant improvements made in the past decade regarding the etch resistance of photoresists, much of the fundamental chemistry and physics that could explain the behaviour of these materials has to be better understood. Such knowledge is necessary in order to propose materials and etch processes for the next technology nodes (45nm and below). In this paper, we report our studies on the etch behaviour of different 193nm resist materials as a function of etch chemistry. In a first step, we focus our attention on the interactions between photoresists and the reactive species of a plasma during a dry etch step. Etch experiments were carried out in a DPS (Decoupled Plasma Source) high density chamber. The gas chemistry in particular was changed to check the role of the plasma reactive species on the resist. O II, Cl II, CF 4, HBr and Ar gas were used. Etch rates and chemical modifications of different materials were quantified by ellipsometry, Fourier Transformed Infrared Spectroscopy (FTIR), and X-Ray Photoelectrons Spectroscopy (XPS). We evaluated different materials including 248nm model polymer backbones (pure PHS or functionalized PHS), and 193nm model polymers (PMMA and acrylate polymers) or resist formulations. Besides the influence of resist chemistry, the impact of plasma parameters was addressed.

  8. Solvent immersion nanoimprint lithography of fluorescent conjugated polymers

    SciTech Connect

    Whitworth, G. L.; Zhang, S.; Stevenson, J. R. Y.; Ebenhoch, B.; Samuel, I. D. W.; Turnbull, G. A.

    2015-10-19

    Solvent immersion imprint lithography (SIIL) was used to directly nanostructure conjugated polymer films. The technique was used to create light-emitting diffractive optical elements and organic semiconductor lasers. Gratings with lateral features as small as 70 nm and depths of ∼25 nm were achieved in poly(9,9-dioctylfluorenyl-2,7-diyl). The angular emission from the patterned films was studied, comparing measurement to theoretical predictions. Organic distributed feedback lasers fabricated with SIIL exhibited thresholds for lasing of ∼40 kW/cm{sup 2}, similar to those made with established nanoimprint processes. The results show that SIIL is a quick, convenient and practical technique for nanopatterning of polymer photonic devices.

  9. Immersion defectivity study with volume production immersion lithography tool for 45 nm node and below

    NASA Astrophysics Data System (ADS)

    Nakano, Katsushi; Nagaoka, Shiro; Yoshida, Masato; Iriuchijima, Yasuhiro; Fujiwara, Tomoharu; Shiraishi, Kenichi; Owa, Soichi

    2008-03-01

    Volume production of 45nm node devices utilizing Nikon's S610C immersion lithography tool has started. Important to the success in achieving high-yields in volume production with immersion lithography has been defectivity reduction. In this study we evaluate several methods of defectivity reduction. The tools used in our defectivity analysis included a dedicated immersion cluster tools consisting of a Nikon S610C, a volume production immersion exposure tool with NA of 1.3, and a resist coater-developer LITHIUS i+ from TEL. In our initial procedure we evaluated defectivity behavior by comparing on a topcoat-less resist process to a conventional topcoat process. Because of its simplicity the topcoatless resist shows lower defect levels than the topcoat process. In a second study we evaluated the defect reduction by introducing the TEL bevel rinse and pre-immersion bevel cleaning techniques. This technique was shown to successfully reduce the defect levels by reducing the particles at the wafer bevel region. For the third defect reduction method, two types of tool cleaning processes are shown. Finally, we discuss the overall defectivity behavior at the 45nm node. To facilitate an understanding of the root cause of the defects, defect source analysis (DSA) was applied to separate the defects into three classes according to the source of defects. DSA analysis revealed that more than 99% of defects relate to material and process, and less than 1% of the defects relate to the exposure tool. Material and process optimization by collaborative work between exposure tool vendors, track vendors and material vendors is a key for success of 45nm node device manufacturing.

  10. Novel single-layer photoresist containing cycloolefins for 193 nm

    NASA Astrophysics Data System (ADS)

    Park, Joo Hyeon; Seo, Dong-Chul; Kim, Ki-Dae; Park, Sun-Yi; Kim, Seong-Ju; Lee, Hosull; Jung, Jae Chang; Bok, Cheol-Kyu; Baik, Ki-Ho

    1998-06-01

    New matrix resins containing maleic anhydride and cycloolefin units for ArF excimer laser resist have been developed. Several series of these matrix resins having good dry-etching durability were prepared by free radical polymerization using AlBN as free radical initiator. All of the resists using the matrix resins revealed good coating uniformity and adhesion to silicon wafer, and were readily soluble in a variety of resist solvents such as MMP, EEP, PGMEA and EL. In preliminary 193 nm testing a resist formulated with the matrix resins sulfonium triflate as photoacid generator afforded positive images with 0.14 micrometers L/S resolution. In this paper, we will discuss the polymerization results and lithographic properties for 193 nm exposure tool.

  11. 193 nm photodissociation of larger multiply-charged biomolecules

    NASA Astrophysics Data System (ADS)

    Guan, Ziqiang; Kelleher, Neil L.; O'Connor, Peter B.; Aaserud, David J.; Little, Daniel P.; McLafferty, Fred W.

    1996-12-01

    In contrast to most ion dissociation methods, 193 nm ultraviolet photodissociation of electrosprayed melittin (2.8 kDa) and ubiquitin (8.6 kDa) molecular ions yields new c and z ions (backbone amine bond dissociation) that provide additional sequence information. Dissociation by collisions or infrared photons produce b and y ions; for cleavages between the same amino acids the c ion represents the addition of NH2 to the b ion, and z the loss of NH2 from the y ion, so that these ions can be differentiated by this ± 16.02 Da difference. However, 193 nm photodissociation of 12-29 kDa ions as yet does not give collectable product ions, and that of the very stable y182+ ion from ubiquitin only effects a side chain loss. 193 nm irradiation of negative ions of all-T 30-mer DNA appears to eject electrons; apparently this is the first observation of electron photodetachment from multiply-charged negative ions.

  12. Advances in 193 nm excimer lasers for mass spectrometry applications

    NASA Astrophysics Data System (ADS)

    Delmdahl, Ralph; Esser, Hans-Gerd; Bonati, Guido

    2016-03-01

    Ongoing progress in mass analysis applications such as laser ablation inductively coupled mass spectrometry of solid samples and ultraviolet photoionization mediated sequencing of peptides and proteins is to a large extent driven by ultrashort wavelength excimer lasers at 193 nm. This paper will introduce the latest improvements achieved in the development of compact high repetition rate excimer lasers and elaborate on the impact on mass spectrometry instrumentation. Various performance and lifetime measurements obtained in a long-term endurance test over the course of 18 months will be shown and discussed in view of the laser source requirements of different mass spectrometry tasks. These sampling type applications are served by excimer lasers delivering pulsed 193 nm output of several mJ as well as fast repetition rates which are already approaching one Kilohertz. In order to open up the pathway from the laboratory to broader market industrial use, sufficient component lifetimes and long-term stable performance behavior have to be ensured. The obtained long-term results which will be presented are based on diverse 193 nm excimer laser tube improvements aiming at e.g. optimizing the gas flow dynamics and have extended the operational life the laser tube for the first time over several billion pulses even under high duty-cycle conditions.

  13. High performance Si immersion gratings patterned with electron beam lithography

    NASA Astrophysics Data System (ADS)

    Gully-Santiago, Michael A.; Jaffe, Daniel T.; Brooks, Cynthia B.; Wilson, Daniel W.; Muller, Richard E.

    2014-07-01

    Infrared spectrographs employing silicon immersion gratings can be significantly more compact than spectro- graphs using front-surface gratings. The Si gratings can also offer continuous wavelength coverage at high spectral resolution. The grooves in Si gratings are made with semiconductor lithography techniques, to date almost entirely using contact mask photolithography. Planned near-infrared astronomical spectrographs require either finer groove pitches or higher positional accuracy than standard UV contact mask photolithography can reach. A collaboration between the University of Texas at Austin Silicon Diffractive Optics Group and the Jet Propulsion Laboratory Microdevices Laboratory has experimented with direct writing silicon immersion grating grooves with electron beam lithography. The patterning process involves depositing positive e-beam resist on 1 to 30 mm thick, 100 mm diameter monolithic crystalline silicon substrates. We then use the facility JEOL 9300FS e-beam writer at JPL to produce the linear pattern that defines the gratings. There are three key challenges to produce high-performance e-beam written silicon immersion gratings. (1) E- beam field and subfield stitching boundaries cause periodic cross-hatch structures along the grating grooves. The structures manifest themselves as spectral and spatial dimension ghosts in the diffraction limited point spread function (PSF) of the diffraction grating. In this paper, we show that the effects of e-beam field boundaries must be mitigated. We have significantly reduced ghost power with only minor increases in write time by using four or more field sizes of less than 500 μm. (2) The finite e-beam stage drift and run-out error cause large-scale structure in the wavefront error. We deal with this problem by applying a mark detection loop to check for and correct out minuscule stage drifts. We measure the level and direction of stage drift and show that mark detection reduces peak-to-valley wavefront error

  14. Study of effects of sidewall angle on process window using 193nm CPL masks in a 300mm wafer manufacturing environment

    NASA Astrophysics Data System (ADS)

    Cheng, Yung Feng; Chou, Yueh Lin; Lin, C. L.; Huang, Peter

    2005-11-01

    As semiconductor process technology moves down below 90nm and 65nm, more and more wafer fabs are starting to apply 193nm CPL (Chromeless Phase Lithography) technology as the main lithography strategy for their most critical layers. However the 3D pattern profile is another critical factor, which affects image intensity and final process window. Since 193nm CPL is a relatively new technology in the semiconductor industry, it is important for us to understand the key mask specifications of 193nm CPL and their impact on wafer-level imaging. In this paper, we will study the effects of sidewall angle on process window and wafer CD using 193nm CPL masks in a 300mm wafer manufacturing environment. We begin our experiment by making several special 193nm CPL masks. These masks have been specially designed with different sidewall angles (SWA) with phase of 180 degrees. The sidewall angle spread represents approximately 10 degrees. We use specially designed test patterns that are compatible at the 65nm technology node. In our experiment, we first study the correlation between AFM (atomic force microscope)-determined profile angle and lithographic process behavior. In addition, simulation was also used to predict the impact of 3D profile on process performance. All lithographic experiments were performed on 300mm wafers using a high NA ASML 193nm scanner and high contrast resist. In this study, we have focused on the impact of sidewall angle on wafer process performance by comparing the wafer CD and pattern profile through focus. In order to establish more effective specifications of angle control in 193nm CPL between mask shop and wafer fabs, all AFM, wafer CD, and simulation results will be compared and correlated.

  15. Development of high coherence high power 193nm laser

    NASA Astrophysics Data System (ADS)

    Tanaka, Satoshi; Arakawa, Masaki; Fuchimukai, Atsushi; Sasaki, Yoichi; Onose, Takashi; Kamba, Yasuhiro; Igarashi, Hironori; Qu, Chen; Tamiya, Mitsuru; Oizumi, Hiroaki; Ito, Shinji; Kakizaki, Koji; Xuan, Hongwen; Zhao, Zhigang; Kobayashi, Yohei; Mizoguchi, Hakaru

    2016-03-01

    We have been developing a hybrid 193 nm ArF laser system that consists of a solid state seeding laser and an ArF excimer laser amplifier for power-boosting. The solid state laser consists of an Yb-fiber-solid hybrid laser system and an Er-fiber laser system as fundamentals, and one LBO and three CLBO crystals for frequency conversion. In an ArF power amplifier, the seed laser passes through the ArF gain media three times, and an average power of 110 W is obtained. As a demonstration of the potential applications of the laser, an interference exposure test is performed.

  16. SEM metrology for advanced lithographies

    NASA Astrophysics Data System (ADS)

    Bunday, Benjamin; Allgair, John; Rice, Bryan J.; Byers, Jeff; Avitan, Yohanan; Peltinov, Ram; Bar-zvi, Maayan; Adan, Ofer; Swyers, John; Shneck, Roni Z.

    2007-03-01

    For many years, lithographic resolution has been the main obstacle for keeping the pace of transistor densification to meet Moore's Law. The industry standard lithographic wavelength has evolved many times, from G-line to I-line, deep ultraviolet (DUV) based on KrF, and 193nm based on ArF. At each of these steps, new photoresist materials have been used. For the 45nm node and beyond, new lithography techniques are being considered, including immersion ArF lithography and extreme ultraviolet (EUV) lithography. As in the past, these techniques will use new types of photoresists with the capability of printing 45nm node (and beyond) feature widths and pitches. This paper will show results of an evaluation of the critical dimension-scanning electron microscopy (CD-SEM)-based metrology capabilities and limitations for the 193nm immersion and EUV lithography techniques that are suggested in the International Technology Roadmap for Semiconductors. In this study, we will print wafers with these emerging technologies and evaluate the performance of SEM-based metrology on these features. We will conclude with preliminary findings on the readiness of SEM metrology for these new challenges.

  17. 300-mW narrow-linewidth deep-ultraviolet light generation at 193 nm by frequency mixing between Yb-hybrid and Er-fiber lasers.

    PubMed

    Xuan, Hongwen; Zhao, Zhigang; Igarashi, Hironori; Ito, Shinji; Kakizaki, Kouji; Kobayashi, Yohei

    2015-04-20

    A narrow-linewidth, high average power deep-ultraviolet (DUV) coherent laser emitting at 193 nm is demonstrated by frequency mixing a Yb-hybrid laser with an Er-fiber laser. The Yb-hybrid laser consists of Yb-fiber lasers and an Yb:YAG amplifier. The average output power of the 193 nm laser is 310 mW at 6 kHz, which corresponds to a pulse energy of 51 μJ. To the best of our knowledge, this is the highest average power and pulse energy ever reported for a narrow-linewidth 193 nm light generated by a combination of solid-state and fiber lasers with frequency mixing. We believe this laser will be beneficial for the application of interference lithography by seeding an injection-locking ArF eximer laser. PMID:25969096

  18. Development of high coherence, 200mW, 193nm solid-state laser at 6 kHz

    NASA Astrophysics Data System (ADS)

    Nakazato, T.; Tsuboi, M.; Onose, T.; Tanaka, Y.; Sarukura, N.; Ito, S.; Kakizaki, K.; Watanabe, S.

    2015-02-01

    The high coherent, high power 193-nm ArF lasers are useful for interference lithography and microprosessing applications. In order to achieve high coherence ArF lasers, we have been developing a high coherence 193 nm solid state laser for the seeding to a high power ArF laser. We used the sum frequency mixing of the fourth harmonic (FH) of a 904-nm Ti:sapphire laser with a Nd:YVO4 laser (1342 nm) to generate 193-nm light. The laser system consists of a single-mode Ti:sapphire oscillator seeded by a 904-nm external cavity laser diode, a Pockels cell, a 6-pass amplifier, a 4-pass amplifier, a 2-pass amplifier and a wavelength conversion stage. The required repetition rate of 6 kHz corresponding to the ArF laser, along with a low gain at 904 nm induces serious thermal lens effects; extremely short focal lengths of the order of cm and bi-foci in the vertical and horizontal directions. From the analysis of thermal lens depending on pump intensity, we successfully compensated the thermal lens by dividing a 527-nm pump power with 15, 25 and 28 W to 3-stage amplifiers with even passes, resulting in the output power above 10W with a nearly diffraction limited beam. This 904-nm output was converted to 3.8 W in the second harmonic by LBO, 0.5 W in FH by BBO sequentially. Finally the output power of 230 mW was obtained at 193 nm by mixing the FH with a 1342-nm light in CLBO.

  19. Tuning and simulating a 193-nm resist for 2D applications

    NASA Astrophysics Data System (ADS)

    Howard, William B.; Wiaux, Vincent; Ercken, Monique; Bui, Bang; Byers, Jeff D.; Pochkowski, Mike

    2002-07-01

    For some applications, the usefulness of lithography simulation results depends strongly on the matching between experimental conditions and the simulation input parameters. If this matching is optimized and other sources of error are minimized, then the lithography model can be used to explain printed wafer experimental results. Further, simulation can be useful in predicting the results or in choosing the correct set of experiments. In this paper, PROLITH and ProDATA AutoTune were used to systematically vary simulation input parameters to match measured results on printed wafers used in a 193 nm process. The validity of the simulation parameters was then checked using 3D simulation compared to 2D top-down SEM images. The quality of matching was evaluated using the 1D metrics of average gate CD and Line End Shortening (LES). To ensure the most accurate simulation, a new approach was taken to create a compound mask from GDSII contextual information surrounding an accurate SEM image of the reticle region of interest. Corrections were made to account for all metrology offsets.

  20. Lactones in 193 nm resists: What do they do?

    NASA Astrophysics Data System (ADS)

    Ito, Hiroshi; Truong, Hoa D.; Brock, Phil J.

    2008-03-01

    Lactones are almost ubiquitously employed in 193 nm resists to increase the polarity of hydrophobic alicyclic polymers. What else do lactones do in 193 nm resists? We studied the behavior of methacrylate (MA) resists consisting of different protecting groups, hexafluoroalcohols, and norbornane lactone methacrylate (NLM, 2-oxo-3-oxatricyclo[4.2.1.04,8]nonan-5-yl methacrylate). When the protecting group is large [ethylcyclooctyl (ECO) and methyladamantyl (MAd)], thinning of the resist film that occurs in highly exposed areas upon postexposure bake (PEB) is significantly smaller than what is expected from the polymer composition. When the concentration of isopropylhexafluoroalcohol methacrylate (iPrHFAMA) is increased in the ECOMA-NLM polymer, the thinning increases and reaches 100% of theory and the ECOMA-norbornenehexafluoroalcohol methacrylate (NBHFAMA) resist loses quantitative thickness in highly-exposed areas upon PEB at 90 °C. This indicates that small lactones which are more basic than esters can trap deprotection fragments especially when the protecting group is large. Such entrapment was detected by IR spectroscopy and also observed at temperatures as high as 200 °C in thermogravimetric analysis (TGA). Incorporation of lactone appears to decrease the bake temperature sensitivity and the sensitivity of the resist perhaps due to trapping of photochemically generated acids by basic lactone. The lactone ring can be hydrolyzed during aqueous base development but does not seem to affect the dissolution rate, indicating that hydrolysis occurs in aqueous base solution after dissolution. Poly(methacrylic acid-NLM) dissolves as fast as poly(methacrylic acid) in 0.26 N tetramethylammonium hydroxide (TMAH) aqueous solution. While exposed P(ECOMA 47-NLM 53) resist dissolves in 0.26 N developer at about the same rate as authentically prepared poly(methacrylic acid 47-NLM 53), the dissolution rate of highly-exposed P(MAdMA 44-NLM 56) resist is much slower, indicating

  1. Advances in hardware, software, and automation for 193nm aerial image measurement systems

    NASA Astrophysics Data System (ADS)

    Zibold, Axel M.; Schmid, R.; Seyfarth, A.; Waechter, M.; Harnisch, W.; Doornmalen, H. v.

    2005-05-01

    A new, second generation AIMS fab 193 system has been developed which is capable of emulating lithographic imaging of any type of reticles such as binary and phase shift masks (PSM) including resolution enhancement technologies (RET) such as optical proximity correction (OPC) or scatter bars. The system emulates the imaging process by adjustment of the lithography equivalent illumination and imaging conditions of 193nm wafer steppers including circular, annular, dipole and quadrupole type illumination modes. The AIMS fab 193 allows a rapid prediction of wafer printability of critical mask features, including dense patterns and contacts, defects or repairs by acquiring through-focus image stacks by means of a CCD camera followed by quantitative image analysis. Moreover the technology can be readily applied to directly determine the process window of a given mask under stepper imaging conditions. Since data acquisition is performed electronically, AIMS in many applications replaces the need for costly and time consuming wafer prints using a wafer stepper/ scanner followed by CD SEM resist or wafer analysis. The AIMS fab 193 second generation system is designed for 193nm lithography mask printing predictability down to the 65nm node. In addition to hardware improvements a new modular AIMS software is introduced allowing for a fully automated operation mode. Multiple pre-defined points can be visited and through-focus AIMS measurements can be executed automatically in a recipe based mode. To increase the effectiveness of the automated operation mode, the throughput of the system to locate the area of interest, and to acquire the through-focus images is increased by almost a factor of two in comparison with the first generation AIMS systems. In addition a new software plug-in concept is realised for the tools. One new feature has been successfully introduced as "Global CD Map", enabling automated investigation of global mask quality based on the local determination of

  2. Performance of immersion lithography for 45-nm-node CMOS and ultra-high density SRAM with 0.25um2

    NASA Astrophysics Data System (ADS)

    Mimotogi, Shoji; Uesawa, Fumikatsu; Tominaga, Makoto; Fujise, Hiroharu; Sho, Koutaro; Katsumata, Mikio; Hane, Hiroki; Ikegami, Atsushi; Nagahara, Seiji; Ema, Tatsuhiko; Asano, Masafumi; Kanai, Hideki; Kimura, Taiki; Iwai, Masaaki

    2007-03-01

    Immersion lithography was applied to 45nm node logic and 0.25um2 ultra-high density SRAM. The predictable enhancement of focus margin and resolution were obtained for all levels which were exposed by immersion tool. In particular, the immersion lithography enabled to apply the attenuating phase shift mask to the gate level. The enough lithography margin for the alternating phase shift mask was also obtained by using not only immersion tool but also dry tool for gate level. The immersion lithography shrunk the minimum hole pitch from 160nm to 140nm. Thus, the design rule for 45nm node became available by using immersion lithography.

  3. Fundamental study of droplet spray characteristics in photomask cleaning for advanced lithography

    NASA Astrophysics Data System (ADS)

    Lu, C. L.; Yu, C. H.; Liu, W. H.; Hsu, Luke; Chin, Angus; Lee, S. C.; Yen, Anthony; Lee, Gaston; Dress, Peter; Singh, Sherjang; Dietze, Uwe

    2010-09-01

    The fundamentals of droplet-based cleaning of photomasks are investigated and performance regimes that enable the use of binary spray technologies in advanced mask cleaning are identified. Using phase Doppler anemometry techniques, the effect of key performance parameters such as liquid and gas flow rates and temperature, nozzle design, and surface distance on droplet size, velocity, and distributions were studied. The data are correlated to particle removal efficiency (PRE) and feature damage results obtained on advanced photomasks for 193-nm immersion lithography.

  4. Directed Self Assembly (DSA) compliant flow with immersion lithography: from material to design and patterning

    NASA Astrophysics Data System (ADS)

    Ma, Yuansheng; Wang, Yan; Word, James; Lei, Junjiang; Mitra, Joydeep; Torres, J. Andres; Hong, Le; Fenger, Germain; Khaira, Daman; Preil, Moshe; Yuan, Lei; Kye, Jongwook; Levinson, Harry J.

    2016-03-01

    In this paper, we present a DSA compliant flow for contact/via layers with immersion lithography assuming the grapho-epitaxy process for cylinders' formation. We demonstrate that the DSA technology enablement needs co-optimization among material, design, and lithography. We show that the number of DSA grouping constructs is countable for the gridded-design architecture. We use Template Error Enhancement Factor (TEEF) to choose DSA material, determine grouping design rules, and select the optimum guiding patterns. Our post-pxOPC imaging data shows that it is promising to achieve 2-mask solution with DSA for the contact/via layer using 193i at 5nm node.

  5. Lithography equipment

    NASA Astrophysics Data System (ADS)

    Levinson, Harry J.

    1996-07-01

    Until recently, lithography capability evolved consistently with Moore's law. It appears that semiconductor manufacturers are now deviating from Moore's law, which has implications for lithography equipment. DUV lithography is moving into production in a mix-and-match environment. Step- and-scan technology is the wave of the near-future, as a way to contend with the difficulty of manufacturing wide-field lenses. Resist processing equipment will undergo few fundamental changes, but will often be integrated with steppers, particularly for DUV applications. Metrology is being stretched beyond its limits for technologies below 250 nm. The move is on to 300 m diameter wafers, and 193 nm lithography is under consideration.

  6. Charting CEBL's role in mainstream semiconductor lithography

    NASA Astrophysics Data System (ADS)

    Lam, David K.

    2013-09-01

    historically kept it out of mainstream fabs. Thanks to continuing EBDW advances combined with the industry's move to unidirectional (1D) gridded layout style, EBDW promises to cost-efficiently complement 193nm ArF immersion (193i) optical lithography in high volume manufacturing (HVM). Patterning conventional 2D design layouts with 193i is a major roadblock in device scaling: the resolution limitations of optical lithography equipment have led to higher mask cost and increased lithography complexity. To overcome the challenge, IC designers have used 1D layouts with "lines and cuts" in critical layers.1 Leading logic and memory chipmakers have been producing advanced designs with lines-and-cuts in HVM for several technology nodes in recent years. However, cut masks in multiple optical patterning are getting extremely costly. Borodovsky proposes Complementary Lithography in which another lithography technology is used to pattern line-cuts in critical layers to complement optical lithography.2 Complementary E-Beam Lithography (CEBL) is a candidate to pattern the Cuts of optically printed Lines. The concept of CEBL is gaining acceptance. However, challenges in throughput, scaling, and data preparation rate are threatening to deny CEBL's role in solving industry's lithography problem. This paper will examine the following issues: The challenges of massively parallel pixel writing The solutions of multiple mini-column design/architecture in: Boosting CEBL throughput Resolving issues of CD control, CDU, LER, data rate, higher resolution, and 450mm wafers The role of CEBL in next-generation solution of semiconductor lithography

  7. Evolution of light source technology to support immersion and EUV lithography

    NASA Astrophysics Data System (ADS)

    Blumenstock, Gerry M.; Meinert, Christine; Farrar, Nigel R.; Yen, Anthony

    2005-01-01

    Since the early 1980's, the resolution of optical projection lithography has improved dramatically primarily due to three factors: increases in projection lens numerical aperture, reduction of the imaging source wavelength, and continued reduction of the k1 factor. These three factors have been enabled by the concurrent improvements in lens making technology, DUV light sources, photoresist technology, and resolution enhancement techniques. The DUV light source, excimer KrF and ArF lasers, has entered main stream production and now images more than 50% of the critical layers in today's leading edge devices. Looking forward to both immersion lithography and beyond to EUV lithography, new light source technologies must be created to enable the continued progression of shrinking feature sizes embodied by Moore's law.

  8. Plasma assisted deposition of metal fluorides for 193nm applications

    NASA Astrophysics Data System (ADS)

    Bischoff, Martin; Sode, Maik; Gaebler, Dieter; Kaiser, Norbert; Tuennermann, Andreas

    2008-10-01

    The ArF lithography technology requires a minimization of optical losses due to scattering and absorption. Consequently it is necessary to optimize the coating process of metal fluorides. The properties of metal fluoride thin films are mainly affected by the deposition methods, their parameters, and the vacuum conditions. Until now the best results were achieved by metal boat evaporation with high substrate temperature and without plasma assistance. In fact, it was demonstrated that the plasma assisted deposition process results in optical thin films with high packing density but the losses due to absorption were extremely high for deep and vacuum ultraviolet applications. This paper will demonstrate that most of the common metal fluorides can be deposited by electron beam evaporation with plasma assistance. In comparison to other deposition methods, the prepared thin films show low absorption in the VUV spectral range, high packing density, and less water content. The densification of the thin films was performed by a Leybold LION plasma source. As working gas, a variable mixture of fluorine and argon gas was chosen. To understand the deposition process and the interaction of the plasma with the deposition material, various characterization methods like plasma emission spectroscopy and ion current measurements were implemented.

  9. A new high-aperture 193 nm microscope for the traceable dimensional characterization of micro- and nanostructures

    NASA Astrophysics Data System (ADS)

    Ehret, G.; Pilarski, F.; Bergmann, D.; Bodermann, B.; Buhr, E.

    2009-08-01

    A new deep UV transmission microscope for traceable micro- and nanometrology is currently being set up at the Physikalisch-Technische Bundesanstalt (PTB), the National Metrology Institute of Germany. The new microscope is especially designed to enable linewidth measurements of micro- and nanostructures with an unsurpassed absolute measurement uncertainty of down to 10 nm (95% confidence interval). The optical resolution is about 100 nm. The main field of this tool will be critical dimension (CD) metrology of photomasks used in optical lithography. In particular, this system offers the possibility of 'at-wavelength' metrology for the currently applied 193 nm lithography technology. The high lateral resolution will be attained by means of 193 nm excimer laser radiation for illumination in conjunction with a high-aperture objective (NA = 0.9). The illumination and imaging system will provide various imaging modalities, ranging from ordinary brightfield to specially structured illumination schemes. Traceability to the SI unit 'meter' will be accomplished by means of laser interferometry. The mechanical set-up is characterized by an ultra-stable bridge construction on a granite base and has been designed with special emphasis on realizing a positioning stability in the nanometer range. The instrument is being set up in the Clean Room Centre of the PTB and will be ready for operation in mid 2009. Simulation calculations, based on a rigorous optical modeling of the expected microscope images, are presented. These simulations are made for the important application of measuring Cr structures on quartz photomasks. Based on these simulations and on available data of the uncertainties of various experimental parameters—including instrument and sample parameters—expected uncertainty budgets for the measurement of the width of Cr lines on quartz substrates are estimated.

  10. Cycloolefin/cyanoacrylate (COCA) copolymers for 193-nm and 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Dammel, Ralph R.; Sakamuri, Raj; Lee, Sang-Ho; Rahman, Dalil; Kudo, Takanori; Romano, Andrew R.; Rhodes, Larry F.; Lipian, John-Henry; Hacker, Cheryl; Barnes, Dennis A.

    2002-07-01

    The copolymerization reaction between methyl cyanoacrylate (MCA) and a variety of cycloolefins (CO) was investigated. Cycololefin/cyanoacrylate (COCA) copolymers were obtained in good yields and with lithographically interesting molecular weights for all cycoolefins studied. Anionic MCA homopolymerization could be largely suppressed using acetic acid. Based on NMR data, the copolymerization may tend to a 1:1 CO:MCA incorporation ratio but further work with better suppression of the anionic component is needed to confirm this. Lithographic tests on copolymers of appropriately substituted norbornenes and MCA showed semi-dense and isolated line performance down to 90 nm.

  11. Water-developable resists based on glyceryl methacrylate for 193-nm lithography

    NASA Astrophysics Data System (ADS)

    Kim, Jin-Baek; Jang, Ji-Hyun; Choi, Jae-Hak; Lee, Kwan-Ku; Ko, Jong-Sung

    2004-05-01

    Novel water-developable negative resists were designed to induce both cross-linking and polarity change upon exposure and bake. The matrix polymers were synthesized by copolymerization of glyceryl methacrylate and methacrolein. The acid-catalyzed acetalization of the polymer induced cross-linking, polarity change, and increase in dry-etch resistance. The resist formulated with this polymer and cast in a water-ethanol mixture, showed 0.7 μm line and space patterns using a mercury-xenone lamp in a contact printing mode and pure water as a developer.

  12. The art of photomask materials for low-k1-193nm lithography

    NASA Astrophysics Data System (ADS)

    Hashimoto, Masahiro; Iwashita, Hiroyuki; Mitsui, Hideaki

    2009-04-01

    The resolution of photomask patterns were improved with a hardmask (HM) system. The system which is thin Sicompounds layer is easily etched by the hyper-thin resist (below 100nm thickness). The HM material has sufficient etching selectivity against the chrome-compounds which is the second layer chrome absorber for the phase-shifter. This hardmask layer has been completely removed during the phase-shifter etching. It means that the conventional phase-shit mask (PSM) has been made with the ultimately high-resolution without configuration changes. Below 50nm resolution of PSM was made with 90nm thickness resist on HM layer in this paper. The CD bias between a resist feature CD and a chrome feature CD was almost zero (below 1nm) in the optimized etching condition. We confirmed that the mask performances were the equal to COMS (Cr-HM on MoSi binary mask) in resolution and CD linearity. The performances of hardmask blanks will be defined by resist performance because of almost zero bias.

  13. Absorption coefficients for water vapor at 193 nm from 300 to 1073 K

    NASA Technical Reports Server (NTRS)

    Kessler, W. J.; Carleton, K. L.; Marinelli, W. J.

    1993-01-01

    Measurements of the water absorption coefficient at 193 nm from 300 to 1073 K are reported. The measurements were made using broadband VUV radiation and a monochromator-based detection system. The water vapor was generated by a saturator and metered into a flowing, 99 cm absorption cell via a water vapor mass flow meter. The 193 nm absorption coefficient measurements are compared to room temperature and high temperature shock tube measurements with good agreement. The absorption can be parameterized by a nu3 vibrational mode reaction coordinate and the thermal population of the nu3 mode.

  14. Lithography of choice for the 45-nm node: new medium, new wavelength, or new beam?

    NASA Astrophysics Data System (ADS)

    Uesawa, Fumikatsu; Katsumata, Mikio; Ogawa, Kazuhisa; Takeuchi, Koichi; Omori, Shinji; Yoshizawa, Masaki; Kawahira, Hiroichi

    2004-05-01

    In order to clarify the direction of the lithography for the 45 nm node, the feasibilities of various lithographic techniques for gate, metal, and contact layers are studied by using experimental data and aerial image simulations. The focus and exposure budget have been determined from the actual data and the realistic estimation such as the focus distributions across a wafer measured by the phase shift focus monitor (PSFM), the focus and exposure reproducibility of the latest exposure tools, and the anticipated 45 nm device topography, etc. 193 nm lithography with a numerical aperture (NA) of 0.93 achieves the half pitch of 70 nm (hp70) by using an attenuated phase shift mask (att-PSM) and annular illumination. 193 nm immersion lithography has the possibility to achieve the hp60 without an alternative PSM (alt-PSM). For a gate layer, 50-nm/130-nm line-and-space (L/S) patterns as well as 50 nm isolated lines can be fabricated by an alt-PSM. Although specific aberrations degrade the critical dimension (CD) variation of an alt-PSM, +/-2.6 nm CD uniformity (CDU) is demonstrated by choosing the well-controlled projection lens and using a high flatness wafer. For a contact layers, printing 90 nm contacts is very critical by optical lithography even if the aggressive resolution enhancement technique (RET) is used. Especially for dense contact, the mask error factor (MEF) increases to around 10 and practical process margin is not available at all. On the other hand, low-energy electron-beam proximity-projection lithography (LEEPL) can fabricate 80 nm contact with large process margin. As a lithography tool for the contact layers of the 45 nm node devices, LEEPL is expected to replace 193 nm lithography.

  15. Developing an integrated imaging system for the 70-nm node using high numerical aperture ArF lithography

    NASA Astrophysics Data System (ADS)

    Petersen, John S.; Beach, James V.; Gerold, David J.; Maslow, Mark J.

    2002-07-01

    At its conception, 193 nm lithography was thought to be the best way to take optical lithography to the 180 nm node. It was expected that 193 nm could support the now-defunct 160 nm node before optical lithography would have to yield to an undetermined non-optical solution. Today, 193 nm must compete with 248 nm for the 130 nm node and is expected to support lithography until it is replaced by 157 nm at the 70 nm node. Given the challenges facing 157 nm, it is likely that lithographers will attempt to extend the utility of 193 nm to its theoretical limits.

  16. Properties of AlF3 and LaF3 films at 193nm

    NASA Astrophysics Data System (ADS)

    Xue, Chunrong; Shao, Jianda

    2010-10-01

    In order to develop low loss, high-performance 193nm Fluoride HR mirrors and anti-reflection coatings, LaF3 and AlF3 materials, used for a single-layer coating, were deposited by a molybdenum boat evaporation process. Various microstructures that formed under different substrate temperatures and with deposition rates were investigated. The relation between these microstructures (including cross section morphology, surface roughness and crystalline structure), the optical properties (including refractive index and optical loss) and mechanical properties (stress) were investigated. Furthermore, AlF3 used as a low-index material and LaF3 used as a high-index material were designed and deposited for multilayer coatings. Transmittance, reflectance, stress, and the laser-induced damage threshold (LIDT) were studied. It is shown that AlF3 and LaF3 thin films, deposited on the substrate at a temperature of 300 °C, obtained good quality thin films with high transmittance and little optical loss at 193 nm. For multilayer coatings, the absorption mainly comes from LaF3. Based on these studies, The thickness of 193nm films was controled by a 1/3 baffle with pre-coating technology. the LaF3/AlF3 AR coantings and HR mirrors at 193nm were designed and deposited. Under the present experimental conditions, the reflectance of LaF3/AlF3 HR mirror is up to 96%, and its transmittance is 1.5%. the LaF3/AlF3 AR coanting's residual reflectance is less than 0.14%, and single-sided transmittance is 93.85%. To get a high-performance 193nm AR coating, super-polished substrate is the best choice.

  17. High refractive index Fresnel lens on a fiber fabricated by nanoimprint lithography for immersion applications

    NASA Astrophysics Data System (ADS)

    Koshelev, Alexander; Calafiore, Giuseppe; Piña-Hernandez, Carlos; Allen, Frances I.; Dhuey, Scott; Sassolini, Simone; Wong, Edward; Lum, Paul; Munechika, Keiko; Cabrini, Stefano

    2016-08-01

    In this Letter we present a Fresnel lens fabricated on the end of an optical fiber. The lens is fabricated using nanoimprint lithography of a functional high refractive index material, which is suitable for mass production. The main advantage of the presented Fresnel lens compared to a conventional fiber lens is its high refractive index (n=1.69), which enables efficient light focusing even inside other media such as water or adhesive. Measurement of the lens performance in an immersion liquid (n=1.51) shows a near diffraction limited focal spot of 810 nm in diameter at the 1/e2 intensity level for a wavelength of 660 nm. Applications of such fiber lenses include integrated optics, optical trapping and fiber probes.

  18. High refractive index Fresnel lens on a fiber fabricated by nanoimprint lithography for immersion applications.

    PubMed

    Koshelev, Alexander; Calafiore, Giuseppe; Piña-Hernandez, Carlos; Allen, Frances I; Dhuey, Scott; Sassolini, Simone; Wong, Edward; Lum, Paul; Munechika, Keiko; Cabrini, Stefano

    2016-08-01

    In this Letter, we present a Fresnel lens fabricated on the end of an optical fiber. The lens is fabricated using nanoimprint lithography of a functional high refractive index material, which is suitable for mass production. The main advantage of the presented Fresnel lens compared to a conventional fiber lens is its high refractive index (n=1.68), which enables efficient light focusing even inside other media, such as water or an adhesive. Measurement of the lens performance in an immersion liquid (n=1.51) shows a near diffraction limited focal spot of 810 nm in diameter at the 1/e2 intensity level for a wavelength of 660 nm. Applications of such fiber lenses include integrated optics, optical trapping, and fiber probes. PMID:27472584

  19. Solutions with precise prediction for thermal aberration error in low-k1 immersion lithography

    NASA Astrophysics Data System (ADS)

    Fukuhara, Kazuya; Mimotogi, Akiko; Kono, Takuya; Aoyama, Hajime; Ogata, Taro; Kita, Naonori; Matsuyama, Tomoyuki

    2013-04-01

    Thermal aberration becomes a serious problem in the production of semiconductors for which low-k1 immersion lithography with a strong off-axis illumination, such as dipole setting, is used. The illumination setting localizes energy of the light in the projection lens, bringing about localized temperature rise. The temperature change varies lens refractive index and thus generates aberrations. The phenomenon is called thermal aberration. For realizing manufacturability of fine patterns with high productivity, thermal aberration control is important. Since heating areas in the projection lens are determined by source shape and distribution of diffracted light by a mask, the diffracted pupilgram convolving illumination source shape with diffraction distribution can be calculated using mask layout data for the thermal aberration prediction. Thermal aberration is calculated as a function of accumulated irradiation power. We have evaluated the thermal aberration computational prediction and control technology "Thermal Aberration Optimizer" (ThAO) on a Nikon immersion system. The thermal aberration prediction consists of two steps. The first step is prediction of the diffraction map on the projection pupil. The second step is computing thermal aberration from the diffraction map using a lens thermal model and an aberration correction function. We performed a verification test for ThAO using a mask of 1x-nm memory and strong off-axis illumination. We clarified the current performance of thermal aberration prediction, and also confirmed that the impacts of thermal aberration of NSR-S621D on CD and overlay for our 1x-nm memory pattern are very small. Accurate thermal aberration prediction with ThAO will enable thermal aberration risk-free lithography for semiconductor chip production.

  20. High-performance 193-nm photoresist materials based on a new class of polymers containing spaced ester finctionalities

    NASA Astrophysics Data System (ADS)

    Khojasteh, Mahmoud; Chen, K. Rex; Kwong, Ranee W.; Lawson, Margaret C.; Varanasi, Pushkara R.; Patel, Kaushal S.; Kobayashi, Eiichi

    2003-06-01

    ArF lithography has been selected as the imaging method for the 90 nm technology node. Manufacturing related issues will have to be addressed when designing advanced 193 nm resists that are production worthy. Post exposure bake (PEB) sensitivity, dissolution properties and process window are some issues that need continuous improvement. Initially our investigation focused on a cyclic olefin (CO) platform which led us to a better understanding of the relationship between polymer structure and physical properties and how to improve cyclic olefin resist performance. Since then we have developed a new class of acrylate polymers with pendant "spaced ester" functionality. We have investigated the potential use of "spaced ester" functionality on improving the lithographic performance of CO and acrylate resist platforms. We have found that with "spaced ester" as pending group in CO polymer structures, it can lower the Tg and improve the dissolution properties of the CO resists. Resists formulated with acrylate containing "spaced ester" group exhibit excellent PEB temperature sensitivity (1 nm/°C), and are soluble in PGMEA. In addition, we have demonstrated sub-100 nm resolution with excellent process window through formulation optimization for acrylate based resists. This paper will focus on the "spaced ester" based polymer design, material properties; resist characteristics, and the lithographic performance for logic dense line applications.

  1. Characterization of AlF3 thin films at 193 nm by thermal evaporation

    NASA Astrophysics Data System (ADS)

    Lee, Cheng-Chung; Liu, Ming-Chung; Kaneko, Masaaki; Nakahira, Kazuhide; Takano, Yuuichi

    2005-12-01

    Aluminum fluoride (AlF3) was deposited by a resistive heating boat. To obtain a low optical loss and high laser-induced damage threshold (LIDT) at 193 nm, the films were investigated under different substrate temperatures, deposition rates, and annealing after coating. The optical property (the transmittance, refractive index, extinction coefficient, and optical loss) at 193 nm, microstructure (the cross-sectional morphology, surface roughness, and crystalline structure), mechanical property (stress), and LIDT of AlF3 thin films have been studied. AlF3 thin films deposited at a high substrate temperature and low deposition rate showed a lower optical loss. The highest LIDT occurred at the substrate temperature of 150 °C. The LIDT of the films prepared at a deposition rate of 2 Å/s was higher than that at other deposition rates. The annealing process did not influence the optical properties too much, but it did increase the LIDT and stress.

  2. Characterization of AlF3 thin films at 193 nm by thermal evaporation.

    PubMed

    Lee, Cheng-Chung; Liu, Ming-Chung; Kaneko, Masaaki; Nakahira, Kazuhide; Takano, Yuuichi

    2005-12-01

    Aluminum fluoride (AlF3) was deposited by a resistive heating boat. To obtain a low optical loss and high laser-induced damage threshold (LIDT) at 193 nm, the films were investigated under different substrate temperatures, deposition rates, and annealing after coating. The optical property (the transmittance, refractive index, extinction coefficient, and optical loss) at 193 nm, microstructure (the cross-sectional morphology, surface roughness, and crystalline structure), mechanical property (stress), and LIDT of AlF3 thin films have been studied. AlF3 thin films deposited at a high substrate temperature and low deposition rate showed a lower optical loss. The highest LIDT occurred at the substrate temperature of 150 degrees C. The LIDT of the films prepared at a deposition rate of 2 A/s was higher than that at other deposition rates. The annealing process did not influence the optical properties too much, but it did increase the LIDT and stress. PMID:16353803

  3. Studies on a cross-linking type positive 193nm photoresist material

    NASA Astrophysics Data System (ADS)

    Wang, Liyuan; Guo, Xin; Chu, Zhanxing; Wang, Wenjun

    2006-03-01

    A kind of diacid, acrylpimaric acid, with condensed alicyclic structure and good film-forming property, was prepared by the Diels-Alder reaction of abietic acid and acrylic acid. In their solid film, the diacid can react with divinyl ether, such as 1,3-divinyloxyethoxybenzene when baked above 80 °C and become insoluble in dilute aqueous base. Thus formed compound can be quickly decomposed at the presence of strong acid generated by PAG above 100 °C and become easily soluble in dilute aqueous base. A positive photoresist can be formed by the diacid, divinyl ether and PAG. The measured photosensitivity is less than 50 mj/cm2 when exposed to low pressure Hg lamp (254nm). The diacid mixture displayed lower transparency than estimated at 193 nm and should be further purified to be used in 193 nm photoresist.

  4. Temperature- and pressure-dependent absorption coefficients for CO2 and O2 at 193 nm

    NASA Astrophysics Data System (ADS)

    Hartinger, K. T.; Nord, S.; Monkhouse, P. B.

    Absorption of laser radiation at 193 nm by CO2 and O2 was studied at a series of different temperatures up to 1273 K and pressures up to 1 bar. The spectrum for CO2 was found to be broadband, so that absorption could be fitted to a Beer-Lambert law. On the other hand, the corresponding O2 spectrum is strongly structured and parameterisation requires a more complex relation, depending on both temperature and the product (pressure × absorption path length). In this context, the influence of spectral structure on the resulting spectrally integrated absorption coefficients is discussed. Using the fitting parameters obtained, effective transmissions at 193 nm can be calculated for a wide range of experimental conditions. As an illustration of the practical application of these data, the calculation of effective transmission for a typical industrial flue gas is described.

  5. Rayleigh rejection filters for 193-nm ArF laser Raman spectroscopy

    NASA Technical Reports Server (NTRS)

    Mckenzie, Robert L.

    1993-01-01

    Selected organic absorbers and their solvents are evaluated as spectral filters for the rejection of 193-nm Rayleigh light associated with the use of an ArF excimer laser for Raman spectroscopy. A simply constructed filter cell filled with 0.5 percent acetone in water and an optical path of 7 mm is shown effectively to eliminate stray Rayleigh light underlying the Raman spectrum from air while transmitting 60 percent of the Raman light scattered by O2.

  6. Feasibility study of optical/e-beam complementary lithography

    NASA Astrophysics Data System (ADS)

    Hohle, Christoph; Choi, Kang-Hoon; Freitag, Martin; Gutsch, Manuela; Jaschinsky, Philipp; Kahlenberg, Frank; Klein, Christof; Klikovits, Jan; Paul, Jan; Rudolph, Matthias; Thrun, Xaver

    2012-03-01

    Using electron beam direct write (EBDW) as a complementary approach together with standard optical lithography at 193nm or EUV wavelength has been proposed only lately and might be a reasonable solution for low volume CMOS manufacturing and special applications as well as design rule restrictions. Here, the high throughput of the optical litho can be combined with the high resolution and the high flexibility of the e-beam by using a mix & match approach (Litho- Etch-Litho-Etch, LELE). Complementary Lithography is mainly driven by special design requirements for unidirectional (1-D gridded) Manhattan type design layouts that enable scaling of advanced logic chips. This requires significant data prep efforts such as layout splitting. In this paper we will show recent results of Complementary Lithography using 193nm immersion generated 50nm lines/space pattern addressing the 32nm logic technology node that were cut with electron beam direct write. Regular lines and space arrays were patterned at GLOBALFOUNDRIES Dresden and have been cut in predefined areas using a VISTEC SB3050DW e-beam direct writer (50KV Variable Shaped Beam) at Fraunhofer Center Nanoelectronic Technologies (CNT), Dresden, as well as on the PML2 tool at IMS Nanofabrication, Vienna. Two types of e-beam resists were used for the cut exposure. Integration issues as well as overlay requirements and performance improvements necessary for this mix & match approach will be discussed.

  7. Towards ultimate optical lithography with NXT:1950i dual stage immersion platform

    NASA Astrophysics Data System (ADS)

    Castenmiller, Tom; van de Mast, Frank; de Kort, Toine; van de Vin, Coen; de Wit, Marten; Stegen, Raf; van Cleef, Stefan

    2010-04-01

    Optical lithography, currently being used for 45-nm semiconductor devices, is expected to be extended further towards the 32-nm and 22-nm node. A further increase of lens NA will not be possible but fortunately the shrink can be enabled with new resolution enhancement methods like source mask optimization (SMO) and double patterning techniques (DPT). These new applications lower the k1 dramatically and require very tight overlay control and CD control to be successful. In addition, overall cost per wafer needs to be lowered to make the production of semiconductor devices acceptable. For this ultimate era of optical lithography we have developed the next generation dual stage NXT:1950i immersion platform. This system delivers wafer throughput of 175 wafers per hour together with an overlay of 2.5nm. Several extensions are offered enabling 200 wafers per hour and improved imaging and on product overlay. The high productivity is achieved using a dual wafer stage with planar motor that enables a high acceleration and high scan speed. With the dual stage concept wafer metrology is performed in parallel with the wafer exposure. The free moving planar stage has reduced overhead during chuck exchange which also improves litho tool productivity. In general, overlay contributors are coming from the lithography system, the mask and the processing. Main contributors for the scanner system are thermal wafer and stage control, lens aberration control, stage positioning and alignment. The back-bone of the NXT:1950i enhanced overlay performance is the novel short beam fixed length encoder grid-plate positioning system. By eliminating the variable length interferometer system used in the previous generation scanners the sensitivity to thermal and flow disturbances are largely reduced. The alignment accuracy and the alignment sensitivity for process layers are improved with the SMASH alignment sensor. A high number of alignment marker pairs can be used without throughput loss, and

  8. Collateral damage-free debridement using 193nm ArF laser

    NASA Astrophysics Data System (ADS)

    Wynne, James J.; Felsenstein, Jerome M.; Trzcinski, Robert; Zupanski-Nielsen, Donna; Connors, Daniel P.

    2011-03-01

    Burn eschar and other necrotic areas of the skin and soft tissue are anhydrous compared to the underlying viable tissue. A 193 nm ArF excimer laser, emitting electromagnetic radiation at 6.4 eV at fluence exceeding the ablation threshold, will debride such necrotic areas. Because such radiation is strongly absorbed by aqueous chloride ions through the nonthermal process of electron photodetachment, debridement will cease when hydrated (with chloride ions) viable tissue is exposed, avoiding collateral damage to this tissue. Such tissue will be sterile and ready for further treatment, such as a wound dressing and/or a skin graft.

  9. Substantial H-atom production from the 193 nm photolysis of triethylaluminum

    NASA Astrophysics Data System (ADS)

    Brum, Jeffrey L.; Deshmukh, Subhash; Koplitz, Brent

    1990-01-01

    The 193 nm irradiation of triethylaluminum (TEA) produces a significant amount of atomic hydrogen. Doppler profiles at Lyman-α (121.6 nm) reveal that the H atoms have little kinetic energy, the mean kinetic energy being ⩽ 0.35 eV. These observations are interpreted in the context of possible photodissociation pathways. The most likely route involves a single-photon absorption followed by dissociation to form the ethyl radical, which can further dissociate to produce C 2H 4 and H.

  10. Determination of mask induced polarization effects occurring in hyper NA immersion lithography

    NASA Astrophysics Data System (ADS)

    Teuber, Silvio; Bubke, Karsten; Hollein, Ingo; Ziebold, Ralf; Peters, Jan H.

    2005-05-01

    As the lithographic projection technology of the future will require higher numerical aperture (NA) values, new physical effects will have to be taken into consideration. Immersion lithography will result in NA values of up to 1.2 and above. New optical effects like 3D shadowing, effects from oblique incident angles, mask-induced polarization of the transmitted light and birefringence from the substrate should be considered when the masks optical performance is evaluated. This paper addresses mask induced polarization effects from dense lines-and-space structures of standard production masks. On a binary and on an attenuated phase-shifting mask, which were manufactured at the Advanced Mask Technology Center (AMTC) transmission experimental investigations were performed. Measurements of diffraction efficiencies for TE- and TM-polarized light using three different incident angles are presented for all considered mask types and compared to simulations. The structures under investigation include line-space-pattern with varying pitches as well as varying duty cycles. Experimental results show good agreement with simulations.

  11. Demonstration of EDA flow for massively parallel e-beam lithography

    NASA Astrophysics Data System (ADS)

    Brandt, P.; Belledent, J.; Tranquillin, C.; Figueiro, T.; Meunier, S.; Bayle, S.; Fay, A.; Milléquant, M.; Icard, B.; Wieland, M.

    2014-03-01

    Today's soaring complexity in pushing the limits of 193nm immersion lithography drives the development of other technologies. One of these alternatives is mask-less massively parallel electron beam lithography, (MP-EBL), a promising candidate in which future resolution needs can be fulfilled at competitive cost. MAPPER Lithography's MATRIX MP-EBL platform has currently entered an advanced stage of development. The first tool in this platform, the FLX 1200, will operate using more than 1,300 beams, each one writing a stripe 2.2μm wide. 0.2μm overlap from stripe to stripe is allocated for stitching. Each beam is composed of 49 individual sub-beams that can be blanked independently in order to write in a raster scan pixels onto the wafer.

  12. 193 nm excimer laser sclerostomy in pseudophakic patients with advanced open angle glaucoma.

    PubMed Central

    Allan, B D; van Saarloos, P P; Cooper, R L; Constable, I J

    1994-01-01

    A modified open mask system incorporating an en face air jet to dry the target area during ablation and a conjunctival plication mechanism, which allows ab externo delivery of the 193 nm excimer laser without prior conjunctival dissection, has been developed to form small bore sclerostomies accurately and atraumatically. Full thickness sclerostomies, and sclerostomies guarded by a smaller internal ostium can be created. A pilot therapeutic trial was conducted in pseudophakic patients with advanced open angle glaucoma. Six full thickness sclerostomies (200 microns and 400 microns diameter) and three guarded sclerostomies were created in nine patients by 193 nm excimer laser ablation (fluence per pulse 400 mJ/cm2, pulse rate 16 Hz, air jet pressure intraocular pressure +25 mm Hg). After 6 months' follow up, intraocular pressure was controlled (< or = 16 mm Hg) in eight of the nine patients (6/9 without medication). Early postoperative complications included hyphaema (trace--2.5 mm) (6/9), temporary fibrinous sclerostomy occlusion (4/9), profound early hypotony (all patients without fibrinous occlusion), and suprachoroidal haemorrhage in one case. Conjunctival laser wounds were self sealing. Small bore laser sclerostomy procedures are functionally equivalent to conventional full thickness procedures, producing early postoperative hypotony, with an increased risk of suprachoroidal haemorrhage in association with this. Further research is required to improve control over internal guarding in excimer laser sclerostomy before clinical trials of this technique can safely proceed. Images PMID:8148335

  13. Photodissociation dynamics of propyne at 193 nm: a trajectory surface hopping study.

    PubMed

    Ghosh, Subhendu; Rauta, Akshaya Kumar; Maiti, Biswajit

    2016-03-01

    Photodissociation dynamics of propyne at 193 nm are studied using the fewest switches nonadiabatic trajectory surface hopping method on its first excited singlet electronic state (1(1)A''). The trajectories are propagated based on potential energies, gradients and nonadiabatic couplings calculated at the MRCIS(6,7) level with the 6-31++G(d,p) basis set. Our trajectory calculations have revealed that H + H3CCC is the major dissociation channel, which has also been predicted experimentally. For the primary photodissociation channel H + H3CCC we demonstrate that nonadiabatic dynamics do not play a significant role. This observation is however contradictory to most of the previously reported experimental predictions. The calculated product translation energy distribution for the acetylenic H atom elimination peaked at ∼18 kcal mol(-1), indicating that the dissociation occurs adiabatically on a moderately repulsive excited surface that correlates with the ground state products (CH3C[triple bond, length as m-dash]C + H). The H atom elimination process from the methyl fragment involving a transition state, which has to compete with the acetylenic H atom dissociation channel with no barrier in the excited singlet surface, was found to be too less probable to make a contribution to product branching. We observed that a fewer but significant number of trajectories led to CH3 + CCH product formation which has not been observed experimentally when propyne is excited at 193 nm. PMID:26928947

  14. Double patterning scheme for sub-0.25 k1 single damascene structures at NA=0.75, λ=193nm

    NASA Astrophysics Data System (ADS)

    Maenhoudt, M.; Versluijs, J.; Struyf, H.; Van Olmen, J.; Van Hove, M.

    2005-05-01

    Using 193nm lithography at NA=0.75, the minimum pitch that can be obtained in a single exposure is 160nm for dark field structures that are used in single damascene interconnect processing. In order to evaluate the critical electrical parameters for the smaller technologies, a double patterning scheme has been developed to obtain electrical structures at pitches from 140nm down to 100nm. This corresponds to k1-factors of 0.27 to 0.19 for dense trenches. The designs have been split up into two layers at more relaxed pitch (twice the final pitch). The first step consists in patterning a small semi-isolated trench at this more relaxed pitch. Because of the limited resist resolution for semi-isolated trenches, shrink techniques such as resist reflow or RELACS are needed. After etching this first layer into a low-k material or metal hard mask, planarization of the topography is critical before performing the second exposure. The second exposure is then identical to the first one, but overlay to the first layer is extremely critical in order to get a reasonable process window. In this paper, we illustrate the feasibility of the double patterning technique for early sub-65nm-node evaluation of low-k materials. The resolution and processing limits will be shown for single layer resist processing with RELACS shrink for 193nm lithography at NA=0.75. The planarization for the second photo is done using organic BARC. We will also quantify the overlay requirements to measured and introduced overlay errors.

  15. Photodissociation dynamics of 2-nitropropane and 2-methyl-2-nitropropane at 248 and 193 nm.

    PubMed

    Sengupta, Sumana; Indulkar, Yogesh; Kumar, Awadhesh; Dhanya, Suresh; Naik, Prakash Dattatray; Bajaj, Parma Nand

    2008-12-11

    Dynamics of formation of electronically excited NO2 and formation of OH fragment, during photo dissociation of 2-nitropropane (NP) and 2-methyl-2-nitropropane (MNP), were investigated at 193 and 248 nm. The radiative lifetime of the electronically excited NO2 fragment, observed at 193 nm, was measured to be 1.2 ( 0.1 micros and the rate coefficient of quenching of its emission by MNP was measured as (2.7 ( 0.1) x 10(-10) molecule(-1) cm3 s(-1). Formation of the ground electronic state of OH was confirmed in both molecules. State selective laser induced fluorescence technique was used to detect the nascent OH (X 2Pi, v'', J'') fragments in different ro-vibrational states, and to obtain information on energy partitioning. Though MNP and NP differ in the types of the available H atoms, the dynamics of OH formation is found to be the same in both. The relative population in different rotational states does not follow Boltzmann equilibrium distribution in both the molecules at 193 and 248 nm. The translational energies of the OH fragments, calculated from the Doppler width, are 21.2 ( 7.2 and 25.0 ( 2.5 kcal mol-1 for NP at 248 and 193 nm, respectively. The translational energies of the OH fragments, in the case of MNP, are found to be lower, 17.5 ( 4.1 and 22.0 ( 3.2 kcal mol-1,respectively, at 248 nm 193 nm. These results are compared with the earlier reports on photodissociation of nitromethane (NM), nitroethane (NE), and other nitroalkanes. All possible dissociation pathways of these molecules--NM, NE, NP, and MNPs leading to the formation of the OH fragment were investigated computationally, with geometry optimization at the B3LYP/6-311+G(d,p) level and energy calculation at the MP4(SDQ)/6-311+G (d,p) level. The results suggest that in NM, OH is formed after isomerization to CH2N(OH)O, whereas in all other cases OH is formed from HONO, a primary product of molecular elimination of nitroalkanes, formed with sufficient internal energy. PMID:19053556

  16. Microstructure of magnesium fluoride films deposited by boat evaporation at 193 nm.

    PubMed

    Liu, Ming-Chung; Lee, Cheng-Chung; Kaneko, Masaaki; Nakahira, Kazuhide; Takano, Yuuichi

    2006-10-01

    Single layer magnesium fluoride (MgF2) was deposited on fused-silica substrates by a molybdenum boat evaporation process at 193 nm. The formation of various microstructures in relation to the different substrate temperatures and deposition rates were investigated. The relation between these microstructures (including cross-sectional morphology, surface roughness, and crystalline structures), the optical properties (including refractive index and optical loss) and stress, were all investigated. It was found that the laser-induced damage threshold (LIDT) would be affected by the microstructure, optical loss, and stress of the thin film. To obtain a larger LIDT value and better optical characteristics, MgF2 films should be deposited at a high substrate temperature (300 degrees C) and at a low deposition rate (0.05 nm s(-1)). PMID:16983421

  17. Microstructure of magnesium fluoride films deposited by boat evaporation at 193 nm

    NASA Astrophysics Data System (ADS)

    Liu, Ming-Chung; Lee, Cheng-Chung; Kaneko, Masaaki; Nakahira, Kazuhide; Takano, Yuuichi

    2006-10-01

    Single layer magnesium fluoride (MgF2) was deposited on fused-silica substrates by a molybdenum boat evaporation process at 193 nm. The formation of various microstructures in relation to the different substrate temperatures and deposition rates were investigated. The relation between these microstructures (including cross-sectional morphology, surface roughness, and crystalline structures), the optical properties (including refractive index and optical loss) and stress, were all investigated. It was found that the laser-induced damage threshold (LIDT) would be affected by the microstructure, optical loss, and stress of the thin film. To obtain a larger LIDT value and better optical characteristics, MgF2 films should be deposited at a high substrate temperature (300 °C) and at a low deposition rate (0.05 nm s-1).

  18. Photoinduced absorption and refractive-index induction in phosphosilicate fibres by radiation at 193 nm

    SciTech Connect

    Rybaltovsky, A A; Sokolov, V O; Plotnichenko, V G; Lanin, Aleksei V; Semenov, S L; Dianov, Evgenii M; Gur'yanov, A N; Khopin, V F

    2007-04-30

    The photoinduced room-temperature-stable increase in the refractive index by {approx}5x10{sup -4} at a wavelength of 1.55 {mu}m was observed in phosphosilicate fibres without their preliminary loading with molecular hydrogen. It is shown that irradiation of preliminary hydrogen-loaded fibres by an ArF laser at 193 nm enhances the efficiency of refractive-index induction by an order of magnitude. The induced-absorption spectra of preforms with a phosphosilicate glass core and optical fibres fabricated from them are studied in a broad spectral range from 150 to 5000 nm. The intense induced-absorption band ({approx}800 cm{sup -1}) at 180 nm is found, which strongly affects the formation of the induced refractive index. The quantum-chemical model of a defect related to this band is proposed. (optical fibres)

  19. White-Light Emission from Silicone Rubber Modified by 193 nm ArF Excimer Laser

    NASA Astrophysics Data System (ADS)

    Okoshi, Masayuki; Sekine, Daisuke; Inoue, Narumi; Yamashita, Tsugito

    2007-04-01

    The photochemical surface modification of silicone ([SiO(CH3)2]n) rubber has been successfully demonstrated using a 193 nm ArF excimer laser, and white light of strong intensity was emitted upon exposure to a 325 nm He-Cd laser. The photoluminescence spectra of the modified silicone showed broad peaks centered at 410, 550, and 750 nm wavelengths. The modified surface was carbon-free silicon oxide, and the chemical composition ratio of O/Si was approximately 2. However, the surface was not silica glass (SiO2), as clarified by IR spectroscopy. Instead, nanometer-size particles of silicon oxide were formed on the surface of the modified silicone rubber.

  20. 193 nm Excimer laser processing of Si/Ge/Si(100) micropatterns

    NASA Astrophysics Data System (ADS)

    Gontad, F.; Conde, J. C.; Chiussi, S.; Serra, C.; González, P.

    2016-01-01

    193 nm Excimer laser assisted growth and crystallization of amorphous Si/Ge bilayer patterns with circular structures of 3 μm diameter and around 25 nm total thickness, is presented. Amorphous patterns were grown by Laser induced Chemical Vapor Deposition, using nanostencils as shadow masks and then irradiated with the same laser to induce structural and compositional modifications for producing crystalline SiGe alloys through fast melting/solidification cycles. Compositional and structural analyses demonstrated that pulses of 240 mJ/cm2 lead to graded SiGe alloys with Si rich discs of 2 μm diameter on top, a buried Ge layer, and Ge rich SiGe rings surrounding each feature, as predicted by previous numerical simulation.

  1. Optimization of 193-nm single-layer resists through statistical design

    NASA Astrophysics Data System (ADS)

    Gabor, Allen H.; Dimov, Ognian N.; Medina, Arturo N.; Neisser, Mark O.; Slater, Sydney G.; Wang, Ruey H.; Houlihan, Francis M.; Cirelli, Raymond A.; Dabbagh, Gary; Hutton, Richard S.; Rushkin, Ilya L.; Sweeney, James R.; Timko, Allen G.; Nalamasu, Omkaram; Reichmanis, Elsa

    1999-06-01

    Through a series of statistical design experiments we optimized the lithographic performance of a 193 nm single layer resists based on a norbornene-maleic anhydride matrix resin. Several interesting findings were found including that having the PEB temperature improved the performance of the resist. The polymer composition was found to strongly influence the lithographic performance of the resist. Variables that we examined included acrylate loading and blocking level. By optimizing the composition of the polymer, we have obtained resist with high etch resistance, square profiles and 0.130 micron dense line ultimate resolution in 0.5 micron thick films. The resist formulations are compatible with industry standard 0.262 N TMAH. During exposure the resists does not suffer from the outgassing of volatile species.

  2. Three-body dissociations: The photodissociation of dimethyl sulfoxide at 193 nm

    SciTech Connect

    Blank, D.A.; North, S.W.; Stranges, D.

    1997-04-01

    When a molecule with two equivalent chemical bonds is excited above the threshold for dissociation of both bonds, how the rupture of the two bonds is temporally coupled becomes a salient question. Following absorption at 193 nm dimethyl sulfoxide (CH{sub 3}SOCH{sub 3}) contains enough energy to rupture both C-S bonds. This can happen in a stepwise (reaction 1) or concerted (reaction 2) fashion where the authors use rotation of the SOCH{sub 3} intermediate prior to dissociation to define a stepwise dissociation: (1) CH{sub 3}SOCH{sub 3} {r_arrow} 2CH{sub 3} + SO; (2a) CH{sub 3}SOCH{sub 3} {r_arrow} CH{sub 3} + SOCH{sub 3}; and (2b) SOCH{sub 3} {r_arrow} SO + CH{sub 3}. Recently, the dissociation of dimethyl sulfoxide following absorption at 193 nm was suggested to involve simultaneous cleavage of both C-S bonds on an excited electronic surface. This conclusion was inferred from laser induced fluorescence (LIF) and resonant multiphoton ionization (2+1 REMPI) measurements of the internal energy content in the CH{sub 3} and SO photoproducts and a near unity quantum yield measured for SO. Since this type of concerted three body dissociation is very interesting and a rather rare event in photodissociation dynamics, the authors chose to investigate this system using the technique of photofragment translational spectroscopy at beamline 9.0.2.1. The soft photoionization provided by the VUV undulator radiation allowed the authors to probe the SOCH{sub 3} intermediate which had not been previously observed and provided good evidence that the dissociation of dimethyl sulfoxide primarily proceeds via a two step dissociation, reaction 2.

  3. In die mask overlay control for 14nm double-patterning lithography

    NASA Astrophysics Data System (ADS)

    Chou, William; Cheng, James; Tseng, Alex C. P.; Wu, J. K.; Chang, Chin Kuei; Cheng, Jeffrey; Lee, Adder; Huang, Chain Ting; Peng, N. T.; Hsu, Simon C. C.; Yu, Chun Chi; Lu, Colbert; Yu, Julia; Craig, Peter; Pollock, Chuck; Ham, Young; McMurran, Jeff

    2015-10-01

    According to the ITRS roadmap, semiconductor industry drives the 193nm lithography to its limits, using techniques like Double Pattern Technology (DPT), Source Mask Optimization (SMO) and Inverse Lithography Technology (ILT). In terms of considering the photomask metrology, full in-die measurement capability is required for registration and overlay control with challenging specifications for repeatability and accuracy. Double patterning using 193nm immersion lithography has been adapted as the solution to enable 14nm technology nodes. The overlay control is one of the key figures for the successful realization of this technology. In addition to the various error contributions from the wafer scanner, the reticles play an important role in terms of considering lithographic process contributed errors. Accurate pattern placement of the features on reticles with a registration error below 4nm is mandatory to keep overall photomask contributions to overlay of sub 20nm logic within the allowed error budget. In this paper, we show in-die registration errors using 14nm DPT product masks, by measuring in-die overlay patterns comparing with regular registration patterns. The mask measurements are used to obtain an accurate model to predict mask contribution on wafer overlay of double patterning technology.

  4. An AC phase measuring interferometer for measuring dn/dT of fused silica and calcium fluoride at 193 nm

    SciTech Connect

    Shagam, R.N.

    1998-09-01

    A novel method for the measurement of the change in index of refraction vs. temperature (dn/dT) of fused silica and calcium fluoride at the 193 nm wavelength has been developed in support of thermal modeling efforts for the development of 193 nm-based photolithographic exposure tools. The method, based upon grating lateral shear interferometry, uses a transmissive linear grating to divide a 193 nm laser beam into several beam paths by diffraction which propagate through separate identical material samples. One diffracted order passing through one sample overlaps the undiffracted beam from a second sample and forms interference fringes dependent upon the optical path difference between the two samples. Optical phase delay due to an index change from heating one of the samples causes the interference fringes to change sinusoidally with phase. The interferometer also makes use of AC phase measurement techniques through lateral translation of the grating. Results for several samples of fused silica and calcium fluoride are demonstrated.

  5. Massively-parallel FDTD simulations to address mask electromagnetic effects in hyper-NA immersion lithography

    NASA Astrophysics Data System (ADS)

    Tirapu Azpiroz, Jaione; Burr, Geoffrey W.; Rosenbluth, Alan E.; Hibbs, Michael

    2008-03-01

    In the Hyper-NA immersion lithography regime, the electromagnetic response of the reticle is known to deviate in a complicated manner from the idealized Thin-Mask-like behavior. Already, this is driving certain RET choices, such as the use of polarized illumination and the customization of reticle film stacks. Unfortunately, full 3-D electromagnetic mask simulations are computationally intensive. And while OPC-compatible mask electromagnetic field (EMF) models can offer a reasonable tradeoff between speed and accuracy for full-chip OPC applications, full understanding of these complex physical effects demands higher accuracy. Our paper describes recent advances in leveraging High Performance Computing as a critical step towards lithographic modeling of the full manufacturing process. In this paper, highly accurate full 3-D electromagnetic simulation of very large mask layouts are conducted in parallel with reasonable turnaround time, using a Blue- Gene/L supercomputer and a Finite-Difference Time-Domain (FDTD) code developed internally within IBM. A 3-D simulation of a large 2-D layout spanning 5μm×5μm at the wafer plane (and thus (20μm×20μm×0.5μm at the mask) results in a simulation with roughly 12.5GB of memory (grid size of 10nm at the mask, single-precision computation, about 30 bytes/grid point). FDTD is flexible and easily parallelizable to enable full simulations of such large layout in approximately an hour using one BlueGene/L "midplane" containing 512 dual-processor nodes with 256MB of memory per processor. Our scaling studies on BlueGene/L demonstrate that simulations up to 100μm × 100μm at the mask can be computed in a few hours. Finally, we will show that the use of a subcell technique permits accurate simulation of features smaller than the grid discretization, thus improving on the tradeoff between computational complexity and simulation accuracy. We demonstrate the correlation of the real and quadrature components that comprise the

  6. Photodissociation of the Propargyl (C3D3) Radicals at 248 nm and 193 nm

    SciTech Connect

    Neumark., D.M.; Crider, P.E.; Castiglioni, L.; Kautzman, K.K.

    2009-01-21

    The photodissociation of perdeuterated propargyl (D{sub 2}CCCD) and propynyl (D{sub 3}CCC) radicals was investigated using fast beam photofragment translational spectroscopy. Radicals were produced from their respective anions by photodetachment at 540 nm and 450 nm (below and above the electron affinity of propynyl). The radicals were then photodissociated by 248 nm or 193 nm light. The recoiling photofragments were detected in coincidence with a time- and position-sensitive detector. Three channels were observed: D{sub 2} loss, CD + C{sub 2}D{sub 2}, and CD{sub 3} + C{sub 2}. Obervation of the D loss channel was incompatible with this experiment and was not attempted. Our translational energy distributions for D{sub 2} loss peaked at nonzero translational energy, consistent with ground state dissociation over small (< 1 eV) exit barriers with respect to separated products. Translational energy distributions for the two heavy channels peaked near zero kinetic energy, indicating dissociation on the ground state in the absence of exit barriers.

  7. 193 nm Ultraviolet Photodissociation Mass Spectrometry for Phosphopeptide Characterization in the Positive and Negative Ion Modes.

    PubMed

    Robinson, Michelle R; Taliaferro, Juliana M; Dalby, Kevin N; Brodbelt, Jennifer S

    2016-08-01

    Advances in liquid chromatography tandem mass spectrometry (LC-MS/MS) have permitted phosphoproteomic analysis on a grand scale, but ongoing challenges specifically associated with confident phosphate localization continue to motivate the development of new fragmentation techniques. In the present study, ultraviolet photodissociation (UVPD) at 193 nm is evaluated for the characterization of phosphopeptides in both positive and negative ion modes. Compared to the more standard higher energy collisional dissociation (HCD), UVPD provided more extensive fragmentation with improved phosphate retention on product ions. Negative mode UVPD showed particular merit for detecting and sequencing highly acidic phosphopeptides from alpha and beta casein, but was not as robust for larger scale analysis because of lower ionization efficiencies in the negative mode. HeLa and HCC70 cell lysates were analyzed by both UVPD and HCD. While HCD identified more phosphopeptides and proteins compared to UVPD, the unique matches from UVPD analysis could be combined with the HCD data set to improve the overall depth of coverage compared to either method alone. PMID:27425180

  8. Microsurgery of the retina with a needle-guided 193-nm excimer laser.

    PubMed

    Lewis, A; Palanker, D; Hemo, I; Pe'er, J; Zauberman, H

    1992-07-01

    This article presents a method used to guide the beam from an argon fluoride excimer laser to make it suitable for microsurgical purposes and confine it to areas that can be varied in dimension from 1 micron to tens or hundreds of microns. This approach guides the excimer laser beam with an articulated mechanical arm and confines it with variable-diameter tapered tubes, possibly allowing the use of this laser in in vitro retinal surgery with endolaser techniques. Currently, because of the lack of a delivery and focusing system for the 193-nm argon fluoride beam and its absorption by biologic liquids, this laser is used exclusively in ophthalmology for topical applications, such as corneal sculpting. This new method resolves these problems in a unique way with impressive results. Specifically, it was shown that, with this needle-guided excimer laser, it is possible to remove retinal tissue accurately without detectable damage to surrounding cells. Applications of this new technique in retinal surgery are discussed. PMID:1634334

  9. Product channels in the 193-nm photodissociation of HCNO (fulminic acid)

    NASA Astrophysics Data System (ADS)

    Feng, Wenhui; Hershberger, John F.

    2016-06-01

    IR diode laser spectroscopy was used to detect the products of HCNO (fulminic acid) photolysis at 193 nm. Six product channels are energetically possible at this photolysis wavelength: O + HCN, H + NCO/CNO, CN + OH, CO + NH, NO + CH and HNCO. In some experiments, isotopically labeled 15N18O, C2D6 or C6H12 reagents were included into the photolysis mixture in order to suppress and/or redirect possible secondary reactions. HCN, OC18O, 15N15NO, CO, DCN and HNCO molecules were detected upon laser photolysis of HCNO/reagents/buffer gas mixtures. Analysis of the yields of product molecules leads to the following photolysis quantum yields: ϕ1a (O + HCN) = 0.38 ± 0.04, ϕ1b (H + (NCO)) = 0.07 ± 0.02, ϕ1c (CN + OH) = 0.24 ± 0.03, ϕ1d (CO + NH(a1Δ)) < 0.22 ± 0.1, ϕ1e (HNCO) = 0.02 ± 0.01 and ϕ1f (CH + NO) = 0.21 ± 0.1, respectively.

  10. The stability of allyl radicals following the photodissociation of allyl iodide at 193 nm.

    SciTech Connect

    Fan, H.; Pratt, S. T.; Chemistry

    2006-01-01

    The photodissociation of allyl iodide (C{sub 3}H{sub 5}I) at 193 nm was investigated by using a combination of vacuum-ultraviolet photoionization of the allyl radical, resonant multiphoton ionization of the iodine atoms, and velocity map imaging. The data provide insight into the primary C-I bond fission process and into the dissociative ionization of the allyl radical to produce C{sub 3}H{sup 3+}. The experimental results are consistent with the earlier results of Szpunar et al. [J. Chem. Phys. 119, 5078 (2003)], in that some allyl radicals with internal energies higher than the secondary dissociation barrier are found to be stable. This stability results from the partitioning of available energy between the rotational and vibrational degrees of freedom of the radical, the effects of a centrifugal barrier along the reaction coordinate, and the effects of the kinetic shift in the secondary dissociation of the allyl radical. The present results suggest that the primary dissociation of allyl iodide to allyl radicals plus I*({sup 2}P{sub 1/2}) is more important than previously suspected.

  11. The stability of allyl radicals following the photodissociation of allyl iodide at 193 nm.

    PubMed

    Fan, H; Pratt, S T

    2006-10-14

    The photodissociation of allyl iodide (C3H5I) at 193 nm was investigated by using a combination of vacuum-ultraviolet photoionization of the allyl radical, resonant multiphoton ionization of the iodine atoms, and velocity map imaging. The data provide insight into the primary C-I bond fission process and into the dissociative ionization of the allyl radical to produce C3H3+. The experimental results are consistent with the earlier results of Szpunar et al. [J. Chem. Phys. 119, 5078 (2003)], in that some allyl radicals with internal energies higher than the secondary dissociation barrier are found to be stable. This stability results from the partitioning of available energy between the rotational and vibrational degrees of freedom of the radical, the effects of a centrifugal barrier along the reaction coordinate, and the effects of the kinetic shift in the secondary dissociation of the allyl radical. The present results suggest that the primary dissociation of allyl iodide to allyl radicals plus I*(2P(1/2)) is more important than previously suspected. PMID:17042585

  12. Photoacoustic injury and bone healing following 193nm excimer laser ablation.

    PubMed

    Lustmann, J; Ulmansky, M; Fuxbrunner, A; Lewis, A

    1992-01-01

    The argon-fluoride excimer laser was investigated as a cutting-ablating tool for bone surgery. A total of 52 rats were divided into two experimental groups and two control groups. In one experimental group cortical bone defects were made; in another experimental group defects penetrating into the medullary space were performed. In the two control groups similar defects were achieved using water-cooled carbide burs. The rats were sacrificed on each of the 3, 7, 10, 20, 30, and 40 postoperative day. The cortical bone, the medullary space, and the extrabony tissue were examined by means of light microscopy. In both experimental groups, bone damage, represented by osteocyte destruction, extended to 1,050-1,450 microns ahead from the irradiated site, and bone healing was very much impaired. In the control groups no histological changes could be identified and bone healing appeared to be within normal limits. We believe this extensive bone damage, following 193 nm irradiation, to be a result of photoacoustic waves propagating in the bone following each pulse. In view of our results we feel that excimer lasers presently in use are not suitable for bone surgery. This problem of photoacoustic damage can be overcome in one of two ways: by designing a CW excimer laser or by reducing the pulse width to the picosecond regime. PMID:1495367

  13. Mechanisms involved in HBr and Ar cure plasma treatments applied to 193 nm photoresists

    NASA Astrophysics Data System (ADS)

    Pargon, E.; Menguelti, K.; Martin, M.; Bazin, A.; Chaix-Pluchery, O.; Sourd, C.; Derrough, S.; Lill, T.; Joubert, O.

    2009-05-01

    In this article, we have performed detailed investigations of the 193 nm photoresist transformations after exposure to the so-called HBr and Ar plasma cure treatments using various characterization techniques (x-ray photoelectron spectroscopy, Fourier transformed infrared, Raman analyses, and ellipsometry). By using windows with different cutoff wavelengths patched on the photoresist film, the role of the plasma vacuum ultraviolet (VUV) light on the resist modifications is clearly outlined and distinguished from the role of radicals and ions from the plasma. The analyses reveal that both plasma cure treatments induce severe surface and bulk chemical modifications of the resist films. The synergistic effects of low energetic ion bombardment and VUV plasma light lead to surface graphitization or cross-linking (on the order of 10 nm), while the plasma VUV light (110-210 nm) is clearly identified as being responsible for ester and lactone group removal from the resist bulk. As the resist modification depth depends strongly on the wavelength penetration into the material, it is found that HBr plasma cure that emits near 160-170 nm can chemically modify the photoresist through its entire thickness (240 nm), while the impact of Ar plasmas emitting near 100 nm is more limited. In the case of HBr cure treatment, Raman and ellipsometry analyses reveal the formation of sp2 carbon atoms in the resist bulk, certainly thanks to hydrogen diffusion through the resist film assisted by the VUV plasma light.

  14. Mechanisms involved in HBr and Ar cure plasma treatments applied to 193 nm photoresists

    SciTech Connect

    Pargon, E.; Menguelti, K.; Martin, M.; Bazin, A.; Joubert, O.; Lill, T.

    2009-05-01

    In this article, we have performed detailed investigations of the 193 nm photoresist transformations after exposure to the so-called HBr and Ar plasma cure treatments using various characterization techniques (x-ray photoelectron spectroscopy, Fourier transformed infrared, Raman analyses, and ellipsometry). By using windows with different cutoff wavelengths patched on the photoresist film, the role of the plasma vacuum ultraviolet (VUV) light on the resist modifications is clearly outlined and distinguished from the role of radicals and ions from the plasma. The analyses reveal that both plasma cure treatments induce severe surface and bulk chemical modifications of the resist films. The synergistic effects of low energetic ion bombardment and VUV plasma light lead to surface graphitization or cross-linking (on the order of 10 nm), while the plasma VUV light (110-210 nm) is clearly identified as being responsible for ester and lactone group removal from the resist bulk. As the resist modification depth depends strongly on the wavelength penetration into the material, it is found that HBr plasma cure that emits near 160-170 nm can chemically modify the photoresist through its entire thickness (240 nm), while the impact of Ar plasmas emitting near 100 nm is more limited. In the case of HBr cure treatment, Raman and ellipsometry analyses reveal the formation of sp{sup 2} carbon atoms in the resist bulk, certainly thanks to hydrogen diffusion through the resist film assisted by the VUV plasma light.

  15. Ecology and high-durability injection locked laser with flexible power for double-patterning ArF immersion lithography

    NASA Astrophysics Data System (ADS)

    Umeda, Hiroshi; Tsushima, Hiroaki; Watanabe, Hidenori; Tanaka, Satoshi; Yoshino, Masaya; Matsumoto, Shinich; Tanaka, Hiroshi; Kurosu, Akihiko; Kawasuji, Yasufumi; Matsunaga, Takashi; Fujimoto, Junichi; Mizoguchi, Hakaru

    2011-04-01

    ArF immersion technology has been used widely in volume production for 45nm node. For 32nm node and beyond, double patterning technology with ArF immersion lithography is considered to be the main stream solution until EUV is ready. Our target is to reduce CoO(Cost of ownership) and we aim to develop for ecology and high durability laser. We will introduce the latest performance data of the laser built for ArF immersion lithography under the EcoPhoton concept. Eco-photon concept: -CoC (Cost of Consumable) -CoD (Cost of Downtime) -CoE(Cost of Energy & Environment) We have developed flexible and high power injection-lock ArF excimer laser for double patterning, GT62A-1SxE (Max90W/6000Hz/Flexible power with 10-15mJ/0.30pm (E95)) based on the GigaTwin platform5). A number of innovative and unique technologies are implemented on GT62A-1SxE. In addition, GT62A-1SxE is the laser matching the enhancement technology of advanced illumination systems. For example, in order to provide illumination power optimum for resist sensitivity, it has extendable power from 60W to 90W. We have confirmed durability under these concept with the regulated operation condition with flexible power 60-90W. We show the high durability data of GT62A-1SxE with Eco-Photon concept. In addition to the results the field reliability and availability of our Giga Twin series (GT6XA). We also show technologies which made these performances and its actual data. A number of innovative and unique technologies are implemented on GT62A.

  16. A 193 nm laser photofragmentation time-of-flight mass spectrometric study of chloroiodomethane

    SciTech Connect

    Zhang, Tao; Ng, C.Y.; Qi Fei; Lam, C.-S.; Li, W.-K.

    2005-11-01

    The photodissociation dynamics of chloroiodomethane (CH{sub 2}ICl) at 193 nm has been investigated by employing the photofragment time-of-flight (TOF) mass spectrometric method. Using tunable vacuum ultraviolet undulator synchrotron radiation for photoionization sampling of nascent photofragments, we have identified four primary dissociation product channels: CH{sub 2}Cl+I({sup 2}P{sub 1/2})/I({sup 2}P{sub 3/2}), CH{sub 2}I+Cl({sup 2}P{sub 1/2})/Cl({sup 2}P{sub 3/2}), CHI+HCl, and CH{sub 2}+ICl. The state-selective detection of I({sup 2}P{sub 3/2}) and I({sup 2}P{sub 1/2}) has allowed the estimation of the branching ratio for I({sup 2}P{sub 1/2}):I({sup 2}P{sub 3/2}) to be 0.73: 0.27. Theoretical calculations based on the time-dependent density-functional theory have been also made to investigate excited electronic potential-energy surfaces, plausible intermediates, and transition structures involved in these photodissociation reactions. The translation energy distributions derived from the TOF measurements suggest that at least two dissociation mechanisms are operative for these photodissociation processes. One involves the direct dissociation from the 2 {sup 1}A{sup '} state initially formed by 193 nm excitation, leading to significant kinetic-energy releases. For the I-atom and Cl-atom elimination channels, the fragment kinetic-energy releases observed via this direct dissociation mechanism are consistent with those predicted by the impulsive dissociation models. Other mechanisms are likely predissociative or statistical in nature from the lower 1 {sup 1}A{sup '} and 1 {sup 1}A{sup ''} states and/or the ground X-tilde {sup 1}A{sup '} state populated by internal conversion from the 2 {sup 1}A{sup '} state. On the basis of the maximum kinetic-energy release for the formation of CH{sub 2}Cl+I({sup 2}P{sub 1/2}), we have obtained a value of 53{+-}2 kcal/mol for the 0 K bond dissociation energy of I-CH{sub 2}Cl. The intermediates and transition structures for the CHI

  17. Photolysis of Pure Solid O3 and O2 Films at 193nm

    NASA Technical Reports Server (NTRS)

    Raut, U.; Loeffler, M. J.; Fama, M.; Baragiola, R. A.

    2011-01-01

    We studied quantitatively the photochemistry of solid O3 and O2 films at 193 nm and 22 K with infrared spectroscopy and microgravimetry. Photolysis of pure ozone destroyed O3, but a small amount of ozone remained in the film at high fluence. Photolysis of pure O2 produced O3 in an amount that increased with photon fluence to a stationary level. For both O2 and O3 films, the O3:O2 ratio at large fluences is ?0.07, about two orders of magnitude larger than those obtained in gas phase photolysis. This enhancement is attributed to the increased photodissociation of O2 due to photoabsorption by O2 dimers, a process significant at solid-state densities. We obtain initial quantum yield for ozone synthesis from solid oxygen, phi (O3) = 0.24 0.06, and quantum yields for destruction of O3 and O2 in their parent solids, phi(-O3) = 1.0 0.2 and phi(-O2) = 0.36 0.1. Combined with known photoabsorption cross sections, we estimate probabilities for geminate recombination of 0.5 0.1 for O3 fragments and 0.88 0.03 for oxygen atoms from O2 dissociation. Using a single parameter kinetic model, we deduce the ratio of reaction cross sections for an O atom with O2 vs. O3 to be 0.1 0.2. The general good agreement of the model with the data suggests the validity of the central assumption of efficient energy and spin relaxation of photofragments in the solid prior to their reactions with other species.

  18. Primary and secondary processes in the 193 nm photodissociation of vinyl chloride

    SciTech Connect

    Blank, D.A.; Sun, W.; Suits, A.G.; Lee, Y.T.; North, S.W.; Hall, G.E.

    1998-04-01

    We have investigated the photodissociation of vinyl chloride (H{sub 2}CCHCl) at 193 nm using the technique of photofragment translational spectroscopy. The experiments were performed at the Chemical Dynamics Beamline at the Advanced Light Source and used vacuum ultraviolet synchrotron radiation for product photoionization. We have observed five primary dissociation channels following an initial {pi}{sup {asterisk}}{l_arrow}{pi} excitation. The majority of Cl atoms originate from an excited-state dissociation. The remaining dissociation channels are consistent with competition on the ground electronic state following internal conversion from the optically prepared state. These channels include atomic and molecular hydrogen elimination, HCl elimination, and a translationally slow Cl elimination channel. We have also identified and characterized two secondary decomposition channels: (1) the elimination of Cl from chlorovinyl radicals following the primary atomic hydrogen elimination channel, and (2) hydrogen atom elimination from vinyl radicals following the primary atomic Cl elimination. By measuring the truncation in the translational energy distribution for C{sub 2}H{sub 2}Cl products from primary atomic hydrogen elimination we deduce a barrier for the reverse reaction of Cl+acetylene of 11{plus_minus}2kcal/mol. Since Cl is known to add rapidly to acetylene with no activation barrier, we conclude that H loss primarily forms the ClCCH{sub 2} isomer, and that the observed 11 kcal/mol barrier pertains to a concerted addition/rearrangement path to form the {alpha}-chlorovinyl radical. Finally, we report low-resolution photoionization spectra for the nascent vinyl radical and HCl photoproducts, in which redshifts in the ionization onsets can be related to the internal energy content. {copyright} {ital 1998 American Institute of Physics.}

  19. Dynamics of ions produced by laser ablation of several metals at 193 nm

    SciTech Connect

    Baraldi, G.; Perea, A.; Afonso, C. N.

    2011-02-15

    This work reports the study of ion dynamics produced by ablation of Al, Cu, Ag, Au, and Bi targets using nanosecond laser pulses at 193 nm as a function of the laser fluence from threshold up to 15 J cm{sup -2}. An electrical (Langmuir) probe has been used for determining the ion yield as well as kinetic energy distributions. The results clearly evidence that ablation of Al shows unique features when compared to other metals. The ion yield both at threshold (except for Al, which shows a two-threshold-like behavior) and for a fixed fluence above threshold scale approximately with melting temperature of the metal. Comparison of the magnitude of the yield reported in literature using other wavelengths allows us to conclude its dependence with wavelength is not significant. The evolution of the ion yield with fluence becomes slower for fluences above 4-5 J cm{sup -2} with no indication of saturation suggesting that ionization processes in the plasma are still active up to 15 J cm{sup -2} and production of multiple-charged ions are promoted. This dependence is mirrored in the proportion of ions with kinetic energies higher than 200 eV. This proportion is not significant around threshold fluence for all metals except for Al, which is already 20%. The unique features of Al are discussed in terms of the energy of laser photons (6.4 eV) that is enough to induce direct photoionization from the ground state only in the case of this metal.

  20. Soft-tissue removal by the 193-nm excimer laser in a strongly absorbing liquid environment

    NASA Astrophysics Data System (ADS)

    Palanker, Daniel; Hemo, Itzhak; Turovets, Igor; Lewis, Aaron

    1994-08-01

    The 193 nm excimer laser delivered through special tips into biological liquid environments was applied to two different fields of microsurgery and two mechanism of tissue ablation were found to be operative. In vitreoretinal surgical applications, where the tip exit diameter was about 250 micrometers , the effective cutting regime of retina and vitreoretinal membranes occurred at energy fluences of about 250 - 350 mJ/cm2/pulse with a corresponding cutting depth of 50 - 150 micrometers /pulse. Gas bubbles, formed at the tip exit when it touched the tissue during irradiation, seem to be the driving force underlying the cutting process. This enabled us to achieve a much deeper cut in tissue than a micron-sized laser penetration depth. The system was applied to bovine and rabbit retina and rabbit vitreoretinal membranes and it was found that such tissue removal is fast enough for real vitreoretinal applications and the cut depth control is still good enough for this microsurgery. In the application of this system to drilling of 4 - 8 micrometers diameter holes in the zona pellucida of oocytes the optimal energy fluence is about 40 mJ/cm2/pulse with an ablation depth of about 2 micrometers /pulse. In this case no bubbles are formed and the process seems to be a non-explosive photodissociation of the tissue with subsequent slow dissolution of the products. This mechanism, in contrast to the vitreoretinal tissue removal, was found to be very selective to the type of material being ablated. This process was studied on a model of 20% gelatin gel, which is very close to the ablation properties of the zona pellucida.

  1. Photoinitiated decomposition of substituted ethylenes: The photodissociation of vinyl chloride and acrylonitrile at 193 nm

    SciTech Connect

    Blank, D.A.; Suits, A.G.; Lee, Y.T.

    1997-04-01

    Ethylene and its substituted analogues (H{sub 2}CCHX) are important molecules in hydrogen combustion. As the simplest {pi}-bonded hydrocarbons these molecules serve as prototypical systems for understanding the decomposition of this important class of compounds. The authors have used the technique of photofragment translational spectroscopy at beamline 9.0.2.1 to investigate the dissociation of vinyl chloride (X=Cl) and acrylonitrile (X=CN) following absorption at 193 nm. The technique uses a molecular beam of the reactant seeded in helium which is crossed at 90 degrees with the output of an excimer laser operating on the ArF transition, 193.3 nm. The neutral photoproducts which recoil out of the molecular beam travel 15.1 cm where they are photoionized by the VUV undulator radiation, mass selected, and counted as a function of time. The molecular beam source is rotatable about the axis of the dissociation laser. The authors have directly observed all four of the following dissociation channels for both systems: (1) H{sub 2}CCHX {r_arrow} H + C{sub 2}H{sub 2}X; (2) H{sub 2}CCHX {r_arrow} X + C{sub 2}H{sub 3}; (3) H{sub 2}CCHX {r_arrow} H{sub 2} + C{sub 2}HX; and (4) H{sub 2}CCHX {r_arrow} HX + C{sub 2}H{sub 2}. They measured translational energy distributions for all of the observed channels and measured the photoionization onset for many of the photoproducts which provided information about their chemical identity and internal energy content. In the case of acrylonitrile, selective product photoionization provided the ability to discriminate between channels 2 and 4 which result in the same product mass combination.

  2. New insights into the photodissociation of methyl iodide at 193 nm: stereodynamics and product branching ratios.

    PubMed

    Marggi Poullain, Sonia; González, Marta G; Samartzis, Peter C; Kitsopoulos, Theofanis N; Rubio-Lago, Luis; Bañares, Luis

    2015-11-28

    The stereodynamics of methyl iodide photodissociation after excitation at 193 nm has been studied using a combination of slice imaging and resonance enhanced multiphoton ionization (REMPI) detection of the methyl and iodine products. A weak anisotropic ring appearing in the image corresponding to vibrationally excited CH3(ν1 = 1) confirms the production of ground state I((2)P3/2) atoms at this excitation wavelength as a signature of the predissociation channel reported previously [M. G. González et al., J. Chem. Phys., 2011, 135, 021102] tentatively assigned to the coupling between the B-band (3)R1 Rydberg state and the A-band (1)Q1 repulsive state. Direct REMPI detection of ground state iodine atoms indicates that most of the I((2)P3/2) species are produced in correlation with highly internally excited methyl radicals, in excellent agreement with the recent results of Xu and Pratt [Xu et al., J. Chem. Phys., 2013, 139, 214310; Xu et al., J. Phys. Chem. A, 2015, 119, 7548]. From the comparison between the CH3(ν) second order Dixon's bipolar moments β(2)(0)(20), β(0)(0)(22), β(2)(0)(02) and β(2)(0)(22) measured in this work and those reported previously for the B-band origin and the A-band, a general picture of the CH3I photodissociation stereodynamics in terms of different effects, such as the breakdown of the unique recoil direction (URD) approximation, the non-adiabatic curve crossings and the depolarization induced by the parent molecule rotation, is drawn. PMID:26489797

  3. Photodissociation of vinyl cyanide at 193 nm: Nascent product distributions of the molecular elimination channels

    SciTech Connect

    Wilhelm, Michael J.; Nikow, Matthew; Letendre, Laura; Dai Hailung

    2009-01-28

    The photodissociation dynamics of vinyl cyanide (H{sub 2}CCHCN, acrylonitrile) and deuterated vinyl cyanide (D{sub 2}CCDCN) at 193 nm are examined using time-resolved Fourier transform infrared emission spectroscopy. Prior photofragment translational spectroscopy studies [D. A. Blank et al., J. Chem. Phys. 108, 5784 (1998)] of the dissociation have observed the presence of four main dissociation channels; two molecular and two radical in nature. However, with the exception of a<0.01 quantum yield determined for the CN radical loss channel, the branching ratios of the remaining three elimination channels were not measured. The time-resolved emission spectra, including those from the deuterated samples, revealed the presence of acetylene, hydrogen cyanide (HCN), as well as the energetically less stable isomer hydrogen isocyanide (HNC). Acetylene is found in two distinct energetic distributions, suggesting that both three- and four-centered elimination reactions are occurring significantly in the dissociation. In contrast to prior ab initio studies that have suggested the dominant nature of the three-center elimination of molecular hydrogen (H{sub 2}) and cyanovinylidene (:C=CHCN), we find this reaction channel to be of little importance as there is no evidence to support any significant presence of rovibrationally excited cyanoacetylene. Spectral modeling of the product distributions allows for the first experimental determination of the relative occurrence of the three-centered (resulting in HCN+vinylidene) versus four-centered (HNC+acetylene) elimination channels as 3.34 to 1.00, in contrast to the previously calculated value of 126:1. Rice-Ramsperger-Kassel-Marcus analysis depicts that the transition state energy of the four-centered reaction should be about 10 kcal mole{sup -1} lower than the three-centered reaction.

  4. Extending immersion lithography with high-index materials: results of a feasibility study

    NASA Astrophysics Data System (ADS)

    Sewell, Harry; Mulkens, Jan; Graeupner, Paul; McCafferty, Diane; Markoya, Louis; Donders, Sjoerd; Samarakone, Nandasiri; Duesing, Rudiger

    2007-03-01

    In this paper we report the status of our feasibility work on high index immersion. The development of high index fluids (n>1.64) and high index glass materials (n>1.9) is reported. Questions answered are related to the design of a high NA optics immersion system for fluid containment and fluid handling, and to the compatibility of the fluid with ArF resist processes. Optical design and manufacturing challenges are related to the use of high index glass materials such as crystalline LuAG or ceramic Spinel. Progress on the material development will be reviewed. Progress on immersion fluids development has been sustained. Second-generation fluids are available from many suppliers. For the practical use of second-generation fluids in immersion scanners, we have evaluated and tested fluid recycling concepts in combination with ArF radiation of the fluids. Results on the stability of the fluid and the fluid glass interface will be reported. Fluid containment with immersion hood structures under the lens has been evaluated and tested for several scan speeds and various fluids. Experimental results on scan speed limitations will be presented. The application part of the feasibility study includes the imaging of 29nm L/S structures on a 2-beam interference printer, fluid/resist interaction testing with pre- and post-soak testing. Immersion defect testing using a fluid misting setup was also carried out. Results of these application-related experiments will be presented and discussed.

  5. High hydrophobic topcoat approach for high volume production and yield enhancement of immersion lithography

    NASA Astrophysics Data System (ADS)

    Sagawa, Natsuko; Nakano, Katsushi; Ishii, Yuuki; Kusabiraki, Kazunori; Shima, Motoyuki

    2012-03-01

    Immersion scanner performance is being improved generation by generation. Faster scan speed is required to increase scanner productivity. There are, however, several papers reporting defect increase with higher scan speed1, 2, 3. To overcome this challenge, both material and immersion scanner requires special tuning and optimization. This high stage speed is possible by employing topcoats that have higher hydrophobicity. In general, blob defect are generated at a higher rate with increase in hydrophobicity of topcoat. Nikon and JSR have collaborated to address this challenge by using next generation scanner and a newly developed topcoat material, respectively. JSR, as a topcoat supplier, introduces a new topcoat (TCX279), which shows low blob defects even with very high hydrophobicity. Nikon's latest immersion scanner S621D, equipped with latest nozzle design for optimizing immersion water flow, and an improved tandem stage system to reduce edge particles, resulted in achieving 5x defect reduction compared to S620D. Ultimately, zero immersion defects were realized by a combination of Nikon's S621D scanner and JSR's new topcoat, TCX279.

  6. THE FIRST LASING OF 193 NM SASE, 4TH HARMONIC HGHG AND ESASE AT THE NSLS SDL.

    SciTech Connect

    WANG, X.J.; SHEN Y.; WATANABE, T.; MURPHY, J.B.; ROSE, J.; TSANG, T.

    2006-08-28

    The first lasing of three types of single-pass high-gain FELs, SASE at 193 nm, 4th harmonic HGHG at 199 nm and ESASE at the Source Development Lab (SDL) of Brookhaven National Laboratory (BNL) is reported. The saturation of 4th harmonic HGHG and ESASE FELs was observed. We also observed the spectral broadening and instability of the 4th harmonic HGHG.

  7. Generation of intense 10-ps, 193-nm pulses using simple distributed feedback dye lasers and an ArF(*) amplifier.

    PubMed

    Hatten, D L; Cui, Y; Iii, W T; Mikes, T; Goldhar, J

    1992-11-20

    A pair of holographic distributed feedback dye lasers is used to generate 10-ps pulses at two selected wavelengths that are mixed in a BBO crystal to produce a pulse ~ 10 ps in duration at 193 nm. This seed pulse is subsequently amplified in an ArF(*) excimer laser to an energy of 10-15 mJ with <40 microJ in amplified spontaneous emission. The pulses are nearly transform limited and diffraction limited. PMID:20802565

  8. Photon-controlled fabrication of amorphous superlattice structures using ArF (193 nm) excimer laser photolysis

    SciTech Connect

    Lowndes, D.H.; Geohegan, D.B.; Eres, D.; Pennycook, S.J.; Mashburn, D.N.; Jellison G.E. Jr.

    1988-05-30

    Pulsed ArF (193 nm) excimer laser photolysis of disilane, germane, and disilane-ammonia mixtures has been used to deposit amorphous superlattices containing silicon, germanium, and silicon nitride layers. Transmission electron microscope cross-section views demonstrate that structures having thin (5--25 nm) layers and sharp interlayer boundaries can be deposited at substrate temperatures below the pyrolytic threshold, entirely under laser photolytic control.

  9. E-beam to complement optical lithography for 1D layouts

    NASA Astrophysics Data System (ADS)

    Lam, David K.; Liu, Enden D.; Smayling, Michael C.; Prescop, Ted

    2011-04-01

    The semiconductor industry is moving to highly regular designs, or 1D gridded layouts, to enable scaling to advanced nodes, as well as improve process latitude, chip size and chip energy consumption. The fabrication of highly regular ICs is straightforward. Poly and metal layers are arranged into 1D layouts. These 1D layouts facilitate a two-step patterning approach: a line-creation step, followed by a line-cutting step, to form the desired IC pattern (See Figure 1). The first step, line creation, can be accomplished with a variety of lithography techniques including 193nm immersion (193i) and Self-Aligned Double Patterning (SADP). It appears feasible to create unidirectional parallel lines to at least 11 nm half-pitch, with two applications of SADP for pitch division by four. Potentially, this step can also be accomplished with interference lithography or directed self assembly in the future. The second step, line cutting, requires an extremely high-resolution lithography technique. At advanced nodes, the only options appear to be the costly quadruple patterning with 193i, or EUV or E-Beam Lithography (EBL). This paper focuses on the requirements for a lithography system for "line cutting", using EBL to complement Optical. EBL is the most cost-effective option for line cutting at advanced nodes for HVM.

  10. Improving vacuum-UV (VUV) photolysis of organic compounds in water with a phosphor converted xenon excimer lamp emitting at 193 nm.

    PubMed

    Schulze-Hennings, U; Pötschke, L; Wietor, C; Bringmann, S; Braun, N; Hayashi, D; Linnemann, V; Pinnekamp, J

    2016-01-01

    A novel vacuum ultraviolet excimer lamp emitting light at 193 nm was used to investigate the degradation of organic micropollutants in ultrapure water and wastewater treatment plant (WWTP) effluent. Overall, light at 193 nm proved to be efficient to degrade the investigated micropollutants (diclofenac, diatrizoic acid, sulfamethoxazole). Experiments with WWTP effluent proved the ability of radiation at 193 nm to degrade micropollutants which are hardly removed with commonly used oxidation technologies like ozonation (diatrizoic acid, ethylenediaminetetraacetic acid, perfluorooctanoic acid, and perfluorooctanesulfonic acid). PMID:27533863

  11. The interaction of 193-nm excimer laser irradiation with single-crystal zinc oxide: Neutral atomic zinc and oxygen emission

    SciTech Connect

    Kahn, E. H.; Langford, S. C.; Dickinson, J. T.; Boatner, Lynn A

    2013-01-01

    We report mass-resolved time-of-flight measurements of neutral particles from the surface of single-crystal ZnO during pulsed 193-nm irradiation at laser fluences below the threshold for avalanche breakdown. The major species emitted are atomic Zn and O. We examine the emissions of atomic Zn as a function of laser fluence and laser exposure. Defects at the ZnO surface appear necessary for the detection of these emissions. Our results suggest that the production of defects is necessary to explain intense sustained emissions at higher fluence. Rapid, clean surface etching and high atomic zinc kinetic energies seen at higher laser fluences are also discussed.

  12. Statistical Examination of the a and a + 1 Fragment Ions from 193 nm Ultraviolet Photodissociation Reveals Local Hydrogen Bonding Interactions

    NASA Astrophysics Data System (ADS)

    Morrison, Lindsay J.; Rosenberg, Jake A.; Singleton, Jonathan P.; Brodbelt, Jennifer S.

    2016-05-01

    Dissociation of proteins and peptides by 193 nm ultraviolet photodissociation (UVPD) has gained momentum in proteomic studies because of the diversity of backbone fragments that are produced and subsequent unrivaled sequence coverage obtained by the approach. The pathways that form the basis for the production of particular ion types are not completely understood. In this study, a statistical approach is used to probe hydrogen atom elimination from a + 1 radical ions, and different extents of elimination are found to vary as a function of the identity of the C-terminal residue of the a product ions and the presence or absence of hydrogen bonds to the cleaved residue.

  13. Statistical Examination of the a and a + 1 Fragment Ions from 193 nm Ultraviolet Photodissociation Reveals Local Hydrogen Bonding Interactions

    NASA Astrophysics Data System (ADS)

    Morrison, Lindsay J.; Rosenberg, Jake A.; Singleton, Jonathan P.; Brodbelt, Jennifer S.

    2016-09-01

    Dissociation of proteins and peptides by 193 nm ultraviolet photodissociation (UVPD) has gained momentum in proteomic studies because of the diversity of backbone fragments that are produced and subsequent unrivaled sequence coverage obtained by the approach. The pathways that form the basis for the production of particular ion types are not completely understood. In this study, a statistical approach is used to probe hydrogen atom elimination from a + 1 radical ions, and different extents of elimination are found to vary as a function of the identity of the C-terminal residue of the a product ions and the presence or absence of hydrogen bonds to the cleaved residue.

  14. Influence of thermal annealing and ultraviolet light irradiation on LaF3 thin films at 193 nm.

    PubMed

    Lee, Cheng-Chung; Liu, Ming-Chung; Kaneko, Masaaki; Nakahira, Kazuhide; Takano, Yuuichi

    2005-11-10

    Lanthanum fluoride (LaF3) thin films were prepared by resistive heating evaporation and electron-beam gun evaporation under the same deposition rate, deposition substrate temperature, and vacuum pressure. The coated LaF3 films were then treated by heat annealing and UV light irradiation. The optical properties, microstructures, stress, and laser-induced damage threshold (LIDT) at a wavelength of 193 nm were investigated. The surface roughness, optical loss, stress, and LIDT of the films were improved after the annealing. The films had better properties when irradiated by UV light as compared with heat annealing. PMID:16294967

  15. Experimental demonstration of line-width modulation in plasmonic lithography using a solid immersion lens-based active nano-gap control

    SciTech Connect

    Lee, Won-Sup; Kim, Taeseob; Choi, Guk-Jong; Lim, Geon; Joe, Hang-Eun; Gang, Myeong-Gu; Min, Byung-Kwon; Park, No-Cheol; Moon, Hyungbae; Kim, Do-Hyung; Park, Young-Pil

    2015-02-02

    Plasmonic lithography has been used in nanofabrication because of its utility beyond the diffraction limit. The resolution of plasmonic lithography depends on the nano-gap between the nanoaperture and the photoresist surface—changing the gap distance can modulate the line-width of the pattern. In this letter, we demonstrate solid-immersion lens based active non-contact plasmonic lithography, applying a range of gap conditions to modulate the line-width of the pattern. Using a solid-immersion lens-based near-field control system, the nano-gap between the exit surface of the nanoaperture and the media can be actively modulated and maintained to within a few nanometers. The line-widths of the recorded patterns using 15- and 5-nm gaps were 47 and 19.5 nm, respectively, which matched closely the calculated full-width at half-maximum. From these results, we conclude that changing the nano-gap within a solid-immersion lens-based plasmonic head results in varying line-width patterns.

  16. Photodissociation dynamics of the methyl perthiyl radical at 248 and 193 nm using fast-beam photofragment translational spectroscopy

    NASA Astrophysics Data System (ADS)

    Harrison, Aaron W.; Ryazanov, Mikhail; Sullivan, Erin N.; Neumark, Daniel M.

    2016-07-01

    The photodissociation dynamics of the methyl perthiyl radical (CH3SS) have been investigated using fast-beam coincidence translational spectroscopy. Methyl perthiyl radicals were produced by photodetachment of the CH3SS- anion followed by photodissociation at 248 nm (5.0 eV) and 193 nm (6.4 eV). Photofragment mass distributions and translational energy distributions were measured at each dissociation wavelength. Experimental results show S atom loss as the dominant (96%) dissociation channel at 248 nm with a near parallel, anisotropic angular distribution and translational energy peaking near the maximal energy available to ground state CH3S and S fragments, indicating that the dissociation occurs along a repulsive excited state. At 193 nm, S atom loss remains the major fragmentation channel, although S2 loss becomes more competitive and constitutes 32% of the fragmentation. The translational energy distributions for both channels are very broad at this wavelength, suggesting the formation of the S2 and S atom products in several excited electronic states.

  17. 193 nm Ultraviolet Photodissociation Mass Spectrometry of Tetrameric Protein Complexes Provides Insight into Quaternary and Secondary Protein Topology.

    PubMed

    Morrison, Lindsay J; Brodbelt, Jennifer S

    2016-08-31

    Protein-protein interfaces and architecture are critical to the function of multiprotein complexes. Mass spectrometry-based techniques have emerged as powerful strategies for characterization of protein complexes, particularly for heterogeneous mixtures of structures. In the present study, activation and dissociation of three tetrameric protein complexes (streptavidin, transthyretin, and hemoglobin) in the gas phase was undertaken by 193 nm ultraviolet photodissociation (UVPD) for the characterization of higher order structure. High pulse energy UVPD resulted in the production of dimers and low charged monomers exhibiting symmetrical charge partitioning among the subunits (the so-called symmetrical dissociation pathways), consistent with the subunit organization of the complexes. In addition, UVPD promoted backbone cleavages of the monomeric subunits, the abundances of which corresponded to the more flexible loop regions of the proteins. PMID:27480400

  18. Collision-induced desorption in 193-nm photoinduced reactions in (O{sub 2}+CO) adlayers on Pt(112)

    SciTech Connect

    Han Song; Ma Yunsheng; Matsushima, Tatsuo

    2005-09-01

    The spatial distribution of desorbing O{sub 2} and CO{sub 2} was examined in 193-nm photoinduced reactions in O{sub 2}+CO adlayers on stepped Pt (112)=[(s)3(111)x(001)]. The O{sub 2} desorption collimated in inclined ways in the plane along the surface trough, confirming the hot-atom collision mechanism. In the presence of CO(a), the product CO{sub 2} desorption also collimated in an inclined way, whereas the inclined O{sub 2} desorption was suppressed. The inclined O{sub 2} and CO{sub 2} desorption is explained by a common collision-induced desorption model. At high O{sub 2} coverage, the CO{sub 2} desorption collimated closely along the (111) terrace normal.

  19. Effect of hydrogen bonding on far-ultraviolet water absorption and potential implications for 193-nm ArF excimer laser-tissue interaction

    NASA Astrophysics Data System (ADS)

    Walsh, Joseph T., Jr.; Staveteig, Paul T.

    1995-05-01

    The mechanisms causing transient 193-nm optical absorption of collagen during ablative-fluence ArF excimer pulses are poorly understood. The preponderance of hypotheses proposed to explain this phenomenon, such as ultrafast secondary-structure denaturation of proteins and transient free radical formation, focus on the protein matrix and ignore potential contributions from other tissue components such as water. A substantial body of spectroscopic literature places 193 nm adjacent to a steep absorption edge of water that rises to 60,000 cm-1 at 163 nm; other evidence shows that this absorption edge shifts toward 193 nm upon hydrogen-bond breakage. In this paper we show that heating of water from 20-100°C increases the liquid's absorption coefficient. Further investigations using an infrared pump laser show a significant increase in absorption by water of a 193-nm probe beam. Based on this evidence, we speculate that 193-nm laser ablation of tissue may contain a photothermal component related to dynamic absorption of incident radiation by water.

  20. Demonstration of lithography patterns using reflective e-beam direct write

    NASA Astrophysics Data System (ADS)

    Freed, Regina; Sun, Jeff; Brodie, Alan; Petric, Paul; McCord, Mark; Ronse, Kurt; Haspeslagh, Luc; Vereecke, Bart

    2011-04-01

    Traditionally, e-beam direct write lithography has been too slow for most lithography applications. E-beam direct write lithography has been used for mask writing rather than wafer processing since the maximum blur requirements limit column beam current - which drives e-beam throughput. To print small features and a fine pitch with an e-beam tool requires a sacrifice in processing time unless one significantly increases the total number of beams on a single writing tool. Because of the uncertainty with regards to the optical lithography roadmap beyond the 22 nm technology node, the semiconductor equipment industry is in the process of designing and testing e-beam lithography tools with the potential for high volume wafer processing. For this work, we report on the development and current status of a new maskless, direct write e-beam lithography tool which has the potential for high volume lithography at and below the 22 nm technology node. A Reflective Electron Beam Lithography (REBL) tool is being developed for high throughput electron beam direct write maskless lithography. The system is targeting critical patterning steps at the 22 nm node and beyond at a capital cost equivalent to conventional lithography. Reflective Electron Beam Lithography incorporates a number of novel technologies to generate and expose lithographic patterns with a throughput and footprint comparable to current 193 nm immersion lithography systems. A patented, reflective electron optic or Digital Pattern Generator (DPG) enables the unique approach. The Digital Pattern Generator is a CMOS ASIC chip with an array of small, independently controllable lens elements (lenslets), which act as an array of electron mirrors. In this way, the REBL system is capable of generating the pattern to be written using massively parallel exposure by ~1 million beams at extremely high data rates (~ 1Tbps). A rotary stage concept using a rotating platen carrying multiple wafers optimizes the writing strategy of

  1. Photodissociation of the CHFCl 2 and CHCl 3 molecules and the CHCl 2 radical in a beam at 193 nm

    NASA Astrophysics Data System (ADS)

    Yang, Xuefeng; Felder, Peter; Robert Huber, J.

    1994-11-01

    The collision-free photodissociation of CHFCl 2 and CHCl 3 at 193 nm has been studied by photofragment translational spectroscopy. In both systems the primary dissociation proceeds: exclusively via the rupture of a CCl bond. The broad and unstructured UV spectra of the parent molecules and the rather high kinetic energy release ˜45% of the available energy) in conjunction with the narrow translational energy distributions of the fragments are consistent with the CCl bond fission being a direct dissociation process. The photofragment angular distributions are characterized by anisotropy parameter β=0.5±0.1 (CHFCl 2) and β=0.0±0.1 (CHCl 3). Therefore, the photolysis of CHFCl2 involves an electronic transition polarised parallel to the line connecting the two Cl atoms. In the case of CHCl3, the nearly isotropic fragment recoil is attributed to the excitation of overlapping transitions of A 1←A 1 and E←A 1 type, respectively, hence leading to an effective anisotropy parameter βeff= aβA1 + bβE˜0. The CHCl 2 radical produced in the primary reaction CHCl 3 + hν→ CHCl 2 + Cl can absorb a further photon and is then selectively dissociated by molecular elimination of HCl according to CHCl 2 + hν→CCl + HCl

  2. Photodissociation of the CHFCl2 and CHCl3 molecules and the CHCl2 radical in a beam at 193 nm

    NASA Astrophysics Data System (ADS)

    Yang, Xuefeng; Felder, Peter; Huber, J. Robert

    1994-11-01

    The collision-free photodissociation of CHFCl2 and CHCl3 at 193 nm has been studied by photofragment translational spectroscopy. In both systems the primary dissociation proceeds exclusively via the rupture of a C-Cl bond. The broad and unstructured UV spectra of the parent molecules and the rather high kinetic energy release (approximately = 45% of the available energy) in conjunction with the narrow translational energy distributions of the fragments are consistent with the C-Cl bond fission being a direct dissociation process. The photofragment angular distributions are characterized by anisotropy parameters beta = 0.5 +/- 0.1 (CHFCl2) and beta = 0.0 +/- 0.1 (CHCl3). Therefore, the photolysis of CHFCl2 involves an electronic transition polarised parallel to the line connecting the two Cl atoms. In the case of CHCl3, the nearly isotropic fragment recoil is attributed to the excitation of overlapping transitions of A(sub 1) from A(sub 1) and E from A(sub 1) type, respectively, hence leading to an effective anisotropy parameter beta(sub eff) = a(beta) A(sub 1) +b(beta)(sub E) approximately = 0. The CHCl2 radical produced in the primary reaction CHCl3 + h(nu) yields CHCl2 + Cl can absorb a further photon and is then selectively dissociated by molecular elimination of HCl according to CHCl2 + h(nu) yields CCl + HCl.

  3. Top-Down 193-nm Ultraviolet Photodissociation Mass Spectrometry for Simultaneous Determination of Polyubiquitin Chain Length and Topology

    PubMed Central

    2016-01-01

    Protein ubiquitin modifications present a vexing analytical challenge, because of the dynamic changes in the site of modification on the substrate, the number of ubiquitin moieties attached, and the diversity of linkage patterns in which they are attached. Presented here is a method to confidently assign size and linkage type of polyubiquitin modifications. The method combines intact mass measurement to determine the number of ubiquitin moieties in the chain with backbone fragmentation by 193-nm ultraviolet photodissociation (UVPD) to determine the linkage pattern. UVPD fragmentation of proteins leads to reproducible backbone cleavage at almost every inter-residue position, and in polyubiquitin chains, the N-terminally derived fragments from each constituent monomer are identical, up to the site of conjugation. The N-terminal ubiquitin fragment ions are superimposed to create a diagnostic pattern that allows easy recognition of the dominant chain linkages. The method is demonstrated by achieving almost-complete fragmentation of monoubiquitin and then, subsequently, fragmentation of dimeric, tetrameric, and longer Lys48- and Lys63-linked ubiquitin chains. The utility of the method for the analysis of mixed linkage chains is confirmed for mixtures of Lys48 and Lys63 tetramers with known relative concentrations and for an in vitro-formulated ubiquitin chain attached to a substrate protein. PMID:25559986

  4. Update on laser vision correction using wavefront analysis with the CustomCornea system and LADARVision 193-nm excimer laser

    NASA Astrophysics Data System (ADS)

    Maguen, Ezra I.; Salz, James J.; McDonald, Marguerite B.; Pettit, George H.; Papaioannou, Thanassis; Grundfest, Warren S.

    2002-06-01

    A study was undertaken to assess whether results of laser vision correction with the LADARVISION 193-nm excimer laser (Alcon-Autonomous technologies) can be improved with the use of wavefront analysis generated by a proprietary system including a Hartman-Schack sensor and expressed using Zernicke polynomials. A total of 82 eyes underwent LASIK in several centers with an improved algorithm, using the CustomCornea system. A subgroup of 48 eyes of 24 patients was randomized so that one eye undergoes conventional treatment and one eye undergoes treatment based on wavefront analysis. Treatment parameters were equal for each type of refractive error. 83% of all eyes had uncorrected vision of 20/20 or better and 95% were 20/25 or better. In all groups, uncorrected visual acuities did not improve significantly in eyes treated with wavefront analysis compared to conventional treatments. Higher order aberrations were consistently better corrected in eyes undergoing treatment based on wavefront analysis for LASIK at 6 months postop. In addition, the number of eyes with reduced RMS was significantly higher in the subset of eyes treated with a wavefront algorithm (38% vs. 5%). Wavefront technology may improve the outcomes of laser vision correction with the LADARVISION excimer laser. Further refinements of the technology and clinical trials will contribute to this goal.

  5. Surface morphology and subsurface damaged layer of various glasses machined by 193-nm ArF excimer laser

    NASA Astrophysics Data System (ADS)

    Liao, Yunn-shiuan; Chen, Ying-Tung; Chao, Choung-Lii; Liu, Yih-Ming

    2005-01-01

    Owing to the high bonding energy, most of the glasses are removed by photo-thermal rather than photo-chemical effect when they are ablated by the 193 or 248nm excimer lasers. Typically, the machined surface is covered by re-deposited debris and the sub-surface, sometimes surface as well, is scattered with micro-cracks introduced by thermal stress generated during the process. This study aimed to investigate the nature and extent of the surface morphology and sub-surface damaged (SSD) layer induced by the laser ablation. The effects of laser parameters such as fluence, shot number and repetition rate on the morphology and SSD were discussed. An ArF excimer laser (193 nm) was used in the present study to machine glasses such as soda-lime, Zerodur and BK-7. It is found that the melt ejection and debris deposition tend to pile up higher and become denser in structure under a higher energy density, repetition rate and shot number. There are thermal stress induced lateral cracks when the debris covered top layer is etched away. Higher fluence and repetition rate tend to generate more lateral and median cracks which propagate into the substrate. The changes of mechanical properties of the SSD layer were also investigated.

  6. Characterization of Therapeutic Monoclonal Antibodies at the Subunit-Level using Middle-Down 193 nm Ultraviolet Photodissociation.

    PubMed

    Cotham, Victoria C; Brodbelt, Jennifer S

    2016-04-01

    Monoclonal antibodies (mAbs) are a rapidly advancing class of therapeutic glycoproteins that possess wide clinical utility owing to their biocompatibility, high antigen specificity, and targeted immune stimulation. These therapeutic properties depend greatly on the composition of the immunoglobulin G (IgG) structure, both in terms of primary sequence and post-translational modifications (PTMs); however, large-scale production in cell culture often results in heterogeneous mixtures that can profoundly affect clinical safety and efficacy. This places a high demand on analytical methods that afford comprehensive structural characterization of mAbs to ensure their stringent quality control. Here we report the use of targeted middle-down 193 nm ultraviolet photodissociation (UVPD) to provide detailed primary sequence analysis and PTM site localization of therapeutic monoclonal antibody subunits (∼25 kDa) generated upon digestion with recombinant immunoglobulin G-degrading enzyme of Streptococcus pyogenes (IdeS) followed by chemical reduction. Under optimal conditions, targeted UVPD resulted in approximately 60% overall coverage of the IgG sequence, in addition to unambiguous glycosylation site localization and extensive coverage of the antigen-binding complementarity determining regions (CDRs) in a single LC-MS/MS experiment. Combining UVPD and ETD data afforded even deeper sequencing and greater overall characterization of IgG subunits. Overall, this targeted UVPD approach represents a promising new strategy for the comprehensive characterization of antibody-based therapeutics. PMID:26947921

  7. 193-nm excimer laser sclerostomy using a modified open mask delivery system in rhesus monkeys with experimental glaucoma.

    PubMed

    Allan, B D; van Saarloos, P P; Cooper, R L; Keogh, E J; Constable, I J

    1993-11-01

    Excimer laser sclerostomy is a new glaucoma filtration procedure in which the argon fluoride excimer laser at 193 nm is delivered ab externo through a modified open mask system incorporating an en-face air jet to dry the target area and preserve hemostasis during ablation and a conjunctival plication mechanism, which allows the conjunctival and scleral wounds created by through-and-through ablation to separate once the mask is removed. No preparatory dissection of the conjunctiva is required. Five 200-microns and five 500-microns sclerostomies were formed by ablation at a pulse repetition rate of 20 Hz and a fluence per pulse of 400 mJ/cm2 in fellow eyes of five rhesus monkeys with experimental glaucoma. Overall, seven of the ten eyes attained a functional result, with intraocular pressures remaining below 21 mmHg for 6 +/- 1 days and rising to the pre-operative level after 10 +/- 3 days without adjunctive antifibroblast medication. The duration of filtration for 200-microns and 500-microns sclerostomies was similar, and parallels that previously observed for posterior lip sclerectomy in the same animal model. The three eyes with no functional result all had incorrectly positioned sclerostomies. Choroidal detachment and significant shallowing of the anterior chamber did not occur. Excimer laser sclerostomy appears to be a viable technique for filtration, provided that mask placement is accurate. PMID:8258402

  8. Sub-20nm hybrid lithography using optical, pitch-division, and e-beam

    NASA Astrophysics Data System (ADS)

    Belledent, J.; Smayling, M.; Pradelles, J.; Pimenta-Barros, P.; Barnola, S.; Mage, L.; Icard, B.; Lapeyre, C.; Soulan, S.; Pain, L.

    2012-03-01

    A roadmap extending far beyond the current 22nm CMOS node has been presented several times. [1] This roadmap includes the use of a highly regular layout style which can be decomposed into "lines and cuts."[2] The "lines" can be done with existing optical immersion lithography and pitch division with self-aligned spacers.[3] The "cuts" can be done with either multiple exposures using immersion lithography, or a hybrid solution using either EUV or direct-write ebeam.[ 4] The choice for "cuts" will be driven by the availability of cost-effective, manufacturing-ready equipment and infrastructure. Optical lithography improvements have enabled scaling far beyond what was expected; for example, soft x-rays (aka EUV) were in the semiconductor roadmap as early as 1994 since optical resolution was not expected for sub-100nm features. However, steady improvements and innovations such as Excimer laser sources and immersion photolithography have allowed some manufacturers to build 22nm CMOS SOCs with single-exposure optical lithography. With the transition from random complex 2D shapes to regular 1D-patterns at 28nm, the "lines and cuts" approach can extend CMOS logic to at least the 7nm node. The spacer double patterning for lines and optical cuts patterning is expected to be used down to the 14nm node. In this study, we extend the scaling to 18nm half-pitch which is approximately the 10-11nm node using spacer pitch division and complementary e-beam lithography. For practical reasons, E-Beam lithography is used as well to expose the "mandrel" patterns that support the spacers. However, in a production mode, it might be cost effective to replace this step by a standard 193nm exposure and applying the spacer technique twice to divide the pitch by 3 or 4. The Metal-1 "cut" pattern is designed for a reasonably complex logic function with ~100k gates of combinatorial logic and flip-flops. Since the final conductor is defined by a Damascene process, the "cut" patterns become islands

  9. Advances with the new AIMS fab 193 2nd generation: a system for the 65 nm node including immersion

    NASA Astrophysics Data System (ADS)

    Zibold, Axel M.; Poortinga, E.; Doornmalen, H. v.; Schmid, R.; Scherubl, T.; Harnisch, W.

    2005-06-01

    The Aerial Image Measurement System, AIMS, for 193nm lithography emulation is established as a standard for the rapid prediction of wafer printability for critical structures including dense patterns and defects or repairs on masks. The main benefit of AIMS is to save expensive image qualification consisting of test wafer exposures followed by wafer CD-SEM resist or wafer analysis. By adjustment of numerical aperture (NA), illumination type and partial coherence (σ) to match any given stepper/ scanner, AIMS predicts the printability of 193nm reticles such as binary with, or without OPC and phase shifting. A new AIMS fab 193 second generation system with a maximum NA of 0.93 is now available. Improvements in field uniformity, stability over time, measurement automation and higher throughput meet the challenging requirements of the 65nm node. A new function, "Global CD Map" can be applied to automatically measure and analyse the global CD uniformity of repeating structures across a reticle. With the options of extended depth-of-focus (EDOF) software and the upcoming linear polarisation capability in the illumination the new AIMS fab 193 second generation system is able to cover both dry and immersion requirements for NA < 1. Rigorous simulations have been performed to study the effects of polarisation for imaging by comparing the aerial image of the AIMS to the resist image of the scanner.

  10. Overlay progress in EUV lithography towards adoption for manufacturing

    NASA Astrophysics Data System (ADS)

    Hermans, Jan V.; Laidler, David; Pigneret, Charles; van Dijk, Andre; Voznyi, Oleg; Dusa, Mircea; Hendrickx, Eric

    2011-04-01

    Extreme Ultra-Violet (EUV) lithography is a candidate for semiconductor manufacturing for the 16nm technology node and beyond. Due to the very short wavelength of 13.5nm, EUV lithography provides the capability to continue single exposure scaling with improved resolution and higher pattern fidelity compared to 193nm immersion lithography. However, reducing the wavelength brings new equipment and process challenges. To enable EUV photon transmission through the optical system, the entire optical path of an EUV exposure tool operates under vacuum, and in addition reticle and optics are reflective. To obtain the required CD and overlay performance, both wafer and reticle front surfaces need to have near-perfect flatness, as non-flatness directly contributes to focus and image placement errors, in the case of the reticle due to non-telecentricity. Traditional vacuum chucks, both for reticle and wafer, cannot be used and are replaced by electrostatic chucks. Any contribution of this new clamping method on CD and overlay control therefore needs to be investigated, including avoidance of particle contamination over time. This work was performed on ASML's EUV Alpha Demo Tool (ADT). We investigated the different, non-conventional contributions to overlay control on the ADT, with particular attention to the wafer clamping performance of the exposure chuck. We demonstrate that we were able to improve the overlay performance by compensating for the wafer clamping error during the wafer alignment sequence. The impact of different wafer types on overlay was also evaluated. In addition to clamping effects, thermal effects have also been shown to impact overlay and were evaluated by monitoring the thermal behavior of a wafer during exposure on the ADT and correlating to the resulting overlay.

  11. Development of high-power, 6 kHz, single-mode Ti:sapphire laser at 904 nm for generating 193 nm light

    NASA Astrophysics Data System (ADS)

    Tsuboi, Mizuki; Nakazato, Tomoharu; Onose, Takashi; Tanaka, Yuichi; Sarukura, Nobuhiko; Kakizaki, Kouji; Watanabe, Shuntaro

    2015-04-01

    A high power, 6 kHz, single-mode Ti:sapphire laser operating at 904 nm has been developed to produce a 193 nm light source. The output power was above 10 W with a bandwidth of 160 MHz. The Hänsch-Couillaud locking scheme was successfully applied to stabilize the frequency of the pulse laser. The thermal lens in the Ti:sapphire crystal having a focal length down to 10 mm along with strong astigmatism was compensated by distributing thermal load to three amplifiers with an even number of passes, resulting in a nearly diffraction limited beam. This Ti:sapphire laser contributed to the generation of 193 nm light with an output power above 200 mW.

  12. Study of the mask materials for PTD process and NTD process in practical ArF immersion lithography

    NASA Astrophysics Data System (ADS)

    Adachi, Takashi; Tani, Ayako; Hayano, Katsuya; Takamizawa, Hideyoshi

    2014-07-01

    In this report, we compared the lithographic performances between the conventional positive tone development (PTD) process and the negative tone development (NTD) process, using the lithography simulation. We selected the MoSi-binary mask and conventional 6% attenuated phase shift mask as mask materials. The lithographic performance was evaluated and compared after applying the optical proximity correction (OPC). The evaluation items of lithographic performance were the aerial image profile, the aerial image contrast, normalized image log slope (NILS), mask error enhancement factor (MEEF), and the bossung curves, etc. The designs for the evaluation were selected the simple contact hole and the metal layer sample design.

  13. Green solution: 120W ArF immersion light source supporting the next-generation multiple-pattering lithography

    NASA Astrophysics Data System (ADS)

    Kumazaki, Takahito; Ohta, Takeshi; Ishida, Keisuke; Tsushima, Hiroaki; Kurosu, Akihiko; Kakizaki, Kouji; Matsunaga, Takashi; Mizoguchi, Hakaru

    2015-03-01

    The difficulty of EUV lithography system development has prolonged the industry's dependence on ArF excimer lasers to realize further advancements in lithography process technologies. Smaller CD with reduced cost requires tighter specifications, and the potential extension to 450mm wafers introduces extremely difficult performance challenges on lasers. One of the most important features of the next generation lasers will be the ability to support green operations while further improving cost of ownership and performance. For example, electricity consumption costs and the dependence on rare gases, such as neon and helium, will become critical considerations for HVM process going forward. As a laser vendor, Gigaphoton continues to innovate and develop solutions that address these important issues. The latest model GT64A with its field-proven, twin-chamber platform has reduced environmental impact while upgrading performance and power. A variety of green technologies are employed on the GT64A. The first is the reduction of gas usage. Parameters, such as input power and gas pressure are closely monitored during operations and fed back to the injection/exhaust gas controller system. By applying a special algorithm, the laser gas consumption can be reduced by up to 50%. More than 96% of the gas used by the lasers is neon. Another rare gas that requires attention is Helium. Recently the unstable supply of helium became a serious worldwide issue. To cope with this situation, Gigaphoton is developing lasers that support completely helium-free operations.

  14. 7nm logic optical lithography with OPC-Lite

    NASA Astrophysics Data System (ADS)

    Smayling, Michael C.; Tsujita, Koichiro; Yaegashi, Hidetami; Axelrad, Valery; Nakayama, Ryo; Oyama, Kenichi; Yamauchi, Shohei; Ishii, Hiroyuki; Mikami, Koji

    2015-03-01

    The CMOS logic 22nm node was the last one done with single patterning. It used a highly regular layout style with Gridded Design Rules (GDR). Smaller nodes have required the same regular layout style but with multiple patterning for critical layers. A "line/cut" approach is being used to achieve good pattern fidelity and process margin.[1] As shown in Fig. 1, even with "line" patterns, pitch division will eventually be necessary. For the "cut" pattern, Design-Source-Mask Optimization (DSMO) has been demonstrated to be effective at the 20nm node and below.[2,3,4] Single patterning was found to be suitable down to 16nm, while double patterning extended optical lithography for cuts to the 10-12nm nodes. Design optimization avoided the need for triple patterning. Lines can be patterned with 193nm immersion with no complex OPC. The final line dimensions can be achieved by applying pitch division by two or four.[5] In this study, we extend the scaling using simplified OPC to the 7nm node for critical FEOL and BEOL layers. The test block is a reasonably complex logic function with ~100k gates of combinatorial logic and flip-flops, scaled from previous experiments. Simulation results show that for cuts at 7nm logic dimensions, the gate layer can be done with single patterning whose minimum pitch is 53nm, possibly some of the 1x metal layers can be done with double patterning whose minimum pitch is 53nm, and the contact layer will require triple patterning whose minimum pitch is 68nm. These pitches are less than the resolution limit of ArF NA=1.35 (72nm). However these patterns can be separated by a combination of innovative SMO for less than optical resolution limit and a process trick of hole-repair technique. An example of triple patterning coloring is shown in Fig 3. Fin and local interconnect are created by lines and trims. The number of trim patterns are 3 times (min. pitch=90nm) and twice (min. pitch=120nm), respectively. The small number of masks, large pitches, and

  15. Building an immersion topcoat from the ground up: materials perspective

    NASA Astrophysics Data System (ADS)

    Khojasteh, Mahmoud; Popova, Irene; Varanasi, P. Rao; Sundberg, Linda; Robinson, C.; Corliss, D.; Lawson, Margaret; Dabbagh, G.; Slezak, M.; Colburn, Matthew; Petrillo, K.

    2007-03-01

    Over a period of last several years 193 nm immersion lithography from a remote and unlikely possibility gradually became a reality in many fabrication facilities across the globe and solid candidate for high volume manufacturing for the next generation technology node. It is being widely understood in the industry that top-coatless resist approach is a desirable final stage of the immersion process development. However creating low-defect high performance top-coatless resist materials requires understanding of the fundamental material properties of the top layer, responsible for leaching suppression, immersion fluid meniscus stability, and in this way enabling high speed low-defect scanning. While a lot of progress has been made in implementing specific top coat materials into the process flow, clear understanding effects of the top coat properties on the lithographic conditions and printing capability is still lacking. This paper will discuss top coat materials design, properties and functional characteristics in application to novel fluoroalcohol polymer-based immersion top coat. We have used our fluoroalcohol based-series designs (titled MVP top coat materials further on in the paper) as a test vehicle for establishing correlations between top coat performance and its physical and chemical properties including hydrophobicity, molecular weight/dispersity etc. Effects of polymer-solvent interactions on the contact angle and characteristics of the top coat material are explored, providing valuable understanding transferable to design of new generation top coats and top-coatless materials. Our resultant new designs demonstrated excellent lithographic performance, profiles and low leaching levels with commercially available resist and high receding contact angles, comparable to the commercial top coat materials.

  16. Laser ablation of ceramic Al2O3 at 193 nm and 248 nm: The importance of single-photon ionization processes

    NASA Astrophysics Data System (ADS)

    Peláez, R. J.; Afonso, C. N.; Bator, M.; Lippert, T.

    2013-06-01

    The aim of this work is to demonstrate that single-photon photoionization processes make a significant difference in the expansion and temperature of the plasma produced by laser ablation of ceramic Al2O3 in vacuum as well as to show their consequences in the kinetic energy distribution of the species that eventually will impact on the film properties produced by pulsed laser deposition. This work compares results obtained by mass spectrometry and optical spectroscopy on the composition and features of the plasma produced by laser ablation at 193 nm and 248 nm, i.e., photon energies that are, respectively, above and below the ionization potential of Al, and for fluences between threshold for visible plasma and up to ≈2 times higher. The results show that the ionic composition and excitation of the plasma as well as the ion kinetic energies are much higher at 193 nm than at 248 nm and, in the latter case, the population of excited ions is even negligible. The comparison of Maxwell-Boltzmann temperature, electron temperatures, and densities of the plasmas produced with the two laser wavelengths suggests that the expansion of the plasma produced at 248 nm is dominated by a single population. Instead, the one produced at 193 nm is consistent with the existence of two populations of cold and hot species, the latter associated to Al+ ions that travel at the forefront and produced by single photon ionization as well as Al neutrals and double ionized ions produced by electron-ion impact. The results also show that the most energetic Al neutrals in the plasma produced at the two studied wavelengths are in the ground state.

  17. Effect of the rinse solution to avoid 193-nm resist line collapse: a study for modification of resist polymer and process conditions

    NASA Astrophysics Data System (ADS)

    Masuda, Seiya; Kobayashi, Masakazu; Kim, Woo-Kyu; Anyadiegwu, Clement; Padmanaban, Munirathna; Dammel, Ralph R.; Tanaka, Keiichi; Yamada, Yoshiaki

    2004-05-01

    The device design rule is continuously shrinking toward optical resolution limit where k1 factor is below 0.3. The requirement for 193 nm photoresist below 90 nm node is quite challenging at the manufacturing phase. Using DI water rinse after development gives a significant amount of line collapse when the aspect ratio is over 3. To avoid line collapse, we co-developed special rinse solution for FIRM process with Tokyo Electron Ltd. Utilizing FIRM process, 90 nm dense line collapse was measured by CD SEM using focus-exposure matrices. The line collapse property has been observed using experimental 193 nm positive tone resist by varying monomer ratio of the polymer and process conditions. The surface property of the resist was also studied to investigate the interaction with rinse solution at the de-protected polymer region. However, a high surfactant concentration in the DI water rinse leads the swelling of the resist pattern profile. The resist component is the key to determine adequate surfactant concentration in rinse solution to minimize line collapse and pattern deformation

  18. Future trends in high-resolution lithography

    NASA Astrophysics Data System (ADS)

    Lawes, R. A.

    2000-02-01

    A perennial question is "what is the future of high-resolution lithography, a key technology that drives the semiconductor industry"? The dominant technology over the last 30 years has been optical lithography, which by lowering wavelengths to 193 nm (ArF) and 157 nm (F 2) and by using optical "tricks" such as phase shift masks, off-axis illumination and phase filters, should be capable of 100 nm CMOS technology. So where does this leave the competition? The 100-nm lithography used to be the domain of electron beam lithography but only in research laboratories. Significant efforts are being made to increase throughput by electron projection (scattering with angular limitation projection electron beam lithography or SCALPEL). X-ray lithography remains a demonstrated R&D tool waiting to be commercially exploited but the initial expenditure to do so is very high. Ion beam lithography and extreme ultraviolet (EUV) ( λ<12 nm) have also received attention in recent years. This paper will concentrate on some of the key issues and speculate on how and when an alternative to optical lithography will be embraced by industry.

  19. Two new design methods for lithography mask: phase-shifting scattering bar and interlaced phase-shifting mask

    NASA Astrophysics Data System (ADS)

    Yeh, Kwei-Tin; Huang, Chao-Yi

    2014-07-01

    For 193 nm immersion lithography, it is hard to print clear 4X nm dense images (ex. contact holes) on wafer without any modifications due to lower light intensity. In the past, the most common method is to add the scattering bars, which can enhance the light intensity of contact holes. However, with tinier pattern, the distance between scattering bars and contact holes will get quite close. Hence, the error tolerance for mask making was reduced. On the other hand, this method may also cause the pattern twist which will induce pattern crosslink. To solve this issue, a new design method for lithography mask was proposed, which is named "Phase-shifting Scattering Bar", and it shows better performance in 1D chain array patterns than those with traditional scattering bars. However, for even tinier patterns, it is quite difficult to put these scattering bars on mask. Hence, another special design named "Interlaced Phase-shifting Mask" was proposed to handle such tiny dense patterns. In this design, main patterns are also the scattering bars for adjacent patterns. Hence, there is no need for additional tiny scattering bars, and the mask making requirement can be also relaxed. Both of these two mask design are useful tools to trim and modify light intensity profile on wafer. The image contrast was largely enhanced which means a better resolution and a larger process window can be gained without the cost of new illumination equipments.

  20. Competing C-Br and O-NO Photofission upon Excitation of BrCH2CH2ONO at 193 nm.

    PubMed

    Wang, Lei; Scrape, Preston G; Roberts, Trevor D; Joshi, Prakriti P; Butler, Laurie J

    2015-12-17

    This study characterizes two of the primary photodissociation channels of 2-bromoethyl nitrite, BrCH2CH2ONO, at 193 nm and the subsequent unimolecular dissociation channels of the nascent vibrationally excited BrCH2CH2O radicals produced from the O-NO bond photofission. We use a crossed laser-molecular beam scattering apparatus with electron bombardment detection. Upon photodissociation of BrCH2CH2ONO at 193 nm, the measured branching ratio between primary O-NO photofission and C-Br photofission is 3.9:1 (O-NO/C-Br). The measured O-NO photofission recoil kinetic energy distribution (P(ET)) peaks near 30 kcal/mol and extends from 20 to 50 kcal/mol. We use the O-NO photofission P(ET) to characterize the internal energy distribution in the nascent ground-electronic-state BrCH2CH2O radicals. At 193 nm, all of the BrCH2CH2O radicals are formed with enough internal energy to unimolecularly dissociate to CH2Br + H2CO or to BrCH2CHO + H. We also investigated the possibility of the BrCH2CH2O → CH2CHO + HBr reaction arising from the vibrationally excited BrCH2CH2O radicals produced from O-NO primary photodissociation. Signal strengths at HBr(+), however, demonstrate that the vinoxy product does not have HBr as a cofragment, so the BrCH2CH2O → HBr + vinoxy channel is negligible compared to the CH2Br + H2CO channel. We also report our computational prediction of the unimolecular dissociation channels of the vibrational excited CH2CH2ONO radical resulting from C-Br bond photofission. Our theoretical calculations on the ground-state CH2CH2ONO potential energy surface at the G4//B3LYP/6-311++G(3df,2p) level of theory give the energetics of the zero-point corrected minima and transition states. The lowest accessible barrier height for the unimolecular dissociation of CH2CH2ONO is a 12.7 kcal/mol barrier from the cis-ONO conformer, yielding NO2 + ethene. Our measured internal energy distribution of the nascent CH2CH2ONO radicals together with this computational result suggests

  1. Optimal design and fabrication method for antireflection coatings for P-polarized 193 nm laser beam at large angles of incidence (68°-74°).

    PubMed

    Jin, Jingcheng; Jin, Chunshui; Li, Chun; Deng, Wenyuan; Chang, Yanhe

    2013-09-01

    Most of the optical axes in modern systems are bent for optomechanical considerations. Antireflection (AR) coatings for polarized light at oblique incidence are widely used in optical surfaces like prisms or multiform lenses to suppress undesirable reflections. The optimal design and fabrication method for AR coatings with large-angle range (68°-74°) for a P-polarized 193 nm laser beam is discussed in detail. Experimental results showed that after coating, the reflection loss of a P-polarized laser beam at large angles of incidence on the optical surfaces is reduced dramatically, which could greatly improve the output efficiency of the optical components in the deep ultraviolet vacuum range. PMID:24323257

  2. Directed Self-assembly for Lithography Applications

    NASA Astrophysics Data System (ADS)

    Cheng, Joy

    2010-03-01

    Economics dictated that semiconductor devices need to be scaled approximately to 70 percent linearly in order to follow the pace of Moore's law and maintain cost effectiveness. Optical lithography has been the driving force for scaling; however, it approaches its physical limit to print patterns beyond 22nm node. Directed self-assembly (DSA), which combines ``bottom-up'' self-assembled polymers and ``top-down'' lithographically defined substrates, has been considered as a potential candidate to extend optical lithography. Benefit from nanometer-scale self-assembly features and the registration precision of advanced lithography, DSA provides precise and programmable nanopatterns beyond the resolution limit of conventional lithography. We have demonstrated DSA concepts including frequency multiplication and pattern rectification using guiding prepattern with proper chemical and topographical information generated by e-beam lithography. In addition, we seek to integrate DSA with 193 nm optical lithography in a straightforward manner in order to move DSA from the research stage to a viable manufacturing technology. Recently, we implemented various integration strategies using photolithography to produce guiding patterns for DSA. This new ability enables DSA to be applied to large areas with state-of-the-art lithography facilities.

  3. Extreme ultraviolet lithography and three dimensional integrated circuit—A review

    NASA Astrophysics Data System (ADS)

    Wu, Banqiu; Kumar, Ajay

    2014-03-01

    Extreme ultraviolet lithography (EUVL) and three dimensional integrated circuit (3D IC) were thoroughly reviewed. Since proposed in 1988, EUVL obtained intensive studies globally and, after 2000, became the most promising next generation lithography method even though challenges were present in almost all aspects of EUVL technology. Commercial step-and-scan tools for preproduction are installed now with full field capability; however, EUV source power at intermediate focus (IF) has not yet met volume manufacturing requirements. Compared with the target of 200 W in-band power at IF, current tools can supply only approximately 40-55 W. EUVL resist has improved significantly in the last few years, with 13 nm line/space half-pitch resolution being produced with approximately 3-4 nm line width roughness (LWR), but LWR needs 2× improvement. Creating a defect-free EUVL mask is currently an obstacle. Actual adoption of EUVL for 22 nm and beyond technology nodes will depend on the extension of current optical lithography (193 nm immersion lithography, combined with multiple patterning techniques), as well as other methods such as 3D IC. Lithography has been the enabler for IC performance improvement by increasing device density, clock rate, and transistor rate. However, after the turn of the century, IC scaling resulted in short-channel effect, which decreases power efficiency dramatically, so clock frequency almost stopped increasing. Although further IC scaling by lithography reduces gate delay, interconnect delay and memory wall are dominant in determining the IC performance. 3D IC technology is a critical technology today because it offers a reasonable route to further improve IC performance. It increases device density, reduces the interconnect delay, and breaks memory wall with the application of 3D stacking using through silicon via. 3D IC also makes one chip package have more functional diversification than those enhanced only by shrinking the size of the features

  4. The economic impact of EUV lithography on critical process modules

    NASA Astrophysics Data System (ADS)

    Mallik, Arindam; Horiguchi, Naoto; Bömmels, Jürgen; Thean, Aaron; Barla, Kathy; Vandenberghe, Geert; Ronse, Kurt; Ryckaert, Julien; Mercha, Abdelkarim; Altimime, Laith; Verkest, Diederik; Steegen, An

    2014-04-01

    Traditionally, semiconductor density scaling has been supported by optical lithography. The ability of the exposure tools to provide shorter exposure wavelengths or higher numerical apertures have allowed optical lithography be on the forefront of dimensional scaling for the semiconductor industry. Unfortunately, the roadmap for lithography is currently at a juncture of a major paradigm shift. EUV Lithography is steadily maturing but not fully ready to be inserted into HVM. Unfortunately, there are no alternative litho candidates on the horizon that can take over from 193nm. As a result, it is important to look into the insertion point of EUV that would be ideal for the industry from an economical perspective. This paper details the benefit observed by such a transition. Furthermore, it looks into such detail with an EUV throughput sensitivity study.

  5. Internal energy of HCl upon photolysis of 2-chloropropene at 193 nm investigated with time-resolved Fourier-transform spectroscopy and quasiclassical trajectories

    SciTech Connect

    Chang, C.-M.; Huang, Y.-H.; Liu, S.-Y.; Lee, Y.-P.; Pombar-Perez, Marta; Martinez-Nunez, Emilio; Vazquez, Saulo A.

    2008-12-14

    Following photodissociation of 2-chloropropene (H{sub 2}CCClCH{sub 3}) at 193 nm, vibration-rotationally resolved emission spectra of HCl ({upsilon}{<=}6) in the spectral region of 1900-2900 cm{sup -1} were recorded with a step-scan time-resolved Fourier-transform spectrometer. All vibrational levels show a small low-J component corresponding to {approx}400 K and a major high-J component corresponding to 7100-18 700 K with average rotational energy of 39{+-}{sub 3}{sup 11} kJ mol{sup -1}. The vibrational population of HCl is inverted at {upsilon}=2, and the average vibrational energy is 86{+-}5 kJ mol{sup -1}. Two possible channels of molecular elimination producing HCl+propyne or HCl+allene cannot be distinguished positively based on the observed internal energy distribution of HCl. The observed rotational distributions fit qualitatively with the distributions of both channels obtained with quasiclassical trajectories (QCTs), but the QCT calculations predict negligible populations for states at small J. The observed vibrational distribution agrees satisfactorily with the total QCT distribution obtained as a weighted sum of contributions from both four-center elimination channels. Internal energy distributions of HCl from 2-chloropropene and vinyl chloride are compared.

  6. Electron stimulated desorption of the metallic substrate at monolayer coverage: Sensitive detection via 193 nm laser photoionization of neutral aluminum desorbed from CH3O/Al(111)

    NASA Astrophysics Data System (ADS)

    Young, C. E.; Whitten, J. E.; Pellin, M. J.; Gruen, D. M.; Jones, P. L.

    A fortuitous overlap between the gain profile of the 193 nm ArF excimer laser and the Al autoionizing transition (sup 2)S(sub 1/2) (512753/cm) yields to the left (sup 2)P(sup 0)J has been exploited in the direct observation of substrate metal atoms in an electron simulated desorption (ESD) process from the monolayer adsorbate system CH3O/Al(111). The identity of the mass 27 photoion was established as Al(+) by (1) isotopic substitution of C-13 in the methanol employed for methoxy formation, and (2) tunable laser scans utilizing the DJ-2 (J = 3/2, 5/2) intermediate levels at approximately 32436/cm and a 248 nm ionization step. An ESD yield of approximately x 10(exp -6) Al atoms/(electron at 1 keV) was established by comparison with a sputtering experiment in the same apparatus. Velocity distributions measured for the desorbed Al species showed some differences in comparison with methoxy velocity data: a slightly lower peak velocity and a significantly less prominent high-velocity component.

  7. Analyzing velocity map images to distinguish the primary methyl photofragments from those produced upon C-Cl bond photofission in chloroacetone at 193 nm.

    PubMed

    Alligood, Bridget W; Straus, Daniel B; Butler, Laurie J

    2011-07-21

    We use a combination of crossed laser-molecular beam scattering experiments and velocity map imaging experiments to investigate the three primary photodissociation channels of chloroacetone at 193 nm: C-Cl bond photofission yielding CH(3)C(O)CH(2) radicals, C-C bond photofission yielding CH(3)CO and CH(2)Cl products, and C-CH(3) bond photofission resulting in CH(3) and C(O)CH(2)Cl products. Improved analysis of data previously reported by our group quantitatively identifies the contribution of this latter photodissociation channel. We introduce a forward convolution procedure to identify the portion of the signal, derived from the methyl image, which results from a two-step process in which C-Cl bond photofission is followed by the dissociation of the vibrationally excited CH(3)C(O)CH(2) radicals to CH(3) + COCH(2). Subtracting this from the total methyl signal identifies the methyl photofragments that result from the CH(3) + C(O)CH(2)Cl photofission channel. We find that about 89% of the chloroacetone molecules undergo C-Cl bond photofission to yield CH(3)C(O)CH(2) and Cl products; approximately 8% result in C-C bond photofission to yield CH(3)CO and CH(2)Cl products, and the remaining 2.6% undergo C-CH(3) bond photofission to yield CH(3) and C(O)CH(2)Cl products. PMID:21786998

  8. Analyzing velocity map images to distinguish the primary methyl photofragments from those produced upon C-Cl bond photofission in chloroacetone at 193 nm

    SciTech Connect

    Alligood, Bridget W.; Straus, Daniel B.; Butler, Laurie J.

    2011-07-21

    We use a combination of crossed laser-molecular beam scattering experiments and velocity map imaging experiments to investigate the three primary photodissociation channels of chloroacetone at 193 nm: C-Cl bond photofission yielding CH{sub 3}C(O)CH{sub 2} radicals, C-C bond photofission yielding CH{sub 3}CO and CH{sub 2}Cl products, and C-CH{sub 3} bond photofission resulting in CH{sub 3} and C(O)CH{sub 2}Cl products. Improved analysis of data previously reported by our group quantitatively identifies the contribution of this latter photodissociation channel. We introduce a forward convolution procedure to identify the portion of the signal, derived from the methyl image, which results from a two-step process in which C-Cl bond photofission is followed by the dissociation of the vibrationally excited CH{sub 3}C(O)CH{sub 2} radicals to CH{sub 3}+ COCH{sub 2}. Subtracting this from the total methyl signal identifies the methyl photofragments that result from the CH{sub 3}+ C(O)CH{sub 2}Cl photofission channel. We find that about 89% of the chloroacetone molecules undergo C-Cl bond photofission to yield CH{sub 3}C(O)CH{sub 2} and Cl products; approximately 8% result in C-C bond photofission to yield CH{sub 3}CO and CH{sub 2}Cl products, and the remaining 2.6% undergo C-CH{sub 3} bond photofission to yield CH{sub 3} and C(O)CH{sub 2}Cl products.

  9. A complete look at the multi-channel dissociation of propenal photoexcited at 193 nm: branching ratios and distributions of kinetic energy.

    PubMed

    Chaudhuri, Chanchal; Lee, Shih-Huang

    2011-04-28

    We observed fifteen photofragments upon photolysis of propenal (acrolein, CH(2)CHCHO) at 193 nm using photofragment translational spectroscopy and selective vacuum-ultraviolet (VUV) photoionization. All the photoproducts arise from nine primary and two secondary dissociation pathways. We measured distributions of kinetic energy of products and determined branching ratios of dissociation channels. Dissociation to CH(2)CHCO + H and CH(2)CH + HCO are two major primary channels with equivalent branching ratios of 33%. The CH(2)CHCO fragment spontaneously decomposes to CH(2)CH + CO. A proportion of primary products CH(2)CH from the fission of bond C-C of propenal further decompose to CHCH + H but secondary dissociation HCO → H + CO is negligibly small. Binary dissociation to CH(2)CH(2) (or CH(3)CH) + CO and concerted three-body dissociation to C(2)H(2) + CO + H(2) have equivalent branching ratios of 14%-15%. The other channels have individual branching ratios of ∼1%. The production of HCCO + CH(3) indicates the formation of intermediate methyl ketene (CH(3)CHCO) and the production of CH(2)CCH + OH and CH(2)CC + H(2)O indicate the formation of intermediate hydroxyl propadiene (CH(2)CCHOH) from isomerization of propenal. Distributions of kinetic energy release and dissociation mechanisms are discussed. This work provides a complete look and profound insight into the multi-channel dissociation mechanisms of propenal. The combination of a molecular beam apparatus and synchrotron VUV ionization allowed us to untangle the complex mechanisms of nine primary and two secondary dissociation channels. PMID:21423979

  10. Resolution improvement and pattern generator development for the maskless micro-ion-beam reduction lithography system

    NASA Astrophysics Data System (ADS)

    Jiang, Ximan

    The shrinking of IC devices has followed the Moore's Law for over three decades, which states that the density of transistors on integrated circuits will double about every two years. This great achievement is obtained via continuous advance in lithography technology. With the adoption of complicated resolution enhancement technologies, such as the phase shifting mask (PSM), the optical proximity correction (OPC), optical lithography with wavelength of 193 nm has enabled 45 nm printing by immersion method. However, this achievement comes together with the skyrocketing cost of masks, which makes the production of low volume application-specific IC (ASIC) impractical. In order to provide an economical lithography approach for low to medium volume advanced IC fabrication, a maskless ion beam lithography method, called Maskless Micro-ion-beam Reduction Lithography (MMRL), has been developed in the Lawrence Berkeley National Laboratory. The development of the prototype MMRL system has been described by Dr. Vinh Van Ngo in his Ph.D. thesis. But the resolution realized on the prototype MMRL system was far from the design expectation. In order to improve the resolution of the MMRL system, the ion optical system has been investigated. By integrating a field-free limiting aperture into the optical column, reducing the electromagnetic interference and cleaning the RF plasma, the resolution has been improved to around 50 nm. Computational analysis indicates that the MMRL system can be operated with an exposure field size of 0.25 mm and a beam half angle of 1.0 mrad on the wafer plane. Ion-ion interactions have been studied with a two-particle physics model. The results are in excellent agreement with those published by the other research groups. The charge-interaction analysis of MMRL shows that the ion-ion interactions must be reduced in order to obtain a throughput higher than 10 wafers per hour on 300-mm wafers. In addition, two different maskless lithography strategies

  11. EUV lithography imaging using novel pellicle membranes

    NASA Astrophysics Data System (ADS)

    Pollentier, Ivan; Vanpaemel, Johannes; Lee, Jae Uk; Adelmann, Christoph; Zahedmanesh, Houman; Huyghebaert, Cedric; Gallagher, Emily E.

    2016-03-01

    EUV mask protection against defects during use remains a challenge for EUV lithography. A stand-off protective membrane - a pellicle - is targeted to prevent yield losses in high volume manufacturing during handling and exposure, just as it is for 193nm lithography. The pellicle is thin enough to transmit EUV exposure light, yet strong enough to remain intact and hold any particles out of focus during exposure. The development of pellicles for EUV is much more challenging than for 193nm lithography for multiple reasons including: high absorption of most materials at EUV wavelength, pump-down sequences in the EUV vacuum system, and exposure to high intensity EUV light. To solve the problems of transmission and film durability, various options have been explored. In most cases a thin core film is considered, since the deposition process for this is well established and because it is the simplest option. The transmission specification typically dictates that membranes are very thin (~50nm or less), which makes both fabrication and film mechanical integrity difficult. As an alternative, low density films (e.g. including porosity) will allow thicker membranes for a given transmission specification, which is likely to improve film durability. The risk is that the porosity could influence the imaging. At imec, two cases of pellicle concepts based on reducing density have been assessed : (1) 3D-patterned SiN by directed self-assembly (DSA), and (2) carbon nanomaterials such as carbon nanotubes (CNT) and carbon nanosheets (CNS). The first case is based on SiN membranes that are 3D-patterned by Directed Self Assembly (DSA). The materials are tested relative to the primary specifications: EUV transmission and film durability. A risk assessment of printing performance is provided based on simulations of scattered energy. General conclusions on the efficacy of various approaches will provided.

  12. Determining the CH3SO2 --> CH3 + SO2 barrier from methylsulfonyl chloride photodissociation at 193 nm using velocity map imaging.

    PubMed

    Ratliff, Britni J; Tang, Xiaonan; Butler, Laurie J; Szpunar, David E; Lau, Kai-Chung

    2009-07-28

    These imaging experiments study the formation of the methylsulfonyl radical, CH(3)SO(2), from the photodissociation of CH(3)SO(2)Cl at 193 nm and determine the energetic barrier for the radical's subsequent dissociation to CH(3) + SO(2). We first state-selectively detect the angular and recoil velocity distributions of the Cl((2)P(3/2)) and Cl((2)P(1/2)) atoms to further refine the distribution of internal energy partitioned to the momentum-matched CH(3)SO(2) radicals. The internal energy distribution of the radicals is bimodal, indicating that CH(3)SO(2) is formed in both the ground state and low-lying excited electronic states. All electronically excited CH(3)SO(2) radicals dissociate, while those formed in the ground electronic state have an internal energy distribution which spans the dissociation barrier to CH(3) + SO(2). We detect the recoil velocities of the energetically stable methylsulfonyl radicals with 118 nm photoionization. Comparison of the total recoil translational energy distribution for all radicals to the distribution obtained from the detection of stable radicals yields an onset for dissociation at a translational energy of 70+/-2 kcal/mol. This onset allows us to derive a CH(3)SO(2) --> CH(3) + SO(2) barrier height of 14+/-2 kcal/mol; this determination relies on the S-Cl bond dissociation energy, taken here as the CCSD(T) predicted energy of 65.6 kcal/mol. With 118 nm photoionization, we also detect the velocity distribution of the CH(3) radicals produced in this experiment. Using the velocity distributions of the SO(2) products from the dissociation of CH(3)SO(2) to CH(3) + SO(2) presented in the following paper, we show that our fastest detected methyl radicals are not from these radical dissociation channels, but rather from a primary S-CH(3) bond photofission channel in CH(3)SO(2)Cl. We also present critical points on the ground state potential energy surface of CH(3)SO(2) at the //CCSD(T)/aug-cc-pV(Q + d)ZCCSD(T)/6-311++G(2df,p) level

  13. Intersystem crossing and nonadiabatic product channels in the photodissociation of N{sub 2}O{sub 4} at 193 nm

    SciTech Connect

    Mueller, J.A.; Morton, M.L.; Curry, S.L.; Abbatt, J.P.D.; Butler, L.J.

    2000-06-01

    This paper presents velocity and angular distribution measurements of the products of N{sub 2}O{sub 4} photodissociated at 193 nm. The data show evidence for only N-N bond fission, with no significant branching to N-O bond fission or NO elimination products. The translational energy distribution of the N-N bond fission products is bimodal, indicating that at least two different NO{sub 2} + NO{sub 2} product channels contribute significantly to the observed products. Both product channels have an anisotropy parameter of {beta} = 1.7 {+-} 0.2. Using a Franck-Condon-like sudden analysis, the authors tentatively assign the two fragmentation channels observed as NO{sub 2}({tilde X}{sup 2}A{sub 1}) + NO{sub 2}(1{sup 4}B{sub 2}/1{sup 4}A{sub 2}) and NO{sub 2}({tilde X}{sup 2}A{sub 1}) + NO{sub 2}(2{sup 2}B{sub 2}). To further characterize the system the authors present ab initio calculations (at the level of configuration interaction with single excitations) of the relevant excites states of N{sub 2}O{sub 4}. The data considered together with the calculations suggest a model for the product branching in which there is spin-orbit coupling in the Franck-Condon region between the excited state, which has mixed singlet {pi}{pi}* and n{sigma}* character, and a state with {sup 3}{pi}{sigma}* character. Branching to the NO{sub 2}({tilde X}) + NO{sub 2}(1{sup 4}B{sub 2}/1{sup 4}A{sub 2}) channel occurs upon intersystem crossing to the triplet surface, and formation of the {pi}{pi}* diabatic products NO{sub 2}(X) + NO{sub 2}(2{sup 2}B{sub 2}) occurs from the singlet {pi}{pi}* state nonadiabatic dynamics. Finally, the authors note that the observed parallel photofragment anisotropy, unexpected for {pi}{pi}* electronic excitation of N{sub 2}O{sub 4}, likely results from vibronic coupling with a {sigma}{sigma}* electronic state.

  14. Resolution Improvement and Pattern Generator Development for theMaskless Micro-Ion-Beam Reduction Lithography System

    SciTech Connect

    Jiang, Ximan

    2006-05-18

    The shrinking of IC devices has followed the Moore's Law for over three decades, which states that the density of transistors on integrated circuits will double about every two years. This great achievement is obtained via continuous advance in lithography technology. With the adoption of complicated resolution enhancement technologies, such as the phase shifting mask (PSM), the optical proximity correction (OPC), optical lithography with wavelength of 193 nm has enabled 45 nm printing by immersion method. However, this achievement comes together with the skyrocketing cost of masks, which makes the production of low volume application-specific IC (ASIC) impractical. In order to provide an economical lithography approach for low to medium volume advanced IC fabrication, a maskless ion beam lithography method, called Maskless Micro-ion-beam Reduction Lithography (MMRL), has been developed in the Lawrence Berkeley National Laboratory. The development of the prototype MMRL system has been described by Dr. Vinh Van Ngo in his Ph.D. thesis. But the resolution realized on the prototype MMRL system was far from the design expectation. In order to improve the resolution of the MMRL system, the ion optical system has been investigated. By integrating a field-free limiting aperture into the optical column, reducing the electromagnetic interference and cleaning the RF plasma, the resolution has been improved to around 50 nm. Computational analysis indicates that the MMRL system can be operated with an exposure field size of 0.25 mm and a beam half angle of 1.0 mrad on the wafer plane. Ion-ion interactions have been studied with a two-particle physics model. The results are in excellent agreement with those published by the other research groups. The charge-interaction analysis of MMRL shows that the ion-ion interactions must be reduced in order to obtain a throughput higher than 10 wafers per hour on 300-mm wafers. In addition, two different maskless lithography strategies

  15. Scatterometry for EUV lithography at the 22-nm node

    NASA Astrophysics Data System (ADS)

    Bunday, Benjamin; Vartanian, Victor; Ren, Liping; Huang, George; Montgomery, Cecilia; Montgomery, Warren; Elia, Alex; Liu, Xiaoping

    2011-03-01

    Moore's Law continues to drive improvements to lithographic resolution to increase integrated circuit transistor density, improve performance, and reduce cost. For the 22 nm node and beyond, extreme ultraviolet lithography (EUVL) is a promising technology with λ=13.5 nm, a larger k1 value and lower cost of ownership than other available technologies. For small feature sizes, process control will be increasingly challenging, as small features will create measurement uncertainties, yet with tighter specifications. Optical scatterometry is a primary candidate metrology for EUV lithography process control. Using simulation and experimental data, this work will explore scatterometry's application to a typical lithography process being used for EUV development, which should be representative of lithography processes that will be utilized for EUV High Volume manufacturing (HVM). EUV lithography will be performed using much thinner photoresist thicknesses than were used at the 248nm or 193nm lithography generations, and will probably include underlayers for adhesion improvement; these new processes conditions were investigated in this metrological study.

  16. An ice lithography instrument

    NASA Astrophysics Data System (ADS)

    Han, Anpan; Chervinsky, John; Branton, Daniel; Golovchenko, J. A.

    2011-06-01

    We describe the design of an instrument that can fully implement a new nanopatterning method called ice lithography, where ice is used as the resist. Water vapor is introduced into a scanning electron microscope (SEM) vacuum chamber above a sample cooled down to 110 K. The vapor condenses, covering the sample with an amorphous layer of ice. To form a lift-off mask, ice is removed by the SEM electron beam (e-beam) guided by an e-beam lithography system. Without breaking vacuum, the sample with the ice mask is then transferred into a metal deposition chamber where metals are deposited by sputtering. The cold sample is then unloaded from the vacuum system and immersed in isopropanol at room temperature. As the ice melts, metal deposited on the ice disperses while the metals deposited on the sample where the ice had been removed by the e-beam remains. The instrument combines a high beam-current thermal field emission SEM fitted with an e-beam lithography system, cryogenic systems, and a high vacuum metal deposition system in a design that optimizes ice lithography for high throughput nanodevice fabrication. The nanoscale capability of the instrument is demonstrated with the fabrication of nanoscale metal lines.

  17. An ice lithography instrument

    SciTech Connect

    Han, Anpan; Chervinsky, John; Branton, Daniel; Golovchenko, J. A.

    2011-06-15

    We describe the design of an instrument that can fully implement a new nanopatterning method called ice lithography, where ice is used as the resist. Water vapor is introduced into a scanning electron microscope (SEM) vacuum chamber above a sample cooled down to 110 K. The vapor condenses, covering the sample with an amorphous layer of ice. To form a lift-off mask, ice is removed by the SEM electron beam (e-beam) guided by an e-beam lithography system. Without breaking vacuum, the sample with the ice mask is then transferred into a metal deposition chamber where metals are deposited by sputtering. The cold sample is then unloaded from the vacuum system and immersed in isopropanol at room temperature. As the ice melts, metal deposited on the ice disperses while the metals deposited on the sample where the ice had been removed by the e-beam remains. The instrument combines a high beam-current thermal field emission SEM fitted with an e-beam lithography system, cryogenic systems, and a high vacuum metal deposition system in a design that optimizes ice lithography for high throughput nanodevice fabrication. The nanoscale capability of the instrument is demonstrated with the fabrication of nanoscale metal lines.

  18. An ice lithography instrument.

    PubMed

    Han, Anpan; Chervinsky, John; Branton, Daniel; Golovchenko, J A

    2011-06-01

    We describe the design of an instrument that can fully implement a new nanopatterning method called ice lithography, where ice is used as the resist. Water vapor is introduced into a scanning electron microscope (SEM) vacuum chamber above a sample cooled down to 110 K. The vapor condenses, covering the sample with an amorphous layer of ice. To form a lift-off mask, ice is removed by the SEM electron beam (e-beam) guided by an e-beam lithography system. Without breaking vacuum, the sample with the ice mask is then transferred into a metal deposition chamber where metals are deposited by sputtering. The cold sample is then unloaded from the vacuum system and immersed in isopropanol at room temperature. As the ice melts, metal deposited on the ice disperses while the metals deposited on the sample where the ice had been removed by the e-beam remains. The instrument combines a high beam-current thermal field emission SEM fitted with an e-beam lithography system, cryogenic systems, and a high vacuum metal deposition system in a design that optimizes ice lithography for high throughput nanodevice fabrication. The nanoscale capability of the instrument is demonstrated with the fabrication of nanoscale metal lines. PMID:21721733

  19. An ice lithography instrument

    PubMed Central

    Han, Anpan; Chervinsky, John; Branton, Daniel; Golovchenko, J. A.

    2011-01-01

    We describe the design of an instrument that can fully implement a new nanopatterning method called ice lithography, where ice is used as the resist. Water vapor is introduced into a scanning electron microscope (SEM) vacuum chamber above a sample cooled down to 110 K. The vapor condenses, covering the sample with an amorphous layer of ice. To form a lift-off mask, ice is removed by the SEM electron beam (e-beam) guided by an e-beam lithography system. Without breaking vacuum, the sample with the ice mask is then transferred into a metal deposition chamber where metals are deposited by sputtering. The cold sample is then unloaded from the vacuum system and immersed in isopropanol at room temperature. As the ice melts, metal deposited on the ice disperses while the metals deposited on the sample where the ice had been removed by the e-beam remains. The instrument combines a high beam-current thermal field emission SEM fitted with an e-beam lithography system, cryogenic systems, and a high vacuum metal deposition system in a design that optimizes ice lithography for high throughput nanodevice fabrication. The nanoscale capability of the instrument is demonstrated with the fabrication of nanoscale metal lines. PMID:21721733

  20. Hydrogen Migration and Vinylidene Pathway for Formation of Methane in the 193 nm Photodissociation of Propene: CH3CH=CH2 and CD3CD=CD2

    NASA Technical Reports Server (NTRS)

    Zhao, Yi-Lei; Laufer, Allan H.; Halpern, Joshua B.; Fahr, Askar

    2007-01-01

    Photodissociation channels and the final product yields from the 193 nm photolysis of propene-h6 (CH2=CHCH3) and propene-d6 (CD2=CDCD3) have been investigated, employing gas chromatography, mass spectroscopy, and flame ionization (GC/MS/FID) detection methods. The yields of methane as well as butadiene relative to ethane show considerable variations when propene-h6 or propene-d6 are photolyzed. This suggests significant variances in the relative importance of primary photolytic processes and/or secondary radical reactions, occurring subsequent to the photolysis. Theoretical calculations suggest the potential occurrence of an intramolecular dissociation through a mechanism involving vinylidene formation, accompanied by an ethylenic H-migration through the pi-orbitals. This process affects the final yields of methane-h4 versus methane-d4 with respect to other products. The product yields from previous studies of the 193 nm photolysis of methyl vinyl ketone-h6 and -d6 (CH2=CHCOCH3, CD2=CDCOCD3), alternative precursors for generating methyl and vinyl radicals, are compared with the current results for propene.

  1. Combined overlay, focus and CD metrology for leading edge lithography

    NASA Astrophysics Data System (ADS)

    Ebert, Martin; Cramer, Hugo; Tel, Wim; Kubis, Michael; Megens, Henry

    2011-04-01

    and Focus measurements respectively. In addition CD profile information can be measured enabling proximity matching applications. By using a technique [2][3][4] to de-convolve dose and focus based on the profile measurement of a well-characterized process monitor target, we show that the dose and focus signature of a high NA 193nm immersion scanner can be effectively measured and corrected. A similar approach was also taken to address overlay errors using the diffraction based overlay capability [5] of the same metrology tool. We demonstrate the advantage of having a single metrology tool solution, which enables us to reduce dose, focus and overlay variability to their minimum non-correctable signatures. This technique makes use of the high accuracy and repeatability of the YieldStar tool and provides a common reference of scanner setup and user process. Using ASML's YieldStar in combination with ASML scanners, and control solutions allows for a direct link from the metrology tool to the system settings, ensuring that the appropriate system settings can be easily and directly updated.

  2. Spectroscopic Ellipsometry Applications in Advanced Lithography Research

    NASA Astrophysics Data System (ADS)

    Synowicki, R. A.; Pribil, Greg K.; Hilfiker, James N.; Edwards, Kevin

    2005-09-01

    Spectroscopic ellipsometry (SE) is an optical metrology technique widely used in the semiconductor industry. For lithography applications SE is routinely used for measurement of film thickness and refractive index of polymer photoresist and antireflective coatings. While this remains a primary use of SE, applications are now expanding into other areas of advanced lithography research. New applications include immersion lithography, phase-shift photomasks, transparent pellicles, 193 and 157 nm lithography, stepper optical coatings, imprint lithography, and even real-time monitoring of etch development rate in liquid ambients. Of recent interest are studies of immersion fluids where knowledge of the fluid refractive index and absorption are critical to their use in immersion lithography. Phase-shift photomasks are also of interest as the thickness and index of the phase-shift and absorber layers must be critically controlled for accurate intensity and phase transmission. Thin transparent pellicles to protect these masks must be also characterized for thickness and refractive index. Infrared ellipsometry is sensitive to chemical composition, film thickness, and how film chemistry changes with processing. Real-time monitoring of polymer film thickness during etching in a liquid developer allows etch rate and endpoint determination with monolayer sensitivity. This work considers these emerging applications to survey the current status of spectroscopic ellipsometry as a characterization technique in advanced lithography applications.

  3. Preliminary characterisation of new glass reference materials (GSA-1G, GSC-1G, GSD-1G and GSE-1G) by laser ablation-inductively coupled plasma-mass spectrometry using 193 nm, 213 nm and 266 nm wavelengths

    USGS Publications Warehouse

    Guillong, M.; Hametner, K.; Reusser, E.; Wilson, S.A.; Gunther, D.

    2005-01-01

    New glass reference materials GSA-1G, GSC-1G, GSD-1G and GSE-1G have been characterised using a prototype solid state laser ablation system capable of producing wavelengths of 193 nm, 213 nm and 266 nm. This system allowed comparison of the effects of different laser wavelengths under nearly identical ablation and ICP operating conditions. The wavelengths 213 nm and 266 nm were also used at higher energy densities to evaluate the influence of energy density on quantitative analysis. In addition, the glass reference materials were analysed using commercially available 266 nm Nd:YAG and 193 nm ArF excimer lasers. Laser ablation analysis was carried out using both single spot and scanning mode ablation. Using laser ablation ICP-MS, concentrations of fifty-eight elements were determined with external calibration to the NIST SRM 610 glass reference material. Instead of applying the more common internal standardisation procedure, the total concentration of all element oxide concentrations was normalised to 100%. Major element concentrations were compared with those determined by electron microprobe. In addition to NIST SRM 610 for external calibration, USGS BCR-2G was used as a more closely matrix-matched reference material in order to compare the effect of matrix-matched and non matrix-matched calibration on quantitative analysis. The results show that the various laser wavelengths and energy densities applied produced similar results, with the exception of scanning mode ablation at 266 nm without matrix-matched calibration where deviations up to 60% from the average were found. However, results acquired using a scanning mode with a matrix-matched calibration agreed with results obtained by spot analysis. The increased abundance of large particles produced when using a scanning ablation mode with NIST SRM 610, is responsible for elemental fractionation effects caused by incomplete vaporisation of large particles in the ICP.

  4. Toward a universal resist dissolution model for lithography simulation

    NASA Astrophysics Data System (ADS)

    Robertson, Stewart A.; Mack, Chris A.; Maslow, Mark J.

    2001-04-01

    In lithography simulation dissolution rate equations are used to map development rate to the resist latent image. This work examines the quality of fit of four rate equations to experimental dissolution data for a wide variety of different resists ranging from medium contrast i-line novolak/DNQ materials to the state-of-the-art 248nm and 193nm chemically amplified photoresists. Three of the rate equations are routinely used for modeling: the Mack rate equation, the Enhanced Mack rate equation, and the Notch rate equation. The fourth is the recently developed Enhanced Notch model. Although each class of photoresist can be fitted reasonably well by one of the conventional rate equations, the Enhanced Notch model yields the best fit to the experimental data in all cases.

  5. Chloroacetone photodissociation at 193 nm and the subsequent dynamics of the CH3C(O)CH2 radical--an intermediate formed in the OH + allene reaction en route to CH3 + ketene.

    PubMed

    Alligood, Bridget W; FitzPatrick, Benjamin L; Szpunar, David E; Butler, Laurie J

    2011-02-01

    We use a combination of crossed laser-molecular beam experiments and velocity map imaging experiments to investigate the primary photofission channels of chloroacetone at 193 nm; we also probe the dissociation dynamics of the nascent CH(3)C(O)CH(2) radicals formed from C-Cl bond fission. In addition to the C-Cl bond fission primary photodissociation channel, the data evidence another photodissociation channel of the precursor, C-C bond fission to produce CH(3)CO and CH(2)Cl. The CH(3)C(O)CH(2) radical formed from C-Cl bond fission is one of the intermediates in the OH + allene reaction en route to CH(3) + ketene. The 193 nm photodissociation laser allows us to produce these CH(3)C(O)CH(2) radicals with enough internal energy to span the dissociation barrier leading to the CH(3) + ketene asymptote. Therefore, some of the vibrationally excited CH(3)C(O)CH(2) radicals undergo subsequent dissociation to CH(3) + ketene products; we are able to measure the velocities of these products using both the imaging and scattering apparatuses. The results rule out the presence of a significant contribution from a C-C bond photofission channel that produces CH(3) and COCH(2)Cl fragments. The CH(3)C(O)CH(2) radicals are formed with a considerable amount of energy partitioned into rotation; we use an impulsive model to explicitly characterize the internal energy distribution. The data are better fit by using the C-Cl bond fission transition state on the S(1) surface of chloroacetone as the geometry at which the impulsive force acts, not the Franck-Condon geometry. Our data suggest that, even under atmospheric conditions, the reaction of OH with allene could produce a small branching to CH(3) + ketene products, rather than solely producing inelastically stabilized adducts. This additional channel offers a different pathway for the OH-initiated oxidation of such unsaturated volatile organic compounds, those containing a C=C=C moiety, than is currently included in atmospheric models

  6. Lithography for enabling advances in integrated circuits and devices.

    PubMed

    Garner, C Michael

    2012-08-28

    Because the transistor was fabricated in volume, lithography has enabled the increase in density of devices and integrated circuits. With the invention of the integrated circuit, lithography enabled the integration of higher densities of field-effect transistors through evolutionary applications of optical lithography. In 1994, the semiconductor industry determined that continuing the increase in density transistors was increasingly difficult and required coordinated development of lithography and process capabilities. It established the US National Technology Roadmap for Semiconductors and this was expanded in 1999 to the International Technology Roadmap for Semiconductors to align multiple industries to provide the complex capabilities to continue increasing the density of integrated circuits to nanometre scales. Since the 1960s, lithography has become increasingly complex with the evolution from contact printers, to steppers, pattern reduction technology at i-line, 248 nm and 193 nm wavelengths, which required dramatic improvements of mask-making technology, photolithography printing and alignment capabilities and photoresist capabilities. At the same time, pattern transfer has evolved from wet etching of features, to plasma etch and more complex etching capabilities to fabricate features that are currently 32 nm in high-volume production. To continue increasing the density of devices and interconnects, new pattern transfer technologies will be needed with options for the future including extreme ultraviolet lithography, imprint technology and directed self-assembly. While complementary metal oxide semiconductors will continue to be extended for many years, these advanced pattern transfer technologies may enable development of novel memory and logic technologies based on different physical phenomena in the future to enhance and extend information processing. PMID:22802500

  7. Advanced light source technologies that enable high-volume manufacturing of DUV lithography extensions

    NASA Astrophysics Data System (ADS)

    Cacouris, Theodore; Rao, Rajasekhar; Rokitski, Rostislav; Jiang, Rui; Melchior, John; Burfeindt, Bernd; O'Brien, Kevin

    2012-03-01

    Deep UV (DUV) lithography is being applied to pattern increasingly finer geometries, leading to solutions like double- and multiple-patterning. Such process complexities lead to higher costs due to the increasing number of steps required to produce the desired results. One of the consequences is that the lithography equipment needs to provide higher operating efficiencies to minimize the cost increases, especially for producers of memory devices that experience a rapid decline in sales prices of these products over time. In addition to having introduced higher power 193nm light sources to enable higher throughput, we previously described technologies that also enable: higher tool availability via advanced discharge chamber gas management algorithms; improved process monitoring via enhanced on-board beam metrology; and increased depth of focus (DOF) via light source bandwidth modulation. In this paper we will report on the field performance of these technologies with data that supports the desired improvements in on-wafer performance and operational efficiencies.

  8. Lithography optics: its present and future

    NASA Astrophysics Data System (ADS)

    Matsumoto, Koichi; Mori, Takashi

    1998-09-01

    Firstly, various technical aspects of ArF optics are surveyed. At present, the ArF excimer laser is regarded as one of the most promising candidates as a next-generation light source for optical lithography. Discussions are ranging over some critical issues of ArF optics. The lifetime of ArF optics supposedly limited by the radiation compaction of silica glass is estimated in comparison with KrF optics. Availability of calcium fluoride (CaF2) is also discussed. As a designing issue, a comparative study is made about the optical configuration, dioptric or catadioptric. In the end, our resist-based performance is shown. Secondly, estimated are the future trend regarding minimum geometry and the optical parameters, such as numerical aperture and wavelength. For the estimation, simulations based on aerial images are performed, where in the resolution limit is defined as a minimum feature size which retains practical depth of focus. Pattern geometry is classified into two categories, which are dense lines and isolated lines. Available wavelengths are assumed to be KrF excimer laser ((λ =248 nm), ArF excimer laser (λ =193 nm) and F2 excimer laser (λ =157 nm). Based upon the simulation results, the resolution limit is estimated for each geometry and each wavelength.

  9. Subwavelength-size solid immersion lens.

    PubMed

    Kim, Myun-Sik; Scharf, Toralf; Haq, Mohammad Tahdiul; Nakagawa, Wataru; Herzig, Hans Peter

    2011-10-01

    We report on the fabrication and characterization of nanoscale solid immersion lenses (nano-SILs) with sizes down to a subwavelength range. Submicrometer-scale cylinders fabricated by electron-beam lithography are thermally reflowed to form a spherical shape. Subsequent soft lithography leads to nano-SILs on transparent substrates for optical characterization. The optical characterization is performed using a high-resolution interference microscope with illumination at 642 nm wavelength. The focal spots produced by the nano-SILs show both spot-size reduction and enhanced optical intensity, which are consistent with the immersion effect. PMID:21964145

  10. VUV lithography

    DOEpatents

    George, Edward V.; Oster, Yale; Mundinger, David C.

    1990-01-01

    Deep UV projection lithography can be performed using an e-beam pumped solid excimer UV source, a mask, and a UV reduction camera. The UV source produces deep UV radiation in the range 1700-1300A using xenon, krypton or argon; shorter wavelengths of 850-650A can be obtained using neon or helium. A thin solid layer of the gas is formed on a cryogenically cooled plate and bombarded with an e-beam to cause fluorescence. The UV reduction camera utilizes multilayer mirrors having high reflectivity at the UV wavelength and images the mask onto a resist coated substrate at a preselected demagnification. The mask can be formed integrally with the source as an emitting mask.

  11. VUV lithography

    DOEpatents

    George, E.V.; Oster, Y.; Mundinger, D.C.

    1990-12-25

    Deep UV projection lithography can be performed using an e-beam pumped solid excimer UV source, a mask, and a UV reduction camera. The UV source produces deep UV radiation in the range 1,700--1,300A using xenon, krypton or argon; shorter wavelengths of 850--650A can be obtained using neon or helium. A thin solid layer of the gas is formed on a cryogenically cooled plate and bombarded with an e-beam to cause fluorescence. The UV reduction camera utilizes multilayer mirrors having high reflectivity at the UV wavelength and images the mask onto a resist coated substrate at a preselected demagnification. The mask can be formed integrally with the source as an emitting mask. 6 figs.

  12. Maskless lithography

    DOEpatents

    Sweatt, William C.; Stulen, Richard H.

    1999-01-01

    The present invention provides a method for maskless lithography. A plurality of individually addressable and rotatable micromirrors together comprise a two-dimensional array of micromirrors. Each micromirror in the two-dimensional array can be envisioned as an individually addressable element in the picture that comprises the circuit pattern desired. As each micromirror is addressed it rotates so as to reflect light from a light source onto a portion of the photoresist coated wafer thereby forming a pixel within the circuit pattern. By electronically addressing a two-dimensional array of these micromirrors in the proper sequence a circuit pattern that is comprised of these individual pixels can be constructed on a microchip. The reflecting surface of the micromirror is configured in such a way as to overcome coherence and diffraction effects in order to produce circuit elements having straight sides.

  13. Two HCl-Elimination Channels and Two CO-Formation Channels Detected with Time-Resolved Infrared Emission upon Photolysis of Acryloyl Chloride [CH2CHC(O)Cl] at 193 nm.

    PubMed

    Lee, Pei-Wen; Scrape, Preston G; Butler, Laurie J; Lee, Yuan-Pern

    2015-07-16

    Following photodissociation of gaseous acryloyl chloride, CH2CHC(O)Cl, at 193 nm, temporally resolved vibration-rotational emission spectra of HCl (v ≤ 7, J ≤ 35) in region 2350-3250 cm(-1) and of CO (v ≤ 4, J ≤ 67) in region 1865-2300 cm(-1) were recorded with a step-scan Fourier-transform spectrometer. The HCl emission shows a minor low-J component for v ≤ 4 with average rotational energy Erot = 9 ± 3 kJ mol(-1) and vibrational energy Evib = 28 ± 7 kJ mol(-1) and a major high-J component for v ≤ 7 with average rotational energy Erot = 36 ± 6 kJ mol(-1) and vibrational energy Evib = 49 ± 9 kJ mol(-1); the branching ratio of these two channels is ∼0.2:0.8. Using electronic structure calculations to characterize the transition states and each intrinsic reaction coordinate, we find that the minor pathway corresponds to the four-center HCl-elimination of CH2ClCHCO following a 1,3-Cl-shift of CH2CHC(O)Cl, whereas the major pathway corresponds to the direct four-center HCl-elimination of CH2CHC(O)Cl. Although several channels are expected for CO produced from the secondary dissociation of C2H3CO and H2C═C═C═O, each produced from two possible dissociation channels of CH2CHC(O)Cl, the CO emission shows a near-Boltzmann rotational distribution with average rotational energy Erot = 21 ± 4 kJ mol(-1) and average vibrational energy Evib = 10 ± 4 kJ mol(-1). Consideration of the branching fractions suggests that the CO observed with greater vibrational excitation might result from secondary decomposition of H2C═C═C═O that was produced via the minor low-J HCl-elimination channel, while the internal state distributions of CO produced from the other three channels are indistinguishable. We also introduce a method for choosing the correct point along the intrinsic reaction coordinate for a roaming HCl elimination channel to generate a Franck-Condon prediction for the HCl vibrational energy. PMID:25658197

  14. Evaluation of corneal ablation by an optical parametric oscillator (OPO) at 2.94 μm and an Er:YAG laser and comparison to ablation by a 193-nm excimer laser

    NASA Astrophysics Data System (ADS)

    Telfair, William B.; Hoffman, Hanna J.; Nordquist, Robert E.; Eiferman, Richard A.

    1998-06-01

    Purpose: This study first evaluated the corneal ablation characteristics of (1) an Nd:YAG pumped OPO (Optical Parametric Oscillator) at 2.94 microns and (2) a short pulse Er:YAG laser. Secondly, it compared the histopathology and surface quality of these ablations with (3) a 193 nm excimer laser. Finally, the healing characteristics over 4 months of cat eyes treated with the OPO were evaluated. Methods: Custom designed Nd:YAG/OPO and Er:YAG lasers were integrated with a new scanning delivery system to perform PRK myopic correction procedures. After initial ablation studies to determine ablation thresholds and rates, human cadaver eyes and in-vivo cat eyes were treated with (1) a 6.0 mm Dia, 30 micron deep PTK ablation and (2) a 6.0 mm Dia, -5.0 Diopter PRK ablation. Cadaver eyes were also treated with a 5.0 mm Dia, -5.0 Diopter LASIK ablation. Finally, cats were treated with the OPO in a 4 month healing study. Results: Ablation thresholds below 100 mJ/cm2 and ablation rates comparable to the excimer were demonstrated for both infrared systems. Light Microscopy (LM) showed no thermal damage for low fluence treatments, but noticeable thermal damage at higher fluences. SEM and TEM revealed morphologically similar surfaces for low fluence OPO and excimer samples with a smooth base and no evidence of collagen shrinkage. The Er:YAG and higher fluence OPO treated samples revealed more damage along with visible collagen coagulation and shrinkage in some cases. Healing was remarkably unremarkable. All eyes had a mild healing response with no stromal haze and showed topographic flattening. LM demonstrated nothing except a moderate increase in keratocyte activity in the upper third of the stroma. TEM confirmed this along with irregular basement membranes. Conclusions: A non- thermal ablation process called photospallation is demonstrated for the first time using short pulse infrared lasers yielding damage zones comparable to the excimer and healing which is also comparable to

  15. ITRS lithography roadmap: status and challenges

    NASA Astrophysics Data System (ADS)

    Neisser, Mark; Wurm, Stefan

    2012-09-01

    Recent ITRS lithography roadmaps show a big technology decision approaching the semiconductor industry about how to do leading edge lithography. The need is rapidly approaching for the industry to select an option for the 22-nm half pitch, but no decision has been made yet. The main options for the 22-nm half pitch are extreme ultraviolet (EUV), ArF immersion lithography with multiple patterning, and maskless lithography. For the 16-nm half pitch, directed self-assembly (DSA) is also an option. The EUV has the most industry investment and is the closest to current lithography in the way it works but still faces challenges in tool productivity and defect-free masks. The nanoimprint needs to overcome the defect, contamination, and overlay challenges before it can be applied to the semiconductor production. Maskless lithography may be used first for prototyping and small volume products where mask costs per chip produced would be very high. Double patterning could be extended to multiple pattering, but would give tremendous process complexity and exponentially rising mask costs due to the many exposures needed per level. The DSA, which only recently has emerged from the research stage, has the potential for very high resolution but represents a huge change in how critical dimensions are formed and controlled.

  16. EUV lithography

    NASA Astrophysics Data System (ADS)

    Kemp, Kevin; Wurm, Stefan

    2006-10-01

    Extreme ultraviolet lithography (EUVL) technology and infrastructure development has made excellent progress over the past several years, and tool suppliers are delivering alpha tools to customers. However, requirements in source, mask, optics, and resist are very challenging, and significant development efforts are still needed to support beta and production-level performance. Some of the important advances in the past few years include increased source output power, tool and optics system development and integration, and mask blank defect reduction. For example, source power has increased to levels approaching specification, but reliable source operation at these power levels has yet to be fully demonstrated. Significant efforts are also needed to achieve the resolution, line width roughness, and photospeed requirements for EUV photoresists. Cost of ownership and extendibility to future nodes are key factors in determining the outlook for the manufacturing insertion of EUVL. Since wafer throughput is a critical cost factor, source power, resist sensitivity, and system design all need to be carefully considered. However, if the technical and business challenges can be met, then EUVL will be the likely technology of choice for semiconductor manufacturing at the 32, 22, 16 and 11 nm half-pitch nodes. To cite this article: K. Kemp, S. Wurm, C. R. Physique 7 (2006).

  17. Resists for next generation lithography

    SciTech Connect

    Brainard, Robert L.; Barclay, George G.; Anderson, Erik H.; Ocola, Leonidas E.

    2001-10-03

    Four Next Generation Lithographic options (EUV, x-ray, EPL, IPL) are compared against four current optical technologies (i-line, DUV, 193 nm, 157 nm) for resolution capabilities based on wavelength. As the wavelength of the incident radiation decreases, the nature of the interaction with the resist changes. At high energies, optical density is less sensitive to molecular structure then at 157 nm.

  18. Determining the CH{sub 3}SO{sub 2}{yields}CH{sub 3}+SO{sub 2} barrier from methylsulfonyl chloride photodissociation at 193 nm using velocity map imaging

    SciTech Connect

    Ratliff, Britni J.; Tang Xiaonan; Butler, Laurie J.; Szpunar, David E.; Lau, Kai-Chung

    2009-07-28

    These imaging experiments study the formation of the methylsulfonyl radical, CH{sub 3}SO{sub 2}, from the photodissociation of CH{sub 3}SO{sub 2}Cl at 193 nm and determine the energetic barrier for the radical's subsequent dissociation to CH{sub 3}+SO{sub 2}. We first state-selectively detect the angular and recoil velocity distributions of the Cl({sup 2}P{sub 3/2}) and Cl({sup 2}P{sub 1/2}) atoms to further refine the distribution of internal energy partitioned to the momentum-matched CH{sub 3}SO{sub 2} radicals. The internal energy distribution of the radicals is bimodal, indicating that CH{sub 3}SO{sub 2} is formed in both the ground state and low-lying excited electronic states. All electronically excited CH{sub 3}SO{sub 2} radicals dissociate, while those formed in the ground electronic state have an internal energy distribution which spans the dissociation barrier to CH{sub 3}+SO{sub 2}. We detect the recoil velocities of the energetically stable methylsulfonyl radicals with 118 nm photoionization. Comparison of the total recoil translational energy distribution for all radicals to the distribution obtained from the detection of stable radicals yields an onset for dissociation at a translational energy of 70{+-}2 kcal/mol. This onset allows us to derive a CH{sub 3}SO{sub 2}{yields}CH{sub 3}+SO{sub 2} barrier height of 14{+-}2 kcal/mol; this determination relies on the S-Cl bond dissociation energy, taken here as the CCSD(T) predicted energy of 65.6 kcal/mol. With 118 nm photoionization, we also detect the velocity distribution of the CH{sub 3} radicals produced in this experiment. Using the velocity distributions of the SO{sub 2} products from the dissociation of CH{sub 3}SO{sub 2} to CH{sub 3}+SO{sub 2} presented in the following paper, we show that our fastest detected methyl radicals are not from these radical dissociation channels, but rather from a primary S-CH{sub 3} bond photofission channel in CH{sub 3}SO{sub 2}Cl. We also present critical points on

  19. Top-surface imaging resists for lithography with strongly attenuated radiation

    SciTech Connect

    Ray-Chaudhuri, A.; Kubiak, G.; Henderson, C.; Wheeler, D.; Pollagi, T.

    1997-09-01

    Strong resist photoabsorption at wavelengths below 248 nm necessitates the use of a thin layer imaging (TLI) scheme for microlithography using 193 nm, 157 nm, or 13.4 nm radiation. Previous to this work, a TLI process commonly known as silylated top surface imaging (TSI) was developed by a Sandia/AT and T team for use in extreme ultraviolet lithography (EUVL) at 13.4 nm. Using this bilayer process, 0.13 {micro}m resolution with 87{degree} sidewalls in 0.7 {micro}m of resist was achieved for EUV exposures. New imaging layer polymers, silylation reagents and crosslinkers, and process conditions were screened for improvement in this TSI process with the ultimate goal of demonstrating a resist technology capable of 0.10 {micro}m critical dimension (CD). The results of these attempted improvements to the TSI process are described in this report.

  20. Immersive video

    NASA Astrophysics Data System (ADS)

    Moezzi, Saied; Katkere, Arun L.; Jain, Ramesh C.

    1996-03-01

    Interactive video and television viewers should have the power to control their viewing position. To make this a reality, we introduce the concept of Immersive Video, which employs computer vision and computer graphics technologies to provide remote users a sense of complete immersion when viewing an event. Immersive Video uses multiple videos of an event, captured from different perspectives, to generate a full 3D digital video of that event. That is accomplished by assimilating important information from each video stream into a comprehensive, dynamic, 3D model of the environment. Using this 3D digital video, interactive viewers can then move around the remote environment and observe the events taking place from any desired perspective. Our Immersive Video System currently provides interactive viewing and `walkthrus' of staged karate demonstrations, basketball games, dance performances, and typical campus scenes. In its full realization, Immersive Video will be a paradigm shift in visual communication which will revolutionize television and video media, and become an integral part of future telepresence and virtual reality systems.

  1. Immersive CAD

    SciTech Connect

    Ames, A.L.

    1999-02-01

    This paper documents development of a capability for performing shape-changing editing operations on solid model representations in an immersive environment. The capability includes part- and assembly-level operations, with part modeling supporting topology-invariant and topology-changing modifications. A discussion of various design considerations in developing an immersive capability is included, along with discussion of a prototype implementation we have developed and explored. The project investigated approaches to providing both topology-invariant and topology-changing editing. A prototype environment was developed to test the approaches and determine the usefulness of immersive editing. The prototype showed exciting potential in redefining the CAD interface. It is fun to use. Editing is much faster and friendlier than traditional feature-based CAD software. The prototype algorithms did not reliably provide a sufficient frame rate for complex geometries, but has provided the necessary roadmap for development of a production capability.

  2. The Application of Silicon Rich Nitride Films for Use as Deep-Ultraviolet Lithography Phase-Shifting Masks

    NASA Astrophysics Data System (ADS)

    Jiang, Zhong-Tao; Yamaguchi, Tomuo; Ohshimo, Kentaro; Aoyama, Mitsuru; Asinovsky, Leo

    1998-02-01

    Silicon rich nitride (SiRN) film prepared by plasma enhanced chemical vapor deposition (PECVD) for use as the phase-shifting mask for Deep-ultraviolet (UV) lithography has been developed. Optical properties and compositional characterizations of the SiRN films using Auger electron spectroscopy (AES) and spectroscopic ellipsometry (SE) combined with an empirical dielectric function (EDF), as well as phase-shifting mask simulation show that the SiRN is feasible for use in the application of single layer halftone phase-shifting mask (SLHTPSM) in the Deep-UV range. Optical constants of n ≈ 2.5 and k < 0.6 at 193 nm were realized by approaching the N/Si composition to the stoichiometric ratio of Si3N4. The deposition conditions for the films having the transmittance of 5 - 10% with a 180° phase shift at 193 nm (ArF) have been determined. Short wavelength extrapolation by EDF best-fit parameters based on a proper film-stack model provides a potential method to characterize the optical properties of amorphous SiRN down to about 190 nm, which is outside the range of most commercial SE's.

  3. Lithography imaging control by enhanced monitoring of light source performance

    NASA Astrophysics Data System (ADS)

    Alagna, Paolo; Zurita, Omar; Lalovic, Ivan; Seong, Nakgeuon; Rechsteiner, Gregory; Thornes, Joshua; D'havé, Koen; Van Look, Lieve; Bekaert, Joost

    2013-04-01

    Reducing lithography pattern variability has become a critical enabler of ArF immersion scaling and is required to ensure consistent lithography process yield for sub-30nm device technologies. As DUV multi-patterning requirements continue to shrink, it is imperative that all sources of lithography variability are controlled throughout the product life-cycle, from technology development to high volume manufacturing. Recent developments of new ArF light-source metrology and monitoring capabilities have been introduced in order to improve lithography patterning control.[1] These technologies enable performance monitoring of new light-source properties, relating to illumination stability, and enable new reporting and analysis of in-line performance.

  4. Exposure tool control for advanced semiconductor lithography

    NASA Astrophysics Data System (ADS)

    Matsuyama, Tomoyuki

    2015-08-01

    This is a review paper to show how we control exposure tool parameters in order to satisfy patterning performance and productivity requirements for advanced semiconductor lithography. In this paper, we will discuss how we control illumination source shape to satisfy required imaging performance, heat-induced lens aberration during exposure to minimize the aberration impact on imaging, dose and focus control to realize uniform patterning performance across the wafer and patterning position of circuit patterns on different layers. The contents are mainly about current Nikon immersion exposure tools.

  5. Plasma etch challenges with new EUV lithography material introduction for patterning for MOL and BEOL

    NASA Astrophysics Data System (ADS)

    Lee, Changwoo; Nagabhirava, Bhaskar; Goss, Michael; Wang, Peng; Friddle, Phil; Schmitz, Stafan; Wu, Jian; Yang, Richard; Mignot, Yann; Rassoul, Nouradine; Hamieh, Bassem; Beique, Genevieve; Labonte, Andre; Labelle, Catherine; Arnold, John; Mucci, John

    2015-03-01

    As feature critical dimension (CD) shrinks towards and beyond the 7nm node, patterning techniques for optical lithography with double and triple exposure will be replaced by EUV patterning. EUV enables process and overlay improvement, as well as a potential cost reduction due to fewer wafer passes and masks required for patterning. However, the EUV lithography technique introduces newer types of resists that are thinner and softer compared to conventional 193nm resists currently being used. The main challenge is to find the key etch process parameters to improve the EUV resist selectivity, reduce LER and LWR, minimize line end shrink, improve tip-to-tip degradation, and avoid line wiggling while still enabling previous schemes such as trench-first-metal-hard-mask (TFMHM), self-aligned via (SAV) and self-aligned contact (SAC). In this paper, we will discuss some of the approaches that we have investigated to define the best etch process adjustments to enable EUV patterning. RF pulsing is one of the key parameters utilized to overcome most of the previously described challenges, and has also been coupled with stack optimization. This study will focus on RF pulsing (high vs. low frequency results) and bias control (RF frequency dependence). In particular, pulsing effects on resist morphology, selectivity and profile management will be reported, as well as the role of aspect ratio and etch chemistry on organic mask wiggling and collapse. This work was performed by the Research Alliance Teams at various IBM Research and Development Facilities.

  6. Current Status and Perspective of EUV Lithography

    NASA Astrophysics Data System (ADS)

    Nishiyama, Iwao

    The EUV lithography (EUVL) utilizes 13-nm photons as a light source. Because of the short wavelength, it provides a very high resolution and is applicable to the fabrication of multiple generations of semiconductor devices from 45 nm hp down to 32 and even 22 nm hp. This makes EUVL the most promising next-generation lithography, which will follow ArF immersion lithography. However, because the wavelength is so short, bringing EUVL to the level of a practical production tool involves many difficult challenges, such as the development of a high-power light source, high-precision reflective optics, low-defect multilayer masks, a high-resolution high-sensitivity resist, and so on. To overcome the technical difficulties and accelerate the development of EUVL, various projects have been launched and are currently running under the management of SEMATECH (US), NEDEA+ (Europe), and ASET and EUVA (Japan). These activities have produced great advances in EUVL technology in the past several years. A full-field exposure tool for process development (α tool) will be delivered in 2006, and an exposure tool for mass production (γ tool) will be delivered two or three years after that. This presentation gives an overview of recent progress in EUVL.

  7. Advanced Mask Aligner Lithography (AMALITH)

    NASA Astrophysics Data System (ADS)

    Voelkel, Reinhard; Vogler, Uwe; Bramati, Arianna

    2015-03-01

    Mask aligner lithography is very attractive for less-critical lithography layers and is widely used for LED, display, CMOS image sensor, micro-fluidics and MEMS manufacturing. Mask aligner lithography is also a preferred choice the semiconductor back-end for 3D-IC, TSV interconnects, advanced packaging (AdP) and wafer-level-packaging (WLP). Mask aligner lithography is a mature technique based on shadow printing and has not much changed since the 1980s. In shadow printing lithography a geometric pattern is transferred by free-space propagation from a photomask to a photosensitive layer on a wafer. The inherent simplicity of the pattern transfer offers ease of operation, low maintenance, moderate capital expenditure, high wafers-per-hour (WPH) throughput, and attractive cost-of-ownership (COO). Advanced mask aligner lithography (AMALITH) comprises different measures to improve shadow printing lithography beyond current limits. The key enabling technology for AMALITH is a novel light integrator systems, referred to as MO Exposure Optics® (MOEO). MOEO allows to fully control and shape the properties of the illumination light in a mask aligner. Full control is the base for accurate simulation and optimization of the shadow printing process (computational lithography). Now photolithography enhancement techniques like customized illumination, optical proximity correction (OPC), phase masks (AAPSM), half-tone lithography and Talbot lithography could be used in mask aligner lithography. We summarize the recent progress in advanced mask aligner lithography (AMALITH) and discuss possible measures to further improve shadow printing lithography.

  8. Ion beam lithography system

    DOEpatents

    Leung, Ka-Ngo

    2005-08-02

    A maskless plasma-formed ion beam lithography tool provides for patterning of sub-50 nm features on large area flat or curved substrate surfaces. The system is very compact and does not require an accelerator column and electrostatic beam scanning components. The patterns are formed by switching beamlets on or off from a two electrode blanking system with the substrate being scanned mechanically in one dimension. This arrangement can provide a maskless nano-beam lithography tool for economic and high throughput processing.

  9. Mask defect printing mechanisms for future lithography generations

    NASA Astrophysics Data System (ADS)

    Erdmann, Andreas; Graf, Thomas; Bubke, Karsten; Höllein, Ingo; Teuber, Silvio

    2006-03-01

    Mask defects are of increasing concern for future lithography generations. The improved resolution capabilities of immersion and EUV systems increase also the sensitivity of these systems with respect to small imperfections of the mask. Advanced mask technologies such as alternating phase shift masks (AltPSM), chromeless phase shift lithography (CPL), or "thick" absorbers on EUV masks introduce new defect types. The paper presents an application of rigorous electromagnetic field modeling for the study of typical defect printing mechanisms in ArF immersion lithography and in EUV lithography. For standard imaging and mask technologies, such as binary masks or attenuated phase shift masks, small defects usually print as linewidth or critical dimension (CD) errors with the largest effect at best focus. For AltPSM, CPL masks, and EUV masks this is not always the case. Several unusual printing scenarios were observed: placement errors due to defects can become more critical than CD-errors, defects may print more critical at defocus positions different from the center of the process window, the defect printing may become asymmetric through focus, and the risk of defect printing depends on the polarization of the used light source. Several simulation examples will demonstrate these effects. Rigorous EMF simulations in combination with vector imaging simulations are very useful to understand the origins of the observed defect printing mechanisms.

  10. Analysis of laser durability of CaF2 for optical lithography

    NASA Astrophysics Data System (ADS)

    Grabosch, Guenter; Parthier, Lutz; Natura, Ute; Poehl, Karin; Letz, Martin; Muehlig, Christian; Knapp, Konrad

    2005-02-01

    Photolithography is a key technolgoy for the production of semiconductor devices. It supports the continuing trend towards higher integration density of microelectronic devices. The material used in the optics of lithography tools has to be of extremely high quality to ensure the high demand of the imaging. Due to its properties CaF2 is a material of choice for the application in lithography systems. Because of the compexity of the lithography tools single lenses or lens system modules cannot be replaced. Therefore the lens material has to last the full lifetime of the tool without major degradation. According to the roadmap for next generation of optical lithography tools, like immersion lithography, the requirements of CaF2 for radiation hardness are increasing considerably. We will present a detailed analysis of the key factors influencing the laser hardness covering the complete production chain. Some aspects of the evaluation methods for testing CaF2 laser durability will be presented.

  11. Thirty years of lithography simulation

    NASA Astrophysics Data System (ADS)

    Mack, Chris A.

    2005-05-01

    Thirty years ago Rick Dill and his team at IBM published the first account of lithography simulation - the accurate description of semiconductor optical lithography by mathematical equations. Since then, lithography simulation has grown dramatically in importance in four important areas: as a research tool, as a development tool, as a manufacturing tool, and as a learning tool. In this paper, the history of lithography simulations is traced from its roots to today"s indispensable tools for lithographic technology development. Along the way, an attempt will be made to define the true value of lithography simulation to the semiconductor industry.

  12. Beam pen lithography

    NASA Astrophysics Data System (ADS)

    Huo, Fengwei; Zheng, Gengfeng; Liao, Xing; Giam, Louise R.; Chai, Jinan; Chen, Xiaodong; Shim, Wooyoung; Mirkin, Chad A.

    2010-09-01

    Lithography techniques are currently being developed to fabricate nanoscale components for integrated circuits, medical diagnostics and optoelectronics. In conventional far-field optical lithography, lateral feature resolution is diffraction-limited. Approaches that overcome the diffraction limit have been developed, but these are difficult to implement or they preclude arbitrary pattern formation. Techniques based on near-field scanning optical microscopy can overcome the diffraction limit, but they suffer from inherently low throughput and restricted scan areas. Highly parallel two-dimensional, silicon-based, near-field scanning optical microscopy aperture arrays have been fabricated, but aligning a non-deformable aperture array to a large-area substrate with near-field proximity remains challenging. However, recent advances in lithographies based on scanning probe microscopy have made use of transparent two-dimensional arrays of pyramid-shaped elastomeric tips (or `pens') for large-area, high-throughput patterning of ink molecules. Here, we report a massively parallel scanning probe microscopy-based approach that can generate arbitrary patterns by passing 400-nm light through nanoscopic apertures at each tip in the array. The technique, termed beam pen lithography, can toggle between near- and far-field distances, allowing both sub-diffraction limit (100 nm) and larger features to be generated.

  13. Native Language Immersion.

    ERIC Educational Resources Information Center

    Reyhner, Jon

    This paper describes the benefits of indigenous mother tongue immersion programs, examining the Total Physical Response approach to immersion for beginning learners and focusing on the development of Maori and Hawaiian mother tongue language immersion programs. The paper discusses the importance of immersing students in a language-risk…

  14. Characteristics of low E a 193-nm chemical amplification resists

    NASA Astrophysics Data System (ADS)

    Ogata, Toshiyuki; Kinoshita, Yohei; Furuya, Sanae; Matsumaru, Shogo; Takahashi, Motoki; Shiono, Daiju; Dazai, Takahiro; Hada, Hideo; Shirai, Masamitsu

    2006-03-01

    Polymers with methyl acetal ester moiety in the side chain as acid labile protecting group were synthesized and their thermal property, plasma stability and chemical amplification (CA) positive-tone resist characteristics were investigated. 2-Admantyloxymethyl (AdOM) groups in the copolymer indicated lower glass transition temperatures and higher thermal decomposition temperatures than those of 2-methyl-2-admantyl (MAd) groups in the copolymer. AdOM polymer film showed smooth surface roughness after Ar plasma exposure compared with MAd polymer film due to the high thermal stability. The activation energies (E a) of these deprotection reactions were calculated from Arrhenius plots of these deprotection reaction rate constants. In the low post exposure bake (PEB) temperature region, the E a of these resists decreased in the order MAd > AdOM. The low E a methyl acetal resists displayed good thermal flow resist characteristics for contact holes printing. In addition, the low E a methyl acetal resist achieved a wide exposure latitude of 8.1 % and depth of focus of 400 nm for printing 80 nm 1:1 dense line pattern using NSR-306C (NA 0.78, 2/3 annular). Furthermore, the 65 nm 1:1 dense lines using ASML XT1400 (NA 0.93, C-Quad) for low E a methyl acetal resist pattern showed no tapered and no footing profiles and small roughness on the lines pattern sidewall was observed.

  15. Mechanism of single-layer 193-nm dissolution inhibition resist

    NASA Astrophysics Data System (ADS)

    Yan, Zhenglin; Houlihan, Francis M.; Reichmanis, Elsa; Nalamasu, Omkaram; Reiser, Arnost; Dabbagh, Gary; Hutton, Richard S.; Osei, Dan; Sousa, Jose; Bolan, Kevin J.

    2000-06-01

    We have found that the progress of developer base into films of terpolymers of norbornene (NB)-maleic anhydride (MA) and acrylic acid (AA) is a percolation process with a critical site concentration of x(c) equals 0.084 which suggests that every acrylic acid site in the terpolymer of norbornene-maleic anhydride-acrylic acid can make 12 monomer units of the polymer water compatible. In practice these systems are being used with various tert-butyl esters of cholic acid as dissolution inhibitors. The cholates differ very much in their dissolution inhibition factors (lowest t-butyl cholate (1.3) to highest t-butyl lithocholate glutarate dimer (7.4). The change in these factors corrected for molarity follow the hydrophobic character of the dissolution as measured by log(p). A quick screening method has also been established to evaluate dissolution inhibitors based on our observation that the cloud point (the volume % acetone in a water/acetone which gives persistent cloudiness) parallels the dissolution inhibiting power as measured by the dissolution inhibition factor. For dissolution promotion, optimal results are obtained with t-butyl 1,3,5-cyclohexanetricarboxylate (f equals -6.3) and poorest results with t-butyl lithocholate (f equals -2.8); this appears to track with the number of carboxyl groups and the hydrophobicity of the carboxylic acids. The Rmax found for resist formulations tracks well with these findings. Another factor in determining the ultimate achievable contrast is the degree of acidolytic deprotection achieved by the material. It appears that acidolyticaly cleaveable carboxylate esters with a higher concentration of electron withdrawing groups such as t-butyl 1,3,5-cyclohexanetricarboxylate are more effective.

  16. Neutral particle lithography

    NASA Astrophysics Data System (ADS)

    Craver, Barry Paul

    Neutral particle lithography (NPL) is a high resolution, proximity exposure technique where a broad beam of energetic neutral particles floods a stencil mask and transmitted beamlets transfer the mask pattern to resist on a substrate, such that each feature is printed in parallel, rather than in the serial manner of electron beam lithography. It preserves the advantages of ion beam lithography (IBL), including extremely large depth-of-field, sub-5 nm resist scattering, and the near absence of diffraction, yet is intrinsically immune to charge-related artifacts including line-edge roughness and pattern placement errors due to charge accumulation on the mask and substrate. In our experiments, a neutral particle beam is formed by passing an ion beam (e.g., 30 keV He+) through a high pressure helium gas cell (e.g., 100 mTorr) to convert the ions to energetic neutrals through charge transfer scattering. The resolution of NPL is generally superior to that of IBL for applications involving insulating substrates, large proximity gaps, and ultra-small features. High accuracy stepped exposures with energetic neutral particles, where magnetic or electrostatic deflection is impossible, have been obtained by clamping the mask to the wafer, setting the proximity gap with a suitable spacer, and mechanically inclining the mask/wafer stack relative to the beam. This approach is remarkably insensitive to vibration and thermal drift; nanometer scale image offsets have been obtained with +/-2 nm placement accuracy for experiments lasting over one hour. Using this nanostepping technique, linewidth versus dose curves were obtained, from which the NPL lithographic blur was determined as 4.4+/-1.4 nm (1sigma), which is 2-3 times smaller than the blur of electron beam lithography. Neutral particle lithography has the potential to form high density, periodic patterns with sub-10 nm resolution.

  17. Colloidal pen lithography.

    PubMed

    Xue, Mianqi; Cai, Xiaojing; Chen, Ghenfu

    2015-02-01

    Colloidal pen lithography, a low-cost, high-throughput scanning probe contact printing method, has been developed, which is based on self-assembled colloidal arrays embedded in a soft elastomeric stamp. Patterned protein arrays are demonstrated using this method, with a feature size ranging from 100 nm to several micrometers. A brief study into the specificity reorganization of protein gives evidence for the feasibility of this method for writing protein chips. PMID:25288364

  18. Industrial strength lithography APC

    NASA Astrophysics Data System (ADS)

    Ausschnitt, Christopher P.; Barker, Brian; Muth, William A.; Postiglione, Marc; Walentosky, Thomas

    2003-06-01

    Fully automated semiconductor manufacturing, becoming a reality with the ramping of 300mm fabricators throughout the world, demands the integration of advanced process control (APC). APC is particularly critical for the lithography sector, whose performance correlates to yield and whose productivity often gates the line. We describe the implementation of a comprehensive lithography APC system at the IBM Center for Nanoelectronics, a 300mm manufacturing and development facility. The base lithography APC function encompasses closed-loop run-to-run control of exposure tool inputs to sustain the overlay and critical dimension outputs consistent with product specifications. Automation demands that no decision regarding the appropriate exposure tool run-time settings be left to human judgment. For each lot, the APC system provides optimum settings based on existing data derived from pertinent process streams. In the case where insufficient prior data exists, the APC system either invokes the appropriate combination of send ahead processing and/or pre-determined defaults. We give specific examples of the application of APC to stitched field and dose control, and quantify its technical benefits. Field matching < 0.1 ppm and critical dimension control < 2.5% is achieved among multiple exposure tools and masks.

  19. Microfluidic Applications of Soft Lithography

    SciTech Connect

    Rose, K A; Krulevitch, P; Hamilton, J

    2001-04-10

    The soft lithography fabrication technique was applied to three microfluidic devices. The method was used to create an original micropump design and retrofit to existing designs for a DNA manipulation device and a counter biological warfare sample preparation device. Each device presented unique and original challenges to the soft lithography application. AI1 design constraints of the retrofit devices were satisfied using PDMS devices created through variation of soft lithography methods. The micropump utilized the versatility of PDMS, creating design options not available with other materials. In all cases, the rapid processing of soft lithography reduced the fabrication time, creating faster turnaround for design modifications.

  20. Evidence of CH{sub 2}O (a-tilde{sup 3}A{sub 2}) and C{sub 2}H{sub 4} (a-tilde{sup 3}B{sub 1u}) produced from photodissociation of 1,3-trimethylene oxide at 193 nm

    SciTech Connect

    Lee, S.-H.; Ong, C.-S.; Lee, Yuan T.

    2006-02-21

    We investigated the dissociative ionization of formaldehyde (CH{sub 2}O) and ethene (C{sub 2}H{sub 4}) produced from photolysis of 1,3-trimethylene oxide at 193 nm using a molecular-beam apparatus and vacuum-ultraviolet radiation from an undulator for direct ionization. The CH{sub 2}O (C{sub 2}H{sub 4}) product suffers from severe dissociative ionization to HCO{sup +} (C{sub 2}H{sub 3}{sup +} and C{sub 2}H{sub 2}{sup +}) even though photoionization energy is as small as 9.8 eV. Branching ratios of fragmentation of CH{sub 2}O and C{sub 2}H{sub 4} following ionization are revealed as a function of kinetic energy of products using ionizing photons from 9.8 to 14.8 eV. Except several exceptions, branching ratios of daughter ions increase with increasing photon energy but decrease with increasing kinetic energy. The title reaction produces CH{sub 2}O and C{sub 2}H{sub 4} mostly on electronic ground states but a few likely on triplet states; C{sub 2}H{sub 4} (a-tilde{sup 3}B{sub 1u}) seems to have a yield greater than CH{sub 2}O (a-tilde{sup 3}A{sub 2}). The distinct features observed at small kinetic energies of daughter ions are attributed to dissociative ionization of photoproducts CH{sub 2}O (a-tilde{sup 3}A{sub 2}) and C{sub 2}H{sub 4} (a-tilde{sup 3}B{sub 1u}). The observation of triplet products indicates that intersystem crossing occurs prior to fragmentation of 1,3-trimethylene oxide.

  1. Optical simulations for fractional fluorine terminated coatings on nanoimprint lithography masks

    NASA Astrophysics Data System (ADS)

    Seidel, Thomas E.; Goldberg, Alexander; Halls, Mathew D.

    2015-10-01

    Simulations of the optical intensity within Nano Imprint Lithography (NIL) mask features have been made for patterned quartz masks having ultrathin film coatings with different indices of refraction. Fractionally fluorine terminated surfaces, previously proposed for improving the yield of NIL processes, are briefly reviewed. Optical intensity solutions within the feature were obtained using Panoramictech Maxwell solver software for variances in the optical constants of the coating films, aspect ratio, feature size, and wavelength.. The coated masks have conformal surface, higher index of refraction under-layer coating and a fractional terminated fluorine hydrocarbon (FHC) monomolecular layer. The values of optical constants for the FHC layers are unknown, so a range of ad-hoc values were simulated. Optical constants for quartz mask and Al2O3, TiO2 and Si under-layer films are taken from the literature. Wavelengths were varied from 193nm to 365nm. The question of photo-dissociation of the FHC layer for higher energy photons is addressed from first principles, with the result that the F-terminated layers are stable at higher wavelengths. Preliminary simulations for features filled with resist over various substrates are dependent on the antireflection character of the underlying film system. The optical intensity is generally increased within the simulated mask feature when coated with a higher index/FHC films relative to the uncoated reference quartz mask for ~5nm physical feature sizes.

  2. Arrays of metallic micro-/nano-structures by means of colloidal lithography and laser dewetting

    NASA Astrophysics Data System (ADS)

    Constantinescu, C.; Deepak, K. L. N.; Delaporte, P.; Utéza, O.; Grojo, D.

    2016-06-01

    Long-range arrays of prismatoid metal nanostructures are fabricated by a hybrid methodology, i.e. using Langmuir microsphere films and laser-assisted dewetting. As the initial step, we use colloidal lithography. Monolayers of 1-5 μm polystyrene microspheres covered with a thermally evaporated Ag or Au thin film of controlled thickness (5-50 nm) are then used as masks to pattern the surface of quartz, BK7 glass or silicon substrates, typically in the order of cm2. When removing the spheres by physico-chemical means (ultrasound bath and solvent wash), the resulting surface shows an array of nm-size prismatoid structures (Fischer patterns), that can be further processed by laser. Thus, by using two different lasers (355-nm wavelength, 50-ps duration and 193-nm wavelength, 15-ns duration) for the metal dewetting, we control the shape of the deposited nanostructures. A detailed study is presented here on the reshaping of such metal structures through laser annealing. This new hybrid methodology expands the panel of microsphere-assisted technologies employed in preparing surface nanomaterials.

  3. Bubble-Pen Lithography.

    PubMed

    Lin, Linhan; Peng, Xiaolei; Mao, Zhangming; Li, Wei; Yogeesh, Maruthi N; Rajeeva, Bharath Bangalore; Perillo, Evan P; Dunn, Andrew K; Akinwande, Deji; Zheng, Yuebing

    2016-01-13

    Current lithography techniques, which employ photon, electron, or ion beams to induce chemical or physical reactions for micro/nano-fabrication, have remained challenging in patterning chemically synthesized colloidal particles, which are emerging as building blocks for functional devices. Herein, we develop a new technique - bubble-pen lithography (BPL) - to pattern colloidal particles on substrates using optically controlled microbubbles. Briefly, a single laser beam generates a microbubble at the interface of colloidal suspension and a plasmonic substrate via plasmon-enhanced photothermal effects. The microbubble captures and immobilizes the colloidal particles on the substrate through coordinated actions of Marangoni convection, surface tension, gas pressure, and substrate adhesion. Through directing the laser beam to move the microbubble, we create arbitrary single-particle patterns and particle assemblies with different resolutions and architectures. Furthermore, we have applied BPL to pattern CdSe/ZnS quantum dots on plasmonic substrates and polystyrene (PS) microparticles on two-dimensional (2D) atomic-layer materials. With the low-power operation, arbitrary patterning and applicability to general colloidal particles, BPL will find a wide range of applications in microelectronics, nanophotonics, and nanomedicine. PMID:26678845

  4. Diamond nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Taniguchi, Jun; Tokano, Yuji; Miyamoto, Iwao; Komuro, Masanori; Hiroshima, Hiroshi

    2002-10-01

    Electron beam (EB) lithography using polymethylmethacrylate (PMMA) and oxygen gas reactive ion etching (RIE) were used to fabricate fine patterns in a diamond mould. To prevent charge-up during EB lithography, thin conductive polymer was spin-coated over the PMMA resist, yielding dented line patterns 2 μ m wide and 270 nm deep. The diamond mould was pressed into PMMA on a silicon substrate heated to 130, 150 and 170ºC at 43.6, 65.4 and 87.2 MPa. All transferred PMMA convex line patterns were 2 μ m wide. Imprinted pattern depth increased with rising temperature and pressure. PMMA patterns on diamond were transferred by the diamond mould at 150ºC and 65.4 MPa, yielding convex line patterns 2 μ m wide and 200 nm high. Direct aluminium and copper patterns were obtained using the diamond mould at room temperature and 130.8 MPa. The diamond mould is thus useful for replicating patterns on PMMA and metals.

  5. RET masks for the final frontier of optical lithography

    NASA Astrophysics Data System (ADS)

    Chen, J. F.; van den Broeke, Douglas; Hsu, Stephen; Hsu, Michael C. W.; Laidig, Tom; Shi, Xuelong; Chen, Ting; Socha, Robert J.; Hollerbach, Uwe; Wampler, Kurt E.; Park, Jungchul; Park, Sangbong; Gronlund, Keith

    2005-06-01

    With immersion and hyper numerical aperture (NA>1) optics apply to the ITRS 2003/4 roadmap scenario (Figure 1); it is very clear that the IC manufacturing has already stepped into the final frontier of optical lithography. Today"s advanced lithography for DRAM/Flash is operating at k1 close to 0.3. The manufacturing for leading edge logic devices does not follow too far behind. Patterning at near theoretical lithography imaging limit (k1=0.25) even with hyper NA optics, the attainable aerial image contrast is marginal at best for the critical feature. Thus, one of the key objectives for low k1 lithography is to ensure the printing performance of critical features for manufacturing. Resolution enhancement technology (RET) mask in combination with hyper NA and illumination optimization is one primary candidate to enable lithography manufacturing at very low k1 factor. The use of rule-based Scattering Bars (SB) for all types of phase-shifting masks has become the de facto OPC standard since 180nm node. Model-based SB OPC method derives from interference mapping lithography (IML) has shown impressive printing result for both clear (gate) and dark field (contact and via) mask types. There are four basic types of RET mask candidates for 65nm node, namely, alternating phase-shifting mask (altPSM), attenuated PSM (attPSM), chromeless phase lithography (CPL) PSM, and double dipole lithography (DDL) using binary chrome mask. The wafer printing performances from CPL and DDL have proven both are strong candidates for 45nm nodes. One concern for using RET masks to target 45 nm nodes is likely to be the scaling for SB dimension for 4X mask. To assist imaging effectively with high NA, SB cannot be too small in width. However, for SB to be larger than sub-resolution, they can easily cause unwanted SB printing. The other major concern is the unwanted side lobe printing. This may occur for semi-dense pitch ranges under high NA and strong off-axis-illumination (OAI). Looking ahead

  6. Diaphragmatic function during immersion.

    PubMed

    Minh, V D; Dolan, G F; Linaweaver, P G; Friedman, P J; Konopka, R G; Brach, B B

    1977-08-01

    Diaphragmatic function during immersion to midneck level was studied in upright mongrel dogs, using constant electrophrenic stimulation. Effectiveness of diaphragmatic contraction was analyzed in terms of inspired volume (VT) (with airways open), and change in intrathoracic pressure (Pmus) (with the respiratory system occluded). Hydrostatic compression of the immersed body decreased functional residual capacity (FRC) to 55% base-line value (FRCO), resulting in a 2.8-fold increase in Pmus. In spite of this Pmus increase, VT often decreased during immersion, averaging only 83% VTO (base-line value in air). Hence, immersion was associated with a marked stiffening of the respiratory system. The Pmus increase during immersion persisted after restoration of FRC to FRCO, and was related to diaphragmatic length being greater in water than in air under condition of iso-lung volume. In all, there were three factors affecting diaphragmatic function during immersion: FRC reduction, change in thoracic configuration, and stiffening of the respiratory system. PMID:893286

  7. Cryogenic immersion microscope

    DOEpatents

    Le Gros, Mark; Larabell, Carolyn A.

    2010-12-14

    A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

  8. Neon Ion Beam Lithography (NIBL).

    PubMed

    Winston, Donald; Manfrinato, Vitor R; Nicaise, Samuel M; Cheong, Lin Lee; Duan, Huigao; Ferranti, David; Marshman, Jeff; McVey, Shawn; Stern, Lewis; Notte, John; Berggren, Karl K

    2011-10-12

    Existing techniques for electron- and ion-beam lithography, routinely employed for nanoscale device fabrication and mask/mold prototyping, do not simultaneously achieve efficient (low fluence) exposure and high resolution. We report lithography using neon ions with fluence <1 ion/nm(2), ∼1000× more efficient than using 30 keV electrons, and resolution down to 7 nm half-pitch. This combination of resolution and exposure efficiency is expected to impact a wide array of fields that are dependent on beam-based lithography. PMID:21899279

  9. Advances in Nanoimprint Lithography.

    PubMed

    Traub, Matthew C; Longsine, Whitney; Truskett, Van N

    2016-06-01

    Nanoimprint lithography (NIL), a molding process, can replicate features <10 nm over large areas with long-range order. We describe the early development and fundamental principles underlying the two most commonly used types of NIL, thermal and UV, and contrast them with conventional photolithography methods used in the semiconductor industry. We then describe current advances toward full commercial industrialization of UV-curable NIL (UV-NIL) technology for integrated circuit production. We conclude with brief overviews of some emerging areas of research, from photonics to biotechnology, in which the ability of NIL to fabricate structures of arbitrary geometry is providing new paths for development. As with previous innovations, the increasing availability of tools and techniques from the semiconductor industry is poised to provide a path to bring these innovations from the lab to everyday life. PMID:27070763

  10. Programmable imprint lithography template

    DOEpatents

    Cardinale, Gregory F.; Talin, Albert A.

    2006-10-31

    A template for imprint lithography (IL) that reduces significantly template production costs by allowing the same template to be re-used for several technology generations. The template is composed of an array of spaced-apart moveable and individually addressable rods or plungers. Thus, the template can be configured to provide a desired pattern by programming the array of plungers such that certain of the plungers are in an "up" or actuated configuration. This arrangement of "up" and "down" plungers forms a pattern composed of protruding and recessed features which can then be impressed onto a polymer film coated substrate by applying a pressure to the template impressing the programmed configuration into the polymer film. The pattern impressed into the polymer film will be reproduced on the substrate by subsequent processing.

  11. LENS (lithography enhancement toward nano scale): a European project to support double exposure and double patterning technology development

    NASA Astrophysics Data System (ADS)

    Cantu, Pietro; Baldi, Livio; Piacentini, Paolo; Sytsma, Joost; Le Gratiet, Bertrand; Gaugiran, Stéphanie; Wong, Patrick; Miyashita, Hiroyuki; Atzei, Luisa R.; Buch, Xavier; Verkleij, Dick; Toublan, Olivier; Perez-Murano, Francesco; Mecerreyes, David

    2010-04-01

    In 2009 a new European initiative on Double Patterning and Double Exposure lithography process development was started in the framework of the ENIAC Joint Undertaking. The project, named LENS (Lithography Enhancement Towards Nano Scale), involves twelve companies from five different European Countries (Italy, Netherlands, France, Belgium Spain; includes: IC makers (Numonyx and STMicroelectronics), a group of equipment and materials companies (ASML, Lam Research srl, JSR, FEI), a mask maker (Dai Nippon Photomask Europe), an EDA company (Mentor Graphics) and four research and development institutes (CEA-Leti, IMEC, Centro Nacional de Microelectrónica, CIDETEC). The LENS project aims to develop and integrate the overall infrastructure required to reach patterning resolutions required by 32nm and 22nm technology nodes through the double patterning and pitch doubling technologies on existing conventional immersion exposure tools, with the purpose to allow the timely development of 32nm and 22nm technology nodes for memories and logic devices, providing a safe alternative to EUV, Higher Refraction Index Fluids Immersion Lithography and maskless lithography, which appear to be still far from maturity. The project will cover the whole lithography supply chain including design, masks, materials, exposure tools, process integration, metrology and its final objective is the demonstration of 22nm node patterning on available 1.35 NA immersion tools on high complexity mask set.

  12. Extreme ultraviolet lithography machine

    DOEpatents

    Tichenor, Daniel A.; Kubiak, Glenn D.; Haney, Steven J.; Sweeney, Donald W.

    2000-01-01

    An extreme ultraviolet lithography (EUVL) machine or system for producing integrated circuit (IC) components, such as transistors, formed on a substrate. The EUVL machine utilizes a laser plasma point source directed via an optical arrangement onto a mask or reticle which is reflected by a multiple mirror system onto the substrate or target. The EUVL machine operates in the 10-14 nm wavelength soft x-ray photon. Basically the EUV machine includes an evacuated source chamber, an evacuated main or project chamber interconnected by a transport tube arrangement, wherein a laser beam is directed into a plasma generator which produces an illumination beam which is directed by optics from the source chamber through the connecting tube, into the projection chamber, and onto the reticle or mask, from which a patterned beam is reflected by optics in a projection optics (PO) box mounted in the main or projection chamber onto the substrate. In one embodiment of a EUVL machine, nine optical components are utilized, with four of the optical components located in the PO box. The main or projection chamber includes vibration isolators for the PO box and a vibration isolator mounting for the substrate, with the main or projection chamber being mounted on a support structure and being isolated.

  13. Nanowire lithography on silicon.

    PubMed

    Colli, Alan; Fasoli, Andrea; Pisana, Simone; Fu, Yongqing; Beecher, Paul; Milne, William I; Ferrari, Andrea C

    2008-05-01

    Nanowire lithography (NWL) uses nanowires (NWs), grown and assembled by chemical methods, as etch masks to transfer their one-dimensional morphology to an underlying substrate. Here, we show that SiO2 NWs are a simple and compatible system to implement NWL on crystalline silicon and fabricate a wide range of architectures and devices. Planar field-effect transistors made of a single SOI-NW channel exhibit a contact resistance below 20 kOmega and scale with the channel width. Further, we assess the electrical response of NW networks obtained using a mask of SiO2 NWs ink-jetted from solution. The resulting conformal network etched into the underlying wafer is monolithic, with single-crystalline bulk junctions; thus no difference in conductivity is seen between a direct NW bridge and a percolating network. We also extend the potential of NWL into the third dimension, by using a periodic undercutting that produces an array of vertically stacked NWs from a single NW mask. PMID:18386934

  14. Scanning probe nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Dinelli, F.; Menozzi, C.; Baschieri, P.; Facci, P.; Pingue, P.

    2010-02-01

    The present paper reports on a novel lithographic approach at the nanoscale level, which is based on scanning probe microscopy (SPM) and nanoimprint lithography (NIL). The experimental set-up consists of an atomic force microscope (AFM) operated via software specifically developed for the purpose. In particular, this software allows one to apply a predefined external load for a given lapse of time while monitoring in real-time the relative distance between the tip and the sample as well as the normal and lateral force during the embossing process. Additionally, we have employed AFM tips sculptured by means of focused ion beam in order to create indenting tools of the desired shape. Anti-sticking layers can also be used to functionalize the tips if one needs to investigate the effects of different treatments on the indentation and de-molding processes. The lithographic capabilities of this set-up are demonstrated on a polystyrene NIL-patterned sample, where imprinted features have been obtained upon using different normal load values for increasing time intervals, and on a thermoplastic polymer film, where the imprint process has been monitored in real-time.

  15. Holographic lithography for biomedical applications

    NASA Astrophysics Data System (ADS)

    Stankevicius, E.; Balciunas, E.; Malinauskas, M.; Raciukaitis, G.; Baltriukiene, D.; Bukelskiene, V.

    2012-06-01

    Fabrication of scaffolds for cell growth with appropriate mechanical characteristics is top-most important for successful creation of tissue. Due to ability of fast fabrication of periodic structures with a different period, the holographic lithography technique is a suitable tool for scaffolds fabrication. The scaffolds fabricated by holographic lithography can be used in various biomedical investigations such as the cellular adhesion, proliferation and viability. These investigations allow selection of the suitable material and geometry of scaffolds which can be used in creation of tissue. Scaffolds fabricated from di-acrylated poly(ethylene glycol) (PEG-DA-258) over a large area by holographic lithography technique are presented in this paper. The PEG-DA scaffolds fabricated by holographic lithography showed good cytocompatibility for rabbit myogenic stem cells. It was observed that adult rabbit muscle-derived myogenic stem cells grew onto PEG-DA scaffolds. They were attached to the pillars and formed cell-cell interactions. It demonstrates that the fabricated structures have potential to be an interconnection channel network for cell-to-cell interactions, flow transport of nutrients and metabolic waste as well as vascular capillary ingrowth. These results are encouraging for further development of holographic lithography by improving its efficiency for microstructuring three-dimensional scaffolds out of biodegradable hydrogels

  16. Photoinhibition superresolution lithography

    NASA Astrophysics Data System (ADS)

    Forman, Darren Lawrence

    While the prospect of nanoscale manufacturing has generated tremendous excitement, arbitrary patterning at nanometer length scales cannot be brought about with current photolithography---the technology that for decades has driven electronics miniaturization and enabled mass production of digital logic, memory, MEMS and flat-panel displays. This is due to the relatively long wavelength of light and diffraction, which imposes a physical not technological limit on the resolution of a far-field optical pattern. Photoinhibited superresolution (PInSR) lithography is a new scheme designed to beat the diffraction limit through two-color confinement of photopolymerization and, via efficient single-photon absorption kinetics, also be high-throughput capable. This thesis describes development of an integrated optical and materials system for investigating spatiotemporal dynamics of photoinhibited superresolution lithography, with a demonstrated 3x superresolution beyond the diffraction limit. The two-color response, arising from orthogonal photogeneration of species that participate in competing reactions, is shown to be highly complex. This is both a direct and indirect consequence of mobility. Interesting trade-offs arise: thin-film resins (necessitated by single-photon absorption kinetics) require high viscosity for film stability, but the photoinhibition effect is suppressed in viscous resins. Despite this apparent suppression, which can be overcome with high excitation of the photoinhibition system, the low mobility afforded by viscous materials is beneficial for confinement of active species. Diffusion-induced blurring of patterned photoinhibition is problematic in a resin with viscosity = 1,000 cP, and overcome in a resin with viscosity eta = 500,000 cP. Superresolution of factor 3x beyond the diffraction limit is demonstrated at 0.2 NA, with additional results indicating superresolution ability at 1.2 NA. Investigating the effect of diminished photoinhibition efficacy

  17. French Immersion Weekends.

    ERIC Educational Resources Information Center

    Mydlarski, Donna; Klinck, Pat

    1983-01-01

    Describes immersion weekends sponsored by the University of Calgary. The discussion includes examples from actual weekends to describe the planning and implementation. A qualitative evaluation is also discussed. (Author/AMH)

  18. Physical Limitations in Lithography for Microelectronics.

    ERIC Educational Resources Information Center

    Flavin, P. G.

    1981-01-01

    Describes techniques being used in the production of microelectronics kits which have replaced traditional optical lithography, including contact and optical projection printing, and X-ray and electron beam lithography. Also includes limitations of each technique described. (SK)

  19. Porphyrin-Based Photocatalytic Lithography

    SciTech Connect

    Bearinger, J; Stone, G; Christian, A; Dugan, L; Hiddessen, A; Wu, K J; Wu, L; Hamilton, J; Stockton, C; Hubbell, J

    2007-10-15

    Photocatalytic lithography is an emerging technique that couples light with coated mask materials in order to pattern surface chemistry. We excite porphyrins to create radical species that photocatalytically oxidize, and thereby pattern, chemistries in the local vicinity. The technique advantageously does not necessitate mass transport or specified substrates, it is fast and robust and the wavelength of light does not limit the resolution of patterned features. We have patterned proteins and cells in order to demonstrate the utility of photocatalytic lithography in life science applications.

  20. Polymer nanofibers by soft lithography

    NASA Astrophysics Data System (ADS)

    Pisignano, Dario; Maruccio, Giuseppe; Mele, Elisa; Persano, Luana; Di Benedetto, Francesca; Cingolani, Roberto

    2005-09-01

    The fabrication of polymeric fibers by soft lithography is demonstrated. Polyurethane, patterned by capillarity-induced molding with high-resolution elastomeric templates, forms mm-long fibers with a diameter below 0.3μm. The Young's modulus of the fabricated structures, evaluated by force-distance scanning probe spectroscopy, has a value of 0.8MPa. This is an excellent example of nanostructures feasible by the combination of soft nanopatterning and high-resolution fabrication approaches for master templates, and particularly electron-beam lithography.

  1. CD and defect improvement challenges for immersion processes

    NASA Astrophysics Data System (ADS)

    Ehara, Keisuke; Ema, Tatsuhiko; Yamasaki, Toshinari; Nakagawa, Seiji; Ishitani, Seiji; Morita, Akihiko; Kim, Jeonghun; Kanaoka, Masashi; Yasuda, Shuichi; Asai, Masaya

    2009-03-01

    The intention of this study is to develop an immersion lithography process using advanced track solutions to achieve world class critical dimension (CD) and defectivity performance in a state of the art manufacturing facility. This study looks at three important topics for immersion lithography: defectivity, CD control, and wafer backside contamination. The topic of defectivity is addressed through optimization of coat, develop, and rinse processes as well as implementation of soak steps and bevel cleaning as part of a comprehensive defect solution. Develop and rinse processing techniques are especially important in the effort to achieve a zero defect solution. Improved CD control is achieved using a biased hot plate (BHP) equipped with an electrostatic chuck. This electrostatic chuck BHP (eBHP) is not only able to operate at a very uniform temperature, but it also allows the user to bias the post exposure bake (PEB) temperature profile to compensate for systematic within-wafer (WiW) CD non-uniformities. Optimized CD results, pre and post etch, are presented for production wafers. Wafer backside particles can cause focus spots on an individual wafer or migrate to the exposure tool's wafer stage and cause problems for a multitude of wafers. A basic evaluation of the cleaning efficiency of a backside scrubber unit located on the track was performed as a precursor to a future study examining the impact of wafer backside condition on scanner focus errors as well as defectivity in an immersion scanner.

  2. Optical characterization of subwavelength-scale solid immersion lenses

    NASA Astrophysics Data System (ADS)

    Kim, Myun-Sik; Scharf, Toralf; Haq, Mohammad Tahdiul; Nakagawa, Wataru; Herzig, Hans Peter

    2012-03-01

    We present the fabrication and optical characterization of nano-scale solid immersion lenses (nano-SILs) with sizes down to a subwavelength range. Submicron-scale cylinders fabricated by electron-beam lithography (EBL) are thermally reflowed to form a spherical shape. Subsequent soft lithography leads to nano-SILs on transparent substrates, i.e. glass, for optical characterization with visible light. The optical characterization is performed using a high-resolution interference microscope (HRIM) with illumination at 642 nm wavelength. The measurements of the 3D amplitude and phase fields provide information on the spot size and the peak intensity. In particular, the phase measurement is a more convincing proof of the Airy disc size reduction rather than the full-width at half maximum (FWHM) spot size. The focal spots produced by the nano-SILs show both spot-size reduction and enhanced optical intensity, which are consistent with the immersion effect. In this way, we experimentally confirm the immersion effect of a subwavelength-size SIL (d = 530 nm and h = 45 nm) with a spot reduction ratio of 1.35, which is less than the expected value of 1.5, most likely due to the slightly non-ideal shape of the nano-SIL.

  3. Microfabrication using soft lithography

    NASA Astrophysics Data System (ADS)

    Zhao, Xiao-Mei

    Soft Lithography is a group of non-photolithographic techniques currently being explored in our group. Four such techniques-microcontact printing (μCP), replica molding (REM), micromolding in capillaries (MIMIC), and microtransfer molding (μTM)-have been demonstrated for fabricating micro- and nanostructures of a variety of materials with dimension >=30 nm. Part I (Chapters 1-5) reviews several aspects of the three molding techniques REM, MIMIC, and μTM. Chapters 1-3 describe μTM and MIMIC, and the use of these techniques in the fabrication of functional devices. μTM is capable of generating μm-scale structures over large areas, on both planar and contoured surfaces, and is able to make 3-dimensional structures layer by layer. The capability of μTM and MIMIC has been demonstrated in the fabrication of single-mode waveguides, waveguide couplers and interferometers. The coupling between waveguides can be tailored by waveguide spacing or the differential in curing time between the waveguides and the cladding. Chapters 4-5 demonstrate the combination of REM and shrinkable polystyrene (PS) films to reduce the feature size of microstructures and to generate microstructures with high aspect ratios on both planar and curved surfaces. A shrinkable PS film is patterned with relief structures, and then heated and shrinks. Thermal shrinkage results in a 100-fold increase in the aspect ratio of the patterned microstructures in the PS film. The microstructures in the shrunken PS films can be transferred to many other materials by REM. Part II (Chapters 6-7) focuses on two issues in the microfabrication using self-assembled monolayers (SAMs) as ultrathin resists. Chapter 6 describes a selective etching solution for transferring patterns of SAMs of alkanethiolates into the underlying layers (e.g., gold, silver, and copper). This etching solution uses thiosulfate as the ligand that coordinates to the metal ions, and ferricyanide as the oxidant. It has been demonstrated to be

  4. From 120 to 32 nm CMOS technology: development of OPC and RET to rescue optical lithography

    NASA Astrophysics Data System (ADS)

    Trouiller, Yorick

    2006-10-01

    Starting from the 120 nm CMOS technology node down to the 32 nm node, we have entered into a new lithographic regime. The wavelength has not changed (only 193 nm), and we move closer and closer to the theoretical optical resolution limit. Therefore, Resolution Enhancement Techniques (RET) have been developed in order to print all shapes properly and close the resolution gap. The primary RET developed are off-axis illumination, sub-resolution assist features and a phase shift mask. Moreover, working closer to the resolution limit implies bigger image distortion between the mask and the silicon. For this purpose OPC (Optical Proximity Correction) has been widely used by making mask pre-compensation of all non linear effects, optical diffraction and interference effects, resist and etch. RET and OPC are also fundamentally linked. RET such as off-axis illumination generates more distortion, and therefore justifies the need of more aggressive OPC, and RET techniques like Alt PSM and sub-resolution assist features are generated through the OPC infrastructure. From its first industrial utilization for 120 nm node to 32 nm prospectively, many evolutions have been seen for OPC. These include the generalisation to all lithographic layers, moving to pixel based simulation, usage of full chip simulation and verification, the incorporation of process window effects like Energy Latitude or Depth of Focus into the OPC algorithm, and inverse lithography approach. For RET, we have seen huge differentiation depending on the type of application, such as logic or memory. In conclusion, we need to consider design as a third party that is playing a key role in this RET-OPC synergy. To use more aggressive RET and reduce the cycle time of OPC recipe development, more regular designs are considered as a key enabler for the future: they will allow logic makers to consider RET options that are pushed as far as those used by memory makers. To cite this article: Y. Trouiller, C. R. Physique 7

  5. Immersive cyberspace system

    NASA Technical Reports Server (NTRS)

    Park, Brian V. (Inventor)

    1997-01-01

    An immersive cyberspace system is presented which provides visual, audible, and vibrational inputs to a subject remaining in neutral immersion, and also provides for subject control input. The immersive cyberspace system includes a relaxation chair and a neutral immersion display hood. The relaxation chair supports a subject positioned thereupon, and places the subject in position which merges a neutral body position, the position a body naturally assumes in zero gravity, with a savasana yoga position. The display hood, which covers the subject's head, is configured to produce light images and sounds. An image projection subsystem provides either external or internal image projection. The display hood includes a projection screen moveably attached to an opaque shroud. A motion base supports the relaxation chair and produces vibrational inputs over a range of about 0-30 Hz. The motion base also produces limited translation and rotational movements of the relaxation chair. These limited translational and rotational movements, when properly coordinated with visual stimuli, constitute motion cues which create sensations of pitch, yaw, and roll movements. Vibration transducers produce vibrational inputs from about 20 Hz to about 150 Hz. An external computer, coupled to various components of the immersive cyberspace system, executes a software program and creates the cyberspace environment. One or more neutral hand posture controllers may be coupled to the external computer system and used to control various aspects of the cyberspace environment, or to enter data during the cyberspace experience.

  6. Maskless, reticle-free, lithography

    DOEpatents

    Ceglio, Natale M.; Markle, David A.

    1997-11-25

    A lithography system in which the mask or reticle, which usually carries the pattern to be printed onto a substrate, is replaced by a programmable array of binary (i.e. on/off) light valves or switches which can be programmed to replicate a portion of the pattern each time an illuminating light source is flashed. The pattern of light produced by the programmable array is imaged onto a lithographic substrate which is mounted on a scanning stage as is common in optical lithography. The stage motion and the pattern of light displayed by the programmable array are precisely synchronized with the flashing illumination system so that each flash accurately positions the image of the pattern on the substrate. This is achieved by advancing the pattern held in the programmable array by an amount which corresponds to the travel of the substrate stage each time the light source flashes. In this manner the image is built up of multiple flashes and an isolated defect in the array will only have a small effect on the printed pattern. The method includes projection lithographies using radiation other than optical or ultraviolet light. The programmable array of binary switches would be used to control extreme ultraviolet (EUV), x-ray, or electron, illumination systems, obviating the need for stable, defect free masks for projection EUV, x-ray, or electron, lithographies.

  7. ITRS lithography roadmap: 2015 challenges

    NASA Astrophysics Data System (ADS)

    Neisser, Mark; Wurm, Stefan

    2015-08-01

    In the past few years, novel methods of patterning have made considerable progress. In 2011, extreme ultraviolet (EUV) lithography was the front runner to succeed optical lithography. However, although EUV tools for pilot production capability have been installed, its high volume manufacturing (HVM) readiness continues to be gated by productivity and availability improvements taking longer than expected. In the same time frame, alternative and/or complementary technologies to EUV have made progress. Directed self-assembly (DSA) has demonstrated improved defectivity and progress in integration with design and pattern process flows. Nanoimprint improved performance considerably and is pilot production capable for memory products. Maskless lithography has made progress in tool development and could have an α tool ready in the late 2015 or early 2016. But they all have to compete with multiple patterning. Quadruple patterning is already demonstrated and can pattern lines and spaces down to close to 10-nm half pitch. The other techniques have to do something better than quadruple patterning does to be chosen for implementation. DSA and NIL promise a lower cost. EUV promises a simpler and shorter process and the creation of 2-D patterns more easily with much reduced complexity compared to multiple patterning. Maskless lithography promises to make chip personalization easy and to be particularly cost effective for low-volume chip designs. Decision dates for all of the technologies are this year or next year.

  8. Biomolecular Patterning via Photocatalytic Lithography

    SciTech Connect

    Bearinger, J P; Hiddessen, A L; Wu, K J; Christian, A T; Dugan, L C; Stone, G; Camarero, J; Hinz, A K; Hubbell, J A

    2005-02-18

    We have developed a novel method for patterning surface chemistry: Photocatalytic Lithography. This technique relies on inexpensive stamp materials and light; it does not necessitate mass transport or specified substrates, and the wavelength of light should not limit feature resolution. We have demonstrated the utility of this technique through the patterning of proteins, single cells and bacteria.

  9. Graphic Arts/Offset Lithography.

    ERIC Educational Resources Information Center

    Hoisington, James; Metcalf, Joseph

    This revised curriculum for graphic arts is designed to provide secondary and postsecondary students with entry-level skills and an understanding of current printing technology. It contains lesson plans based on entry-level competencies for offset lithography as identified by educators and industry representatives. The guide is divided into 15…

  10. Maskless, reticle-free, lithography

    DOEpatents

    Ceglio, N.M.; Markle, D.A.

    1997-11-25

    A lithography system in which the mask or reticle, which usually carries the pattern to be printed onto a substrate, is replaced by a programmable array of binary (i.e. on/off) light valves or switches which can be programmed to replicate a portion of the pattern each time an illuminating light source is flashed. The pattern of light produced by the programmable array is imaged onto a lithographic substrate which is mounted on a scanning stage as is common in optical lithography. The stage motion and the pattern of light displayed by the programmable array are precisely synchronized with the flashing illumination system so that each flash accurately positions the image of the pattern on the substrate. This is achieved by advancing the pattern held in the programmable array by an amount which corresponds to the travel of the substrate stage each time the light source flashes. In this manner the image is built up of multiple flashes and an isolated defect in the array will only have a small effect on the printed pattern. The method includes projection lithographies using radiation other than optical or ultraviolet light. The programmable array of binary switches would be used to control extreme ultraviolet (EUV), x-ray, or electron, illumination systems, obviating the need for stable, defect free masks for projection EUV, x-ray, or electron, lithographies. 7 figs.

  11. Gasoline immersion injury

    SciTech Connect

    Simpson, L.A.; Cruse, C.W.

    1981-01-01

    Chemical burns and pulmonary complications are the most common problems encountered in the patient immersed in gasoline. Our patient demonstrated a 46-percent total-body-surface area, partial-thickness chemical burn. Although he did not develop bronchitis or pneumonitis, he did display persistent atelectasis, laryngeal edema, and subsequent upper airway obstruction. This had not previously been reported in gasoline inhalation injuries. Hydrocarbon hepatitis secondary to the vascular endothelial damage is apparently a reversible lesion with no reported long-term sequelae. Gasoline immersion injuries may be a series multisystem injury and require the burn surgeon to take a multisystem approach to its diagnosis and treatment.

  12. Total Technology Immersion

    ERIC Educational Resources Information Center

    Vaughn, Sandy

    2010-01-01

    Total technology immersion doesn't happen overnight, but with vision and determination, transformation can take hold and start to grow. Floydada Independent School District (FISD), winner of the 2010 Sylvia Charp Award for District Innovation in Technology, is a great example of what a district can achieve when starting with a modest tech…

  13. Microfabricated rubber microscope using soft solid immersion lenses

    NASA Astrophysics Data System (ADS)

    Gambin, Yann; Legrand, Olivier; Quake, Stephen R.

    2006-04-01

    We show here a technique of soft lithography to microfabricate efficient solid immersion lenses (SIL) out of rubber elastomers. The light collection efficiency of a lens system is described by its numerical aperture (NA), and is critical for applications as epifluorescence microscopy [B. Herman, Fluorescence Microscopy (BIOS Scientific, Oxford/Springer, United Kingdom, 1998). While most simple lens systems have numerical apertures less than 1, the lenses described here have NA =1.25. Better performance can be engineered though the use of compound designs; we used this principle to make compound solid immersion lenses (NA=1.32). An important application of these lenses will be as integrated optics for microfluidic devices. We incorporated them into a handheld rubber microscope for microfluidic flow cytometry and imaged single E. Coli cells by fluorescence.

  14. Direct write electron beam lithography: a historical overview

    NASA Astrophysics Data System (ADS)

    Pfeiffer, Hans C.

    2010-09-01

    of opportunity for EPL had closed with the quick implementation of immersion lithography and the interest of the industry has since shifted back to maskless lithography (ML2). This historical overview of EBDW will highlight opportunities and limitation of the technology with particular focus on technical challenges facing the current ML2 development efforts in Europe and the US. A brief status report and risk assessment of the ML2 approaches will be provided.

  15. X-ray lithography source

    DOEpatents

    Piestrup, Melvin A.; Boyers, David G.; Pincus, Cary

    1991-01-01

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

  16. X-ray lithography source

    DOEpatents

    Piestrup, M.A.; Boyers, D.G.; Pincus, C.

    1991-12-31

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and eliminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an excellent moderate-priced X-ray source for lithography. 26 figures.

  17. Mask technology for EUV lithography

    NASA Astrophysics Data System (ADS)

    Bujak, M.; Burkhart, Scott C.; Cerjan, Charles J.; Kearney, Patrick A.; Moore, Craig E.; Prisbrey, Shon T.; Sweeney, Donald W.; Tong, William M.; Vernon, Stephen P.; Walton, Christopher C.; Warrick, Abbie L.; Weber, Frank J.; Wedowski, Marco; Wilhelmsen, Karl C.; Bokor, Jeffrey; Jeong, Sungho; Cardinale, Gregory F.; Ray-Chaudhuri, Avijit K.; Stivers, Alan R.; Tejnil, Edita; Yan, Pei-yang; Hector, Scott D.; Nguyen, Khanh B.

    1999-04-01

    Extreme UV Lithography (EUVL) is one of the leading candidates for the next generation lithography, which will decrease critical feature size to below 100 nm within 5 years. EUVL uses 10-14 nm light as envisioned by the EUV Limited Liability Company, a consortium formed by Intel and supported by Motorola and AMD to perform R and D work at three national laboratories. Much work has already taken place, with the first prototypical cameras operational at 13.4 nm using low energy laser plasma EUV light sources to investigate issues including the source, camera, electro- mechanical and system issues, photoresists, and of course the masks. EUV lithograph masks are fundamentally different than conventional photolithographic masks as they are reflective instead of transmissive. EUV light at 13.4 nm is rapidly absorbed by most materials, thus all light transmission within the EUVL system from source to silicon wafer, including EUV reflected from the mask, is performed by multilayer mirrors in vacuum.

  18. Nanoimprint lithography for microfluidics manufacturing

    NASA Astrophysics Data System (ADS)

    Kreindl, Gerald; Matthias, Thorsten

    2013-12-01

    The history of imprint technology as lithography method for pattern replication can be traced back to 1970's but the most significant progress has been made by the research group of S. Chou in the 1990's. Since then, it has become a popular technique with a rapidly growing interest from both research and industrial sides and a variety of new approaches have been proposed along the mainstream scientific advances. Nanoimprint lithography (NIL) is a novel method for the fabrication of micro/nanometer scale patterns with low cost, high throughput and high resolution. Unlike traditional optical lithographic approaches, which create pattern through the use of photons or electrons to modify the chemical and physical properties of the resist, NIL relies on direct mechanical deformation of the resist and can therefore achieve resolutions beyond the limitations set by light diffraction or beam scattering that are encountered in conventional lithographic techniques. The ability to fabricate structures from the micro- to the nanoscale with high precision in a wide variety of materials is of crucial importance to the advancement of micro- and nanotechnology and the biotech- sciences as a whole and will be discussed in this paper. Nanoimprinting can not only create resist patterns, as in lithography, but can also imprint functional device structures in various polymers, which can lead to a wide range of applications in electronics, photonics, data storage, and biotechnology.

  19. Progress toward developing high performance immersion compatible materials and processes

    NASA Astrophysics Data System (ADS)

    Petrillo, Karen; Patel, Kaushal; Chen, Rex; Li, Wenjie; Kwong, Ranee; Lawson, Peggy; Varanasi, Rao; Robinson, Chris; Holmes, Steven J.; Gil, Dario; Kimmel, Kurt; Slezak, Mark; Dabbagh, Gary; Chiba, Takashi; Shimokawa, Tsutomu

    2005-05-01

    To make immersion lithography a reality in manufacturing, several challenges related to materials and defects must be addressed. Two such challenges include the development of water immersion compatible materials, and the vigorous pursuit of defect reduction with respect to both the films and the processes. Suitable resists and topcoats must be developed to be compatible with the water-soaked environment during exposure. Going beyond the requisite studies of component leaching from films into the water, and absorption of water into the films, application-specific optimization of photoresists and top coats will be required. This would involve an understanding of how a wide array of resist chemistry and formulations behave under immersion conditions. The intent of this paper is to compare lithographic performance under immersion and dry conditions of resists containing different polymer platforms, protecting groups, and formulations. The compatibility of several developer-soluble top-coat materials with a variety of resists is also studied with emphasis on profile control issues. With respect to defects, the sources are numerous. Bubbles and particles created during the imaging process, material remnants from incomplete removal of topcoats, and image collapse as related to resist swelling from water infusion are all sources of yield-limiting defects. Parallel efforts are required in the material development cycle focusing both on meeting the lithographic requirements, and on understanding and eliminating sources of defects. In this paper, efforts in the characterization and reduction of defects as related to materials chemistry and processing effects will be presented.

  20. Methods to achieve sub-100-nm contact hole lithography

    NASA Astrophysics Data System (ADS)

    Lindsay, Tracy K.; Kavanagh, Robert J.; Pohlers, Gerd; Kanno, Takafumi; Bae, Young C.; Barclay, George G.; Kanagasabapathy, Subbareddy; Mattia, Joseph

    2003-06-01

    There are numerous methods being explored by lithographers to achieve contact holes below 100nm. Regarding optical impact on contact hole imaging, very high numerical aperture tools are becoming available at 193nm (as high as 0.9) and various optical extension techniques such as assist features, focus drilling, phase shift masks, and off-axis illumination are being employed to improve the aerial image. In this paper, the impact of the ArF photoresist is investigated. Polymers capable of thermal reflow of larger (~140nm) to smaller (90nm and below) contact holes are presented. Improved materials to achieve the properties necessary for good contact hole imaging for standard single layer resist (SLR) processing are also discussed. State-of-the-art ultra-thin resists (UTR) for contact holes and 193nm bi-layer resist systems are also studied as viable techniques to achieving very small contact holes.

  1. Tissue optical immersion clearing.

    PubMed

    Genina, Elina A; Bashkatov, Alexey N; Tuchin, Valery V

    2010-11-01

    In this article, we discuss the optical immersion method based on refractive index matching of scatterers (e.g., collagen, elastin fibers, cells and cell compartments) and the ground material (interstitial fluid and/or cytoplasm) of tissue and blood under the action of exogenous optical clearing agents. We analyze the optical clearing of fibrous and cell-structured tissues and blood from the point of view of receiving more valuable, normally hidden, information from spectroscopic and polarization measurements, confocal microscopy, optical coherence and optical projection tomography, as well as from nonlinear spectroscopies, such as two-photon fluorescence and second-harmonic generation techniques. Some important applications of the immersion technique to glucose sensing, drug delivery monitoring, improvements of image contrast and imaging depth, nondistortive delivery of laser radiation and precision tissue laser photodisruption, among others, are also described. PMID:21050092

  2. Maskless, resistless ion beam lithography

    SciTech Connect

    Ji, Qing

    2003-03-10

    As the dimensions of semiconductor devices are scaled down, in order to achieve higher levels of integration, optical lithography will no longer be sufficient for the needs of the semiconductor industry. Alternative next-generation lithography (NGL) approaches, such as extreme ultra-violet (EUV), X-ray, electron-beam, and ion projection lithography face some challenging issues with complicated mask technology and low throughput. Among the four major alternative NGL approaches, ion beam lithography is the only one that can provide both maskless and resistless patterning. As such, it can potentially make nano-fabrication much simpler. This thesis investigates a focused ion beam system for maskless, resistless patterning that can be made practical for high-volume production. In order to achieve maskless, resistless patterning, the ion source must be able to produce a variety of ion species. The compact FIB system being developed uses a multicusp plasma ion source, which can generate ion beams of various elements, such as O{sub 2}{sup +}, BF{sub 2}{sup +}, P{sup +} etc., for surface modification and doping applications. With optimized source condition, around 85% of BF{sub 2}{sup +}, over 90% of O{sub 2}{sup +} and P{sup +} have been achieved. The brightness of the multicusp-plasma ion source is a key issue for its application to maskless ion beam lithography. It can be substantially improved by optimizing the source configuration and extractor geometry. Measured brightness of 2 keV He{sup +} beam is as high as 440 A/cm{sup 2} {center_dot} Sr, which represents a 30x improvement over prior work. Direct patterning of Si thin film using a focused O{sub 2}{sup +} ion beam has been investigated. A thin surface oxide film can be selectively formed using 3 keV O{sub 2}{sup +} ions with the dose of 10{sup 15} cm{sup -2}. The oxide can then serve as a hard mask for patterning of the Si film. The process flow and the experimental results for directly patterned poly-Si features

  3. Extending single-exposure patterning towards 38-nm half-pitch using 1.35 NA immersion

    NASA Astrophysics Data System (ADS)

    Bouchoms, Igor; Engelen, Andre; Mulkens, Jan; Boom, Herman; Moerman, Richard; Liebregts, Paul; de Graaf, Roelof; van Veen, Marieke; Thomassen, Patrick; Emer, Wolfgang; Sperling, Frank

    2009-03-01

    Immersion lithography started to become the main workhorse for volume production of 45-nm devices, and while waiting for EUV lithography, immersion will continue to be the main technology for further shrinks. In a first step single exposure can be stretched towards the 0.25 k1 limit, after which various double patterning methods are lining up to print 32-nm and even 22-nm devices. The immersion exposure system plays a key role here, and continuous improvement steps are required to support tighter CD and overlay budgets. Additionally cost of ownership (COO) needs to be reduced and one important way to achieve this is to increase the wafer productivity. In this paper we discuss the design and performance of a new improved immersion exposure system XT:1950i. This system will extend immersion towards 38-nm half pitch resolution using a 1.35 NA lens and extreme off axis illumination (e.g. dipole). The system improvements result in better CDU, more accurate overlay towards 4-nm and higher wafer productivity towards 148- wph. Last but not least a next step in immersion technology is implemented. A novel immersion hood is introduced giving more robust low and stable defects performance.

  4. Microfield exposure tool enables advances in EUV lithography development

    SciTech Connect

    Naulleau, Patrick

    2009-09-07

    With demonstrated resist resolution of 20 nm half pitch, the SEMATECH Berkeley BUV microfield exposure tool continues to push crucial advances in the areas of BUY resists and masks. The ever progressing shrink in computer chip feature sizes has been fueled over the years by a continual reduction in the wavelength of light used to pattern the chips. Recently, this trend has been threatened by unavailability of lens materials suitable for wavelengths shorter than 193 nm. To circumvent this roadblock, a reflective technology utilizing a significantly shorter extreme ultraviolet (EUV) wavelength (13.5 nm) has been under development for the past decade. The dramatic wavelength shrink was required to compensate for optical design limitations intrinsic in mirror-based systems compared to refractive lens systems. With this significant reduction in wavelength comes a variety of new challenges including developing sources of adequate power, photoresists with suitable resolution, sensitivity, and line-edge roughness characteristics, as well as the fabrication of reflection masks with zero defects. While source development can proceed in the absence of available exposure tools, in order for progress to be made in the areas of resists and masks it is crucial to have access to advanced exposure tools with resolutions equal to or better than that expected from initial production tools. These advanced development tools, however, need not be full field tools. Also, implementing such tools at synchrotron facilities allows them to be developed independent of the availability of reliable stand-alone BUY sources. One such tool is the SEMATECH Berkeley microfield exposure tool (MET). The most unique attribute of the SEMA TECH Berkeley MET is its use of a custom-coherence illuminator made possible by its implementation on a synchrotron beamline. With only conventional illumination and conventional binary masks, the resolution limit of the 0.3-NA optic is approximately 25 nm, however

  5. Stage Cylindrical Immersive Display

    NASA Technical Reports Server (NTRS)

    Abramyan, Lucy; Norris, Jeffrey S.; Powell, Mark W.; Mittman, David S.; Shams, Khawaja S.

    2011-01-01

    Panoramic images with a wide field of view intend to provide a better understanding of an environment by placing objects of the environment on one seamless image. However, understanding the sizes and relative positions of the objects in a panorama is not intuitive and prone to errors because the field of view is unnatural to human perception. Scientists are often faced with the difficult task of interpreting the sizes and relative positions of objects in an environment when viewing an image of the environment on computer monitors or prints. A panorama can display an object that appears to be to the right of the viewer when it is, in fact, behind the viewer. This misinterpretation can be very costly, especially when the environment is remote and/or only accessible by unmanned vehicles. A 270 cylindrical display has been developed that surrounds the viewer with carefully calibrated panoramic imagery that correctly engages their natural kinesthetic senses and provides a more accurate awareness of the environment. The cylindrical immersive display offers a more natural window to the environment than a standard cubic CAVE (Cave Automatic Virtual Environment), and the geometry allows multiple collocated users to simultaneously view data and share important decision-making tasks. A CAVE is an immersive virtual reality environment that allows one or more users to absorb themselves in a virtual environment. A common CAVE setup is a room-sized cube where the cube sides act as projection planes. By nature, all cubic CAVEs face a problem with edge matching at edges and corners of the display. Modern immersive displays have found ways to minimize seams by creating very tight edges, and rely on the user to ignore the seam. One significant deficiency of flat-walled CAVEs is that the sense of orientation and perspective within the scene is broken across adjacent walls. On any single wall, parallel lines properly converge at their vanishing point as they should, and the sense of

  6. Why bother with x-ray lithography?

    NASA Astrophysics Data System (ADS)

    Smith, Henry I.; Schattenburg, Mark L.

    1992-07-01

    The manufacture of state-of-the-art integrated circuits uses UV optical projection lithography. Conventional wisdom (i.e., the trade journals) holds that this technology will take the industry to quarter-micrometer minimum features sizes and below. So, why bother with X-ray lithography? The reason is that lithography is a 'system problem', and proximity X-ray lithography is better matched to that system problem than any other technology, once the initial investment is surmounted. X-ray lithography offers the most cost-effective path to the future of ultra-large-scale integrated circuits with feature sizes of tenth micrometer and below (i.e., gigascale electronics and quantum-effect electronics).

  7. Mask lithography for display manufacturing

    NASA Astrophysics Data System (ADS)

    Sandstrom, T.; Ekberg, P.

    2010-05-01

    The last ten years have seen flat displays conquer our briefcases, desktops, and living rooms. There has been an enormous development in production technology, not least in lithography and photomasks. Current masks for large displays are more than 2 m2 and make 4-6 1X prints on glass substrates that are 9 m2. One of the most challenging aspects of photomasks for displays is the so called mura, stripes or blemishes which cause visible defects in the finished display. For the future new and even tighter maskwriter specifications are driven by faster transistors and more complex pixel layouts made necessary by the market's wish for still better image quality, multi-touch panels, 3D TVs, and the next wave of e-book readers. Large OLED screens will pose new challenges. Many new types of displays will be lowcost and use simple lithography, but anything which can show video and high quality photographic images needs a transistor backplane and sophisticated masks for its production.

  8. Enabling immersive simulation.

    SciTech Connect

    McCoy, Josh; Mateas, Michael; Hart, Derek H.; Whetzel, Jonathan; Basilico, Justin Derrick; Glickman, Matthew R.; Abbott, Robert G.

    2009-02-01

    The object of the 'Enabling Immersive Simulation for Complex Systems Analysis and Training' LDRD has been to research, design, and engineer a capability to develop simulations which (1) provide a rich, immersive interface for participation by real humans (exploiting existing high-performance game-engine technology wherever possible), and (2) can leverage Sandia's substantial investment in high-fidelity physical and cognitive models implemented in the Umbra simulation framework. We report here on these efforts. First, we describe the integration of Sandia's Umbra modular simulation framework with the open-source Delta3D game engine. Next, we report on Umbra's integration with Sandia's Cognitive Foundry, specifically to provide for learning behaviors for 'virtual teammates' directly from observed human behavior. Finally, we describe the integration of Delta3D with the ABL behavior engine, and report on research into establishing the theoretical framework that will be required to make use of tools like ABL to scale up to increasingly rich and realistic virtual characters.

  9. Study on RLS trade-off resist upgrade for production ready EUV lithography

    NASA Astrophysics Data System (ADS)

    Lee, Junghyung; Kim, Jieun; Jeong, Seunguk; Lim, Mijung; Koo, Sunyoung; Lim, Chang-Moon; Kim, Young-Sik

    2016-03-01

    Extreme Ultraviolet (EUV) is the most promising technology as substitute for multiple patterning based on ArF immersion lithography. If enough productivity can be accomplished, EUV will take main role in the chip manufacturing. Since the introduction of NXE3300, many significant results have been achieved in source power and availability, but lots of improvements are still required in various aspects for the implementation of EUV lithography on high volume manufacturing. Among them, it is especially important to attain high sensitivity resist without degrading other resolution performance. In this paper, performances of various resists were evaluated with real device patterns on NXE3300 scanner and technical progress of up-to-date EUV resists will be shown by comparing with the performance of their predecessors. Finally the prospect of overcoming the triangular trade-off between sensitivity, resolution, line edge roughness (LER) and achieving high volume manufacturing will be discussed.

  10. Phase-shifted assist feature OPC for sub-45-nm node optical lithography

    NASA Astrophysics Data System (ADS)

    Yoon, Gi-Sung; Kim, Hee-Bom; Lee, Jeung-Woo; Choi, Seong-Woon; Han, Woo-Sung

    2007-03-01

    Hyper numerical aperture (NA) implemented in immersion exposure system makes the semiconductor business enable to enter sub-45nm node optical lithography. Optical proximity correction(OPC) utilizing SRAF has been an essential technique to control critical dimension (CD) and to enhance across pitch performance in sub-wavelength lithography. Mask lithography, however, is getting more challenging with respect to patterning and processing sub-resolution assist features (SRAFs): the higher aspect ratio of mask structure, the more vulnerable. Mask manufacturing environment for DRAM and Flash becomes harsher mainly due to mask patterning problem especially pattern linearity, which causes pattern broken, inspection issue, and finally CD issue on wafer. When a pattern in relatively isolated pitches has small or large assist features, the assist features may bring unexpected CD or print on wafer. A frequency-preserving assist bar solution is the most preferred one, but it is difficult to realize for opaque assist features due to printability. In this paper, we propose a new type assist feature dubbed "Phase-shifted Assist Bar" to improve process window and to solve the resolution constraint of mask at sub-45nm manufacturing process node. The concept of phase-shift assist bar is applying phase-shift to SRAF realized with trench structure on general mask, such as Binary and Attenuated Phase-Shifted Mask (Att.PSM). The characteristics of phase-shift assist bar are evaluated with rigorous 3D lithography simulation and analyzed through verification mask, which is containing hugely various size and placement of main and assist feature. The analysis of verification mask has been done with aerial image verification tool. This work focuses on the performance of phase-shift assist bar as a promising OPC technique for "immersion era" in terms of resolution enhancement technique, optical proximity correction, and patterning on mask.

  11. Combined dose and geometry correction (DMG) for low energy multi electron beam lithography (5kV): application to the 16nm node

    NASA Astrophysics Data System (ADS)

    Martin, Luc; Manakli, Serdar; Bayle, Sebastien; Belledent, Jérôme; Soulan, Sebastien; Wiedemann, Pablo; Farah, Abdi; Schiavone, Patrick

    2012-03-01

    Lithography faces today many challenges to meet the ITRS road-map. 193nm is still today the only existing industrial option to address high volume production for the 22nm node. Nevertheless to achieve such a resolution, double exposure is mandatory for critical level patterning. EUV lithography is still challenged by the availability of high power source and mask defectivity and suffers from a high cost of ownership perspective. Its introduction is now not foreseen before 2015. Parallel to these mask-based technologies, maskless lithography regularly makes significant progress in terms of potential and maturity. The massively parallel e-beam solution appears as a real candidate for high volume manufacturing. Several industrial projects are under development, one in the US, with the KLA REBL project and two in Europe driven by IMS Nanofabrication (Austria; MAPPER (The Netherlands). Among the developments to be performed to secure the takeoff of the multi-beam technology, the availability of a rapid and robust data treatment solution will be one of the major challenges. Within this data preparation flow, advanced proximity effect corrections must be implemented to address the 16nm node and below. This paper will detail this process and compare correction strategies in terms of robustness and accuracy. It will be based on results obtained using a MAPPER tool within the IMAGINE program driven by CEA-LETI, in Grenoble, France. All proximity effects corrections and the dithering step were performed using the software platform Inscale® from Aselta Nanographics. One important advantage of Inscale® is the ability to combine both model based dose and geometry adjustment to accurately pattern critical features. The paper will focus on the advantage of combining those two corrections at the 16nm node instead of using only geometry corrections. Thanks to the simulation capability of Inscale®, pattern fidelity and correction robustness will be evaluated and compared between

  12. Simultaneous Immersion Mirau Interferometry

    NASA Astrophysics Data System (ADS)

    Lyulko, Oleksandra

    The present work describes a novel imaging technique for label-free no-UV vibration-insensitive imaging of live cells in an epi-illumination geometry. This technique can be implemented in a variety of imaging applications. For example, it can be used for cell targeting as a part of a platform for targeted cell irradiations - single-cell microbeam. The goal of microbeam facilities is to provide biological researchers with tools to study the effects of ionizing radiation on live cells. A common way of cell labeling - fluorescent staining - may alter cellular metabolism and UV illumination presents potential damage for the genetic material. The new imaging technique will allow the researchers to separate radiation-induced effects from the effects caused by confounding factors like fluorescent staining or UV light. Geometry of irradiation endstations at some microbeam facilities precludes the use of transmitted light, e.g. in the Columbia University's Radiological Research Accelerator Facility microbeam endstation, where the ion beam exit window is located just below the sample. Imaging techniques used at such endstations must use epi-illumination. Mirau Interferometry is an epi-illumination, non-stain imaging modality suitable for implementation at a microbeam endstation. To facilitate interferometry and to maintain cell viability, it is desirable that cells stay in cell growth medium during the course of an experiment. To accommodate the use of medium, Immersion Mirau Interferometry has been developed. A custom attachment for a microscope objective has been designed and built for interferometric imaging with the possibility of immersion of the apparatus into cell medium. The implemented data collection algorithm is based on the principles of Phase-Shifting Interferometry. The largest limitation of Phase-Shifting Interferometry is its sensitivity to the vertical position of the sample. In environments where vibration isolation is difficult, this makes image

  13. Immersion echelle spectrograph

    DOEpatents

    Stevens, Charles G.; Thomas, Norman L.

    2000-01-01

    A small spectrograph containing no moving components and capable of providing high resolution spectra of the mid-infrared region from 2 microns to 4 microns in wavelength. The resolving power of the spectrograph exceeds 20,000 throughout this region and at an optical throughput of about 10.sup.-5 cm.sup.2 sr. The spectrograph incorporates a silicon immersion echelle grating operating in high spectral order combined with a first order transmission grating in a cross-dispersing configuration to provide a two-dimensional (2-D) spectral format that is focused onto a two-dimensional infrared detector array. The spectrometer incorporates a common collimating and condensing lens assembly in a near aberration-free axially symmetric design. The spectrometer has wide use potential in addition to general research, such as monitoring atmospheric constituents for air quality, climate change, global warming, as well as monitoring exhaust fumes for smog sources or exhaust plumes for evidence of illicit drug manufacture.

  14. Broadcasting presence: immersive television

    NASA Astrophysics Data System (ADS)

    Harrison, David; Lodge, Nicholas

    2000-06-01

    Being present at a live event is undeniably the most exciting way to experience any entertainment. This is true whether we are talking about a musical concert, a theatrical performance, a cricket match, or even a firework display. The ability to direct your gaze where you wish, to hear sounds from all around you, to experience the immediacy and expectation of an unscripted happening, to feel the buzz of the crowd and to smell the grass or smoke, are all sensory cues which contribute to the powerful experience of being there. This paper examines the ways in which entertainment media have attempted to recreate experiences which encourage the viewer to suspend disbelief and become part of a remote or recorded event. We introduce the concept of immersive television and look at some of the research, spanning many disciplines of science and art, which the ITC is conducting to explore the potential of this new medium.

  15. Method for extreme ultraviolet lithography

    DOEpatents

    Felter, T. E.; Kubiak, G. D.

    2000-01-01

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.

  16. Defect tolerant transmission lithography mask

    DOEpatents

    Vernon, Stephen P.

    2000-01-01

    A transmission lithography mask that utilizes a transparent substrate or a partially transparent membrane as the active region of the mask. A reflective single layer or multilayer coating is deposited on the membrane surface facing the illumination system. The coating is selectively patterned (removed) to form transmissive (bright) regions. Structural imperfections and defects in the coating have negligible effect on the aerial image of the mask master pattern since the coating is used to reflect radiation out of the entrance pupil of the imaging system. Similarly, structural imperfections in the clear regions of the membrane have little influence on the amplitude or phase of the transmitted electromagnetic fields. Since the mask "discards," rather than absorbs, unwanted radiation, it has reduced optical absorption and reduced thermal loading as compared to conventional designs. For EUV applications, the mask circumvents the phase defect problem, and is independent of the thermal load during exposure.

  17. Method for extreme ultraviolet lithography

    DOEpatents

    Felter, T. E.; Kubiak, Glenn D.

    1999-01-01

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.

  18. Miniature electron microscopes for lithography

    NASA Astrophysics Data System (ADS)

    Feinerman, Alan D.; Crewe, David A.; Perng, Dung-Ching; Spindt, Capp A.; Schwoebel, Paul R.; Crewe, Albert V.

    1994-05-01

    Two inexpensive and extremely accurate methods for fabricating miniature 10 - 50 kV and 0.5 - 10 kV electron beam columns have been developed: `slicing,' and `stacking.' Two or three miniature columns could be used to perform a 20 nm or better alignment of an x-ray mask to a substrate. An array of miniature columns could be used for rapid wafer inspection and high throughput electron beam lithography. The column fabrication methods combine the precision of semiconductor processing and fiber optic technologies to create macroscopic structures consisting of charged particle sources, deflecting and focusing electrodes, and detectors. The overall performance of the miniature column also depends on the emission characteristics of the micromachined electron source which is currently being investigated.

  19. Scaling behavior in interference lithography

    SciTech Connect

    Agayan, R.R.; Banyai, W.C.; Fernandez, A.

    1998-02-27

    Interference lithography is an emerging, technology that provides a means for achieving high resolution over large exposure areas (approximately 1 m{sup 2}) with virtually unlimited depth of field. One- and two-dimensional arrays of deep submicron structures can be created using near i-line wavelengths and standard resist processing. In this paper, we report on recent advances in the development of this technology, focusing, in particular, on how exposure latitude and resist profile scale with interference period We present structure width vs dose curves for periods ranging from 200 nm to 1 um, demonstrating that deep submicron structures can be generated with exposure latitudes exceeding 30%. Our experimental results are compared to simulations based on PROLITIV2.

  20. French Immersion Program Evaluation Report.

    ERIC Educational Resources Information Center

    Nanaimo School District #68 (British Columbia).

    The Nanaimo (British Columbia) school district's French immersion program is evaluated. An introductory section gives background on the evaluation, outlines the evaluation process used, and offers brief comments on its outcome. The second section describes the immersion program's history and its current status in terms of enrollment, class size,…

  1. Development of a computational lithography roadmap

    NASA Astrophysics Data System (ADS)

    Chen, J. Fung; Liu, Hua-Yu; Laidig, Thomas; Zuniga, Christian; Cao, Yu; Socha, Robert

    2008-03-01

    While lithography R&D community at large has already gotten the mind set for 32nm, all eyes are on 22nm node. Current consensus is to employ computational lithography to meet wafer CD uniformity (CDU) requirement. Resolution enhancement technologies (RET) and model OPC are the two fundamental components for computational lithography. Today's full-chip CDU specifications are already pushing physical limits at extreme lithography k I factor. While increasingly aggressive RET either by double exposure or double patterning are enabling imaging performance, for CDU control we need ever more accurate OPC at a greater computational efficiency. In this report, we discuss the desire for wanting more robust and accurate OPC models. One important trend is to have predictive OPC models allowing accurate OPC results to be obtained much faster, shortening the qualification process for exposure tools. We investigate several key parameters constitute to accuracy achievable in computational lithography. Such as the choice of image pixel size, numbers of terms needed for transmission cross coefficients (TCC), and "safe" ambit radius for assuring accurate CD prediction. Selections of image pixel size and "safe" ambit radius together determine % utilization for 2D fast Fourier transformation (FFT) for efficient full-chip OPC computation. For IC manufacturing beyond ArF, we made initial observations and estimations on EUV computational lithography. These discussions pave the way for developing a computational lithography roadmap extends to the end of Moore's Law. This computational lithography roadmap aims to be a complement for the current ITRS roadmap on what does it take to achieve CD correction accuracy.

  2. Immersion echelle spectrograph

    SciTech Connect

    Stevens, C.G.; Thomas, N.L.

    2000-06-20

    A small spectrograph is disclosed containing no moving components and capable of providing high resolution spectra of the mid-infrared region from 2 microns to 4 microns in wavelength. The resolving power of the spectrograph exceeds 20,000 throughout this region and at an optical throughput of about 10{sup {minus}5}cm{sup 2}sr. The spectrograph incorporates a silicon immersion echelle grating operating in high spectral order combined with a first order transmission grating in a cross-dispersing configuration to provide a two-dimensional (2-D) spectral format that is focused onto a two-dimensional infrared detector array. The spectrometer incorporates a common collimating and condensing lens assembly in a near aberration-free axially symmetric design. The spectrometer has wide use potential in addition to general research, such as monitoring atmospheric constituents for air quality, climate change, global warming, as well as monitoring exhaust fumes for smog sources or exhaust plumes for evidence of illicit drug manufacture.

  3. Thermal comfort following immersion.

    PubMed

    Guéritée, Julien; Redortier, Bernard; House, James R; Tipton, Michael J

    2015-02-01

    Unlike thermal comfort in air, little research has been undertaken exploring thermal comfort around water sports. We investigated the impact of swimming and cooling in air after swimming on thermal comfort. After 10 min of swimming-and-resting cycles in 28°C water, volunteers wearing two types of garments or in swim briefs, faced winds in 24°C air, at rest or when stepping. Thermal comfort was significantly higher during swimming than resting. Post-immersion, following maximum discomfort, in 45 of 65 tests thermal comfort improved although mean skin temperature was still cooling (0.26 [SD 0.19] °C·min(-1) - max was 0.89°C·min(-1)). When thermal comfort was re-established mean skin temperature was lower than at maximal discomfort in 39 of 54 tests (0.81 [SD 0.58] °C - max difference was 2.68°C). The reduction in thermal discomfort in this scenario could be due to the adaptation of thermoreceptors, or to reductions in cooling rates to levels where discomfort was less stimulated. The relief from the recent discomfort may explain why, later, thermal comfort returned to initial levels in spite of poorer thermal profiles. PMID:25485520

  4. Immersed interface methods. Final report

    SciTech Connect

    LeVeque, R.J.; Adams, L.M.; Bube, K.P.

    1996-11-01

    Cartesian grid methods encompass a wide variety of techniques used to solve partial differential equations in more than one space dimension on uniform Cartesian grids even when the underlying geometry is complex and not aligned with the grid. The authors` groups work on Immersed Interface Methods (IIM) was originally motivated by the desire to understand and improve the ``Immersed Boundary Method``, developed by Charles Peskin to solve incompressible Navier-Stokes equations in complicated geometries with moving elastic boundaries. This report briefly discusses the development of the Immersed Interface Methods and gives examples of application of the method in solving several partial differential equations.

  5. Magnetic nanostructures by colloidal lithography

    NASA Astrophysics Data System (ADS)

    Zhu, Frank Qing

    Structural, magnetic and in some cases magneto-transport properties of (1) symmetric and asymmetric ferromagnetic nanorings and (2) single layer, multilayer, and exchange biased ferromagnetic nanodots prepared by colloidal lithography are presented. A fast, reliable and cost effective method has been developed to fabricate large number (˜ 109) of magnetic nanorings over macroscopic areas (˜ cm2) with large areal densities (up to 45 rings/mum 2). Cobalt nanorings with diameters ranging from 100 nm to 500 nm have been fabricated by sputtering Co onto nanosphere-coated substrates followed by ion beam etching. X-ray diffraction verifies that the Co nanorings still have hexagonal close-packed (hcp) structure. Scanning electron microscopy reveals that the cross-section of the symmetric nanoring is tapered and uniform along the circumference, and the cross-section of the asymmetric nanoring changes progressively along the circumference. Two magnetic reversal processes have been found in magnetic nanorings---the vortex formation process and the onion rotation process. The co-existence of these two processes is the manifestation of the competition between the exchange energy and the magnetostatic energy in the nanorings. Micromagnetics simulations have been carried out to reveal the details of the magnetic reversals. The experimental and the computed hysteresis loops agree both qualitatively and quantitatively. For the 100 nm symmetric Co nanorings, the vortex formation process has a probability of about 40%, while the onion rotation process has 60% chances. To increase the probability of vortex formation process, a desirable process for application, asymmetric nanorings have been fabricated by ion beam etching at oblique angles. Unlike the symmetric nanorings, the probability of the vortex formation process in asymmetric nanorings can be controlled by the direction of the external field. For the 100 nm asymmetric nanorings, the fraction of the vortex formation process

  6. High-productivity immersion scanner enabling 1xnm hp manufacturing

    NASA Astrophysics Data System (ADS)

    Shirata, Yosuke; Shibazaki, Yuichi; Kosugi, Junichi; Kikuchi, Takahisa; Ohmura, Yasuhiro

    2013-04-01

    NSR-S622D, Nikon's new ArF immersion scanner, provides the best and practicable solutions to meet the escalating requirement from device manufactures to accommodate the further miniaturization of device pattern. NSR-S622D has various additional functions compared to the previous model such as the newly developed illumination system, new projection lens, new AF system new wafer table in addition to the matured Streamlign platform. These new features will derive the outstanding performance of NSR, enabling highly controlled CD uniformity, focus accuracy and overlay accuracy. NSR-S622D will provide the adequate capabilities that are demanded from a lithography tool for production of 1x nm hp node and beyond.

  7. Laser produced plasma light source for EUVL

    NASA Astrophysics Data System (ADS)

    Fomenkov, Igor V.; Ershov, Alex I.; Partlo, William N.; Myers, David W.; Brown, Daniel; Sandstrom, Richard L.; La Fontaine, Bruno; Bykanov, Alexander N.; Vaschenko, Georgiy O.; Khodykin, Oleh V.; Böwering, Norbert R.; Das, Palash; Fleurov, Vladimir B.; Zhang, Kevin; Srivastava, Shailendra N.; Ahmad, Imtiaz; Rajyaguru, Chirag; De Dea, Silvia; Hou, Richard R.; Dunstan, Wayne J.; Baumgart, Peter; Ishihara, Toshihiko; Simmons, Rod D.; Jacques, Robert N.; Bergstedt, Robert A.; Brandt, David C.

    2011-04-01

    This paper describes the development of laser-produced-plasma (LPP) extreme-ultraviolet (EUV) source architecture for advanced lithography applications in high volume manufacturing. EUV lithography is expected to succeed 193 nm immersion technology for sub-22 nm critical layer patterning. In this paper we discuss the most recent results from high qualification testing of sources in production. Subsystem performance will be shown including collector protection, out-of-band (OOB) radiation measurements, and intermediate-focus (IF) protection as well as experience in system use. This presentation reviews the experimental results obtained on systems with a focus on the topics most critical for an HVM source.

  8. Nanometer x-ray lithography

    NASA Astrophysics Data System (ADS)

    Hartley, Frank T.; Khan Malek, Chantal G.

    1999-10-01

    New developments for x-ray nanomachining include pattern transfer onto non-planar surfaces coated with electrodeposited resists using synchrotron radiation x-rays through extremely high-resolution mask made by chemically assisted focused ion beam lithography. Standard UV photolithographic processes cannot maintain sub-micron definitions over large variation in feature topography. The ability of x-ray printing to pattern thin or thick layers of photoresist with high resolution on non-planar surfaces of large and complex topographies with limited diffraction and scattering effects and no substrate reflection is known and can be exploited for patterning microsystems with non-planar 3D geometries as well as multisided and multilayered substrates. Thin conformal coatings of electro-deposited positive and negative tone photoresist have been shown to be x-ray sensitive and accommodate sub-micro pattern transfer over surface of extreme topographical variations. Chemically assisted focused ion beam selective anisotropic erosion was used to fabricate x-ray masks directly. Masks with feature sizes less than 20 nm through 7 microns of gold were made on bulk silicon substrates and x-ray mask membranes. The technique is also applicable to other high density materials. Such masks enable the primary and secondary patterning and/or 3D machining of Nano-Electro-Mechanical Systems over large depths or complex relief and the patterning of large surface areas with sub-optically dimensioned features.

  9. Secondary Electrons in EUV Lithography

    SciTech Connect

    Torok, Justin; Re, Ryan Del; Herbol, Henry; Das, Sanjana; Bocharova, Irina; Paolucci, Angela; Ocola, Leonidas E.; Ventrice Jr., Carl; Lifshin, Eric; Denbeaux, Greg; Brainard, Robert L.

    2013-01-01

    Secondary electrons play critical roles in several imaging technologies, including extreme ultraviolet (EUV) lithography. At longer wavelengths of light (e.g. 193 and 248 nm), the photons are directly involved in the photochemistry occurring during photolysis. EUV light (13.5 nm, 92 eV), however, first creates a photoelectron, and this electron, or its subsequent daughter electrons create most of the chemical changes that occur during exposure. Despite the importance of these electrons, the details surrounding the chemical events leading to acid production remain poorly understood. Previously reported experimental results using high PAG-loaded resists have demonstrated that up to five or six photoacids can be generated per incident photon. Until recently, only electron recombination events were thought to play a role in acid generation, requiring that at least as many secondary electrons are produced to yield a given number of acid molecules. However, the initial results we have obtained using a Monte Carlo-based modeling program, LESiS, demonstrate that only two to three secondary electrons are made per absorbed EUV photon. A more comprehensive understanding of EUV-induced acid generation is therefore needed for the development of higher performance resists

  10. Masks for extreme ultraviolet lithography

    SciTech Connect

    Cardinale, G; Goldsmith, J; Kearney, P A; Larson, C; Moore, C E; Prisbrey, S; Tong, W; Vernon, S P; Weber, F; Yan, P-Y

    1998-09-01

    In extreme ultraviolet lithography (EUVL), the technology specific requirements on the mask are a direct consequence of the utilization of radiation in the spectral region between 10 and 15 nm. At these wavelengths, all condensed materials are highly absorbing and efficient radiation transport mandates the use of all-reflective optical systems. Reflectivity is achieved with resonant, wavelength-matched multilayer (ML) coatings on all of the optical surfaces - including the mask. The EUV mask has a unique architecture - it consists of a substrate with a highly reflective ML coating (the mask blank) that is subsequently over-coated with a patterned absorber layer (the mask). Particulate contamination on the EUVL mask surface, errors in absorber definition and defects in the ML coating all have the potential to print in the lithographic process. While highly developed technologies exist for repair of the absorber layer, no viable strategy for the repair of ML coating defects has been identified. In this paper the state-of-the-art in ML deposition technology, optical inspection of EUVL mask blank defects and candidate absorber patterning approaches are reviewed.

  11. Semiconductor foundry, lithography, and partners

    NASA Astrophysics Data System (ADS)

    Lin, Burn J.

    2002-07-01

    The semiconductor foundry took off in 1990 with an annual capacity of less than 0.1M 8-inch-equivalent wafers at the 2-mm node. In 2000, the annual capacity rose to more than 10M. Initially, the technology practiced at foundries was 1 to 2 generations behind that at integrated device manufacturers (IDMs). Presently, the progress in 0.13-mm manufacturing goes hand-in-hand with any of the IDMs. There is a two-order of magnitude rise in output and the progress of technology development outpaces IDMs. What are the reasons of the success? Is it possible to sustain the pace? This paper shows the quick rise of foundries in capacity, sales, and market share. It discusses the their uniqueness which gives rise to advantages in conjunction with challenges. It also shows the role foundries take with their customer partners and supplier partners, their mutual dependencies, as well as expectations. What role then does lithography play in the foundries? What are the lithographic challenges to sustain the pace of technology? The experience of technology development and transfer, at one of the major foundries, is used to illustrate the difficulties and progresses made. Looking into the future, as semiconductor manufacturing will become even more expensive and capital investment more prohibitive, we will make an attempt to suggest possible solutions.

  12. Extreme-UV lithography condenser

    DOEpatents

    Sweatt, William C.; Sweeney, Donald W.; Shafer, David; McGuire, James

    2001-01-01

    Condenser system for use with a ringfield camera in projection lithography where the condenser includes a series of segments of a parent aspheric mirror having one foci at a quasi-point source of radiation and the other foci at the radius of a ringfield have all but one or all of their beams translated and rotated by sets of mirrors such that all of the beams pass through the real entrance pupil of a ringfield camera about one of the beams and fall onto the ringfield radius as a coincident image as an arc of the ringfield. The condenser has a set of correcting mirrors with one of the correcting mirrors of each set, or a mirror that is common to said sets of mirrors, from which the radiation emanates, is a concave mirror that is positioned to shape a beam segment having a chord angle of about 25 to 85 degrees into a second beam segment having a chord angle of about 0 to 60 degrees.

  13. Lithography aware overlay metrology target design method

    NASA Astrophysics Data System (ADS)

    Lee, Myungjun; Smith, Mark D.; Lee, Joonseuk; Jung, Mirim; Lee, Honggoo; Kim, Youngsik; Han, Sangjun; Adel, Michael E.; Lee, Kangsan; Lee, Dohwa; Choi, Dongsub; Liu, Zephyr; Itzkovich, Tal; Levinski, Vladimir; Levy, Ady

    2016-03-01

    We present a metrology target design (MTD) framework based on co-optimizing lithography and metrology performance. The overlay metrology performance is strongly related to the target design and optimizing the target under different process variations in a high NA optical lithography tool and measurement conditions in a metrology tool becomes critical for sub-20nm nodes. The lithography performance can be quantified by device matching and printability metrics, while accuracy and precision metrics are used to quantify the metrology performance. Based on using these metrics, we demonstrate how the optimized target can improve target printability while maintaining the good metrology performance for rotated dipole illumination used for printing a sub-100nm diagonal feature in a memory active layer. The remaining challenges and the existing tradeoff between metrology and lithography performance are explored with the metrology target designer's perspective. The proposed target design framework is completely general and can be used to optimize targets for different lithography conditions. The results from our analysis are both physically sensible and in good agreement with experimental results.

  14. Soft Lithography Using Nectar Droplets.

    PubMed

    Biswas, Saheli; Chakrabarti, Aditi; Chateauminois, Antoine; Wandersman, Elie; Prevost, Alexis M; Chaudhury, Manoj K

    2015-12-01

    In spite of significant advances in replication technologies, methods to produce well-defined three-dimensional structures are still at its infancy. Such a limitation would be evident if we were to produce a large array of simple and, especially, compound convex lenses, also guaranteeing that their surfaces would be molecularly smooth. Here, we report a novel method to produce such structures by cloning the 3D shape of nectar drops, found widely in nature, using conventional soft lithography.The elementary process involves transfer of a thin patch of the sugar solution coated on a glass slide onto a hydrophobic substrate on which this patch evolves into a microdroplet. Upon the absorption of water vapor, such a microdroplet grows linearly with time, and its final size can be controlled by varying its exposure time to water vapor. At any stage of the evolution of the size of the drop, its shape can be cloned onto a soft elastomer by following the well-known methods of molding and cross-linking the same. A unique new science that emerges in our attempt to understand the transfer of the sugar patch and its evolution to a spherical drop is the elucidation of the mechanics underlying the contact of a deformable sphere against a solid support intervening a thin liquid film. A unique aspect of this work is to demonstrate that higher level structures can also be generated by transferring even smaller nucleation sites on the surface of the primary lenses and then allowing them to grow by absorption of water vapor. What results at the end is either a well-controlled distribution of smooth hemispherical lenses or compound structures that could have potential applications in the fundamental studies of contact mechanics, wettability, and even in optics. PMID:26563988

  15. Hybrid lithography for triple patterning decomposition and E-beam lithography

    NASA Astrophysics Data System (ADS)

    Tian, Haitong; Zhang, Hongbo; Xiao, Zigang; Wong, Martin D. F.

    2014-03-01

    As we advances into 14/10nm technology node, single patterning technology is far from enough to fabricate the features with shrinking feature size. According to International Technology Roadmap for Semiconductors in 2011,1 double patterning lithography is already available for massive productions in industry for sub-32nm half pitch technology node. For 14/10nm technology node, double patterning begins to show its limitations as it uses too many stitches to resolve the native coloring conflicts. Stitches will increase the manufacturing cost, lead to potential functional errors of the chip, and cause the yield lost. Triple patterning lithography and E-Beam lithography are two emerging techniques to beat the diffraction limit for current optical lithography system. In this paper, we investigate combining the merits of triple patterning lithography and E-Beam lithography for standard cell based designs. We devise an approach to compute a stitch free decomposition with the optimal number of E-Beam shots for row structure layout. The approach is expected to highlight the necessity and advantages of using hybrid lithography for advanced technology node.

  16. Advanced mask aligner lithography: new illumination system.

    PubMed

    Voelkel, Reinhard; Vogler, Uwe; Bich, Andreas; Pernet, Pascal; Weible, Kenneth J; Hornung, Michael; Zoberbier, Ralph; Cullmann, Elmar; Stuerzebecher, Lorenz; Harzendorf, Torsten; Zeitner, Uwe D

    2010-09-27

    A new illumination system for mask aligner lithography is presented. The illumination system uses two subsequent microlens-based Köhler integrators. The second Köhler integrator is located in the Fourier plane of the first. The new illumination system uncouples the illumination light from the light source and provides excellent uniformity of the light irradiance and the angular spectrum. Spatial filtering allows to freely shape the angular spectrum to minimize diffraction effects in contact and proximity lithography. Telecentric illumination and ability to precisely control the illumination light allows to introduce resolution enhancement technologies (RET) like customized illumination, optical proximity correction (OPC) and source-mask optimization (SMO) in mask aligner lithography. PMID:20940992

  17. Characterizing polarized illumination in high numerical aperture optical lithography with phase shifting masks

    NASA Astrophysics Data System (ADS)

    McIntyre, Gregory Russell

    shifted regions of an alternating PSM and projection lens birefringence, respectively. A secondary objective of this dissertation has been to leverage some of these functions to extend the application of pattern matching software to rapidly identify areas in a circuit design layout that may be vulnerable to polarization and high-NA effects. Additionally, polarization aberrations have been investigated, as they may become important with hyper-NA imaging systems. Three multi-phase test reticles have been developed for this thesis and have pushed the limits of photomask fabrication. Coupled with a variety of experimental and simulation studies at 193nm wavelength, they have validated the scientific principles of the PSM monitors and have offered unique insight into implementation issues such as electromagnetic (EM) effects and mask making tolerances. Although all five classes are novel theoretical concepts, it is believed that PSM Polarimetry is commercially viable. Despite a 70% loss of sensitivity due to mask making limitations and a 20% loss due to EM effects, it can likely still monitor polarization to within 2%. Experimental results are comparable to the only other known technique, which requires special equipment. Taken collectively, the five novel classes of PSM monitors offer the lithographer an independent tool-kit to ensure proper tool operation. They also provide circuit designers an understanding of the impact of imaging on layouts. Although they have been developed for optical lithography, their principles are relevant to any image-forming optical system and are likely to find applications in other fields of optics or acoustics.

  18. Lithography and design in partnership: a new roadmap

    NASA Astrophysics Data System (ADS)

    Kahng, Andrew B.

    2008-10-01

    We discuss the notion of a 'shared technology roadmap' between lithography and design from several perspectives. First, we examine cultural gaps and other intrinsic barriers to a shared roadmap. Second, we discuss how lithography technology can change the design technology roadmap. Third, we discuss how design technology can change the lithography technology roadmap. We conclude with an example of the 'flavor' of technology roadmapping activity that can truly bridge lithography and design.

  19. LAVA: lithography analysis using virtual access

    NASA Astrophysics Data System (ADS)

    Hsu, Chang; Yang, Rona; Cheng, Jeffery; Chien, Peter; Wen, Victor; Neureuther, Andrew R.

    1998-06-01

    A web site allowing remote operation of the SPLAT, SAMPLE, TEMPEST and SIMPL simulators has been developed to promote collaborative work on lithography and in particular on EUV technology. Based on the extensive use of platform independent programming languages, LAVA is accessible from all modern computing platforms. The software supporting the web site is available to others in creating similar web site sites and in making simulators such as those from other universities 'play' together. The web site explores new paradigms in remote operation of lithography simulators and introduces more application-oriented modes of interaction with technologists. The LAVA web site URL is http://cuervo.eecs.berkeley.edu/Volcano/

  20. Simple method for measuring acid generation quantum efficiency at 193 nm

    NASA Astrophysics Data System (ADS)

    Szmanda, Charles R.; Kavanagh, Robert J.; Bohland, John F.; Cameron, James F.; Trefonas, Peter, III; Blacksmith, Robert F.

    1999-06-01

    Traditional methods of measuring the Dill C Parameter involve monitoring the absorbance of a resist as a function of exposure. In chemically amplified resist, absorbance changes with exposure are small and frequently have little correlation to the amount of photoacid generated.

  1. Microstructure-related properties of magnesium fluoride films at 193nm by oblique-angle deposition.

    PubMed

    Guo, Chun; Kong, Mingdong; Lin, Dawei; Liu, Cunding; Li, Bincheng

    2013-01-14

    Magnesium fluoride (MgF2) films deposited by resistive heating evaporation with oblique-angle deposition have been investigated in details. The optical and micro-structural properties of single-layer MgF2 films were characterized by UV-VIS and FTIR spectrophotometers, scanning electron microscope (SEM), atomic force microscope (AFM), and x-ray diffraction (XRD), respectively. The dependences of the optical and micro-structural parameters of the thin films on the deposition angle were analyzed. It was found that the MgF2 film in a columnar microstructure was negatively inhomogeneous of refractive index and polycrystalline. As the deposition angle increased, the optical loss, extinction coefficient, root-mean-square (rms) roughness, dislocation density and columnar angle of the MgF2 films increased, while the refractive index, packing density and grain size decreased. Furthermore, IR absorption of the MgF2 films depended on the columnar structured growth. PMID:23388989

  2. Patterning of Ta/SiO2 high transmission EAPSM material for 193nm technology

    NASA Astrophysics Data System (ADS)

    Koepernik, Corinna; Becker, H. W.; Butschke, J.; Buttgereit, U.; Irmscher, M.; Nedelmann, L.; Schmidt, F.; Teuber, S.

    2005-06-01

    For the new Schott EAPSM Material, comprising a Ta/SiO2/Cr stack, a patterning process has been developed. The material offers the advantage of an independent adjustment of phase shift and transmission and is applicable for different wavelengths. Because of very homogenous Ta and SiO2 films and perfect etch selectivities it has been achieved a phase shift uniformity of 1.1° and a tight transmission deviation of 0.34% (absolute) across the entire mask. First dry etch process development has been focused on profiles and selectivities. The influence of process parameters on sidewall angle, profile bow, resist loss and Cr loss of the three patterning steps are shown. We have achieved excellent selectivities and a final sidewall angle of > 88°. The aerial image contrast of the first test plate is comparable to known attenuated phase shift material.

  3. The photodissociation of oxetane at 193 nm as the reverse of the Paterno-Buchi reaction

    SciTech Connect

    Lee, Shih-Huang

    2009-12-14

    We investigated the photodissociation of oxetane (1,3-trimethylene oxide) at 193.3 nm in a molecular-beam apparatus using photofragment-translational spectroscopy and selective photoionization. We measured time-of-flight (TOF) spectra and angular anisotropy parameters {beta}(t) as a function of flight time of products at m/z=26-30 u utilizing photoionization energies from 9.8 to 14.8 eV. The TOF distributions of the products alter greatly with the employed photon energy, whereas their {beta}(t) distributions are insensitive to the photon energy. Dissociation to H{sub 2}CO+C{sub 2}H{sub 4} is the major channel in the title reaction. Three distinct dissociation paths with branching ratios 0.923:0.058:0.019 are responsible for the three features observed in the distribution of kinetic energy released in the channel H{sub 2}CO+C{sub 2}H{sub 4}. The observation of H{sub 2} and H atoms, {approx}1% in branching, indicates that products H{sub 2}CO and C{sub 2}H{sub 4} spontaneously decompose to only a small extent. Most HCO, C{sub 2}H{sub 3}, and C{sub 2}H{sub 2} ions originate from dissociative photoionization of products H{sub 2}CO and C{sub 2}H{sub 4}. Except atomic H and H{sub 2}, the photoproducts have large angular anisotropies, {beta}{>=}-0.8, which reflects rapid dissociation of oxetane following optical excitation at 193.3 nm. The mechanisms of dissociation of oxetane are addressed. Our results confirm the quantum-chemical calculations of Palmer et al. and provide profound insight into the Paterno-Buchi reaction.

  4. Excimer laser photochemistry of silane-ammonia mixtures at 193 nm

    SciTech Connect

    Beach, D.B.; Jasinski, J.M. )

    1990-04-05

    The ArF excimer laser induced photochemistry of silane-ammonia mixtures has been studied with molecular beam sampling mass spectrometry. The observed products include disilane, trisilane, and all possible aminosilanes, SiH{sub x}(NH{sub 2}){sub 4-x}, x = 0-3. These products are formed under steady-state photolysis conditions and under single-laser-pulse conditions. A mechanism for the formation of these species is proposed and quantitatively evaluated.

  5. Lithography light source fault detection

    NASA Astrophysics Data System (ADS)

    Graham, Matthew; Pantel, Erica; Nelissen, Patrick; Moen, Jeffrey; Tincu, Eduard; Dunstan, Wayne; Brown, Daniel

    2010-04-01

    High productivity is a key requirement for today's advanced lithography exposure tools. Achieving targets for wafers per day output requires consistently high throughput and availability. One of the keys to high availability is minimizing unscheduled downtime of the litho cell, including the scanner, track and light source. From the earliest eximer laser light sources, Cymer has collected extensive performance data during operation of the source, and this data has been used to identify the root causes of downtime and failures on the system. Recently, new techniques have been developed for more extensive analysis of this data to characterize the onset of typical end-of-life behavior of components within the light source and allow greater predictive capability for identifying both the type of upcoming service that will be required and when it will be required. The new techniques described in this paper are based on two core elements of Cymer's light source data management architecture. The first is enhanced performance logging features added to newer-generation light source software that captures detailed performance data; and the second is Cymer OnLine (COL) which facilitates collection and transmission of light source data. Extensive analysis of the performance data collected using this architecture has demonstrated that many light source issues exhibit recognizable patterns in their symptoms. These patterns are amenable to automated identification using a Cymer-developed model-based fault detection system, thereby alleviating the need for detailed manual review of all light source performance information. Automated recognition of these patterns also augments our ability to predict the performance trending of light sources. Such automated analysis provides several efficiency improvements for light source troubleshooting by providing more content-rich standardized summaries of light source performance, along with reduced time-to-identification for previously

  6. SYSTEM CONSIDERATIONS FOR MASKLESS LITHOGRAPHY

    SciTech Connect

    Karnowski, Thomas Paul; Joy, David; Allard Jr, Lawrence Frederick; Clonts, Lloyd G

    2004-01-01

    Lithographic processes for printing device structures on integrated circuits (ICs) are the fundamental technology behind Moore's law. Next-generation techniques like maskless lithography or ML2 have the advantage that the long, tedious and expensive process of fabricating a unique mask for the manufactured chip is not necessary. However, there are some rather daunting problems with establishing ML2 as a viable commercial technology. The data rate necessary for ML2 to be competitive in manufacturing is not feasible with technology in the near future. There is also doubt that the competing technologies for the writing mechanisms and corresponding photoresist (or analogous medium) will be able to accurately produce the desired patterns necessary to produce multi-layer semiconductor devices. In this work, we model the maskless printing system from a signal processing point of view, utilizing image processing algorithms and concepts to study the effects of various real-world constraints and their implications for a ML2 system. The ML2 elements are discrete devices, and it is doubtful that their motion can be controlled to the level where a one-for-one element to exposed pixel relationship is allowable. Some level of sub-element resolution can be achieved with gray scale levels, but with the highly integrated manufacturing practices required to achieve massive parallelism, the most effective elements will be simple on-off switches that fire a fixed level of energy at the target medium. Consequently gray-scale level devices are likely not an option. Another problem with highly integrated manufacturing methods is device uniformity. Consequently, we analyze the redundant scanning array concept (RSA) conceived by Berglund et al. which can defeat many of these problems. We determine some basic equations governing its application and we focus on applying the technique to an array of low-energy electron emitters. Using the results of Monte Carlo simulations on electron beam

  7. System considerations for maskless lithography

    NASA Astrophysics Data System (ADS)

    Karnowski, Thomas; Joy, David; Allard, Larry; Clonts, Lloyd

    2004-05-01

    Lithographic processes for printing device structures on integrated circuits (ICs) are the fundamental technology behind Moore's law. Next-generation techniques like maskless lithography or ML2 have the advantage that the long, tedious and expensive process of fabricating a unique mask for the manufactured chip is not necessary. However, there are some rather daunting prblems with establishing ML2 as a viable commercial technology. The data rate necessary for ML2 to be competitive in manufacturing is not feasible with technology in the near future. There is also doubt that the competing technologies for the writing mechanisms and corresponding photoresist (or analogous medium) will be able to accurately produce the desired patterns necessary to produce multi-layer semiconductor devices. In this work, we model the maskless printing system from a signal processing point of view, utilizing image processing algorithms and concepts to study the effects of various real-world constraints and their implications for a ML2 system. The ML2 elements are discrete devices, and it is doubtful that their motion can be controlled to the level where a one-for-one element to exposed pixel relationship is allowable. Some level of sub-element resolution can be achieved with gray scale levels, but with the highly integrated manufacturing practices required to achieve massive parallelism, the most effective elements will be simple on-ofrf switches that fire a fixed level of energy at the target medium. Consequently gray-scale level devidces are likely not an option. Another problem with highly integrated manufacturing methods is device uniformity. Consequently, we analyze the redundant scanning array concept (RSA) conceived by Berglund et al. which can defeat many of these problems. We determine some basic equations governing its application and we focus on applying the technique to an array of low-energy electron emitters. Using the results of Monte Carlo simulations on electron beam

  8. Immersible solar heater for fluids

    DOEpatents

    Kronberg, James W.

    1995-01-01

    An immersible solar heater comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.

  9. Immersion francaise precoce. Early French Immersion: Administrator's Resource Book.

    ERIC Educational Resources Information Center

    Burt, Andy

    This handbook (in English) is part of a series of early French immersion program teaching guides--all written in French--and is designed to serve as a guide for administrators in schools with classes of students who are being instructed in French for a large part of their school program. It addresses itself to areas of concern which are unique to…

  10. Development of MOEMS technology in maskless lithography

    NASA Astrophysics Data System (ADS)

    Smith, David; Klenk, Dieter

    2009-02-01

    Micro-opto-electro-mechanical-systems (MOEMS) have proven to be a facilitating technology in the lithography industry. Recently, there have been significant advancements in digital micromirror device (DMD) based maskless lithography. These advancements have been in the areas of throughput, resolution, accuracy, and cost reduction. This progression in digital micromirror evolution provides considerable opportunities to displace existing lithographic techniques. Precise control of the individual mircormirrors, including scrolling, and full utilization of the FPGA, have allowed DMD-based lithography systems to reach new levels of throughput and repeatability, while reducing production and warranty costs. Throughput levels have far surpassed scanning laser techniques. Chip level cooling technologies allow for higher incident power to be reliably distributed over larger areas of the substrate. Resolution roadmaps are in place to migrate from the current 2400dpi (11μm) to 4800dpi (5.3μm). Without the constraints of mask requirements, mask alignment, storage, and defect analysis are not required, thus increasing accuracy and reducing cost. This contribution will examine the advancements in and benefits of DMD based maskless lithography.

  11. Recent Progress On Submicron Electron Beam Lithography

    NASA Astrophysics Data System (ADS)

    Takigawa, Tadahiro; Shimazaki, Kuniya; Kusui, Naoki

    1986-06-01

    In order to fabricate submicron pattern, total electron beam (EB) lithography system has been developed. Upper submicron pattern will be realized by optical lithography, which requires reticle with high accuracy. An EB writing system, EBM-130/40, has the performance of drawing capability of 4 M bit DRAM reticle pattern in about 40 minutes. The EB system incorporated with peripheral technologies including data compaction conversion software, reticle inspection system, APC-130R, and EBR-9 resist process can produce advanced reticles of number of about 600 per month. For lower submicron pattern formation, next generation lithography system is required. The EBM-130V is the variable shaped EB system with high acceleration voltage of 50 kV and high dosage of 50 μC/cm2 for direct writing and X-ray mask fabrication for development of the high bit density VLSI pattern. This system makes possible EB/optical combined lithography. Its metrology function allows it to measure X-ray mask distortion.

  12. Immersive Education, an Annotated Webliography

    ERIC Educational Resources Information Center

    Pricer, Wayne F.

    2011-01-01

    In this second installment of a two-part feature on immersive education a webliography will provide resources discussing the use of various types of computer simulations including: (a) augmented reality, (b) virtual reality programs, (c) gaming resources for teaching with technology, (d) virtual reality lab resources, (e) virtual reality standards…

  13. Learning immersion without getting wet

    NASA Astrophysics Data System (ADS)

    Aguilera, Julieta C.

    2012-03-01

    This paper describes the teaching of an immersive environments class on the Spring of 2011. The class had students from undergraduate as well as graduate art related majors. Their digital background and interests were also diverse. These variables were channeled as different approaches throughout the semester. Class components included fundamentals of stereoscopic computer graphics to explore spatial depth, 3D modeling and skeleton animation to in turn explore presence, exposure to formats like a stereo projection wall and dome environments to compare field of view across devices, and finally, interaction and tracking to explore issues of embodiment. All these components were supported by theoretical readings discussed in class. Guest artists presented their work in Virtual Reality, Dome Environments and other immersive formats. Museum professionals also introduced students to space science visualizations, which utilize immersive formats. Here I present the assignments and their outcome, together with insights as to how the creation of immersive environments can be learned through constraints that expose students to situations of embodied cognition.

  14. Advanced mask technique to improve bit line CD uniformity of 90 nm node flash memory in low-k1 lithography

    NASA Astrophysics Data System (ADS)

    Kim, Jong-doo; Choi, Jae-young; Kim, Jea-hee; Han, Jae-won

    2008-10-01

    As devices size move toward 90nm technology node or below, defining uniform bit line CD of flash devices is one of the most challenging features to print in KrF lithography. There are two principal difficulties in defining bit line on wafer. One is insufficient process margin besides poor resolution compared with ArF lithography. The other is that asymmetric bit line should be made for OPC(Optical Proximity Correction) modeling. Therefore advanced ArF lithography scanner should be used for define bit line with RETs (Resolution Enhancement Techniques) such as immersion lithography, OPC, PSM(Phase Shift Mask), high NA(Numerical Aperture), OAI(Off-Axis Illumination), SRAF(Sub-resolution Assistant Feature), and mask biasing.. Like this, ArF lithography propose the method of enhancing resolution, however, we must spend an enormous amount of CoC(cost of ownership) to utilize ArF photolithography process than KrF. In this paper, we suggest method to improve of bit line CD uniformity, patterned by KrF lithographic process in 90nm sFlash(stand alone Flash) devices. We applied new scheme of mask manufacturing, which is able to realize 2 different types of mask, binary and phase-shift, into one plate. Finally, we could get the more uniform bit lines and we expect to get more stable properties then before applying this technique.

  15. Hybrid immersed interface-immersed boundary methods for AC dielectrophoresis

    SciTech Connect

    Hossan, Mohammad Robiul; Dillon, Robert; Dutta, Prashanta

    2014-08-01

    Dielectrophoresis, a nonlinear electrokinetic transport mechanism, has become popular in many engineering applications including manipulation, characterization and actuation of biomaterials, particles and biological cells. In this paper, we present a hybrid immersed interface–immersed boundary method to study AC dielectrophoresis where an algorithm is developed to solve the complex Poisson equation using a real variable formulation. An immersed interface method is employed to obtain the AC electric field in a fluid media with suspended particles and an immersed boundary method is used for the fluid equations and particle transport. The convergence of the proposed algorithm as well as validation of the hybrid scheme with experimental results is presented. In this paper, the Maxwell stress tensor is used to calculate the dielectrophoretic force acting on particles by considering the physical effect of particles in the computational domain. Thus, this study eliminates the approximations used in point dipole methods for calculating dielectrophoretic force. A comparative study between Maxwell stress tensor and point dipole methods for computing dielectrophoretic forces are presented. The hybrid method is used to investigate the physics of dielectrophoresis in microfluidic devices using an AC electric field. The numerical results show that with proper design and appropriate selection of applied potential and frequency, global electric field minima can be obtained to facilitate multiple particle trapping by exploiting the mechanism of negative dielectrophoresis. Our numerical results also show that electrically neutral particles form a chain parallel to the applied electric field irrespective of their initial orientation when an AC electric field is applied. This proposed hybrid numerical scheme will help to better understand dielectrophoresis and to design and optimize microfluidic devices.

  16. Hybrid immersed interface-immersed boundary methods for AC dielectrophoresis

    NASA Astrophysics Data System (ADS)

    Hossan, Mohammad Robiul; Dillon, Robert; Dutta, Prashanta

    2014-08-01

    Dielectrophoresis, a nonlinear electrokinetic transport mechanism, has become popular in many engineering applications including manipulation, characterization and actuation of biomaterials, particles and biological cells. In this paper, we present a hybrid immersed interface-immersed boundary method to study AC dielectrophoresis where an algorithm is developed to solve the complex Poisson equation using a real variable formulation. An immersed interface method is employed to obtain the AC electric field in a fluid media with suspended particles and an immersed boundary method is used for the fluid equations and particle transport. The convergence of the proposed algorithm as well as validation of the hybrid scheme with experimental results is presented. In this paper, the Maxwell stress tensor is used to calculate the dielectrophoretic force acting on particles by considering the physical effect of particles in the computational domain. Thus, this study eliminates the approximations used in point dipole methods for calculating dielectrophoretic force. A comparative study between Maxwell stress tensor and point dipole methods for computing dielectrophoretic forces are presented. The hybrid method is used to investigate the physics of dielectrophoresis in microfluidic devices using an AC electric field. The numerical results show that with proper design and appropriate selection of applied potential and frequency, global electric field minima can be obtained to facilitate multiple particle trapping by exploiting the mechanism of negative dielectrophoresis. Our numerical results also show that electrically neutral particles form a chain parallel to the applied electric field irrespective of their initial orientation when an AC electric field is applied. This proposed hybrid numerical scheme will help to better understand dielectrophoresis and to design and optimize microfluidic devices.

  17. 46 CFR 199.273 - Immersion suits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Immersion suits. 199.273 Section 199.273 Shipping COAST... SYSTEMS FOR CERTAIN INSPECTED VESSELS Additional Requirements for Cargo Vessels § 199.273 Immersion suits. (a) Each cargo vessel must carry an immersion suit approved under approval series 160.171 of...

  18. High Efficiency Germanium Immersion Gratings

    SciTech Connect

    Kuzmenko, P J; Davis, P J; Little, S L; Little, L M; Bixler, J V

    2006-05-01

    We have fabricated several germanium immersion gratings by single crystal, single point diamond flycutting on an ultra-precision lathe. Use of a dead sharp tool produces groove corners less than 0.1 micron in radius and consequently high diffraction efficiency. We measured first order efficiencies in immersion of over 80% at 10.6 micron wavelength. Wavefront error was low averaging 0.06 wave rms (at 633 nm) across the full aperture. The grating spectral response was free of ghosts down to our detection limit of 1 part in 10{sup 4}. Scatter should be low based upon the surface roughness. Measurement of the spectral line profile of a CO{sub 2} laser sets an upper bound on total integrated scatter of 0.5%.

  19. Planar immersion lens with metasurfaces

    NASA Astrophysics Data System (ADS)

    Ho, John S.; Qiu, Brynan; Tanabe, Yuji; Yeh, Alexander J.; Fan, Shanhui; Poon, Ada S. Y.

    2015-03-01

    The solid immersion lens is a powerful optical tool that allows light entering material from air or a vacuum to focus to a spot much smaller than the free-space wavelength. Conventionally, however, the lenses rely on semispherical topographies and are nonplanar and bulky, which limits their integration in many applications. Recently, there has been considerable interest in using planar structures, referred to as metasurfaces, to construct flat optical components for manipulating light in unusual ways. Here, we propose and demonstrate the concept of a planar immersion lens based on metasurfaces. The resulting planar device, when placed near an interface between air and dielectric material, can focus electromagnetic radiation incident from air to a spot in the material smaller than the free-space wavelength. As an experimental demonstration, we fabricate an ultrathin and flexible microwave lens and further show that it achieves wireless energy transfer in material mimicking biological tissue.

  20. High efficiency germanium immersion gratings

    NASA Astrophysics Data System (ADS)

    Kuzmenko, Paul J.; Davis, Pete J.; Little, Steve L.; Little, Liesl M.; Bixler, Jay V.

    2006-06-01

    We have fabricated several germanium immersion gratings by single crystal, single point diamond flycutting on an ultra-precision lathe. Use of a dead sharp tool produces groove corners less than 0.1 micron in radius and consequently high diffraction efficiency. We measured first order efficiencies in immersion of over 80% at 10.6 micron wavelength. Wavefront error was low averaging 0.06 wave rms (at 633 nm) across the full aperture. The grating spectral response was free of ghosts down to our detection limit of 1 part in 104. Scatter should be low based upon the surface roughness. Measurement of the spectral line profile of a CO II laser sets an upper bound on total integrated scatter of 0.5%.

  1. Immersive Environments - A Connectivist Approach

    NASA Astrophysics Data System (ADS)

    Loureiro, Ana; Bettencourt, Teresa

    We are conducting a research project with the aim of achieving better and more efficient ways to facilitate teaching and learning in Higher Level Education. We have chosen virtual environments, with particular emphasis to Second Life® platform augmented by web 2.0 tools, to develop the study. The Second Life® environment has some interesting characteristics that captured our attention, it is immersive; it is a real world simulator; it is a social network; it allows real time communication, cooperation, collaboration and interaction; it is a safe and controlled environment. We specifically chose tools from web 2.0 that enable sharing and collaborative way of learning. Through understanding the characteristics of this learning environment, we believe that immersive learning along with other virtual tools can be integrated in today's pedagogical practices.

  2. Immersible solar heater for fluids

    DOEpatents

    Hazen, T.C.; Fliermans, C.B.

    1994-01-01

    An immersible solar heater is described comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.

  3. Immersible solar heater for fluids

    DOEpatents

    Kronberg, J.W.

    1995-07-11

    An immersible solar heater is described comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater. 11 figs.

  4. Nanoimprint lithography using IR laser irradiation

    NASA Astrophysics Data System (ADS)

    Grigaliūnas, V.; Tamulevičius, S.; Muehlberger, M.; Jucius, D.; Guobienė, A.; Kopustinskas, V.; Gudonytė, A.

    2006-11-01

    A new technique called "infrared laser-assisted nanoimprint lithography" was utilised to soften the thermoplastic polymer material mR-I 8020 during nanoimprint lithography. A laser setup and a sample holder with pressure and temperature control were designed for the imprint experiments. The polymer was spin coated onto crystalline Si <1 1 1> substrates. A prepatterned Si <1 1 1> substrate, which is transparent for the CO 2 laser irradiation, was used as an imprint stamp as well. It was shown, that the thermoplastic resist mR-I 8020 could be successfully imprinted using the infrared CW CO 2 laser irradiation ( λ = 10.6 μm). The etching rate of the CO 2 laser beam irradiated mR-I 8020 resist film under O 2 RF (13.56 MHz) plasma treatment and during O 2 reactive ion beam etching was investigated as well.

  5. Synchrotron beamlines for x-ray lithography

    NASA Astrophysics Data System (ADS)

    Trippe, Anthony P.; Pearce, W. J.

    1994-02-01

    Louisiana State University established the J. Bennett Johnston, Sr., Center for Advanced Microstructures and Devices (CAMD). Designed and constructed by the Brobeck Division of Maxwell Laboratories, the CAMD synchrotron light source is the first electron storage ring to be built by a commercial company in the United States. The synchrotron x-ray radiation generated at CAMD is an extremely useful exposure source for both thin and thick film lithography. Passing through a beamline containing two plane mirrors, the synchrotron light is used to expose thin resists for lithography of patterns with feature sizes of 0.25 micron and smaller. Two thick-resist beamlines, one using a single aspheric (collimating) mirror and one using a plane mirror, provide the higher flux photons required for miniaturization in silicon to produce microscopic mechanical devices including gears, motors, filters, and valves.

  6. Optimization criteria for SRAM design: lithography contribution

    NASA Astrophysics Data System (ADS)

    Cole, Daniel C.; Bula, Orest; Conrad, Edward W.; Coops, Daniel S.; Leipold, William C.; Mann, Randy W.; Oppold, Jeffrey H.

    1999-07-01

    Here we discuss the use of well calibrated resist and etch bias models, in conjunction with a fast microlithography aerial image simulator, to predict and 'optimize' the printed shapes through all critical levels in a dense SRAM design. Our key emphasis here is on 'optimization criteria', namely, having achieved good predictability for printability with lithography models, how to use this capability in conjunction of best electrical performance, yield, and density. The key lithography/design optimization issues discussed here are: (1) tightening of gate width variation by reducing spatial curvature in the source and drain regions, (2) achieving sufficient contact areas, (3) maximizing process window for overlay, (4) reducing leakage mechanisms by reducing contributions of stress and strain due to the printed shape of oxide isolation regions, (5) examining topological differences in design during the optimization process, (6) accounting for mask corner rounding, and (7) designing for scalability to smaller dimensions to achieve optical design reusability issues without hardware.

  7. Compact Imaging Spectrometer Utilizing Immersed Gratings

    DOEpatents

    Chrisp, Michael P.; Lerner, Scott A.; Kuzmenko, Paul J.; Bennett, Charles L.

    2006-03-21

    A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, a system for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the system for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the system for receiving the light and the system for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light through an optical element to the detector array.

  8. The ultimate chrome absorber in photomask making

    NASA Astrophysics Data System (ADS)

    Hashimoto, Masahiro; Iwashita, Hiroyuki; Kominato, Atsushi; Shishido, Hiroaki; Ushida, Masao; Mitsui, Hideaki

    2008-05-01

    193nm-immersion lithography is the most promising technology for 32nm-node device fabrication. A new Cr absorber (TFC) for 193-nm attenuated phase-shift blanks was developed to meet the photomask requirements without any additional process step, such as hardmask etching. TFC was introduced with a design concept of the vertical profile for shorter etching time, the over etching time reduction. As a result, the dry-etching time was dramatically improved by more than 20% shorter than the conventional Cr absorber (TF11) without any process changes. We confirmed that 150nm-resist thickness was possible by TFC. The 32nm technology-node requirement is fully supported by TFC with thinner CAR, such as resolution and CD performance.

  9. Implementation of assist features in EUV lithography

    NASA Astrophysics Data System (ADS)

    Jiang, Fan; Burkhardt, Martin; Raghunathan, Ananthan; Torres, Andres; Gupta, Rachit; Word, James

    2015-03-01

    The introduction of EUV lithography will happen at a critical feature pitch which corresponds to a k1 factor of roughly 0.45. While this number seems not very aggressive compared to recent ArF lithography nodes, the number is sufficiently low that the introduction of assist features has to be considered. While the small NA makes the k1 factor larger, the depth of focus still needs to be scaled down with wavelength. However the exposure tool's focus control is not greatly improved over the ArF tools, so other solutions to improve the depth of focus, e.g. SRAFs, are needed. On the other hand, sub-resolution assist features (SRAFs) require very small mask dimensions, which make masks more costly to write and inspect. Another disadvantage of SRAFs is the fact that they may cause pattern-dependent best focus shift due to thick mask effects. Those effects can be predicted, but the shift of best focus and the associated tilt of Bossung curves make the process more difficult to control. We investigate the impact of SRAFs on printing in EUV lithography and evaluate advantages and disadvantages. By using image quality parameters such as best focus (BF), and depth of focus (DOF), respectively with and without SRAFs, we will answer the question if we can gain a net benefit for 1D and 2D patterns by adding SRAFs. SRAFs will only be introduced if any net improvement in process variation (PV) outweighs the additional expense of assist patterning on the mask. In this paper, we investigate the difference in printing behavior of symmetric and asymmetric SRAF placement and whether through slit effect needs to be considered in SRAF placement for EUV lithography.

  10. Formation of Magnetic Anisotropy by Lithography.

    PubMed

    Kim, Si Nyeon; Nam, Yoon Jae; Kim, Yang Doo; Choi, Jun Woo; Lee, Heon; Lim, Sang Ho

    2016-01-01

    Artificial interface anisotropy is demonstrated in alternating Co/Pt and Co/Pd stripe patterns, providing a means of forming magnetic anisotropy using lithography. In-plane hysteresis loops measured along two principal directions are explained in depth by two competing shape and interface anisotropies, thus confirming the formation of interface anisotropy at the Co/Pt and Co/Pd interfaces of the stripe patterns. The measured interface anisotropy energies, which are in the range of 0.2-0.3 erg/cm(2) for both stripes, are smaller than those observed in conventional multilayers, indicating a decrease in smoothness of the interfaces when formed by lithography. The demonstration of interface anisotropy in the Co/Pt and Co/Pd stripe patterns is of significant practical importance, because this setup makes it possible to form anisotropy using lithography and to modulate its strength by controlling the pattern width. Furthermore, this makes it possible to form more complex interface anisotropy by fabricating two-dimensional patterns. These artificial anisotropies are expected to open up new device applications such as multilevel bits using in-plane magnetoresistive thin-film structures. PMID:27216420

  11. Formation of Magnetic Anisotropy by Lithography

    PubMed Central

    Kim, Si Nyeon; Nam, Yoon Jae; Kim, Yang Doo; Choi, Jun Woo; Lee, Heon; Lim, Sang Ho

    2016-01-01

    Artificial interface anisotropy is demonstrated in alternating Co/Pt and Co/Pd stripe patterns, providing a means of forming magnetic anisotropy using lithography. In-plane hysteresis loops measured along two principal directions are explained in depth by two competing shape and interface anisotropies, thus confirming the formation of interface anisotropy at the Co/Pt and Co/Pd interfaces of the stripe patterns. The measured interface anisotropy energies, which are in the range of 0.2–0.3 erg/cm2 for both stripes, are smaller than those observed in conventional multilayers, indicating a decrease in smoothness of the interfaces when formed by lithography. The demonstration of interface anisotropy in the Co/Pt and Co/Pd stripe patterns is of significant practical importance, because this setup makes it possible to form anisotropy using lithography and to modulate its strength by controlling the pattern width. Furthermore, this makes it possible to form more complex interface anisotropy by fabricating two-dimensional patterns. These artificial anisotropies are expected to open up new device applications such as multilevel bits using in-plane magnetoresistive thin-film structures. PMID:27216420

  12. Metallic resist for phase-change lithography

    PubMed Central

    Zeng, Bi Jian; Huang, Jun Zhu; Ni, Ri Wen; Yu, Nian Nian; Wei, Wei; Hu, Yang Zhi; Li, Zhen; Miao, Xiang Shui

    2014-01-01

    Currently, the most widely used photoresists in optical lithography are organic-based resists. The major limitations of such resists include the photon accumulation severely affects the quality of photolithography patterns and the size of the pattern is constrained by the diffraction limit. Phase-change lithography, which uses semiconductor-based resists such as chalcogenide Ge2Sb2Te5 films, was developed to overcome these limitations. Here, instead of chalcogenide, we propose a metallic resist composed of Mg58Cu29Y13 alloy films, which exhibits a considerable difference in etching rate between amorphous and crystalline states. Furthermore, the heat distribution in Mg58Cu29Y13 thin film is better and can be more easily controlled than that in Ge2Sb2Te5 during exposure. We succeeded in fabricating both continuous and discrete patterns on Mg58Cu29Y13 thin films via laser irradiation and wet etching. Our results demonstrate that a metallic resist of Mg58Cu29Y13 is suitable for phase change lithography, and this type of resist has potential due to its outstanding characteristics. PMID:24931505

  13. REBL nanowriter: Reflective Electron Beam Lithography

    NASA Astrophysics Data System (ADS)

    Petric, Paul; Bevis, Chris; Brodie, Alan; Carroll, Allen; Cheung, Anthony; Grella, Luca; McCord, Mark; Percy, Henry; Standiford, Keith; Zywno, Marek

    2009-03-01

    REBL (Reflective Electron Beam Lithography) is being developed for high throughput electron beam direct write maskless lithography. The system is specifically targeting 5 to 7 wafer levels per hour throughput on average at the 45 nm node, with extendibility to the 32 nm node and beyond. REBL incorporates a number of novel technologies to generate and expose lithographic patterns at estimated throughputs considerably higher than electron beam lithography has been able to achieve as yet. A patented reflective electron optic concept enables the unique approach utilized for the Digital Pattern Generator (DPG). The DPG is a CMOS ASIC chip with an array of small, independently controllable cells or pixels, which act as an array of electron mirrors. In this way, the system is capable of generating the pattern to be written using massively parallel exposure by ~1 million beams at extremely high data rates (~ 1Tbps). A rotary stage concept using a rotating platen carrying multiple wafers optimizes the writing strategy of the DPG to achieve the capability of high throughput for sparse pattern wafer levels. The exposure method utilized by the DPG was emulated on a Vistec VB-6 in order to validate the gray level exposure method used in REBL. Results of these exposure tests are discussed.

  14. Hard-tip, soft-spring lithography.

    PubMed

    Shim, Wooyoung; Braunschweig, Adam B; Liao, Xing; Chai, Jinan; Lim, Jong Kuk; Zheng, Gengfeng; Mirkin, Chad A

    2011-01-27

    Nanofabrication strategies are becoming increasingly expensive and equipment-intensive, and consequently less accessible to researchers. As an alternative, scanning probe lithography has become a popular means of preparing nanoscale structures, in part owing to its relatively low cost and high resolution, and a registration accuracy that exceeds most existing technologies. However, increasing the throughput of cantilever-based scanning probe systems while maintaining their resolution and registration advantages has from the outset been a significant challenge. Even with impressive recent advances in cantilever array design, such arrays tend to be highly specialized for a given application, expensive, and often difficult to implement. It is therefore difficult to imagine commercially viable production methods based on scanning probe systems that rely on conventional cantilevers. Here we describe a low-cost and scalable cantilever-free tip-based nanopatterning method that uses an array of hard silicon tips mounted onto an elastomeric backing. This method-which we term hard-tip, soft-spring lithography-overcomes the throughput problems of cantilever-based scanning probe systems and the resolution limits imposed by the use of elastomeric stamps and tips: it is capable of delivering materials or energy to a surface to create arbitrary patterns of features with sub-50-nm resolution over centimetre-scale areas. We argue that hard-tip, soft-spring lithography is a versatile nanolithography strategy that should be widely adopted by academic and industrial researchers for rapid prototyping applications. PMID:21270890

  15. Metallic resist for phase-change lithography.

    PubMed

    Zeng, Bi Jian; Huang, Jun Zhu; Ni, Ri Wen; Yu, Nian Nian; Wei, Wei; Hu, Yang Zhi; Li, Zhen; Miao, Xiang Shui

    2014-01-01

    Currently, the most widely used photoresists in optical lithography are organic-based resists. The major limitations of such resists include the photon accumulation severely affects the quality of photolithography patterns and the size of the pattern is constrained by the diffraction limit. Phase-change lithography, which uses semiconductor-based resists such as chalcogenide Ge₂Sb₂Te₅ films, was developed to overcome these limitations. Here, instead of chalcogenide, we propose a metallic resist composed of Mg₅₈Cu₂₉Y₁₃ alloy films, which exhibits a considerable difference in etching rate between amorphous and crystalline states. Furthermore, the heat distribution in Mg₅₈Cu₂₉Y₁₃ thin film is better and can be more easily controlled than that in Ge₂Sb₂Te₅ during exposure. We succeeded in fabricating both continuous and discrete patterns on Mg₅₈Cu₂₉Y₁₃ thin films via laser irradiation and wet etching. Our results demonstrate that a metallic resist of Mg₅₈Cu₂₉Y₁₃ is suitable for phase change lithography, and this type of resist has potential due to its outstanding characteristics. PMID:24931505

  16. Advanced lithography for micro-optics

    NASA Astrophysics Data System (ADS)

    Zeitner, U. D.; Kley, E.-B.

    2006-08-01

    Since the beginning of micro-optics fabrication most of the used technologies have been adapted from or are related to semiconductor fabrication techniques. These are widely known and the special microelectronics fabrication tools, especially lithography machines, are available at numerous places. Besides the fact that therefore micro-optics was able to took advantage of the steady development of semiconductor technology this tight linkage has also a lot of drawbacks. The adaptation of element properties to the fabrication limits given by the available technologies is very often connected with compromises in optical performance. In nowadays micro-optics fabrication has reached a level which justifies the development of fabrication tools specialized to its own demands. In the article the special demands of optical microstructures on the fabrication technologies are discussed and newly developed mico-optics fabrication tools are introduced. The first one is an electron-beam lithography machine for use with up substrates up to 300mm large and 15mm thick achieving a very high overlay accuracy and writing speed. The second one is a laser-lithography system capable to expose micro-optical structures onto non-planar substrates.

  17. Immersive Earth: Teaching Earth and Space with inexpensive immersive technology

    NASA Astrophysics Data System (ADS)

    Reiff, P. H.; Sumners, C.; Law, C. C.; Handron, K.

    2003-12-01

    In 1995 we pioneered "Space Update", the Digital Library for the rest of us", software that was so simple that a child could use it without a keyboard and yet would allow one-click updating of the daily earth and space science images without the dangers of having an open web browser on display. Thanks to NASA support, it allowed museums and schools to have a powerful exhibit for a tiny price. Over 40,000 disks in our series have been distributed so far to educators and the public. In 2003, with our partners we are again revolutionizing educational technology with a low-cost hardware and software solution to creating and displaying immersive content. Recently selected for funding as part of the REASoN competition, Immersive Earth is a partnership of scientists, museums, educators, and content providers. The hardware consists of a modest projector with a special fisheye lens to be used in an inflatable dome which many schools already have. This, coupled with a modest personal computer, can now easily project images and movies of earth and space, allows training students in 3-D content at a tiny fraction of the cost of a cave or fullscale dome theater. Another low-cost solution is the "Imove" system, where spherical movies can play on a personal computer, with the user changing the viewing direction with a joystick. We were the first to create immersive earth science shows, remain the leader in creating educational content that people want to see. We encourage people with "allsky" images or movies to bring it and see what it looks like inside a dome! Your content could be in our next show!

  18. A mask manufacturer's perspective on maskless lithography

    NASA Astrophysics Data System (ADS)

    Buck, Peter; Biechler, Charles; Kalk, Franklin

    2005-11-01

    Maskless Lithography (ML2) is again being considered for use in mainstream CMOS IC manufacturing. Sessions at technical conferences are being devoted to ML2. A multitude of new companies have been formed in the last several years to apply new concepts to breaking the throughput barrier that has in the past prevented ML2 from achieving the cost and cycle time performance necessary to become economically viable, except in rare cases. Has Maskless Lithography's (we used to call it "Direct Write Lithography") time really come? If so, what is the expected impact on the mask manufacturer and does it matter? The lithography tools used today in mask manufacturing are similar in concept to ML2 except for scale, both in throughput and feature size. These mask tools produce highly accurate lithographic images directly from electronic pattern files, perform multi-layer overlay, and mix-n-match across multiple tools, tool types and sites. Mask manufacturers are already accustomed to the ultimate low volume - one substrate per design layer. In order to achieve the economically required throughput, proposed ML2 systems eliminate or greatly reduce some of the functions that are the source of the mask writer's accuracy. Can these ML2 systems meet the demanding lithographic requirements without these functions? ML2 may eliminate the reticle but many of the processes and procedures performed today by the mask manufacturer are still required. Examples include the increasingly complex mask data preparation step and the verification performed to ensure that the pattern on the reticle is accurately representing the design intent. The error sources that are fixed on a reticle are variable with time on an ML2 system. It has been proposed that if ML2 is successful it will become uneconomical to be in the mask business - that ML2, by taking the high profit masks will take all profitability out of mask manufacturing and thereby endanger the entire semiconductor industry. Others suggest that a

  19. Deep-UV interference lithography combined with masked contact lithography for pixel wiregrid patterns

    NASA Astrophysics Data System (ADS)

    Lombardo, David; Shah, Piyush; Guo, Pengfei; Sarangan, Andrew

    2016-04-01

    Pixelated wiregrids are of great interest in polarimetric imagers, but there are no straightforward methods available for combining the uniform exposures of laser interference with a masking system to achieve pixels at different rotational angles. In this work we demonstrate a 266nm deep-UV interference lithography combined with a traditional i-line contact lithography to create such pixels. Aluminum wiregrids are first made, following by etching to create the pixels, and then a planarizing molybdenum film is used before patterning subsequent pixel arrays. The etch contrast between the molybdenum and the aluminum enables the release of the planarizing layer.

  20. 3-D patterning of silicon by laser-initiated, liquid-assisted colloidal (LILAC) lithography.

    PubMed

    Ulmeanu, M; Grubb, M P; Jipa, F; Quignon, B; Ashfold, M N R

    2015-06-01

    We report a comprehensive study of laser-initiated, liquid-assisted colloidal (LILAC) lithography, and illustrate its utility in patterning silicon substrates. The method combines single shot laser irradiation (frequency doubled Ti-sapphire laser, 50fs pulse duration, 400nm wavelength) and medium-tuned optical near-field effects around arrays of silica colloidal particles to achieve 3-D surface patterning of silicon. A monolayer (or multilayers) of hexagonal close packed silica colloidal particles act as a mask and offer a route to liquid-tuned optical near field enhancement effects. The resulting patterns are shown to depend on the difference in refractive index of the colloidal particles (ncolloid) and the liquid (nliquid) in which they are immersed. Two different topographies are demonstrated experimentally: (a) arrays of bumps, centred beneath the original colloidal particles, when using liquids with nliquidncolloid - and explained with the aid of complementary Mie scattering simulations. The LILAC lithography technique has potential for rapid, large area, organized 3-D patterning of silicon (and related) substrates. PMID:25465198

  1. CD bias reduction in CD-SEM linewidth measurements for advanced lithography

    NASA Astrophysics Data System (ADS)

    Tanaka, Maki; Meessen, Jeroen; Shishido, Chie; Watanabe, Kenji; Minnaert-Janssen, Ingrid; Vanoppen, Peter

    2008-03-01

    The linewidth measurement capability of the model-based library (MBL) matching technique was evaluated experimentally. This technique estimates the dimensions and shape of a target pattern by comparing a measured SEM image profile to a library of simulated line scans. The simulation model uses a non-linear least squares method to estimate pattern geometry parameters. To examine the application of MBL matching in an advanced lithography process, a focus-exposure matrix wafer was prepared with a leading-edge immersion lithography tool. The evaluation used 36 sites with target structures having various linewidths from 45 to 200 nm. The measurement accuracy was evaluated by using an atomic force microscope (AFM) as a reference measurement system. The results of a first trial indicated that two or more solutions could exist in the parameter space in MBL matching. To solve this problem, we obtained a rough estimation of the scale parameter in SEM imaging, based on experimental results, in order to add a constraint in the matching process. As a result, the sensitivity to sidewall variation in MBL matching was improved, and the measurement bias was reduced from 22.1 to 16 nm. These results indicate the possibility of improving the CD measurement capability by applying this tool parameter appropriately.

  2. The study of lithography conditions to use advanced resist performance properly

    NASA Astrophysics Data System (ADS)

    Yang, Zhengkai; Wang, Wuping; Chen, Quan; Aoyama, Hajime; Takemasa, Kengo; Sei, Toshihiko; Miyazawa, Tami; Matsuyama, Tomoyuki; Shao, Chun

    2015-03-01

    Correlation of resist modeling of printed features with lithographic data is a necessary part of developing new lithographic processes. Recently, we have found a case in which the most advanced resist types sometimes show better behavior than expectations from optical simulation in terms of dose latitude, MEEF (mask error enhancement factor), and even CD variation through different pitches. This superior resist performance may allow greater margin for error in each component, such as mask, scanner, and metrology in very low-k1 lithography. On the other hand, since the resist pattern CD for the most advanced resist is very much different from the prediction of optical simulation, it is a challenge to build OPC models using the exposure result with the resist. In order to solve this issue, we have tried to use several litho parameters to reduce the gap between optical simulation and resist CDs for OPC modeling. In this paper we discuss the effect of the parameters to reduce the gap between optical model and actual resist behavior with keeping superior performance as much as possible. The method we mention may be a key to use the most advanced resist in near future. As a result the life of ArF immersion lithography in the critical layer would be extended than we expect today.

  3. 75 FR 44015 - Certain Semiconductor Products Made by Advanced Lithography Techniques and Products Containing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... COMMISSION Certain Semiconductor Products Made by Advanced Lithography Techniques and Products Containing... importation of certain semiconductor products made by advanced lithography techniques and products containing... certain semiconductor products made by advanced lithography techniques or products containing same...

  4. Canoeists' disorientation following cold immersion

    PubMed Central

    Baker, S.; Atha, J.

    1981-01-01

    As an initial step to a broader study of the disorientating effects of cold water immersions on top class competitive canoeists a survey was made of the incidence of hazardous immersions amongst a majority sample of the better canoeists in the country. Virtually the entire entry to one of the most important national competitive meets was canvassed. A total of 288 canoeists in the 1st and 2nd divisions were identified and asked to participate. Replies were received from 247 (86%). All those responding had had extensive experience of canoeing in winter spate and were capable of fast and efficient first-time canoe rolls in cases of capsize. Particular interest was focussed on the 85 (34%) who had experienced at least one capsize in cold water during training or competition in mid-winter. Respondents viewed the winter capsize seriously. Despite their familiarity with the conditions in which they trained all 85, recalling their capsize experiences, reported being concerned, most (79%) only modestly so, but a significant proportion (21%) confessed to feelings of extreme alarm. A number of marked physical symptoms that regularly attend on a capsize were widely reported, the most usual of which was severe pain in the forehead (89%) and breathing and speaking difficulties when afloat (64%). Additionally 62% reported sensory problems including visual difficulties, dizziness and disorientation. Five canoeists admitted fainting. Despite these hazards few preventive measures were taken and clothing with negligible thermal insulation properties was commonly worn. It is concluded that transient cold immersions can be disturbing, and can disorientate the canoeist, but that although conscious of this and to his own potentially high cost, he takes little notice of it in his desire to compete successfully. Imagesp111-ap111-bp112-ap113-ap114-a PMID:7272652

  5. Gestural interfaces for immersive environments

    NASA Astrophysics Data System (ADS)

    Margolis, Todd

    2014-02-01

    We are witnessing an explosion of new forms of Human Computer Interaction devices lately for both laboratory research and home use. With these new affordance in user interfaces (UI), how can gestures be used to improve interaction for large scale immersive display environments. Through the investigation of full body, head and hand tracking, this paper will discuss various modalities of gesture recognition and compare their usability to other forms of interactivity. We will explore a specific implementation of hand gesture tracking within a large tiled display environment for use with common collaborative media interaction activities.

  6. Fabrication of metallic nanowires and nanoribbons using laser interference lithography and shadow lithography

    SciTech Connect

    Park, Joong- Mok; Nalwa, Kanwar Singh; Leung, Wai; Constant, Kristen; Chaudhary, Sumit; Ho, Kai-Ming

    2010-04-30

    Ordered and free-standing metallic nanowires were fabricated by e-beam deposition on patterned polymer templates made by interference lithography. The dimensions of the nanowires can be controlled through adjustment of deposition conditions and polymer templates. Grain size, polarized optical transmission and electrical resistivity were measured with ordered and free-standing nanowires.

  7. Materials Design for Block Copolymer Lithography

    NASA Astrophysics Data System (ADS)

    Sweat, Daniel Patrick

    Block copolymers (BCPs) have attracted a great deal of scientific and technological interest due to their ability to spontaneously self-assemble into dense periodic nanostructures with a typical length scale of 5 to 50 nm. The use of self-assembled BCP thin-films as templates to form nanopatterns over large-area is referred to as BCP lithography. Directed self-assembly of BCPs is now viewed as a viable candidate for sub-20 nm lithography by the semiconductor industry. However, there are multiple aspects of assembly and materials design that need to be addressed in order for BCP lithography to be successful. These include substrate modification with polymer brushes or mats, tailoring of the block copolymer chemistry, understanding thin-film assembly and developing epitaxial like methods to control long range alignment. The rational design, synthesis and self-assembly of block copolymers with large interaction parameters (chi) is described in the first part of this dissertation. Two main blocks were chosen for introducing polarity into the BCP system, namely poly(4-hydroxystyrene) and poly(2-vinylpyridine). Each of these blocks are capable of ligating Lewis acids which can increase the etch contrast between the blocks allowing for facile pattern transfer to the underlying substrate. These BCPs were synthesized by living anionic polymerization and showed excellent control over molecular weight and dispersity, providing access to sub 5-nm domain sizes. Polymer brushes consist of a polymer chain with one end tethered to the surface and have wide applicability in tuning surface energy, forming responsive surfaces and increasing biocompatibility. In the second part of the dissertation, we present a universal method to grow dense polymer brushes on a wide range of substrates and combine this chemistry with BCP assembly to fabricate nanopatterned polymer brushes. This is the first demonstration of introducing additional functionality into a BCP directing layer and opens up

  8. Illumination optimization in optical projective lithography

    NASA Astrophysics Data System (ADS)

    Jiang, Hai-bo; Xing, Ting-wen; Du, Meng; Chen, An

    2013-08-01

    As lithography still pushing toward to lower K1 imaging, traditional illumination source shapes may perform marginally in resolving complex layouts, freeform source shapes are expected to achieve better image quality. Illumination optimization as one of inverse lithography techniques attempts to synthesize the input source which leads to the desired output wafer pattern by inverting the forward model from mask to wafer. Usually, inverse lithography problem could be solved by standard numerical methods. Recently, a set of gradient-based numerical methods have been developed to solve the mask optimization problem based on Hopkins' approach. In this study, the same method is also applied to resolve the illumination optimization but based on Abbe imaging formulation for partially coherent illumination. Firstly we state a pixel-based source representation, and analyze the constraint condition for source intensity. Secondly, we propose an objective function which includes three aspects: image fidelity, source smoothness and discretization penalty. Image fidelity is to ensure that the image is as close to the given mask as possible. Source smoothness and discretization penalty are to decrease the source complexity. All of the three items could be described mathematically. Thirdly, we describe the detailed optimization flow, and present the advantages of using Abbe imaging formulation as calculation mode of light intensity. Finally, some simulations were done with initial conventional illumination for 90nm isolated, dense and elbow features separately. As a result, we get irregular dipole source shapes for isolated and dense pattern, and irregular quadrupole for elbow pattern. The results also show that our method could provide great improvements in both image fidelity and source complexity.

  9. Molecular resists for EUV and EB lithography

    NASA Astrophysics Data System (ADS)

    Takemoto, Ichiki; Ando, Nobuo; Edamatsu, Kunishige; Lee, Youngjoon; Takashima, Masayuki; Yokoyama, Hiroyuki

    2008-03-01

    Extreme ultraviolet lithography at a wavelength of 13.5 nm has been prepared for next generation lithography for several years. Of primary concern in EUV lithography is line edge roughness as well as high sensitivity. In recent years, various types of resist, such as protected PHS resin resist and molecular resist, have been investigated. In order to reduce LER, we have studied novel molecular resists which are promising alternative to polymeric photoresists for use as imaging materials with improved resolution and line edge roughness. The work reported in this paper has focused on the development of a new class of chemically amplified molecular resists that are composed of a single molecule which contains all of the different functionalities desired in a chemically amplified resists. For the purpose of improvement of the resist performance, we have designed the resist material of a protected polyphenol derivative (protected Compound A). PAG moiety is bonded to Compound A to achieve uniform PAG density and to control the acid diffusion length in a resist film. We analyzed uniformity of PAG density in a resist film by using gradient shaving preparation and TOF-SIMS analysis. From the TOF-SIMS spectra, the ions intensities of the PAG moiety are almost constant from the surface to the bottom of the film. Therefore, we can conclude that PAG is distributed homogeneously. Under e-beam exposure, a 100nm thick film of the PAG bonded molecular resist resolved lines down to 100nm. We also discussed the new design for molecular resists, their synthesis and lithographic performance.

  10. Plasma formed ion beam projection lithography system

    SciTech Connect

    Leung, Ka-Ngo; Lee, Yung-Hee Yvette; Ngo, Vinh; Zahir, Nastaran

    2002-01-01

    A plasma-formed ion-beam projection lithography (IPL) system eliminates the acceleration stage between the ion source and stencil mask of a conventional IPL system. Instead a much thicker mask is used as a beam forming or extraction electrode, positioned next to the plasma in the ion source. Thus the entire beam forming electrode or mask is illuminated uniformly with the source plasma. The extracted beam passes through an acceleration and reduction stage onto the resist coated wafer. Low energy ions, about 30 eV, pass through the mask, minimizing heating, scattering, and sputtering.

  11. Wave and Particle in Molecular Interference Lithography

    SciTech Connect

    Juffmann, Thomas; Truppe, Stefan; Geyer, Philipp; Major, Andras G.; Arndt, Markus; Deachapunya, Sarayut; Ulbricht, Hendrik

    2009-12-31

    The wave-particle duality of massive objects is a cornerstone of quantum physics and a key property of many modern tools such as electron microscopy, neutron diffraction or atom interferometry. Here we report on the first experimental demonstration of quantum interference lithography with complex molecules. Molecular matter-wave interference patterns are deposited onto a reconstructed Si(111) 7x7 surface and imaged using scanning tunneling microscopy. Thereby both the particle and the quantum wave character of the molecules can be visualized in one and the same image. This new approach to nanolithography therefore also represents a sensitive new detection scheme for quantum interference experiments.

  12. Wave and particle in molecular interference lithography.

    PubMed

    Juffmann, Thomas; Truppe, Stefan; Geyer, Philipp; Major, András G; Deachapunya, Sarayut; Ulbricht, Hendrik; Arndt, Markus

    2009-12-31

    The wave-particle duality of massive objects is a cornerstone of quantum physics and a key property of many modern tools such as electron microscopy, neutron diffraction or atom interferometry. Here we report on the first experimental demonstration of quantum interference lithography with complex molecules. Molecular matter-wave interference patterns are deposited onto a reconstructed Si(111) 7x7 surface and imaged using scanning tunneling microscopy. Thereby both the particle and the quantum wave character of the molecules can be visualized in one and the same image. This new approach to nanolithography therefore also represents a sensitive new detection scheme for quantum interference experiments. PMID:20366311

  13. Nanoimprint lithography: an enabling technology for nanophotonics

    NASA Astrophysics Data System (ADS)

    Yao, Yuhan; Liu, He; Wang, Yifei; Li, Yuanrui; Song, Boxiang; Bratkovsk, Alexandre; Wang, Shih-Yuan; Wu, Wei

    2015-11-01

    Nanoimprint lithography (NIL) is an indispensable tool to realize a fast and accurate nanoscale patterning in nanophotonics due to high resolution and high yield. The number of publication on NIL has increased from less than a hundred per year to over three thousand per year. In this paper, the most recent developments on NIL patterning transfer processes and its applications on nanophotonics are discussed and reviewed. NIL has been opening up new opportunities for nanophotonics, especially in fabricating optical meta-materials. With more researches on this low-cost high-throughput fabrication technology, we should anticipate a brighter future for nanophotonics and NIL.

  14. EUV lithography: progress, challenges, and outlook

    NASA Astrophysics Data System (ADS)

    Wurm, S.

    2014-10-01

    Extreme Ultraviolet Lithography (EUVL) has been in the making for more than a quarter century. The first EUVL production tools have been delivered over the past year and chip manufacturers and suppliers are maturing the technology in pilot line mode to prepare for high volume manufacturing (HVM). While excellent progress has been made in many technical and business areas to prepare EUVL for HVM introduction, there are still critical technical and business challenges to be addressed before the industry will be able to use EUVL in HVM.

  15. Atom Lithography with a Holographic Light Mask

    NASA Astrophysics Data System (ADS)

    Mützel, M.; Tandler, S.; Haubrich, D.; Meschede, D.; Peithmann, K.; Flaspöhler, M.; Buse, K.

    2002-02-01

    In atom lithography with optical masks, deposition of an atomic beam on a given substrate is controlled by a standing light-wave field. The lateral intensity distribution of the light field is transferred to the substrate with nanometer scale. We have tailored a complex pattern of this intensity distribution through diffraction of a laser beam from a hologram that is stored in a photorefractive crystal. This method can be extended to superpose 1000 or more laser beams. The method is furthermore applicable during growth processes and thus allows full 3D structuring of suitable materials with periodic and nonperiodic patterns at nanometer scales.

  16. Antiadhesion considerations for UV nanoimprint lithography

    SciTech Connect

    Houle, F. A.; Rettner, C. T.; Miller, D. C.; Sooriyakumaran, R.

    2007-05-21

    Low surface energy fluorosilane layers are widely used as release coatings for quartz templates in UV nanoimprint lithography, yet they are generally found to degrade with use. It is found that these layers are chemically attacked when used with UV cured methacrylate and vinyl ether resists, as found previously for acrylate resists, leading to the conclusion that low reactivity and not low surface energy is of importance for effective release layers. It is shown that an ion-beam deposited diamondlike carbon release coating is a useful alternative, having both stability in a reactive environment and lower adhesion despite its higher surface energy.

  17. Laser lithography by photon scanning tunneling microscopy

    SciTech Connect

    Lee, I.; Warmack, R.J.; Ferrell, T.L.

    1993-06-01

    We have investigated the possibility of using a photon scanning tunneling microscope (PSTM) for laser lithography. A contrast enhancement material (CEM) is coated onto a sample slide and coupled to the prism of a PSTM. The CEM becomes transparent above a laser (HeCd at a wavelength of 442 nm) intensity threshold attained due to the proximity of the probe tip. The same surface can then be inspected using the given experimental configuration by replacing the HeCd laser line with a non-exposing 633-nm HeNe laser line. Direct patterns can be produced by varying the exposure time and the shape of the probe tip.

  18. Pathogenesis of sudden death following water immersion (immersion syndrome)

    NASA Technical Reports Server (NTRS)

    Buhring, M.; Spies, H. F.

    1981-01-01

    Sympathetic activity under cold stress is investigated. Predominantly vagal cardio-depressive reflexes are discussed besides currently known mechanisms of sudden death after water immersion. Pronounced circulatory centralization in diving animals as well as following exposure in cold water indicates additional sympathetic activity. In cold water baths of 15 C, measurements indicate an increase in plasma catecholamine levels by more than 300 percent. This may lead to cardiac arrhythmias by the following mechanisms: cold water essentially induces sinus bradycardia; brady-and tachycardiarrhythmias may supervene as secondary complications; sinusbradycardia may be enhanced by sympathetic hypertonus. Furthermore, ectopic dysrhythmias are liable to be induced by the strictly sympathetic innervation of the ventricle. Myocardial ischemia following a rise in peripheral blood pressure constitutes another arrhythmogenic factor. Some of these reactions are enhanced by alcohol intoxication.

  19. A review of roll-to-roll nanoimprint lithography

    PubMed Central

    2014-01-01

    Since its introduction in 1995, nanoimprint lithography has been demonstrated in many researches as a simple, low-cost, and high-throughput process for replicating micro- and nanoscale patterns. Due to its advantages, the nanoimprint lithography method has been rapidly developed over the years as a promising alternative to conventional nanolithography processes to fulfill the demands generated from the recent developments in the semiconductor and flexible electronics industries, which results in variations of the process. Roll-to-roll (R2R) nanoimprint lithography (NIL) is the most demanded technique due to its high-throughput fulfilling industrial-scale application. In the present work, a general literature review on the various types of nanoimprint lithography processes especially R2R NIL and the methods commonly adapted to fabricate imprint molds are presented to provide a clear view and understanding on the nanoimprint lithography technique as well as its recent developments. PACS 81.16.Nd PMID:25024682

  20. Learning Relative Motion Concepts in Immersive and Non-Immersive Virtual Environments

    ERIC Educational Resources Information Center

    Kozhevnikov, Michael; Gurlitt, Johannes; Kozhevnikov, Maria

    2013-01-01

    The focus of the current study is to understand which unique features of an immersive virtual reality environment have the potential to improve learning relative motion concepts. Thirty-seven undergraduate students learned relative motion concepts using computer simulation either in immersive virtual environment (IVE) or non-immersive desktop…

  1. Absolute dosimetry for extreme-ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Berger, Kurt W.; Campiotti, Richard H.

    2000-06-01

    The accurate measurement of an exposure dose reaching the wafer on an extreme ultraviolet (EUV) lithographic system has been a technical challenge directly applicable to the evaluation of candidate EUV resist materials and calculating lithography system throughputs. We have developed a dose monitoring sensor system that can directly measure EUV intensities at the wafer plane of a prototype EUV lithographic system. This sensor system, located on the wafer stage adjacent to the electrostatic chuck used to grip wafers, operates by translating the sensor into the aerial image, typically illuminating an 'open' (unpatterned) area on the reticle. The absolute signal strength can be related to energy density at the wafer, and thus used to determine resist sensitivity, and the signal as a function of position can be used to determine illumination uniformity at the wafer plane. Spectral filtering to enhance the detection of 13.4 nm radiation was incorporated into the sensor. Other critical design parameters include the packaging and amplification technologies required to place this device into the space and vacuum constraints of a EUV lithography environment. We describe two approaches used to determine the absolute calibration of this sensor. The first conventional approach requires separate characterization of each element of the sensor. A second novel approach uses x-ray emission from a mildly radioactive iron source to calibrate the absolute response of the entire sensor system (detector and electronics) in a single measurement.

  2. Dynamic maskless holographic lithography and applications

    NASA Astrophysics Data System (ADS)

    McAdams, Daniel R.

    The purpose of this research is to improve the resolution of dynamic maskless holographic lithography (DMHL) by using two-photon absorption, to provide a more thorough characterization of the process, and to expand the functionality of the process by adding previously undemonstrated patterning modes. Two-photon DMHL will be performed in both 2D and 3D configurations with specific characterization relating to process resolution and repeatability. The physical limits of DMHL will be discussed and ways to circumvent them will be proposed and tested. DMHL eliminates the need for a separate mask for every different pattern exposure and allows for real-time shaping of the exposure pattern. It uses an electrically addressable spatial light modulator (SLM) to create an arbitrary intensity pattern at the specimen plane. The SLM is a phase mask that displays a hologram. An algorithm is used to find an appropriate phase hologram for each desired intensity pattern. Each pixel of the SLM shapes the wavefront of the incoming laser light so that the natural Fourier transforming property of a lens causes the desired image to appear in the specimen plane. The process enables one-off projects to be done without the cost of fabricating a mask, and makes it possible to perform lithography with fewer (or even no) moving parts.

  3. Pattern-integrated interference lithography instrumentation

    NASA Astrophysics Data System (ADS)

    Burrow, G. M.; Leibovici, M. C. R.; Kummer, J. W.; Gaylord, T. K.

    2012-06-01

    Multi-beam interference (MBI) provides the ability to form a wide range of sub-micron periodic optical-intensity distributions with applications to a variety of areas, including photonic crystals (PCs), nanoelectronics, biomedical structures, optical trapping, metamaterials, and numerous subwavelength structures. Recently, pattern-integrated interference lithography (PIIL) was presented as a new lithographic method that integrates superposed pattern imaging with interference lithography in a single-exposure step. In the present work, the basic design and systematic implementation of a pattern-integrated interference exposure system (PIIES) is presented to realize PIIL by incorporating a projection imaging capability in a novel three-beam interference configuration. A fundamental optimization methodology is presented to model the system and predict MBI-patterning performance. To demonstrate the PIIL method, a prototype PIIES experimental configuration is presented, including detailed alignment techniques and experimental procedures. Examples of well-defined PC structures, fabricated with a PIIES prototype, are presented to demonstrate the potential of PIIL for fabricating dense integrated optical circuits, as well as numerous other subwavelength structures.

  4. Hard Transparent Arrays for Polymer Pen Lithography.

    PubMed

    Hedrick, James L; Brown, Keith A; Kluender, Edward J; Cabezas, Maria D; Chen, Peng-Cheng; Mirkin, Chad A

    2016-03-22

    Patterning nanoscale features across macroscopic areas is challenging due to the vast range of length scales that must be addressed. With polymer pen lithography, arrays of thousands of elastomeric pyramidal pens can be used to write features across centimeter-scales, but deformation of the soft pens limits resolution and minimum feature pitch, especially with polymeric inks. Here, we show that by coating polymer pen arrays with a ∼175 nm silica layer, the resulting hard transparent arrays exhibit a force-independent contact area that improves their patterning capability by reducing the minimum feature size (∼40 nm), minimum feature pitch (<200 nm for polymers), and pen to pen variation. With these new arrays, patterns with as many as 5.9 billion features in a 14.5 cm(2) area were written using a four hundred thousand pyramid pen array. Furthermore, a new method is demonstrated for patterning macroscopic feature size gradients that vary in feature diameter by a factor of 4. Ultimately, this form of polymer pen lithography allows for patterning with the resolution of dip-pen nanolithography across centimeter scales using simple and inexpensive pen arrays. The high resolution and density afforded by this technique position it as a broad-based discovery tool for the field of nanocombinatorics. PMID:26928012

  5. Mask cost of ownership for advanced lithography

    NASA Astrophysics Data System (ADS)

    Muzio, Edward G.; Seidel, Philip K.

    2000-07-01

    As technology advances, becoming more difficult and more expensive, the cost of ownership (CoO) metric becomes increasingly important in evaluating technical strategies. The International SEMATECH CoC analysis has steadily gained visibility over the past year, as it attempts to level the playing field between technology choices, and create a fair relative comparison. In order to predict mask cots for advanced lithography, mask process flows are modeled using bets-known processing strategies, equipment cost, and yields. Using a newly revised yield mode, and updated mask manufacture flows, representative mask flows can be built. These flows are then used to calculate mask costs for advanced lithography down to the 50 nm node. It is never the goal of this type of work to provide absolute cost estimates for business planning purposes. However, the combination of a quantifiable yield model with a clearly defined set of mask processing flows and a cost model based upon them serves as an excellent starting point for cost driver analysis and process flow discussion.

  6. Mask and lithography techniques for FPD

    NASA Astrophysics Data System (ADS)

    Sandstrom, T.; Wahlsten, M.; Sundelin, E.; Hansson, G.; Svensson, A.

    2015-09-01

    Large-field projection lithography for FPDs has developed gradually since the 90s. The LCD screen technology has remained largely unchanged and incremental development has given us better image quality, larger screen sizes, and above all lower cost per area. Recently new types of mobile devices with very high pixel density and/or OLED displays have given rise to dramatically higher requirem ents on photomask technology. Devices with 600 ppi or m ore need lithography with higher optical resolution and better linewidth control. OLED di splays pose new challenges with high sensitivity to transistor parameters and to capacitive cross-talk. New mask requirements leads to new maskwriter requirements and Mycronic has developed a new generation of large -area mask writers with significantly improved properties. This paper discusses and shows data for the improved writers. Mask production to high er quality stan dards also need metrology to verify the quality and Mycronic has introduced a 2D metrology tool with accuracy adequate for current and future masks. New printing or additive methods of producing disp lays on plastic or metal foil will make low-cost disp lays available. This inexpensive type of disp lays will exist side by side with the photographic quality displays of TVs and mobile devices, which will continue to be a challenge in terms of mask and production quality.

  7. Economic consequences of high throughput maskless lithography

    NASA Astrophysics Data System (ADS)

    Hartley, John G.; Govindaraju, Lakshmi

    2005-11-01

    Many people in the semiconductor industry bemoan the high costs of masks and view mask cost as one of the significant barriers to bringing new chip designs to market. All that is needed is a viable maskless technology and the problem will go away. Numerous sites around the world are working on maskless lithography but inevitably, the question asked is "Wouldn't a one wafer per hour maskless tool make a really good mask writer?" Of course, the answer is yes, the hesitation you hear in the answer isn't based on technology concerns, it's financial. The industry needs maskless lithography because mask costs are too high. Mask costs are too high because mask pattern generators (PG's) are slow and expensive. If mask PG's become much faster, mask costs go down, the maskless market goes away and the PG supplier is faced with an even smaller tool demand from the mask shops. Technical success becomes financial suicide - or does it? In this paper we will present the results of a model that examines some of the consequences of introducing high throughput maskless pattern generation. Specific features in the model include tool throughput for masks and wafers, market segmentation by node for masks and wafers and mask cost as an entry barrier to new chip designs. How does the availability of low cost masks and maskless tools affect the industries tool makeup and what is the ultimate potential market for high throughput maskless pattern generators?

  8. Benchtop Micromolding of Polystyrene by Soft Lithography

    PubMed Central

    Wang, Yuli; Balowski, Joseph; Phillips, Colleen; Phillips, Ryan; Sims, Christopher E.; Allbritton, Nancy L.

    2012-01-01

    Polystyrene (PS), a standard material for cell culture consumable labware, was molded into microstructures with high fidelity of replication by an elastomeric polydimethylsiloxane (PDMS) mold. The process was a simple, benchtop method based on soft lithography using readily available materials. The key to successful replica molding by this simple procedure relies on the use of a solvent, for example, gamma-butyrolactone, which dissolves PS without swelling the PDMS mold. PS solution was added to the PDMS mold, and evaporation of solvent was accomplished by baking the mold on a hotplate. Microstructures with feature sizes as small as 3 µm and aspect ratios as large as 7 were readily molded. Prototypes of microfluidic chips made from PS were prepared by thermal bonding of a microchannel molded in PS with a flat PS substrate. The PS microfluidic chip displayed much lower adsorption and absorption of hydrophobic molecules (e.g. rhodamine B) compared to a comparable chip created from PDMS. The molded PS surface exhibited stable surface properties after plasma oxidation as assessed by contact angle measurement. The molded, oxidized PS surface remained an excellent surface for cell culture based on cell adhesion and proliferation. The micromolded PS possessed properties that were ideal for biological and bioanalytical needs, thus making it an alternative material to PDMS and suitable for building lab-on-a-chip devices by soft lithography methods. PMID:21811715

  9. Game engines and immersive displays

    NASA Astrophysics Data System (ADS)

    Chang, Benjamin; Destefano, Marc

    2014-02-01

    While virtual reality and digital games share many core technologies, the programming environments, toolkits, and workflows for developing games and VR environments are often distinct. VR toolkits designed for applications in visualization and simulation often have a different feature set or design philosophy than game engines, while popular game engines often lack support for VR hardware. Extending a game engine to support systems such as the CAVE gives developers a unified development environment and the ability to easily port projects, but involves challenges beyond just adding stereo 3D visuals. In this paper we outline the issues involved in adapting a game engine for use with an immersive display system including stereoscopy, tracking, and clustering, and present example implementation details using Unity3D. We discuss application development and workflow approaches including camera management, rendering synchronization, GUI design, and issues specific to Unity3D, and present examples of projects created for a multi-wall, clustered, stereoscopic display.

  10. Immersive video for virtual tourism

    NASA Astrophysics Data System (ADS)

    Hernandez, Luis A.; Taibo, Javier; Seoane, Antonio J.

    2001-11-01

    This paper describes a new panoramic, 360 degree(s) video system and its use in a real application for virtual tourism. The development of this system has required to design new hardware for multi-camera recording, and software for video processing in order to elaborate the panorama frames and to playback the resulting high resolution video footage on a regular PC. The system makes use of new VR display hardware, such as WindowVR, in order to make the view dependent on the viewer's spatial orientation and so enhance immersiveness. There are very few examples of similar technologies and the existing ones are extremely expensive and/or impossible to be implemented on personal computers with acceptable quality. The idea of the system starts from the concept of Panorama picture, developed in technologies such as QuickTimeVR. This idea is extended to the concept of panorama frame that leads to panorama video. However, many problems are to be solved to implement this simple scheme. Data acquisition involves simultaneously footage recording in every direction, and latter processing to convert every set of frames in a single high resolution panorama frame. Since there is no common hardware capable of 4096x512 video playback at 25 fps rate, it must be stripped in smaller pieces which the system must manage to get the right frames of the right parts as the user movement demands it. As the system must be immersive, the physical interface to watch the 360 degree(s) video is a WindowVR, that is, a flat screen with an orientation tracker that the user holds in his hands, moving it like if it were a virtual window through which the city and its activity is being shown.

  11. Initiation of immersed granular avalanches

    NASA Astrophysics Data System (ADS)

    Mutabaruka, Patrick; Delenne, Jean-Yves; Soga, Kenichi; Radjai, Farhang

    2014-05-01

    By means of coupled molecular dynamics-computational fluid dynamics simulations, we analyze the initiation of avalanches in a granular bed of spherical particles immersed in a viscous fluid and inclined above its angle of repose. In quantitative agreement with experiments, we find that the bed is unstable for a packing fraction below 0.59 but is stabilized above this packing fraction by negative excess pore pressure induced by the effect of dilatancy. From detailed numerical data, we explore the time evolution of shear strain, packing fraction, excess pore pressures, and granular microstructure in this creeplike pressure redistribution regime, and we show that they scale excellently with a characteristic time extracted from a model based on the balance of granular stresses in the presence of a negative excess pressure and its interplay with dilatancy. The cumulative shear strain at failure is found to be ≃0.2, in close agreement with the experiments, irrespective of the initial packing fraction and inclination angle. Remarkably, the avalanche is triggered when dilatancy vanishes instantly as a result of fluctuations while the average dilatancy is still positive (expanding bed) with a packing fraction that declines with the initial packing fraction. Another nontrivial feature of this creeplike regime is that, in contrast to dry granular materials, the internal friction angle of the bed at failure is independent of dilatancy but depends on the inclination angle, leading therefore to a nonlinear dependence of the excess pore pressure on the inclination angle. We show that this behavior may be described in terms of the contact network anisotropy, which increases with a nearly constant connectivity and levels off at a value (critical state) that increases with the inclination angle. These features suggest that the behavior of immersed granular materials is controlled not only directly by hydrodynamic forces acting on the particles but also by the influence of the

  12. Initiation of immersed granular avalanches.

    PubMed

    Mutabaruka, Patrick; Delenne, Jean-Yves; Soga, Kenichi; Radjai, Farhang

    2014-05-01

    By means of coupled molecular dynamics-computational fluid dynamics simulations, we analyze the initiation of avalanches in a granular bed of spherical particles immersed in a viscous fluid and inclined above its angle of repose. In quantitative agreement with experiments, we find that the bed is unstable for a packing fraction below 0.59 but is stabilized above this packing fraction by negative excess pore pressure induced by the effect of dilatancy. From detailed numerical data, we explore the time evolution of shear strain, packing fraction, excess pore pressures, and granular microstructure in this creeplike pressure redistribution regime, and we show that they scale excellently with a characteristic time extracted from a model based on the balance of granular stresses in the presence of a negative excess pressure and its interplay with dilatancy. The cumulative shear strain at failure is found to be ≃ 0.2, in close agreement with the experiments, irrespective of the initial packing fraction and inclination angle. Remarkably, the avalanche is triggered when dilatancy vanishes instantly as a result of fluctuations while the average dilatancy is still positive (expanding bed) with a packing fraction that declines with the initial packing fraction. Another nontrivial feature of this creeplike regime is that, in contrast to dry granular materials, the internal friction angle of the bed at failure is independent of dilatancy but depends on the inclination angle, leading therefore to a nonlinear dependence of the excess pore pressure on the inclination angle. We show that this behavior may be described in terms of the contact network anisotropy, which increases with a nearly constant connectivity and levels off at a value (critical state) that increases with the inclination angle. These features suggest that the behavior of immersed granular materials is controlled not only directly by hydrodynamic forces acting on the particles but also by the influence of the

  13. Social Interaction Development through Immersive Virtual Environments

    ERIC Educational Resources Information Center

    Beach, Jason; Wendt, Jeremy

    2014-01-01

    The purpose of this pilot study was to determine if participants could improve their social interaction skills by participating in a virtual immersive environment. The participants used a developing virtual reality head-mounted display to engage themselves in a fully-immersive environment. While in the environment, participants had an opportunity…

  14. The Balancing Act of Bilingual Immersion

    ERIC Educational Resources Information Center

    Hadi-Tabassum, Samina

    2005-01-01

    Hadi-Tabassum believes having a separate life context for each language she learned in childhood enabled her to switch easily among five different tongues. She states that the success of dual immersion bilingual programs is largely dependent on whether they immerse students in each of the involved languages separately and help students have a…

  15. Immersion Education in China: Teachers' Perspectives

    ERIC Educational Resources Information Center

    Kong, Stella; Hoare, Philip; Chi, Yanping

    2011-01-01

    This paper investigates the views of immersion teachers in Hong Kong and Xi'an towards the immersion curriculum they are teaching. Teachers are important stakeholders in any curriculum implementation and their views are significant in both evaluating progress and determining future directions. The teachers' views were gathered from questionnaires…

  16. Immersive virtual reality simulations in nursing education.

    PubMed

    Kilmon, Carol A; Brown, Leonard; Ghosh, Sumit; Mikitiuk, Artur

    2010-01-01

    This article explores immersive virtual reality as a potential educational strategy for nursing education and describes an immersive learning experience now being developed for nurses. This pioneering project is a virtual reality application targeting speed and accuracy of nurse response in emergency situations requiring cardiopulmonary resuscitation. Other potential uses and implications for the development of virtual reality learning programs are discussed. PMID:21086871

  17. Compact imaging spectrometer utilizing immersed gratings

    DOEpatents

    Lerner, Scott A.

    2005-12-20

    A compact imaging spectrometer comprising an entrance slit for directing light, lens means for receiving the light, refracting the light, and focusing the light; an immersed diffraction grating that receives the light from the lens means and defracts the light, the immersed diffraction grating directing the detracted light back to the lens means; and a detector that receives the light from the lens means.

  18. The Two-Way Immersion Toolkit

    ERIC Educational Resources Information Center

    Howard, Elizabeth; Sugarman, Julie; Perdomo, Marleny; Adger, Carolyn Temple

    2005-01-01

    This Toolkit is meant to be a resource for teachers, parents, and administrators involved with two-way immersion (TWI) programs, particularly those at the elementary level. Two-way immersion is a form of dual language instruction that brings together students from two native language groups for language, literacy, and academic content instruction…

  19. Immersive 3D Geovisualization in Higher Education

    ERIC Educational Resources Information Center

    Philips, Andrea; Walz, Ariane; Bergner, Andreas; Graeff, Thomas; Heistermann, Maik; Kienzler, Sarah; Korup, Oliver; Lipp, Torsten; Schwanghart, Wolfgang; Zeilinger, Gerold

    2015-01-01

    In this study, we investigate how immersive 3D geovisualization can be used in higher education. Based on MacEachren and Kraak's geovisualization cube, we examine the usage of immersive 3D geovisualization and its usefulness in a research-based learning module on flood risk, called GEOSimulator. Results of a survey among participating students…

  20. Research on evaluation techniques for immersive multimedia

    NASA Astrophysics Data System (ADS)

    Hashim, Aslinda M.; Romli, Fakaruddin Fahmi; Zainal Osman, Zosipha

    2013-03-01

    Nowadays Immersive Multimedia covers most usage in tremendous ways, such as healthcare/surgery, military, architecture, art, entertainment, education, business, media, sport, rehabilitation/treatment and training areas. Moreover, the significant of Immersive Multimedia to directly meet the end-users, clients and customers needs for a diversity of feature and purpose is the assembly of multiple elements that drive effective Immersive Multimedia system design, so evaluation techniques is crucial for Immersive Multimedia environments. A brief general idea of virtual environment (VE) context and `realism' concept that formulate the Immersive Multimedia environments is then provided. This is followed by a concise summary of the elements of VE assessment technique that is applied in Immersive Multimedia system design, which outlines the classification space for Immersive Multimedia environments evaluation techniques and gives an overview of the types of results reported. A particular focus is placed on the implications of the Immersive Multimedia environments evaluation techniques in relation to the elements of VE assessment technique, which is the primary purpose of producing this research. The paper will then conclude with an extensive overview of the recommendations emanating from the research.

  1. Depth of immersion as a determinant of the natriuresis of water immersion

    NASA Technical Reports Server (NTRS)

    Epstein, M.; Miller, M.; Schneider, N.

    1974-01-01

    The current study was undertaken to further assess the contribution of an immersion-induced hydrostatic pressure gradient on the redistribution of blood volume. The rate of sodium excretion by seated subjects was significantly increased by water immersion up to the chest and neck compared to waist immersion and controls. These results are consistent with the hypothesis that whereas immersion to the level of the diaphragm merely cancels the intravascular hydrostatic pressure gradient by providing an identical external gradient, immersion above the diaphragm level results in increased water pressure which tends to favor a shift in blood volume from the lower extremities.

  2. Compact imaging spectrometer utilizing immersed gratings

    DOEpatents

    Chrisp, Michael P.; Lerner, Scott A.; Kuzmenko, Paul J.; Bennett, Charles L.

    2007-07-03

    A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, means for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the means for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the means for receiving the light and the means for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light to the means for receiving the light, and the means for receiving the light directs the light to the detector array.

  3. Liftoff lithography of metals for extreme ultraviolet lithography mask absorber layer patterning

    NASA Astrophysics Data System (ADS)

    Lyons, Adam; Teki, Ranganath; Hartley, John

    2012-03-01

    The authors present a process for patterning Extreme Ultraviolet Lithography (EUVL) mask absorber metal using electron beam evaporation and bi-layer liftoff lithography. The Line Edge Roughness (LER) and Critical Dimension Uniformity (CDU) of patterned chrome absorber are determined for various chrome thicknesses on silicon substrates, and the viability of the method for use with nickel absorber and on EUVL masks is demonstrated. Scanning Electron Microscope (SEM) data is used with SuMMIT software to determine the absorber LER and CDU. The Lawrence Berkeley National Labs Actinic Inspection Tool (AIT) is used to verify the printability of the pattern down to 24nm half pitch. The effect of processing on the integrity of the mask multilayer is measured using an actinic reflectometer at the College of Nanoscale Science and Engineering.

  4. Throughput enhancement technique for MAPPER maskless lithography

    NASA Astrophysics Data System (ADS)

    Wieland, M. J.; Derks, H.; Gupta, H.; van de Peut, T.; Postma, F. M.; van Veen, A. H. V.; Zhang, Y.

    2010-03-01

    MAPPER Lithography is developing a maskless lithography technology based on massively-parallel electron-beam writing in combination with high speed optical data transport for switching the electron beams. With 13,000 electron beams each delivering a current of 13nA on the wafer, a throughput of 10 wph is realized for 22nm node lithography. By clustering several of these systems together high throughputs can be realized in a small footprint. This enables a highly cost-competitive alternative to double patterning and EUV. The most mature and reliable electron source currently available that combines a high brightness, a high emission current and uniform emission is the dispenser cathode. For this electron source a reduced brightness of 106 A/m2SrV has been measured, with no restrictions on emission current. With this brightness however it is possible to realize a beam current of 0.3nA (@ 25nm spotsize), which is almost a factor 50 lower than the 13nA that is required for 10 wph. Three methods can be distinguished to increase the throughput: 1. Use an electron source with a 50× higher brightness 2. Increase the number of beams and lenses 50× 3. Patterned beams: Image multiple sub-beams with each projection lens MAPPER has selected option 3) 'Patterned beams' as the method to increase the beam current to 13nA. This because an electron source with a 50x higher brightness is simply not available at this time, and increasing the number of beams and lenses 50× leads to undesirable engineering issues. During the past years MAPPER has been developing the concept of 'Patterned beams'. By imaging 7×7 sub-beams per projection lens the beam current is increased to the required 13nA level. This technique will also be used to maintain throughput at 10 wph for smaller technology nodes by further increasing the number of sub-beams per projection lens. In this paper we will describe the electron optical design used to image these multiple sub-beams per lens, as well as

  5. EUV mask process specifics and development challenges

    NASA Astrophysics Data System (ADS)

    Nesladek, Pavel

    2014-07-01

    EUV lithography is currently the favorite and most promising candidate among the next generation lithography (NGL) technologies. Decade ago the NGL was supposed to be used for 45 nm technology node. Due to introduction of immersion 193nm lithography, double/triple patterning and further techniques, the 193 nm lithography capabilities was greatly improved, so it is expected to be used successfully depending on business decision of the end user down to 10 nm logic. Subsequent technology node will require EUV or DSA alternative technology. Manufacturing and especially process development for EUV technology requires significant number of unique processes, in several cases performed at dedicated tools. Currently several of these tools as e.g. EUV AIMS or actinic reflectometer are not available on site yet. The process development is done using external services /tools with impact on the single unit process development timeline and the uncertainty of the process performance estimation, therefore compromises in process development, caused by assumption about similarities between optical and EUV mask made in experiment planning and omitting of tests are further reasons for challenges to unit process development. Increased defect risk and uncertainty in process qualification are just two examples, which can impact mask quality / process development. The aim of this paper is to identify critical aspects of the EUV mask manufacturing with respect to defects on the mask with focus on mask cleaning and defect repair and discuss the impact of the EUV specific requirements on the experiments needed.

  6. Double patterning combined with shrink technique to extend ArF lithography for contact holes to 22nm node and beyond

    NASA Astrophysics Data System (ADS)

    Miao, Xiangqun; Huli, Lior; Chen, Hao; Xu, Xumou; Woo, Hyungje; Bencher, Chris; Shu, Jen; Ngai, Chris; Borst, Christopher

    2008-03-01

    Lithography becomes much more challenging when CD shrinks to 22nm nodes. Since EUV is not ready, double patterning combined with Resolution Enhancement Technology (RET) such as shrink techniques seems to be the most possible solution. Companies such as TSMC [1] and IBM [2] etc. are pushing out EUV to extend immersion ArF lithography to 32nm/22nm nodes. Last year, we presented our development work on 32nm node contact (50nm hole at 100nm pitch) using dry ArF lithography by double patterning with SAFIER shrink process[3]. To continue the work, we further extend our dry litho capability towards the 22nm node. We demonstrated double patterning capability of 40nm holes at 80nm pitch using ASML XT1400E scanner. It seems difficult to print pitches below 140nm on dry scanner in single exposure which is transferred into 70nm pitch with double patterning. To push the resolution to 22nm node and beyond, we developed ArF immersion process on ASML XT1700i-P system at the College of Nanoscale Science and Engineering (Albany, NY) combined with a SAFIER process. We achieved single exposure process capability of 25nm holes at 128nm pitch after shrink. It enables us to print ~25nm holes at pitch of 64nm with double patterning. Two types of hard mask (HM), i.e. TIN and a-Si were used in both dry and immersion ArF DP processes. The double patterning process consists of two HM litho-shrink-etch steps. The dense feature is designed into two complementary parts on two masks such that the density is reduced by half and minimum pitch is increased by at least a factor of 21/2 depending on design. The complete pattern is formed after the two HM litho-shrink-etch steps are finished.

  7. Direct three-dimensional patterning using nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Li, Mingtao; Chen, Lei; Chou, Stephen Y.

    2001-05-01

    We demonstrated that nanoimprint lithography (NIL) can create three-dimensional patterns, sub-40 nm T-gates, and air-bridge structures, in a single step imprint in polymer and metal by lift-off. A method based on electron beam lithography and reactive ion etching was developed to fabricate NIL molds with three-dimensional protrusions. The low-cost and high-throughput nanoimprint lithography for three-dimensional nanostructures has many significant applications such as monolithic microwave integrated circuits and nanoelectromechanical system.

  8. Lithography trends based on projections of the ITRS (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Arden, Wolfgang

    2005-06-01

    The microelectronic industry has gone through an enormous technical evolution in the last four decades. Both the tech-nological and economic challenges of microelectronics were increasing consistently in the past few years. This paper discusses the future trends in micro- and nano-technologies with special emphasis on lithography. The trends of minia-turization will be sketched with reference to the International Technology Roadmap for Semiconductors (ITRS). After a description of general trends in technology node timing, an overview will be given on the future lithography require-ments and the technical solutions including options for post-optical lithography as, for example, Extreme UV.

  9. High resolution fabrication of nanostructures using controlled proximity nanostencil lithography

    NASA Astrophysics Data System (ADS)

    Jain, T.; Aernecke, M.; Liberman, V.; Karnik, R.

    2014-02-01

    Nanostencil lithography has a number of distinct benefits that make it an attractive nanofabrication processes, but the inability to fabricate features with nanometer precision has significantly limited its utility. In this paper, we describe a nanostencil lithography process that provides sub-15 nm resolution even for 40-nm thick structures by using a sacrificial layer to control the proximity between the stencil and substrate, thereby enhancing the correspondence between nanostencil patterns and fabricated nanostructures. We anticipate that controlled proximity nanostencil lithography will provide an environmentally stable, clean, and positive-tone candidate for fabrication of nanostructures with high resolution.

  10. Workshop on compact storage ring technology: applications to lithography

    SciTech Connect

    Not Available

    1986-05-30

    Project planning in the area of x-ray lithography is discussed. Three technologies that are emphasized are the light source, the lithographic technology, and masking technology. The needs of the semiconductor industry in the lithography area during the next decade are discussed, particularly as regards large scale production of high density dynamic random access memory devices. Storage ring parameters and an overall exposure tool for x-ray lithography are addressed. Competition in this area of technology from Germany and Japan is discussed briefly. The design of a storage ring is considered, including lattice design, magnets, and beam injection systems. (LEW)

  11. Resolution considerations in MeV ion microscopy and lithography

    NASA Astrophysics Data System (ADS)

    Norarat, Rattanaporn; Whitlow, Harry J.

    2015-04-01

    There a disparity between the way the resolution is specified in microscopy and lithography using light compared to MeV ion microscopy and lithography. In this work we explore the implications of the way the resolution is defined with a view to answering the questions; how are the resolving powers in MeV ion microscopy and lithography relate to their optical counterparts? and how do different forms of point spread function affect the modulation transfer function and the sharpness of the edge profile?

  12. Thermoplastic microcantilevers fabricated by nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Greve, Anders; Keller, Stephan; Vig, Asger L.; Kristensen, Anders; Larsson, David; Yvind, Kresten; Hvam, Jørn M.; Cerruti, Marta; Majumdar, Arunava; Boisen, Anja

    2010-01-01

    Nanoimprint lithography has been exploited to fabricate micrometre-sized cantilevers in thermoplastic. This technique allows for very well defined microcantilevers and gives the possibility of embedding structures into the cantilever surface. The microcantilevers are fabricated in TOPAS and are up to 500 µm long, 100 µm wide, and 4.5 µm thick. Some of the cantilevers have built-in ripple surface structures with heights of 800 nm and pitches of 4 µm. The yield for the cantilever fabrication is 95% and the initial out-of-plane bending is below 10 µm. The stiffness of the cantilevers is measured by deflecting the cantilever with a well-characterized AFM probe. An average stiffness of 61.3 mN m-1 is found. Preliminary tests with water vapour indicate that the microcantilevers can be used directly for vapour sensing applications and illustrate the influence of surface structuring of the cantilevers.

  13. Photoresist composition for extreme ultraviolet lithography

    DOEpatents

    Felter, T. E.; Kubiak, G. D.

    1999-01-01

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods. A photoresist composition for extreme ultraviolet radiation of boron carbide polymers, hydrochlorocarbons and mixtures thereof.

  14. Nanoscale plasmonic stamp lithography on silicon.

    PubMed

    Liu, Fenglin; Luber, Erik J; Huck, Lawrence A; Olsen, Brian C; Buriak, Jillian M

    2015-02-24

    Nanoscale lithography on silicon is of interest for applications ranging from computer chip design to tissue interfacing. Block copolymer-based self-assembly, also called directed self-assembly (DSA) within the semiconductor industry, can produce a variety of complex nanopatterns on silicon, but these polymeric films typically require transformation into functional materials. Here we demonstrate how gold nanopatterns, produced via block copolymer self-assembly, can be incorporated into an optically transparent flexible PDMS stamp, termed a plasmonic stamp, and used to directly functionalize silicon surfaces on a sub-100 nm scale. We propose that the high intensity electric fields that result from the localized surface plasmons of the gold nanoparticles in the plasmonic stamps upon illumination with low intensity green light, lead to generation of electron-hole pairs in the silicon that drive spatially localized hydrosilylation. This approach demonstrates how localized surface plasmons can be used to enable functionalization of technologically relevant surfaces with nanoscale control. PMID:25654172

  15. Lithography process window analysis with calibrated model

    NASA Astrophysics Data System (ADS)

    Zhou, Wenzhan; Yu, Jin; Lo, James; Liu, Johnson

    2004-05-01

    As critical-dimension shrink below 0.13 μm, the SPC (Statistical Process Control) based on CD (Critical Dimension) control in lithography process becomes more difficult. Increasing requirements of a shrinking process window have called on the need for more accurate decision of process window center. However in practical fabrication, we found that systematic error introduced by metrology and/or resist process can significantly impact the process window analysis result. Especially, when the simple polynomial functions are used to fit the lithographic data from focus exposure matrix (FEM), the model will fit these systematic errors rather than filter them out. This will definitely impact the process window analysis and determination of the best process condition. In this paper, we proposed to use a calibrated first principle model to do process window analysis. With this method, the systematic metrology error can be filtered out efficiently and give a more reasonable window analysis result.

  16. Nanoimprint lithography using disposable biomass template

    NASA Astrophysics Data System (ADS)

    Hanabata, Makoto; Takei, Satoshi; Sugahara, Kigen; Nakajima, Shinya; Sugino, Naoto; Kameda, Takao; Fukushima, Jiro; Matsumoto, Yoko; Sekiguchi, Atsushi

    2016-04-01

    A novel nanoimprint lithography process using disposable biomass template having gas permeability was investigated. It was found that a disposable biomass template derived from cellulose materials shows an excellent gas permeability and decreases transcriptional defects in conventional templates such as quartz, PMDS, DLC that have no gas permeability. We believe that outgasses from imprinted materials are easily removed through the template. The approach to use a cellulose for template material is suitable as the next generation of clean separation technology. It is expected to be one of the defect-less thermal nanoimprint lithographic technologies. It is also expected that volatile materials and solvent including materials become available that often create defects and peelings in conventional temples that have no gas permeability.

  17. Novel electrostatic column for ion projection lithography

    SciTech Connect

    Chalupka, A.; Stengl, G.; Buschbeck, H.; Lammer, G.; Vonach, H.; Fischer, R.; Hammel, E.; Loeschner, H.; Nowak, R.; Wolf, P. ); Finkelstein, W.; Hill, R.W. ); Berry, I.L. ); Harriott, L.R. ); Melngailis, J. ); Randall, J.N. ); Wolfe, J.C. ); Stroh, H.; Wollnik, H. ); Mondelli, A.A.; Petillo, J.J. ); Leung, K. (Lawrence Berkeley Laboratory, University of Californi

    1994-11-01

    Ion projection lithography (IPL) is being considered for high volume sub-0.25-[mu]m lithography. A novel ion-optical column has been designed for exposing 20[times]20 mm[sup 2] fields at 3[times] reduction from stencil mask to wafer substrates. A diverging lens is realized by using the stencil mask as the first electrode of the ion-optical column. The second and third electrode form an accelerating field lens. The aberrations of the first two lenses (diverging lens and field lens) are compensated by an asymmetric Einzel lens projecting an ion image of the stencil mask openings onto the wafer substrate with better than 2 mrad telecentricity. Less than 30 nm intrafield distortion was calculated within 20[times]20 mm[sup 2] exposure fields. The calculation uncertainty is estimated to be about 10 nm. The calculation holds for helium ions with [approx]10 keV ion energy at the stencil mask and 150 keV ion energy at the wafer plane. A virtual ion source size of 10 [mu]m has been assumed. The calculated chromatic aberrations are less than 60 nm, assuming 6 eV energy spread of the ions extracted from a duoplasmatron source. Recently a multicusp ion source has been developed for which preliminary results indicate an energy spread of less than 2 eV. Thus, with a multicusp source chromatic aberrations of less than 20 nm are to be expected. The ion energy at the crossover between the field lens and the asymmetric Einzel lens is 200 keV. Therefore, stochastic space charge induced degradations in resolution can be kept sufficiently low. The divergence of the ion image projected to the wafer plane is less than 2 mrad. Thus, the usable'' depth of focus for the novel ion optics is in the order of 10 [mu]m.

  18. Integrating nanosphere lithography in device fabrication

    NASA Astrophysics Data System (ADS)

    Laurvick, Tod V.; Coutu, Ronald A.; Lake, Robert A.

    2016-03-01

    This paper discusses the integration of nanosphere lithography (NSL) with other fabrication techniques, allowing for nano-scaled features to be realized within larger microelectromechanical system (MEMS) based devices. Nanosphere self-patterning methods have been researched for over three decades, but typically not for use as a lithography process. Only recently has progress been made towards integrating many of the best practices from these publications and determining a process that yields large areas of coverage, with repeatability and enabled a process for precise placement of nanospheres relative to other features. Discussed are two of the more common self-patterning methods used in NSL (i.e. spin-coating and dip coating) as well as a more recently conceived variation of dip coating. Recent work has suggested the repeatability of any method depends on a number of variables, so to better understand how these variables affect the process a series of test vessels were developed and fabricated. Commercially available 3-D printing technology was used to incrementally alter the test vessels allowing for each variable to be investigated individually. With these deposition vessels, NSL can now be used in conjunction with other fabrication steps to integrate features otherwise unattainable through current methods, within the overall fabrication process of larger MEMS devices. Patterned regions in 1800 series photoresist with a thickness of ~700nm are used to capture regions of self-assembled nanospheres. These regions are roughly 2-5 microns in width, and are able to control the placement of 500nm polystyrene spheres by controlling where monolayer self-assembly occurs. The resulting combination of photoresist and nanospheres can then be used with traditional deposition or etch methods to utilize these fine scale features in the overall design.

  19. Micro-optics and lithography simulation are key enabling technologies for shadow printing lithography in mask aligners

    NASA Astrophysics Data System (ADS)

    Voelkel, Reinhard; Vogler, Uwe; Bramati, Arianna; Noell, Wilfried

    2015-02-01

    Mask aligners are lithographic tools used to transfer a pattern of microstructures by shadow printing lithography onto a planar wafer. Contact lithography allows us to print large mask fields with sub-micron resolution, but requires frequent mask cleaning. Thus, contact lithography is used for small series of wafer production. Proximity lithography, where the mask is located at a distance of typically 30-100 μm above the wafer, provides a resolution of approximately 3-5 μm, limited by diffraction effects. Proximity lithography in mask aligners is a very cost-efficient method widely used in semiconductor, packaging and MEMS manufacturing industry for high-volume production. Micro-optics plays a key role in improving the performance of shadow printing lithography in mask aligners. Refractive or diffractive micro-optics allows us to efficiently collect the light from the light source and to precisely shape the illumination light (customized illumination). Optical proximity correction and phase shift mask technology allow us to influence the diffraction effects in the aerial image and to enhance resolution and critical dimension. The paper describes the status and future trends of shadow printing lithography in mask aligners and the decisive role of micro-optics as key enabling technology.

  20. Photogrammetric Applications of Immersive Video Cameras

    NASA Astrophysics Data System (ADS)

    Kwiatek, K.; Tokarczyk, R.

    2014-05-01

    The paper investigates immersive videography and its application in close-range photogrammetry. Immersive video involves the capture of a live-action scene that presents a 360° field of view. It is recorded simultaneously by multiple cameras or microlenses, where the principal point of each camera is offset from the rotating axis of the device. This issue causes problems when stitching together individual frames of video separated from particular cameras, however there are ways to overcome it and applying immersive cameras in photogrammetry provides a new potential. The paper presents two applications of immersive video in photogrammetry. At first, the creation of a low-cost mobile mapping system based on Ladybug®3 and GPS device is discussed. The amount of panoramas is much too high for photogrammetric purposes as the base line between spherical panoramas is around 1 metre. More than 92 000 panoramas were recorded in one Polish region of Czarny Dunajec and the measurements from panoramas enable the user to measure the area of outdoors (adverting structures) and billboards. A new law is being created in order to limit the number of illegal advertising structures in the Polish landscape and immersive video recorded in a short period of time is a candidate for economical and flexible measurements off-site. The second approach is a generation of 3d video-based reconstructions of heritage sites based on immersive video (structure from immersive video). A mobile camera mounted on a tripod dolly was used to record the interior scene and immersive video, separated into thousands of still panoramas, was converted from video into 3d objects using Agisoft Photoscan Professional. The findings from these experiments demonstrated that immersive photogrammetry seems to be a flexible and prompt method of 3d modelling and provides promising features for mobile mapping systems.

  1. Survey of projection-based immersive displays

    NASA Astrophysics Data System (ADS)

    Wright, Dan

    2000-05-01

    Projection-based immersive displays are rapidly becoming the visualization system of choice for applications requiring the comprehension of complex datasets and the collaborative sharing of insights. The wide variety of display configurations can be grouped into five categories: benches, flat-screen walls, curved-screen theaters, concave-screen domes and spatially-immersive rooms. Each have their strengths and weaknesses with the appropriateness of each dependent on one's application and budget. The paper outlines the components common to all projection-based displays and describes the characteristics of each particular category. Key image metrics, implementation considerations and immersive display trends are also considered.

  2. New ArF immersion light source introduces technologies for high-volume 14nm manufacturing and beyond

    NASA Astrophysics Data System (ADS)

    Cacouris, T.; Conley, W.; Thornes, J.; Bibby, T.; Melchior, J.; Aggarwal, T.; Gross, E.

    2015-03-01

    Semiconductor market demand for improved performance at lower cost continues to drive enhancements in excimer light source technologies. Multi-patterning lithography solutions to extend deep-UV (DUV) immersion have driven requirements such as higher throughput and higher efficiencies to maximize the utilization of leading-edge lithography equipment. Three key light source parameters have direct influence on patterning performance - energy, wavelength and bandwidth stability - and they have been the primary areas of continuous improvement. With 14nm node development, a number of studies have shown the direct influence of bandwidth stability on CD uniformity for certain patterns and geometries, leading to the desire for further improvements in this area. More recent studies also examined the impact of bandwidth on 10nm logic node patterning [1]. Alongside these drivers, increasing cost per patterning layer continues to demand further improvements in operating costs and efficiencies from the lithography tools, and the light source can offer further gains in these areas as well. This paper introduces several light source technologies that are embodied in a next-generation light source, the Cymer XLR® 700ix, which is an extension of the ring laser architecture introduced 8 years ago. These technologies enable a significant improvement in bandwidth stability as well as notable reductions in operating costs through more efficient gas management algorithms and lower facilities costs.

  3. Impacts of cost functions on inverse lithography patterning.

    PubMed

    Yu, Jue-Chin; Yu, Peichen

    2010-10-25

    For advanced CMOS processes, inverse lithography promises better patterning fidelity than conventional mask correction techniques due to a more complete exploration of the solution space. However, the success of inverse lithography relies highly on customized cost functions whose design and know-how have rarely been discussed. In this paper, we investigate the impacts of various objective functions and their superposition for inverse lithography patterning using a generic gradient descent approach. We investigate the most commonly used objective functions, which are the resist and aerial images, and also present a derivation for the aerial image contrast. We then discuss the resulting pattern fidelity and final mask characteristics for simple layouts with a single isolated contact and two nested contacts. We show that a cost function composed of a dominant resist-image component and a minor aerial-image or image-contrast component can achieve a good mask correction and contour targets when using inverse lithography patterning. PMID:21164674

  4. Manipulation of heat-diffusion channel in laser thermal lithography.

    PubMed

    Wei, Jingsong; Wang, Yang; Wu, Yiqun

    2014-12-29

    Laser thermal lithography is a good alternative method for forming small pattern feature size by taking advantage of the structural-change threshold effect of thermal lithography materials. In this work, the heat-diffusion channels of laser thermal lithography are first analyzed, and then we propose to manipulate the heat-diffusion channels by inserting thermal conduction layers in between channels. Heat-flow direction can be changed from the in-plane to the out-of-plane of the thermal lithography layer, which causes the size of the structural-change threshold region to become much smaller than the focused laser spot itself; thus, nanoscale marks can be obtained. Samples designated as "glass substrate/thermal conduction layer/thermal lithography layer (100 nm)/thermal conduction layer" are designed and prepared. Chalcogenide phase-change materials are used as thermal lithography layer, and Si is used as thermal conduction layer to manipulate heat-diffusion channels. Laser thermal lithography experiments are conducted on a home-made high-speed rotation direct laser writing setup with 488 nm laser wavelength and 0.90 numerical aperture of converging lens. The writing marks with 50-60 nm size are successfully obtained. The mark size is only about 1/13 of the focused laser spot, which is far smaller than that of the light diffraction limit spot of the direct laser writing setup. This work is useful for nanoscale fabrication and lithography by exploiting the far-field focusing light system. PMID:25607209

  5. A survey of advanced excimer optical imaging and lithography

    NASA Astrophysics Data System (ADS)

    Matsumoto, Koichi; Suwa, Kyoichi

    1998-11-01

    The first item discussed in this paper is to estimate the future trend regarding minimum geometry and the optical parameters, such as NA and wavelength. Simulations based on aerial images are performed for the estimation. The resolution limit is defined as a minimum feature size which retains practical depth of focus (DOF). Pattern geometry is classified into two categories, which are dense lines and isolated lines. Available wavelengths are assumed to be KrF excimer laser (λ=248 nm), ArF excimer laser (λ=193 nm) and F2 excimer laser (λ=157 nm). Based upon the simulation results, the resolution limit is estimated for each geometry and each wavelength. The second item is to survey ArF optics. At present, the ArF excimer laser is regarded as one of the most promising candidates as a next-generation light source. Discussions are ranging over some critical issues. The lifetime of ArF optics supposedly limited by the radiation compaction of silica glass is estimated in comparison with KrF optics. Availability of calcium fluoride (CaF2) is also discussed. As a designing issue, a comparative study is made about the optical configuration, dioptric or catadioptric. In the end, our resist-based performance is shown.

  6. Immersion diuresis without expected suppression of vasopressin

    NASA Technical Reports Server (NTRS)

    Keil, L. C.; Silver, J. E.; Wong, N.; Spaul, W. A.; Greenleaf, J. E.; Kravik, S. E.

    1984-01-01

    There is a shift of blood from the lower parts of the body to the thoracic circulation during bed rest, water immersion, and presumably during weightlessness. On earth, this central fluid shift is associated with a profound diuresis. However, the mechanism involved is not yet well understood. The present investigation is concerned with measurements regarding the plasma vasopressin, fluid, electrolyte, and plasma renin activity (PRA) responses in subjects with normal preimmersion plasma vasopressin (PVP) concentration. In the conducted experiments, PRA was suppressed significantly at 30 min of immersion and had declined by 74 percent by the end of the experiment. On the basis of previously obtained results, it appears that sodium excretion during immersion may be independent of aldosterone action. Experimental results indicate that PVP is not suppressed by water immersion in normally hydrated subjects and that other factors may be responsible for the diuresis.

  7. Directed self-assembly process integration: Fin patterning approaches and challenges

    NASA Astrophysics Data System (ADS)

    Sayan, Safak; Chan, B. T.; Gronheid, Roel; Van Roey, Frieda; Kim, Min-Soo; Williamson, Lance; Nealey, Paul

    2014-03-01

    Resolution requirements for photolithography have reached beyond the wavelength of light. Consequently, it is becoming increasingly complicated and expensive to further minimize feature dimensions as required to push the limits of Moore's law. EUV lithography has been the much anticipated solution; however, its insertion timing for High Volume Manufacturing is still an uncertainty due to source power and EUV mask infrastructure limitations. Extending the limits of 193nm immersion lithography requires pitch division using either Double Patterning Pitch Division (DPPD), and/or Spacer Based Pitch Division (SBPD) schemes (e.g. Hard mask image transfer methods (Double, Triple, Quadruple)). While these approaches reduce pitch, there is an associated risk/compromise of process complexity, and overlay accuracy budget issues. Directed Self Assembly (DSA) processes offer the promise of providing alternative ways to extend optical lithography cost-effectively for sub-10nm nodes and present itself as an alternative pitch division approach. As a result, DSA has gained increased momentum in recent years, as a means for extending optical lithography past its current limits. The availability of a DSA processing line can enable to further push the limits of 193nm immersion lithography and overcome some of the critical concerns for EUV lithography. Robust etch transfer of DSA patterns into commonly used device integration materials such as silicon, silicon nitride, and silicon dioxide had been previously demonstrated [1,2]. However DSA integration to CMOS process flows, including cut/keep structures to form fin arrays, is yet to be demonstrated on relevant film stacks (front-end-of-line device integration such as hard mask stacks, and STI stacks). Such a demonstration will confirm and reinforce its viability as a candidate for sub-10nm technology nodes.

  8. Application of optical CD metrology for alternative lithography

    NASA Astrophysics Data System (ADS)

    Asano, Masafumi; Kawamoto, Akiko; Matsuki, Kazuto; Godny, Stephane; Lin, Tingsheng; Wakamoto, Koichi

    2013-04-01

    Directed self-assembly (DSA) and nanoimprint lithography (NIL) have been widely developed for low-cost nanoscale patterning. Although they are currently regarded as "alternative lithography," some papers show their potential to be candidates for next-generation lithography (NGL). To actualize the potential, the contribution of metrology engineers is necessary. Since the characteristics of the lithography techniques are different from those of conventional lithography, new metrology schemes correlated with each characteristic are required. In DSA of block copolymer (BCP), a guide is needed to control the direction and position of BCP. Therefore, it is necessary to monitor the relationship between the guide and the BCP pattern. Since the depth of guide or the coating thickness variation of BCP over guide influences the behavior of phase separation of BCP, 3D metrology becomes increasingly important. In NIL, residual resist thickness (RLT) underneath the pattern should be measured because its variation affects the CD variation of transferred pattern. 3D metrology is also important in NIL. Optical critical dimension (OCD) metrology will be a powerful tool for 3D metrology. In this work, some applications of OCD for alternative lithography have been studied. For DSA, we have tried to simultaneously monitor the guide and BCP pattern in a DSA-based contact hole shrinking process. Sufficient measurement accuracy for CD and shapes for guide and BCP patterns was achievable. For NIL, sufficient sensitivity to RLT measurement was obtained.

  9. Conformal Visualization for Partially-Immersive Platforms

    PubMed Central

    Petkov, Kaloian; Papadopoulos, Charilaos; Zhang, Min; Kaufman, Arie E.; Gu, Xianfeng

    2010-01-01

    Current immersive VR systems such as the CAVE provide an effective platform for the immersive exploration of large 3D data. A major limitation is that in most cases at least one display surface is missing due to space, access or cost constraints. This partially-immersive visualization results in a substantial loss of visual information that may be acceptable for some applications, however it becomes a major obstacle for critical tasks, such as the analysis of medical data. We propose a conformal deformation rendering pipeline for the visualization of datasets on partially-immersive platforms. The angle-preserving conformal mapping approach is used to map the 360°3D view volume to arbitrary display configurations. It has the desirable property of preserving shapes under distortion, which is important for identifying features, especially in medical data. The conformal mapping is used for rasterization, realtime raytracing and volume rendering of the datasets. Since the technique is applied during the rendering, we can construct stereoscopic images from the data, which is usually not true for image-based distortion approaches. We demonstrate the stereo conformal mapping rendering pipeline in the partially-immersive 5-wall Immersive Cabin (IC) for virtual colonoscopy and architectural review. PMID:26279083

  10. Human adaptation to repeated cold immersions.

    PubMed Central

    Golden, F S; Tipton, M J

    1988-01-01

    1. The present investigation was designed to examine human adaptation to intermittent severe cold exposure and to assess the effect of exercise on any adaptation obtained. 2. Sixteen subjects were divided into two equal groups. Each subject performed ten head-out immersions; two into thermoneutral water which was then cooled until they shivered vigorously, and eight into water at 15 degrees C for 40 min. During the majority of the 15 degrees C immersions, one group (dynamic group) exercised whilst the other (static group) rested. 3. Results showed that both groups responded to repeated cold immersions with a reduction in their initial responses to cold. The time course of these reductions varied, however, between responses. 4. Only the static group developed a reduced metabolic response to prolonged resting immersion. 5. It is concluded that repeated resting exposure to cold was the more effective way of producing an adaptation. The performance of exercise during repeated exposure to cold prevented the development of an adaptive reduction in the metabolic response to cold during a subsequent resting immersion. In addition, many of the adaptations obtained during repeated resting exposure were overridden or masked during a subsequent exercising immersion. PMID:3411500

  11. Successful demonstration of a comprehensive lithography defect monitoring strategy

    NASA Astrophysics Data System (ADS)

    Peterson, Ingrid B.; Breaux, Louis H.; Cross, Andrew; von den Hoff, Michael

    2003-07-01

    This paper describes the validation of the methodology, the model and the impact of an optimized Lithography Defect Monitoring Strategy at two different semiconductor manufacturing factories. The lithography defect inspection optimization was implemented for the Gate Module at both factories running 0.13-0.15μm technologies on 200mm wafers, one running microprocessor and the other memory devices. As minimum dimensions and process windows decrease in the lithography area, new technologies and technological advances with resists and resist systems are being implemented to meet the demands. Along with these new technological advances in the lithography area comes potentially unforeseen defect issues. The latest lithography processes involve new resists in extremely thin, uniform films, exposing the films under conditions of highly optimized focus and illumination, and finally removing the resist completely and cleanly. The lithography cell is defined as the cluster of process equipment that accomplishes the coating process (surface prep, resist spin, edge-bead removal and soft bake), the alignment and exposure, and the developing process (post-exposure bake, develop, rinse) of the resist. Often the resist spinning process involves multiple materials such as BARC (bottom ARC) and / or TARC (top ARC) materials in addition to the resist itself. The introduction of these new materials with the multiple materials interfaces and the tightness of the process windows leads to an increased variety of defect mechanisms in the lithography area. Defect management in the lithography area has become critical to successful product introduction and yield ramp. The semiconductor process itself contributes the largest number and variety of defects, and a significant portion of the total defects originate within the lithography cell. From a defect management perspective, the lithography cell has some unique characteristics. First, defects in the lithography process module have the

  12. 46 CFR 111.85-1 - Electric oil immersion heaters.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Electric oil immersion heaters. 111.85-1 Section 111.85... SYSTEMS-GENERAL REQUIREMENTS Electric Oil Immersion Heaters § 111.85-1 Electric oil immersion heaters. Each oil immersion heater must have the following: (a) An operating thermostat. (b) Heating...

  13. 46 CFR 111.85-1 - Electric oil immersion heaters.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Electric oil immersion heaters. 111.85-1 Section 111.85... SYSTEMS-GENERAL REQUIREMENTS Electric Oil Immersion Heaters § 111.85-1 Electric oil immersion heaters. Each oil immersion heater must have the following: (a) An operating thermostat. (b) Heating...

  14. 46 CFR 111.85-1 - Electric oil immersion heaters.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Electric oil immersion heaters. 111.85-1 Section 111.85... SYSTEMS-GENERAL REQUIREMENTS Electric Oil Immersion Heaters § 111.85-1 Electric oil immersion heaters. Each oil immersion heater must have the following: (a) An operating thermostat. (b) Heating...

  15. 46 CFR 111.85-1 - Electric oil immersion heaters.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Electric oil immersion heaters. 111.85-1 Section 111.85... SYSTEMS-GENERAL REQUIREMENTS Electric Oil Immersion Heaters § 111.85-1 Electric oil immersion heaters. Each oil immersion heater must have the following: (a) An operating thermostat. (b) Heating...

  16. 46 CFR 111.85-1 - Electric oil immersion heaters.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Electric oil immersion heaters. 111.85-1 Section 111.85... SYSTEMS-GENERAL REQUIREMENTS Electric Oil Immersion Heaters § 111.85-1 Electric oil immersion heaters. Each oil immersion heater must have the following: (a) An operating thermostat. (b) Heating...

  17. Characterization of 'metal resist' for EUV lithography

    NASA Astrophysics Data System (ADS)

    Toriumi, Minoru; Sato, Yuta; Kumai, Reiji; Yamashita, Yoshiyuki; Tsukiyama, Koichi; Itani, Toshiro

    2016-03-01

    We characterized EIDEC metal resist for EUV lithography by various measurement methods. The low-voltage aberration-corrected scanning transmission electron microscopy combined with electron energy-loss spectroscopy showed the morphology of metal resists in nanometer regions and enabled studying the distribution of resist component in the resist film. The zirconium oxide metal resist kept the core-shell structure in the resist films and the titanium oxide metal resist showed the aggregation in the film. X-ray diffractometry and ab initio molecular dynamics simulation showed the amorphous structure with short-range order of the zirconium oxide metal resist. X-ray Photoelectron spectroscopy of the zirconium oxide-methacrylic acid metal resist showed the decomposition of the shell molecules and the increase of electron density at zirconium atoms after the EUV exposure. Infrared (IR) spectra indicated that the shell molecules made the various bindings to the metal core and the specific vibrational mode of shell molecules showed the divergent responsivity to the irradiation wavenumber of the IR Free electron laser.

  18. Metal hierarchical patterning by direct nanoimprint lithography

    PubMed Central

    Radha, Boya; Lim, Su Hui; Saifullah, Mohammad S. M.; Kulkarni, Giridhar U.

    2013-01-01

    Three-dimensional hierarchical patterning of metals is of paramount importance in diverse fields involving photonics, controlling surface wettability and wearable electronics. Conventionally, this type of structuring is tedious and usually involves layer-by-layer lithographic patterning. Here, we describe a simple process of direct nanoimprint lithography using palladium benzylthiolate, a versatile metal-organic ink, which not only leads to the formation of hierarchical patterns but also is amenable to layer-by-layer stacking of the metal over large areas. The key to achieving such multi-faceted patterning is hysteretic melting of ink, enabling its shaping. It undergoes transformation to metallic palladium under gentle thermal conditions without affecting the integrity of the hierarchical patterns on micro- as well as nanoscale. A metallic rice leaf structure showing anisotropic wetting behavior and woodpile-like structures were thus fabricated. Furthermore, this method is extendable for transferring imprinted structures to a flexible substrate to make them robust enough to sustain numerous bending cycles. PMID:23446801

  19. X-ray lithography using holographic images

    DOEpatents

    Howells, Malcolm R.; Jacobsen, Chris

    1995-01-01

    A non-contact X-ray projection lithography method for producing a desired X-ray image on a selected surface of an X-ray-sensitive material, such as photoresist material on a wafer, the desired X-ray image having image minimum linewidths as small as 0.063 .mu.m, or even smaller. A hologram and its position are determined that will produce the desired image on the selected surface when the hologram is irradiated with X-rays from a suitably monochromatic X-ray source of a selected wavelength .lambda.. On-axis X-ray transmission through, or off-axis X-ray reflection from, a hologram may be used here, with very different requirements for monochromaticity, flux and brightness of the X-ray source. For reasonable penetration of photoresist materials by X-rays produced by the X-ray source, the wavelength X, is preferably chosen to be no more than 13.5 nm in one embodiment and more preferably is chosen in the range 1-5 nm in the other embodiment. A lower limit on linewidth is set by the linewidth of available microstructure writing devices, such as an electron beam.

  20. Smartphone sensors for stone lithography authentication.

    PubMed

    Spagnolo, Giuseppe Schirripa; Cozzella, Lorenzo; Papalillo, Donato

    2014-01-01

    Nowadays mobile phones include quality photo and video cameras, access to wireless networks and the internet, GPS assistance and other innovative systems. These facilities open them to innovative uses, other than the classical telephonic communication one. Smartphones are a more sophisticated version of classic mobile phones, which have advanced computing power, memory and connectivity. Because fake lithographs are flooding the art market, in this work, we propose a smartphone as simple, robust and efficient sensor for lithograph authentication. When we buy an artwork object, the seller issues a certificate of authenticity, which contains specific details about the artwork itself. Unscrupulous sellers can duplicate the classic certificates of authenticity, and then use them to "authenticate" non-genuine works of art. In this way, the buyer will have a copy of an original certificate to attest that the "not original artwork" is an original one. A solution for this problem would be to insert a system that links together the certificate and the related specific artwork. To do this it is necessary, for a single artwork, to find unique, unrepeatable, and unchangeable characteristics. In this article we propose an innovative method for the authentication of stone lithographs. We use the color spots distribution captured by means of a smartphone camera as a non-cloneable texture of the specific artworks and an information management system for verifying it in mobility stone lithography. PMID:24811077

  1. Smartphone Sensors for Stone Lithography Authentication

    PubMed Central

    Schirripa Spagnolo, Giuseppe; Cozzella, Lorenzo; Papalillo, Donato

    2014-01-01

    Nowadays mobile phones include quality photo and video cameras, access to wireless networks and the internet, GPS assistance and other innovative systems. These facilities open them to innovative uses, other than the classical telephonic communication one. Smartphones are a more sophisticated version of classic mobile phones, which have advanced computing power, memory and connectivity. Because fake lithographs are flooding the art market, in this work, we propose a smartphone as simple, robust and efficient sensor for lithograph authentication. When we buy an artwork object, the seller issues a certificate of authenticity, which contains specific details about the artwork itself. Unscrupulous sellers can duplicate the classic certificates of authenticity, and then use them to “authenticate” non-genuine works of art. In this way, the buyer will have a copy of an original certificate to attest that the “not original artwork” is an original one. A solution for this problem would be to insert a system that links together the certificate and the related specific artwork. To do this it is necessary, for a single artwork, to find unique, unrepeatable, and unchangeable characteristics. In this article we propose an innovative method for the authentication of stone lithographs. We use the color spots distribution captured by means of a smartphone camera as a non-cloneable texture of the specific artworks and an information management system for verifying it in mobility stone lithography. PMID:24811077

  2. Reflective masks for extreme ultraviolet lithography

    SciTech Connect

    Nguyen, Khanh Bao

    1994-05-01

    Extreme ultraviolet lithographic masks are made by patterning multilayer reflective coatings with high normal incidence reflectivity. Masks can be patterned by depositing a patterned absorber layer above the coating or by etching the pattern directly into the coating itself. Electromagnetic simulations showed that absorber-overlayer masks have superior imaging characteristics over etched masks (less sensitive to incident angles and pattern profiles). In an EUVL absorber overlayer mask, defects can occur in the mask substrate, reflective coating, and absorber pattern. Electromagnetic simulations showed that substrate defects cause the most severe image degradation. A printability study of substrate defects for absorber overlayer masks showed that printability of 25 nm high substrate defects are comparable to defects in optical lithography. Simulations also indicated that the manner in which the defects are covered by multilayer reflective coatings can affect printability. Coverage profiles that result in large lateral spreading of defect geometries amplify the printability of the defects by increasing their effective sizes. Coverage profiles of Mo/Si coatings deposited above defects were studied by atomic force microscopy and TEM. Results showed that lateral spread of defect geometry is proportional to height. Undercut at defect also increases the lateral spread. Reductions in defect heights were observed for 0.15 {mu}m wide defect lines. A long-term study of Mo/Si coating reflectivity revealed that Mo/Si coatings with Mo as the top layer suffer significant reductions in reflectivity over time due to oxidation.

  3. Materials for future lithography (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Chang, Seung Wook; Yang, Da; Dai, Junyan; Felix, Nelson; Bratton, Daniel; Tsuchiya, Kousuke; Kwark, Young-Je; Bravo-Vasquez, Juan-Pablo; Ober, Christopher K.; Cao, Heidi B.; Deng, Hai

    2005-05-01

    The demands for high resolution and issues of line edge roughness require a reconsideration of current resist design strategies. In particular, EUV lithography will provide an opportunity to examine new resist concepts including new elemental compositions and low molar mass resists or molecular resists. In the former case, resist compositions incorporating elements such as silicon and boron have been explored for EUV resists and will be described. In an example of the latter case, molecular glass resists have been designed using synthetic architectures in globular and core-arm forms ranging from one to multiple arms. Moreover, our studies include a series of ring and irregularly shaped small molecules modified to give imaging performance. These materials have been explored to improve line edge roughness (LER) compared to common polymer resists. Several examples of polymeric and molecular glass resists will be described. Several compositions showed high glass transition temperatures (Tg) of ~ 120°C and possessed no crystallinity as seen from XRD studies. Negative-tone molecular glass resists with a T-shaped phenolic core structure, 4-[4-[1,1-Bis(4-hydroxyphenyl)ethyl

  4. Resist profile simulation with fast lithography model

    NASA Astrophysics Data System (ADS)

    He, Yan-Ying; Chou, Chih-Shiang; Tang, Yu-Po; Huang, Wen-Chun; Liu, Ru-Gun; Gau, Tsai-Sheng

    2014-03-01

    A traditional approach to construct a fast lithographic model is to match wafer top-down SEM images, contours and/or gauge CDs with a TCC model plus some simple resist representation. This modeling method has been proven and is extensively used for OPC modeling. As the technology moves forward, this traditional approach has become insufficient in regard to lithography weak point detection, etching bias prediction, etc. The drawback of this approach is from metrology and simulation. First, top-down SEM is only good for acquiring planar CD information. Some 3D metrology such as cross-section SEM or AFM is necessary to obtain the true resist profile. Second, the TCC modeling approach is only suitable for planar image simulation. In order to model the resist profile, full 3D image simulation is needed. Even though there are many rigorous simulators capable of catching the resist profile very well, none of them is feasible for full-chip application due to the tremendous consumption of computational resource. The authors have proposed a quasi-3D image simulation method in the previous study [1], which is suitable for full-chip simulation with the consideration of sidewall angles, to improve the model accuracy of planar models. In this paper, the quasi-3D image simulation is extended to directly model the resist profile with AFM and/or cross-section SEM data. Resist weak points detected by the model generated with this 3D approach are verified on the wafer.

  5. Beyond k1=0.25 lithography: 70-nm L/S patterning using KrF scanners

    NASA Astrophysics Data System (ADS)

    Ebihara, Takeaki; Levenson, Marc D.; Liu, Wei; He, Jim; Yeh, Wendy; Ahn, Sang; Oga, Toshihiro; Shen, Meihua; M'saad, Hichem

    2003-12-01

    The extendibility of optical lithography using KrF and ArF exposure tools is still being investigated, even, being demanded strongly now, due to the unforeseen issues, high cost, and general difficulty of NGLs - including F2 and immersion lithography. In spite of these challenges Moore's Law requires continued shrinks and the ITRS roadmap still keeps its aggressive timetable. In order to follow the ITRS roadmap, the resolution must keep improving by increasing the lens NA for optical exposure tools. However, the conventional limit of optical resolution (kpitch=0.5) is very close for the current technologies, perhaps limiting progress unless NGL becomes available quickly. Therefore we need to find a way to overcome this seemingly fundamental limit of optical resolution. In this paper, we propose two practical two-mask /double-exposure schemes for doubling resolution in future lithography. One method uses a Si-containing bi-layer resist, and the other method uses Applied Materials' APF (a removable hard mask). The basic ideas of both methods are similar: The first exposure forms 1:3 ratio L/S patterns in one resist/hard mask layer, then the second exposure images another 1:3 ratio L/S pattern in-between the two lines (or two spaces) formed by the first exposure. The combination of these two exposures can form, in theory, kpitch=0.25 patterns. In this paper, we will demonstrate 70nm L/S pattern (140nm pitch) or smaller by using a NA0.68 KrF Scanner and a strong-RET reticle, which corresponds to kpitch = 0.38 (k1=0.19). We will also investigate the critical alignment and CD control issues for these two-mask/dual-exposure schemes.

  6. Plasmonic nanostructures fabricated using nanosphere-lithography, soft-lithography and plasma etching

    PubMed Central

    Makaryan, Taron; Enderle, Fabian; Wiedemann, Stefan; Plettl, Alfred; Marti, Othmar; Ziemann, Paul

    2011-01-01

    Summary We present two routes for the fabrication of plasmonic structures based on nanosphere lithography templates. One route makes use of soft-lithography to obtain arrays of epoxy resin hemispheres, which, in a second step, can be coated by metal films. The second uses the hexagonal array of triangular structures, obtained by evaporation of a metal film on top of colloidal crystals, as a mask for reactive ion etching (RIE) of the substrate. In this way, the triangular patterns of the mask are transferred to the substrate through etched triangular pillars. Making an epoxy resin cast of the pillars, coated with metal films, allows us to invert the structure and obtain arrays of triangular holes within the metal. Both fabrication methods illustrate the preparation of large arrays of nanocavities within metal films at low cost. Gold films of different thicknesses were evaporated on top of hemispherical structures of epoxy resin with different radii, and the reflectance and transmittance were measured for optical wavelengths. Experimental results show that the reflectivity of coated hemispheres is lower than that of coated polystyrene spheres of the same size, for certain wavelength bands. The spectral position of these bands correlates with the size of the hemispheres. In contrast, etched structures on quartz coated with gold films exhibit low reflectance and transmittance values for all wavelengths measured. Low transmittance and reflectance indicate high absorbance, which can be utilized in experiments requiring light confinement. PMID:22003451

  7. Learning Environments in Immersion and Non-Immersion Classrooms: Are They Different?

    ERIC Educational Resources Information Center

    Edwards, Viviane; Rehorick, Sally

    1990-01-01

    A study compared immersion and nonimmersion learning environments, as perceived by students, in 95 New Brunswick grade 6, 7, and 9 classes. In grade 6, no significant differences in perception were found; in grade 7, immersion students see their environment more positively; and in grade 9, the differences seem to disappear. (25 references)…

  8. Mix-and-match overlay performance of the NSR-S622D immersion scanner

    NASA Astrophysics Data System (ADS)

    Makino, Katsushi; Kikuchi, Takahisa; Sasamoto, Satoru; Hongki, Park; Mori, Akiko; Takahashi, Nobuyuki; Wakamoto, Shinji

    2013-04-01

    Current technology nodes, as well as subsequent generations necessitate ongoing improvements to the mix-and-match overlay (MMO) capabilities of lithography scanners. This work will introduce newly developed scanner solutions to address this requirement, and performance data from the latest generation immersion scanner, the NSR-S622D, will be introduced. Enhanced MMO accuracy is imperative for the 22 nm half-pitch and future technology nodes. In order for the matched overlay accuracy to approach single machine overlay (SMO) capabilities, MMO errors must be reduced further. The dominant MMO error sources can be divided into three main areas: SMO, lens distortion matching and wafer grid matching. Nikon continues to decrease these matching error contributors over time, and the latest generation NSRS622D immersion scanner provides a number of innovative solutions to satisfy the most demanding overlay matching requirements ; as a result MMO performance within 3nm is achieved on S622D. Moreover, overlay master system is developed for further product overlay accuracy and stability improvement.

  9. Intelligent control system based on ARM for lithography tool

    NASA Astrophysics Data System (ADS)

    Chen, Changlong; Tang, Xiaoping; Hu, Song; Wang, Nan

    2014-08-01

    The control system of traditional lithography tool is based on PC and MCU. The PC handles the complex algorithm, human-computer interaction, and communicates with MCU via serial port; The MCU controls motors and electromagnetic valves, etc. This mode has shortcomings like big volume, high power consumption, and wasting of PC resource. In this paper, an embedded intelligent control system of lithography tool, based on ARM, is provided. The control system used S5PV210 as processor, completing the functions of PC in traditional lithography tool, and provided a good human-computer interaction by using LCD and capacitive touch screen. Using Android4.0.3 as operating system, the equipment provided a cool and easy UI which made the control more user-friendly, and implemented remote control and debug, pushing video information of product by network programming. As a result, it's convenient for equipment vendor to provide technical support for users. Finally, compared with traditional lithography tool, this design reduced the PC part, making the hardware resources efficiently used and reducing the cost and volume. Introducing embedded OS and the concepts in "The Internet of things" into the design of lithography tool can be a development trend.

  10. Antireflective surface patterned by rolling mask lithography

    NASA Astrophysics Data System (ADS)

    Seitz, Oliver; Geddes, Joseph B.; Aryal, Mukti; Perez, Joseph; Wassei, Jonathan; McMackin, Ian; Kobrin, Boris

    2014-03-01

    A growing number of commercial products such as displays, solar panels, light emitting diodes (LEDs and OLEDs), automotive and architectural glass are driving demand for glass with high performance surfaces that offer anti-reflective, self-cleaning, and other advanced functions. State-of-the-art coatings do not meet the desired performance characteristics or cannot be applied over large areas in a cost-effective manner. "Rolling Mask Lithography" (RML™) enables highresolution lithographic nano-patterning over large-areas at low-cost and high-throughput. RML is a photolithographic process performed using ultraviolet (UV) illumination transmitted through a soft cylindrical mask as it rolls across a substrate. Subsequent transfer of photoresist patterns into the substrate is achieved using an etching process, which creates a nanostructured surface. The current generation exposure tool is capable of patterning one-meter long substrates with a width of 300 mm. High-throughput and low-cost are achieved using continuous exposure of the resist by the cylindrical photomask. Here, we report on significant improvements in the application of RML™ to fabricate anti-reflective surfaces. Briefly, an optical surface can be made antireflective by "texturing" it with a nano-scale pattern to reduce the discontinuity in the index of refraction between the air and the bulk optical material. An array of cones, similar to the structure of a moth's eye, performs this way. Substrates are patterned using RML™ and etched to produce an array of cones with an aspect ratio of 3:1, which decreases the reflectivity below 0.1%.

  11. Neutral atom lithography with metastable helium

    NASA Astrophysics Data System (ADS)

    Allred, Claire Shean

    In this dissertation we describe our performance of resist assisted neutral atom lithography using a bright beam of metastable 23S1 Helium (He*). Metastable Helium atoms have 20 eV of internal energy making them easy to detect and able to destroy a resist. The He* is produced by a reverse flow DC discharge source and then collimated with the bichromatic force, followed by three optical molasses velocity compression stages. The atoms in the resulting beam have a mean longitudinal velocity of 1125 m/s and a divergence of 1.1 mrad. The typical beam flux is 2 x 109 atoms/mm2s through a 0.1mm diameter aperture 70 cm away from the source. The internal energy of the atoms damages the molecules of a self assembled monolayer (SAM) of nonanethiol. The undisturbed SAM protects a 200 A layer of gold that has been evaporated onto a prepared Silicon wafer from a wet chemical etch. Two methods are used to pattern the He* atoms before they destroy the SAM. First, a Nickel micro mesh was used to protect the SAM. These experiments established an appropriate dosage and etch time for patterning. The samples were analyzed with an atomic force microscope and found to have an edge resolution of 63 nm. Then, patterning was accomplished using the dipole force the atoms experience while traversing a standing wave of lambda = 1083nm light tuned 500MHz below the 23S 1 → 23P2 transition. Depending on the intensity of the light, the He* atoms are focused or channeled into lines separated by lambda/2. The lines cover the entire exposed length of the substrate, about 3 mm. They are about 3 mm long, corresponding to about twice the beam waist of the laser standing wave. Thus there are 6 x 10 3 lines of length 5500lambda. These results agree with our numerical simulations of the experiment.

  12. Submicrometer Pattern Correction For Optical Lithography

    NASA Astrophysics Data System (ADS)

    Ito, Tetsuo; Kadota, Kazuya; Fukui, Hiroshi; Nagao, Masaki; Sugimoto, Aritoshi; Nozaki, Masahiro; Kato, Takeshi

    1988-01-01

    To realize higher CD controls of submicrometer devices, the submicrometer pattern corrections were investigated in optical reduction steppers considering the primary residual aberrations. The optical pattern fidelities on the reduction pattern transfer were estimated at first using the three-dimensional photoresist image simulator RESPROT (Resist Process Three-Dimensional Simulator), which is examined the Seidel's primary aberrations, i.e. spherical aberration, astigmatism, field curvature, distortion and coma. From RESPROT calculations it was known that astigmatism affects pattern shape depending on image height, coma and distortion make position shifts in exposure field, and image contrast is influenced by field curvature. These results were reflected to device design rules, process latitude enhancements and lens manufacturings. To use premature high NA g-line lenses and minimize the diffraction limit for submicrometer area, reticle pattern corrections are very useful for sub-space patterns writing in contact holes, "tailoring" of W/L for MOS-gate patterns, and sub-field position control for distortion correction on ER writing. For almost of this investigation, 5-10nm order corrections were required from original design on wafer. In order to make good use of higher NA lenses, focus latitude enhancement are required because field curvature control is very severe. For these demand, multi-step superpositions of focus and exposure, FLEX -method, is useful to enhance the depth of focus effectively. These simulated and examined results are covenient to realize submicrometer devices on advantageous optical lithography using more shorter wavelength, i.e. i-line or excirner laser steppers.

  13. Extreme Ultraviolet Lithography - Reflective Mask Technology

    SciTech Connect

    Walton, C.C.; Kearney, P.A.; Mirkarimi, P.B.; Bowers, J.M.; Cerjan, C.; Warrick, A.L.; Wilhelmsen, K.; Fought, E.; Moore, C.; Larson, C.; Baker, S.; Burkhart, S.C.; Hector, S.D.

    2000-05-09

    EUVL mask blanks consist of a distributed Bragg reflector made of 6.7nm-pitch bi-layers of MO and Si deposited upon a precision Si or glass substrate. The layer deposition process has been optimized for low defects, by application of a vendor-supplied but highly modified ion-beam sputter deposition system. This system is fully automated using SMIF technology to obtain the lowest possible environmental- and handling-added defect levels. Originally designed to coat 150mm substrates, it was upgraded in July, 1999 to 200 mm and has coated runs of over 50 substrates at a time with median added defects >100nm below 0.05/cm{sup 2}. These improvements have resulted from a number of ion-beam sputter deposition system modifications, upgrades, and operational changes, which will be discussed. Success in defect reduction is highly dependent upon defect detection, characterization, and cross-platform positional registration. We have made significant progress in adapting and extending commercial tools to this purpose, and have identified the surface scanner detection limits for different defect classes, and the signatures of false counts and non-printable scattering anomalies on the mask blank. We will present key results and how they have helped reduce added defects. The physics of defect reduction and mitigation is being investigated by a program on multilayer growth over deliberately placed perturbations (defects) of varying size. This program includes modeling of multilayer growth and modeling of defect printability. We developed a technique for depositing uniformly sized gold spheres on EUVL substrates, and have studied the suppression of the perturbations during multilayer growth under varying conditions. This work is key to determining the lower limit of critical defect size for EUV Lithography. We present key aspects of this work. We will summarize progress in all aspects of EUVL mask blank development, and present detailed results on defect reduction and mask blank

  14. Fluorinated dissolution inhibitors for 157-nm lithography

    NASA Astrophysics Data System (ADS)

    Hamad, Alyssandrea H.; Bae, Young C.; Liu, Xiang-Qian; Ober, Christopher K.; Houlihan, Francis M.; Dabbagh, Gary; Novembre, Anthony E.

    2002-07-01

    Fluorinated dissolution inhibitors (DIs) for 157 nm lithography were designed and synthesized as part of an ongoing study on the structure/property relationships of photoresist additives. The problem of volatilization of small DI candidates was observed from matrices such as poly(methyl methacrylate) (PMMA) and poly(hexafluorohydroxy-isopropyl styrene) (PHFHIPS) during post-apply bake cycles using Fourier Transform Infrared Spectroscopy (FT-IR). To avoid this problem, low volatility fluorinated inhibitors were designed and synthesized. Three fluorinated DIs, perfluorosuberic acid bis-(2,2,2,-trifluoro-1-phenyl-1-trifluoromethyl-ethyl) ester (PFSE1), perfluorosuberic acid bis-[1-(4-trifluoromethyl-phenyl)-ethyl] ester (PFSE2) and a fluorinated phenylmethanediol diester (FPMD1), largely remained in a PHFHIPS film during the post-apply bake. The dissolution behavior of the two fluorinated diesters was studied and found to slow down the dissolution rate of PHFHIPS with inhibition factors of 1.9 and 1.6, respectively. The absorbance of PHFHIPS films containing 10 wt% of the diester inhibitors is 3.6 AU/micron compared with an absorbance of 3.3 AU/micron for the polymer itself. The absorbance of 10% FPMD1 in PHFHIPS was measured as 3.5 AU/micron compared with an absorbance of 3.4 AU/micron for the polymer itself. Thus, the non-volatility and transparency of the fluorinated inhibitors at 157 nm as well as their ability to reduce the development rate of fluorinated polymers make them suitable for use in a 157 nm resist system.

  15. A case study: Immersion coatings test program

    SciTech Connect

    Harris, W.H.

    1995-12-01

    The performance of several coating systems were tested for immersion exposure in potable water storage tank service. Tests were performed for a period of several months in-situ by application of coating systems test patches to a tank interior and was examined periodically during normal service operation. Concurrent with test patches, prepared test panels were placed in the immersion and vapor zones of the tank. Also, test panels were subjected to immersion and condensing humidity in a laboratory environment. All systems were applied in accordance with the respective manufacturers recommendations. Two levels of abrasive blast surface preparation were employed, SSPC-SP10 and SSPC-SP6. Coal slag and sodium bicarbonate were used as blast media. Additionally, some panels and selected tank areas were intentionally subjected to surface contamination in the form of soluble salts to assess the relative tolerance of the selected system to such steel substrate contamination.

  16. Ventilatory drive during face immersion in man.

    PubMed Central

    Mukhtar, M R; Patrick, J M

    1986-01-01

    Four series of experiments have been performed in normal subjects to determine whether face immersion gives rise to a reduction in ventilatory drive. Such a response might be advantageous, like the cardiovascular components of the 'diving response', in prolonging breath-hold diving. In the first series, ventilatory drive was measured indirectly as the maximal voluntary breath-holding time, starting each breath-hold at the same alveolar partial pressures and at the same lung volume. When the face was immersed in cold water, breath-holding times were increased by 14%. The breaking point occurred at a higher alveolar PCO2 and the rate of rise of PCO2 was not affected. Control immersions in warm water had no effect. In the second and third series, subjects lay prone and breathed either air or 5% CO2 through a valve in the bottom of a bowl. Minute ventilation was measured before, during and after 5 min of face immersion in cold water. Transient hypoventilations of 13% and 10% respectively were seen, accompanied by small rises in alveolar PCO2. In control experiments, immersion of the forearm in cold water produced the opposite responses. In the fourth series, a cold wet pack was applied to the face during moderate steady-state exercise. A small irregular hypoventilation was seen, but not in control experiments when a warm pack was applied. Face temperatures fell by about 10 degrees C in these experiments. No material changes were found in the temperatures of the inspired air or of the aural canal. It is concluded that face immersion in cold water causes a modest reduction in ventilatory drive in man. This appears to be a component of the 'diving response'. PMID:3083097

  17. Experimental verification of PSM polarimetry: monitoring polarization at 193nm high-NA with phase shift masks

    NASA Astrophysics Data System (ADS)

    McIntyre, Gregory; Neureuther, Andrew; Slonaker, Steve; Vellanki, Venu; Reynolds, Patrick

    2006-03-01

    The initial experimental verification of a polarization monitoring technique is presented. A series of phase shifting mask patterns produce polarization dependent signals in photoresist and are capable of monitoring the Stokes parameters of any arbitrary illumination scheme. Experiments on two test reticles have been conducted. The first reticle consisted of a series of radial phase gratings (RPG) and employed special apertures to select particular illumination angles. Measurement sensitivities of about 0.3 percent of the clear field per percent change in polarization state were observed. The second test reticle employed the more sensitive proximity effect polarization analyzers (PEPA), a more robust experimental setup, and a backside pinhole layer for illumination angle selection and to enable characterization of the full illuminator. Despite an initial complication with the backside pinhole alignment, the results correlate with theory. Theory suggests that, once the pinhole alignment is corrected in the near future, the second reticle should achieve a measurement sensitivity of about 1 percent of the clear field per percent change in polarization state. This corresponds to a measurement of the Stokes parameters after test mask calibration, to within about 0.02 to 0.03. Various potential improvements to the design, fabrication of the mask, and experimental setup are discussed. Additionally, to decrease measurement time, a design modification and double exposure technique is proposed to enable electrical detection of the measurement signal.

  18. Modeling the rovibrationally excited C2H4OH radicals from the photodissociation of 2-bromoethanol at 193 nm.

    PubMed

    Ratliff, B J; Womack, C C; Tang, X N; Landau, W M; Butler, L J; Szpunar, D E

    2010-04-15

    This study photolytically generates, from 2-bromoethanol photodissociation, the 2-hydroxyethyl radical intermediate of the OH + ethene reaction and measures the velocity distribution of the stable radicals. We introduce an impulsive model to characterize the partitioning of internal energy in the C(2)H(4)OH fragment. It accounts for zero-point and thermal vibrational motion to determine the vibrational energy distribution of the nascent C(2)H(4)OH radicals and the distribution of total angular momentum, J, as a function of the total recoil kinetic energy imparted in the photodissociation. We render this system useful for the study of the subsequent dissociation of the 2-hydroxyethyl radical to the possible asymptotic channels of the OH + ethene reaction. The competition between these channels depends on the internal energy and the J distribution of the radicals. First, we use velocity map imaging to separately resolve the C(2)H(4)OH + Br((2)P(3/2)) and C(2)H(4)OH + Br((2)P(1/2)) photodissociation channels, allowing us to account for the 10.54 kcal/mol partitioned to the Br((2)P(1/2)) cofragment. We determine an improved resonance enhanced multiphoton ionization (REMPI) line strength for the Br transitions at 233.681 nm (5p (4)P(1/2) <-- 4p (2)P(3/2)) and 234.021 nm (5p (2)S(1/2) <-- 4p (2)P(1/2)) and obtain a spin-orbit branching ratio for Br((2)P(1/2)):Br((2)P(3/2)) of 0.26 +/- 0.03:1. Energy and momentum conservation give the distribution of total internal energy, rotational and vibrational, in the C(2)H(4)OH radicals. Then, using 10.5 eV photoionization, we measure the velocity distribution of the radicals that are stable to subsequent dissociation. The onset of dissociation occurs at internal energies much higher than those predicted by theoretical methods and reflects the significant amount of rotational energy imparted to the C(2)H(4)OH photofragment. Instead of estimating the mean rotational energy with an impulsive model from the equilibrium geometry of 2-bromoethanol, our model explicitly includes weighting over geometries across the quantum wave function with zero, one, and two quanta in the harmonic mode that most strongly alters the exit impact parameter. The model gives a nearly perfect prediction of the measured velocity distribution of stable radicals near the dissociation onset using a G4 prediction of the C-Br bond energy and the dissociation barrier for the OH + ethene channel calculated by Senosiain et al. (J. Phys. Chem. A 2006, 110, 6960). The model also indicates that the excited state dissociation proceeds primarily from a conformer of 2-bromoethanol that is trans across the C-C bond. We discuss the possible extensions of our model and the effect of the radical intermediate's J-distribution on the branching between the OH + ethene product channels. PMID:20302318

  19. Spectroscopic Ellipsometry based Scatterometry enabling 193nm Litho and Etch process control for the 110nm technology node and beyond

    NASA Astrophysics Data System (ADS)

    Hingst, Thomas; Marschner, Thomas; Moert, Manfred; Homilius, Jan; Guevremont, Marco; Hopkins, John; Elazami, Assim

    2003-05-01

    In the production of sub 140nm electronic devices, CD metrology is becoming more critical due to the increased demands placed on process control. CD metrology using CD-SEM is approaching its limits especially with respect to precision, resolution and depth of field. Potentially, scatterometry can measure structures down to 50nm with the appropriate precision. Additionally, as scatterometry is a model based technique it allows a full reconstruction of the line profile and the film stack. In this work we use SE based scatterometry in the control of a 110nm DRAM WSix Gate process at the Litho and the Mask Open step. We demonstrate the use of a single trapezoid as a basic shape model in FEM and field mapping applications as well as in a high volume production test. The scatterometry results are compared to CD-SEM data. We show that for the GC Litho application, n&k variations in some of the stack materials do not affect the scatterometry CD measurement significantly.

  20. Challenges and mitigation strategies for resist trim etch in resist-mandrel based SAQP integration scheme

    NASA Astrophysics Data System (ADS)

    Mohanty, Nihar; Franke, Elliott; Liu, Eric; Raley, Angelique; Smith, Jeffrey; Farrell, Richard; Wang, Mingmei; Ito, Kiyohito; Das, Sanjana; Ko, Akiteru; Kumar, Kaushik; Ranjan, Alok; O'Meara, David; Nawa, Kenjiro; Scheer, Steven; DeVillers, Anton; Biolsi, Peter

    2015-03-01

    Patterning the desired narrow pitch at 10nm technology node and beyond, necessitates employment of either extreme ultra violet (EUV) lithography or multi-patterning solutions based on 193nm-immersion lithography. With enormous challenges being faced in getting EUV lithography ready for production, multi-patterning solutions that leverage the already installed base of 193nm-immersion-lithography are poised to become the industry norm for 10 and 7nm technology nodes. For patterning sub-40nm pitch line/space features, self-aligned quadruple patterning (SAQP) with resist pattern as the first mandrel shows significant cost as well as design benefit, as compared to EUV lithography or other multi-patterning techniques. One of the most critical steps in this patterning scheme is the resist mandrel definition step which involves trimming / reformation of resist profile via plasma etch for achieving appropriate pitch after the final pattern. Being the first mandrel, the requirements for the Line Edge Roughness (LER) / Line Width Roughness (LWR); critical dimension uniformity (CDU); and profile in 3-dimensions for the resist trim / reformation etch is extremely aggressive. In this paper we highlight the unique challenges associated in developing resist trim / reformation plasma etch process for SAQP integration scheme and summarize our efforts in optimizing the trim etch chemistries, process steps and plasma etch parameters for meeting the mandrel definition targets. Finally, we have shown successful patterning of 30nm pitch patterns via the resist-mandrel SAQP scheme and its implementation for Si-fin formation at 7nm node.

  1. Cultural Immersion as a Strategy for Empowerment.

    PubMed

    Charles, Jennell P

    2015-01-01

    Cultural immersion experiences offered through study abroad opportunities for nursing students have been increasing in recent years. Examining the impact of these experiences has largely focused on students and not on the faculty leading the experiences. It is important to understand the impact of these experiences on all participants. Exploring the literature on empowerment provides some clarity on the relationship between studying abroad and its impact on participants. Further research linking cultural immersion experiences with empowerment is needed to better understand this relationship and the possibilities of empowering both students and faculty engaged in these exciting opportunities. PMID:26376576

  2. Predefined planar structures in semiconductor surfaces patterned by NSOM lithography

    NASA Astrophysics Data System (ADS)

    Lettrichova, Ivana; Pudis, Dusan; Laurencikova, Agata; Hasenohrl, Stanislav; Novak, Jozef; Skriniarova, Jaroslava; Kovac, Jaroslav

    2013-09-01

    Near-field scanning optical microscope (NSOM) lithography is one of optical technologies for planar structure fabrication, where exposure process is performed by optical near field produced at tip of fiber probe. Maskless exposure of defined regions is performed so that different periodic and predefined arrangement can be achieved. In this contribution, NSOM lithography is presented as effective tool for semiconductor device surface patterning. Non-contact mode of NSOM lithography was used to pattern planar predefined structures in GaAs, AlGaAs and GaP surfaces. In this way, GaAs/AlGaAs-based LED with patterned structure in the emitting surface was prepared, where patterned air holes show enhancement of radiation in comparison with the surrounding surface. Furthermore, NSOM in combination with lift-off technique was used to prepare metal-catalyst particles on GaP substrate for subsequent growth of GaP nanowires which can be used in photovoltaic applications.

  3. Graphene nanoribbon superlattices fabricated via He ion lithography

    SciTech Connect

    Archanjo, Braulio S.; Fragneaud, Benjamin; Gustavo Cançado, Luiz; Winston, Donald; Miao, Feng; Alberto Achete, Carlos; Medeiros-Ribeiro, Gilberto

    2014-05-12

    Single-step nano-lithography was performed on graphene sheets using a helium ion microscope. Parallel “defect” lines of ∼1 μm length and ≈5 nm width were written to form nanoribbon gratings down to 20 nm pitch. Polarized Raman spectroscopy shows that crystallographic orientation of the nanoribbons was partially maintained at their lateral edges, indicating a high-fidelity lithography process. Furthermore, Raman analysis of large exposure areas with different ion doses reveals that He ions produce point defects with radii ∼ 2× smaller than do Ga ions, demonstrating that scanning-He{sup +}-beam lithography can texture graphene with less damage.

  4. Full phase-shifting methodology for 65-nm node lithography

    NASA Astrophysics Data System (ADS)

    Pierrat, Christophe; Driessen, Frank A. J. M.; Vandenberghe, Geert

    2003-06-01

    A new methodology for completely phase-shifting a poly layout without creating local phase conflicts was proposed for lithographic techniques combining one phase-shifting mask and one binary mask exposure1. Critical and non-critical areas of the layout are identified and phase conflicts are avoided by splitting the shifter regions from non-critical areas to non-critical areas without crossing critical areas. The out-of-phase splits of the shifter regions are removed using the binary exposure. Simulation results and experimental data collected for 90nm technology node show no sign of process latitude loss around the areas where the shifters are split. The overlay latitude is commensurate with 90nm technology scanner requirements (tool to itself). Simulation work shows that the two exposures are balancing each other out of focus in the 45-degree cut regions thus ensuring large focus latitude. The focus latitude reported is larger than the main feature process latitude; this result was confirmed experimentally. A set of phase-shifting design rules commensurate with an aggressive 65nm node technology (140nm pitch) was put together. Under these conditions, we have identified certain types of cuts that should be avoided during the generation of the phase-shifting layout; this is primarily the case for cuts in "elbow" structures which exhibit limited process latitude. Other cuts like line-end cuts will have to be modified. In this case we have proposed a side cut when the line-end is facing a perpendicular line with a minimum spacing. Despite these restrictions, test structures for the 65nm technology node were successfully converted with no phase conflicts. Experimental verification done on test structures using a 0.75 NA, 193nm scanner demonstrates 0.33 k1 capability using the full phase methodology.

  5. Advanced low-complexity compression for maskless lithography data

    NASA Astrophysics Data System (ADS)

    Dai, Vito; Zakhor, Avideh

    2004-05-01

    A direct-write maskless lithography system using 25nm for 50nm feature sizes requires data rates of about 10 Tb/s to maintain a throughput of one wafer per minute per layer achieved by today"s optical lithography systems. In a previous paper, we presented an architecture that achieves this data rate contingent on 25 to 1 compression of lithography data, and on implementation of a real-time decompressor fabricated on the same chip as a massively parallel array of lithography writers for 50 nm feature sizes. A number of compression techniques, including JBIG, ZIP, the novel 2D-LZ, and BZIP2 were demonstrated to achieve sufficiently high compression ratios on lithography data to make the architecture feasible, although no single technique could achieve this for all test layouts. In this paper we present a novel lossless compression algorithm called Context Copy Combinatorial Code (C4) specifically tailored for lithography data. It successfully combines the advantages of context-based modeling in JBIG and copying in ZIP to achieve higher compression ratios across all test layouts. As part of C4, we have developed a low-complexity binary entropy coding technique called combinatorial coding which is simultaneously as efficient as arithmetic coding and as fast as Huffman coding. Compression results show C4 outperforms JBIG, ZIP, BZIP2, and 2D-LZ, and achieves lossless compression ratios greater than 22 for binary layout image data, and greater than 14 for grey-pixel image data. The tradeoff between decoder buffer size, which directly affects implementation complexity and compression ratio is examined. For the same buffer size, C4 achieves higher compression than LZ77, ZIP, and BZIP2.

  6. Mix-and-match lithography for half-micron technology

    NASA Astrophysics Data System (ADS)

    Flack, Warren W.; Dameron, David H.

    1991-08-01

    Half-micron lithography for a production environment is not considered realistic with currently available lithography tools. While optical steppers have high wafer throughputs, they do not have sufficient process latitude at half-micron geometries. In contrast, advanced technologies with sufficient capabilities for half-micron processing such as direct-write e-beam and x-ray lithography are extremely expensive and have low effective throughputs. A mix-and- match lithography approach can take advantage of the best features of both types of systems by sing an optical stepper for noncritical levels and an advanced lithography system for critical levels. In order to facilitate processing of a triple level metal half-micron CMOS technology, a mix-and-match scheme has been developed between a Hitachi HL-700 D e-beam direct write system and an Ultratech 1500 wide-field 1x stepper. The Hitachi is used to pattern an accurate zero or registration level. All critical levels are exposed on the Hitachi and aligned back to this zero level. The Ultratech is used to align all other process levels which do not have critical targets that are placed on subsequent process levels. The mix-and-match approach is discussed, and optical to e-beam as well as e-beam to optical alignment results from seven production lots are presented. The linear alignment error components X translation, Y translation, rotation and magnification are extracted and analyzed to determine their source. It was found that a simple adjustment improved the registration capabilities of these two lithography tools by reducing the X translation, Y translation and rotation standard deviations by a factor of two or more, while greatly reducing the magnification errors between the two tools.

  7. Theoretical study of fabrication of line-and-space patterns with 7 nm quarter-pitch using electron beam lithography with chemically amplified resist process: III. Post exposure baking on quartz substrates

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro

    2015-09-01

    Electron beam (EB) lithography is a key technology for the fabrication of photomasks for ArF immersion and extreme ultraviolet (EUV) lithography and molds for nanoimprint lithography. In this study, the temporal change in the chemical gradient of line-and-space patterns with a 7 nm quarter-pitch (7 nm space width and 21 nm line width) was calculated until it became constant, independently of postexposure baking (PEB) time, to clarify the feasibility of single nano patterning on quartz substrates using EB lithography with chemically amplified resist processes. When the quencher diffusion constant is the same as the acid diffusion constant, the maximum chemical gradient of the line-and-space pattern with a 7 nm quarter-pitch did not differ much from that with a 14 nm half-pitch under the condition described above. Also, from the viewpoint of process control, a low quencher diffusion constant is considered to be preferable for the fabrication of line-and-space patterns with a 7 nm quarter-pitch on quartz substrates.

  8. Boron nitride stamp for ultra-violet nanoimprinting lithography fabricated by focused ion beam lithography.

    PubMed

    Altun, Ali Ozhan; Jeong, Jun-Ho; Rha, Jong-Joo; Kim, Ki-Don; Lee, Eung-Sug

    2007-11-21

    Cubic boron nitride (c-BN) is one of the hardest known materials (second after diamond). It has a high level of chemical resistance and high UV transmittance. In this study, a stamp for ultra-violet nanoimprint lithography (UV-NIL) was fabricated using a bi-layered BN film deposited on a quartz substrate. Deposition of the BN was done using RF magnetron sputtering. A hexagonal boron nitride (h-BN) layer was deposited for 30 min before c-BN was deposited for 30 min. The thickness of the film was measured as 160 nm. The phase of the c-BN layer was investigated using Fourier transform infrared (FTIR) spectrometry, and it was found that the c-BN layer has a 40% cubic phase. The deposited film was patterned using focused ion beam (FIB) lithography for use as a UV-NIL stamp. Line patterns were fabricated with the line width and line distance set at 150 and 150 nm, respectively. The patterning process was performed by applying different currents to observe the effect of the current value on the pattern profile. The fabricated patterns were investigated using AFM, and it was found that the pattern fabricated by applying a current value of 50 picoamperes (pA) has a better profile with a 65 nm line depth. The UV transmittance of the 160 nm thick film was measured to be 70-86%. The hardness and modulus of the BN was measured to be 12 and 150 GPa, respectively. The water contact angle of the stamp surface was measured at 75°. The stamp was applied to UV-NIL without coating with an anti-adhesion layer. Successful imprinting was proved via scanning electron microscope (SEM) images of the imprinted resin. PMID:21730473

  9. Towards Using DNAzyme in Sub-20 nm Lithography

    NASA Astrophysics Data System (ADS)

    Dirar, Qassim

    DNAzyme is a unique molecule with applications ranging from gene regulation to molecular machines. Another attractive venue for the use of DNAzyme is next generation lithography, sub-20 nm lithography, harnessing the unique features of specific recognition and self-assembly. Tools to achieve that goal are discussed and experimental procedures were presented. Loading DNAzyme on gold nanoparticles, depositing self-assembled monolayers and DNA patterning using soft lithographic techniques are tools that are explored. To support the findings, different characterization techniques are employed.

  10. Optimization of high average power FEL beam for EUV lithography

    NASA Astrophysics Data System (ADS)

    Endo, Akira

    2015-05-01

    Extreme Ultraviolet Lithography (EUVL) is entering into high volume manufacturing (HVM) stage, with high average power (250W) EUV source from laser produced plasma at 13.5nm. Semiconductor industry road map indicates a scaling of the source technology more than 1kW average power by high repetition rate FEL. This paper discusses on the lowest risk approach to construct a prototype based on superconducting linac and normal conducting undulator, to demonstrate a high average power 13.5nm FEL equipped with optimized optical components and solid state lasers, to study FEL application in EUV lithography.

  11. The Introduction and Early Use of Lithography in the United States.

    ERIC Educational Resources Information Center

    Barnhill, Georgia B.

    This paper discusses the use of lithography in the United States in the early 1800s. Highlights include: the development of lithography in Germany between 1796 and 1798; early expectations for lithography; competition against the existing technology for the production of images--relief prints and copper-plate engravings; examples of 18th-century…

  12. Nanoimprint lithography for functional polymer patterning

    NASA Astrophysics Data System (ADS)

    Cui, Dehu

    2011-07-01

    Organic semiconductors have generated huge interested in recent years for low-cost and flexible electronics. Current and future device applications for semiconducting polymers include light-emitting diodes, thin-film transistors, photovoltaic cells, photodetectors, lasers, and memories. The performance of conjugated polymer devices depends on two major factors: the chain conformation in polymer film and the device architecture. Highly ordered chain structure usually leads to much improved performance by enhancing interchain interaction to facilitate carrier transport. The goal of this research is to improve the performance of organic devices with the nanoimprint lithography. The work begins with the controlling of polymer chain orientation in patterned nanostructures through nanoimprint mold design and process parameter manipulation, and studying the effect of chain ordering on material properties. Then, step-and-repeat thermal nanoimprint technique for large-scale continuous manufacturing of conjugated polymer nanostructures is developed. After that, Systematic investigation of polymer chain configuration by Raman spectroscopy is carried out to understand how nanoimprint process parameters, such as mold pattern size, temperature, and polymer molecular weight, affects polymer chain configuration. The results indicate that chain orientation in nanoimprinted polymer micro- and nanostructures is highly related to the nanoimprint temperature and the dimensions of the mold structures. The ability to create nanoscale polymer micro- and nanostructures and manipulate their internal chain conformation establishes an original experimental platform that enables studying the properties of functional polymers at the micro- and nanoscale and understanding their fundamental structure-property relationships. In addition to the impact on basic research, the techniques developed in this work are important in applied research and development. Large-area conjugated polymer micro- and

  13. Capillary force lithography for cardiac tissue engineering.

    PubMed

    Macadangdang, Jesse; Lee, Hyun Jung; Carson, Daniel; Jiao, Alex; Fugate, James; Pabon, Lil; Regnier, Michael; Murry, Charles; Kim, Deok-Ho

    2014-01-01

    Cardiovascular disease remains the leading cause of death worldwide(1). Cardiac tissue engineering holds much promise to deliver groundbreaking medical discoveries with the aims of developing functional tissues for cardiac regeneration as well as in vitro screening assays. However, the ability to create high-fidelity models of heart tissue has proven difficult. The heart's extracellular matrix (ECM) is a complex structure consisting of both biochemical and biomechanical signals ranging from the micro- to the nanometer scale(2). Local mechanical loading conditions and cell-ECM interactions have recently been recognized as vital components in cardiac tissue engineering(3-5). A large portion of the cardiac ECM is composed of aligned collagen fibers with nano-scale diameters that significantly influences tissue architecture and electromechanical coupling(2). Unfortunately, few methods have been able to mimic the organization of ECM fibers down to the nanometer scale. Recent advancements in nanofabrication techniques, however, have enabled the design and fabrication of scalable scaffolds that mimic the in vivo structural and substrate stiffness cues of the ECM in the heart(6-9). Here we present the development of two reproducible, cost-effective, and scalable nanopatterning processes for the functional alignment of cardiac cells using the biocompatible polymer poly(lactide-co-glycolide) (PLGA)(8) and a polyurethane (PU) based polymer. These anisotropically nanofabricated substrata (ANFS) mimic the underlying ECM of well-organized, aligned tissues and can be used to investigate the role of nanotopography on cell morphology and function(10-14). Using a nanopatterned (NP) silicon master as a template, a polyurethane acrylate (PUA) mold is fabricated. This PUA mold is then used to pattern the PU or PLGA hydrogel via UV-assisted or solvent-mediated capillary force lithography (CFL), respectively(15,16). Briefly, PU or PLGA pre-polymer is drop dispensed onto a glass coverslip

  14. Immersion versus interactivity and analytic field.

    PubMed

    Civitarese, Giuseppe

    2008-04-01

    Losing oneself in a story, a film or a picture is nothing but another step in the suspension of disbelief that permits one to become immersed in the 'novel' of reality. It is not by chance that the text-world metaphor informs classical aesthetics that, more than anything else, emphasizes emotional involvement. On the contrary, as in much of modern art, self-reflexivity and metafictional attention to the rhetoric of the real, to the framework, to the conventions and to the processes of meaning production, all involve a disenchanted, detached and sceptic vision--in short, an aesthetics of the text as game. By analogy, any analytic style or model that aims to produce a transformative experience must satisfactorily resolve the conflict between immersion (the analyst's emotional participation and sticking to the dreamlike or fictional climate of the session, dreaming knowing it's a dream) and interactivity (for the most part, interpretation as an anti-immersive device that 'wakes' one from fiction and demystifies consciousness). In analytic field theory the setting can be defined--because of the weight given to performativity of language, to the sensory matrix of the transference and the transparency of the medium--the place where an ideal balance is sought between immersion and interaction. PMID:18405284

  15. 21 CFR 890.5100 - Immersion hydrobath.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Immersion hydrobath. 890.5100 Section 890.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5100...

  16. 21 CFR 890.5100 - Immersion hydrobath.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Immersion hydrobath. 890.5100 Section 890.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5100...

  17. 21 CFR 890.5100 - Immersion hydrobath.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Immersion hydrobath. 890.5100 Section 890.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5100...

  18. 21 CFR 890.5100 - Immersion hydrobath.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Immersion hydrobath. 890.5100 Section 890.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5100...

  19. Digital Immersive Virtual Environments and Instructional Computing

    ERIC Educational Resources Information Center

    Blascovich, Jim; Beall, Andrew C.

    2010-01-01

    This article reviews theory and research relevant to the development of digital immersive virtual environment-based instructional computing systems. The review is organized within the context of a multidimensional model of social influence and interaction within virtual environments that models the interaction of four theoretical factors: theory…

  20. How One Class Experienced Cultural Immersion

    ERIC Educational Resources Information Center

    Allery, Virginia

    2009-01-01

    Twenty-one teacher candidates and faculty from Turtle Mountain Community College (TMCC, Belcourt, North Dakota) and Cikana Cankdeska Community College (CCCC, Fort Totten, North Dakota) traveled by train from North Dakota to Minneapolis, Minnesota, for an immersion experience as part of their Human Relations and Multicultural Education. The group…

  1. 21 CFR 890.5100 - Immersion hydrobath.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Immersion hydrobath. 890.5100 Section 890.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5100...

  2. Late Immersion Foundation Document: Teachers and Administrators

    ERIC Educational Resources Information Center

    Alberta Education, 2010

    2010-01-01

    The aim of this document is to give teachers and administrators the contextual and pedagogical tools for the late immersion program. It acts as a guide for beginning and experienced teachers who need to update their knowledge regarding this program and its details. For many working in this area, it also confirms their daily practices as well as…

  3. Using Immersive Virtual Environments for Certification

    NASA Technical Reports Server (NTRS)

    Lutz, R.; Cruz-Neira, C.

    1998-01-01

    Immersive virtual environments (VEs) technology has matured to the point where it can be utilized as a scientific and engineering problem solving tool. In particular, VEs are starting to be used to design and evaluate safety-critical systems that involve human operators, such as flight and driving simulators, complex machinery training, and emergency rescue strategies.

  4. Language and Culture Immersion: A Winning Enterprise.

    ERIC Educational Resources Information Center

    Cormier, Raymond

    A second language program developed at Wilson College (Chambersburg, Pennsylvania) with a federal grant uses the Rassias Method of theatrical, dramatic language saturation. In the first application of the program at the college, peer tutors (who would be assistant teachers in the subsequent immersion program) were trained in a three-day workshop.…

  5. Learning in an immersive digital theater

    NASA Astrophysics Data System (ADS)

    Sumners, C.; Reiff, P.; Weber, W.

    2008-12-01

    The Houston Museum of Natural Science, in collaboration with Rice University has an outreach program taking portable digital theaters to schools and community sites for over five years and has conducted research on student learning in this immersive environment. By using an external independent evaluator, the effectiveness of NASA-funded Education and Public Outreach (EPO) projects can be assessed. This paper documents interactive techniques and learning strategies in full-dome digital theaters. The presentation is divided into Evaluation Strategies and Results and Interactivity Strategies and Results. All learners from grades 3-12 showed statistically significant short-term increase in knowledge of basic Earth science concepts after a single 22-min show. Improvements were more significant on items that were taught using more than one modality of instruction: hearing, seeing, discussion, and immersion. Thus immersive theater can be an effective as well as engaging teaching method for Earth and Space science concepts, particularly those that are intrinsically three-dimensional and thus most effectively taught in an immersive environment. The portable system allows taking the educational experience to rural and tribal sites where the underserved students could not afford the time or expense to travel to museums.

  6. Immersion Teachers' Perceptions of Learning Strategies Instruction.

    ERIC Educational Resources Information Center

    National Capital Language Resource Center, Washington, DC.

    Researchers worked with French, Japanese, and Spanish immersion teachers in metropolitan Washington, DC elementary schools (grades 1-6) to implement language learning strategies in their classrooms. Workshops, materials, and observations were provided for professional support. Teachers were debriefed on the effectiveness of the teacher training…

  7. Architectures for Developing Multiuser, Immersive Learning Scenarios

    ERIC Educational Resources Information Center

    Nadolski, Rob J.; Hummel, Hans G. K.; Slootmaker, Aad; van der Vegt, Wim

    2012-01-01

    Multiuser immersive learning scenarios hold strong potential for lifelong learning as they can support the acquisition of higher order skills in an effective, efficient, and attractive way. Existing virtual worlds, game development platforms, and game engines only partly cater for the proliferation of such learning scenarios as they are often…

  8. Immersion Calorimetry: Molecular Packing Effects in Micropores.

    PubMed

    Madani, S Hadi; Silvestre-Albero, Ana; Biggs, Mark J; Rodríguez-Reinoso, Francisco; Pendleton, Phillip

    2015-12-21

    Repeated and controlled immersion calorimetry experiments were performed to determine the specific surface area and pore-size distribution (PSD) of a well-characterized, microporous poly(furfuryl alcohol)-based activated carbon. The PSD derived from nitrogen gas adsorption indicated a narrow distribution centered at 0.57±0.05 nm. Immersion into liquids of increasing molecular sizes ranging from 0.33 nm (dichloromethane) to 0.70 nm (α-pinene) showed a decreasing enthalpy of immersion at a critical probe size (0.43-0.48 nm), followed by an increase at 0.48-0.56 nm, and a second decrease at 0.56-0.60 nm. This maximum has not been reported previously. After consideration of possible reasons for this new observation, it is concluded that the effect arises from molecular packing inside the micropores, interpreted in terms of 2D packing. The immersion enthalpy PSD was consistent with that from quenched solid density functional theory (QSDFT) analysis of the nitrogen adsorption isotherm. PMID:26394883

  9. Beyond Language in Indigenous Language Immersion Schooling.

    ERIC Educational Resources Information Center

    Stairs, Arlene; Peters, Margaret; Perkins, Elizabeth

    1999-01-01

    The Akwesasne Freedom School, on the Akwesasne Mohawk reservation (New York and Canada), is an independent immersion school that preserves not only the Mohawk language but also socialization patterns, styles of interpersonal relations, ethical principles, and aesthetic sensibilities. The curriculum is based on the Iroquoian Thanksgiving Address,…

  10. Comparison study for sub-0.13-μm lithography between ArF and KrF lithography

    NASA Astrophysics Data System (ADS)

    Kim, Seok-Kyun; Kim, YoungSik; Kim, Jin-Soo; Bok, Cheol-Kyu; Ham, Young-Mog; Baik, Ki-Ho

    2000-07-01

    In this paper we investigated the feasibility of printing sub-0.13 micrometers device patterns with ArF and KrF lithography by using experiment and simulation. To do this we evaluated various cell structures with different sizes from 0.26 micrometers to 0.20 micrometers pitch. In experiment 0.60NA ArF and 0.70NA KrF exposure tools, commercial and in house resists and bottom anti-reflective coating (BARC) materials are used. To predict and compare with experimental data we also used our developed simulation tool HOST base don diffused aerial iamge model. We found that ArF lithography performance is a little bit better than KrF and therefore 0.70NA KrF lithography can be used up to 0.12 micrometers design rule device and 0.60NA ArF lithography can be used up to 0.11 micrometers . But to get more than 10 percent expose latitude, 0.13 micrometers with KrF and 0.12 micrometers with ArF are the minimum design rule size. However to obtain process margin we had to use extreme off-axis illumination (OAI) which results in large isolated- dense bias and poor linearity including isolated pattern. Using higher NA can reduce ID bias and mask error factor. For contact hole it is more effective to use KrF lithography because resist thermal flow process can be used to shrink C/H size. Our developed ArF resist and BARC shows good performance and we can reduce k1 value up to 0.34. Through this study we verified again that ArF lithography can be applied for sub-0.13 micrometers device through sub-0.10 micrometers with high contrast resist and 0.75NA exposure tool.

  11. Waveguide effect in high-NA EUV lithography: The key to extending EUV lithography to the 4-nm node

    NASA Astrophysics Data System (ADS)

    Yeung, Michael; Barouch, Eytan; Oh, Hye-Keun

    2015-06-01

    One of the main concerns about EUV lithography is whether or not it can be extended to very high numerical aperture. In this paper, rigorous electromagnetic simulation is first used to show that there is an interesting waveguide effect occurring in the 4-nm feature size regime. An exact mathematical analysis is then presented to explain the effect observed in the simulation. This waveguide effect is applied to simulate the printing of 4-nm lines and spaces with excellent aerial-image contrast and peak intensity. The feasibility of EUV lithography for printing logic circuits containing general two-dimensional patterns with 4-nm feature size is also demonstrated.

  12. Aerial image measurement technique for automated reticle defect disposition (ARDD) in wafer fabs

    NASA Astrophysics Data System (ADS)

    Zibold, Axel M.; Schmid, Rainer M.; Stegemann, B.; Scheruebl, Thomas; Harnisch, Wolfgang; Kobiyama, Yuji

    2004-08-01

    The Aerial Image Measurement System (AIMS)* for 193 nm lithography emulation has been brought into operation successfully worldwide. A second generation system comprising 193 nm AIMS capability, mini-environment and SMIF, the AIMS fab 193 plus is currently introduced into the market. By adjustment of numerical aperture (NA), illumination type and partial illumination coherence to match the conditions in 193 nm steppers or scanners, it can emulate the exposure tool for any type of reticles like binary, OPC and PSM down to the 65 nm node. The system allows a rapid prediction of wafer printability of defects or defect repairs, and critical features, like dense patterns or contacts on the masks without the need to perform expensive image qualification consisting of test wafer exposures followed by SEM measurements. Therefore, AIMS is a mask quality verification standard for high-end photo masks and established in mask shops worldwide. The progress on the AIMS technology described in this paper will highlight that besides mask shops there will be a very beneficial use of the AIMS in the wafer fab and we propose an Automated Reticle Defect Disposition (ARDD) process. With smaller nodes, where design rules are 65 nm or less, it is expected that smaller defects on reticles will occur in increasing numbers in the wafer fab. These smaller mask defects will matter more and more and become a serious yield limiting factor. With increasing mask prices and increasing number of defects and severability on reticles it will become cost beneficial to perform defect disposition on the reticles in wafer production. Currently ongoing studies demonstrate AIMS benefits for wafer fab applications. An outlook will be given for extension of 193 nm aerial imaging down to the 45 nm node based on emulation of immersion scanners.

  13. Immersion mode ice nucleation measurements with the new Portable Immersion Mode Cooling chAmber (PIMCA)

    NASA Astrophysics Data System (ADS)

    Kohn, Monika; Lohmann, Ulrike; Welti, André; Kanji, Zamin A.

    2016-05-01

    The new Portable Immersion Mode Cooling chAmber (PIMCA) has been developed for online immersion freezing of single-immersed aerosol particles. PIMCA is a vertical extension of the established Portable Ice Nucleation Chamber (PINC). PIMCA immerses aerosol particles into cloud droplets before they enter PINC. Immersion freezing experiments on cloud droplets with a radius of 5-7 μm at a prescribed supercooled temperature (T) and water saturation can be conducted, while other ice nucleation mechanisms (deposition, condensation, and contact mode) are excluded. Validation experiments on reference aerosol (kaolinite, ammonium sulfate, and ammonium nitrate) showed good agreement with theory and literature. The PIMCA-PINC setup was tested in the field during the Zurich AMBient Immersion freezing Study (ZAMBIS) in spring 2014 in Zurich, Switzerland. Significant concentrations of submicron ambient aerosol triggering immersion freezing at T > 236 K were rare. The mean frozen cloud droplet number concentration was estimated to be 7.22·105 L-1 for T < 238 K and determined from the measured frozen fraction and cloud condensation nuclei (CCN) concentrations predicted for the site at a typical supersaturation of SS = 0.3%. This value should be considered as an upper limit of cloud droplet freezing via immersion and homogeneous freezing processes. The predicted ice nucleating particle (INP) concentration based on measured total aerosol larger than 0.5 μm and the parameterization by DeMott et al. (2010) at T = 238 K is INPD10=54 ± 39 L-1. This is a lower limit as supermicron particles were not sampled with PIMCA-PINC during ZAMBIS.

  14. EUV lithography: NXE platform performance overview

    NASA Astrophysics Data System (ADS)

    Peeters, Rudy; Lok, Sjoerd; Mallman, Joerg; van Noordenburg, Martijn; Harned, Noreen; Kuerz, Peter; Lowisch, Martin; van Setten, Eelco; Schiffelers, Guido; Pirati, Alberto; Stoeldraijer, Judon; Brandt, David; Farrar, Nigel; Fomenkov, Igor; Boom, Herman; Meiling, Hans; Kool, Ron

    2014-04-01

    The first NXE3300B systems have been qualified and shipped to customers. The NXE:3300B is ASML's third generation EUV system and has an NA of 0.33. It succeeds the NXE:3100 system (NA of 0.25), which has allowed customers to gain valuable EUV experience. Good overlay and imaging performance has been shown on the NXE:3300B system in line with 22nm device requirements. Full wafer CDU performance of <1.5nm for 22nm dense and iso lines at a dose of ~16mJ/cm2 has been achieved. Matched machine overlay (NXE to immersion) of around 3.5nm has been demonstrated on multiple systems. Dense lines have been exposed down to 13nm half pitch, and contact holes down to 17nm half pitch. 10nm node Metal-1 layers have been exposed with a DOF of 120nm, and using single spacer assisted double patterning flow a resolution of 9nm has been achieved. Source power is the major challenge to overcome in order to achieve cost-effectiveness in EUV and enable introduction into High Volume Manufacturing. With the development of the MOPA+prepulse operation of the source, steps in power have been made, and with automated control the sources have been prepared to be used in a preproduction fab environment. Flexible pupil formation is under development for the NXE:3300B which will extend the usage of the system in HVM, and the resolution for the full system performance can be extended to 16nm. Further improvements in defectivity performance have been made, while in parallel full-scale pellicles are being developed. In this paper we will discuss the current NXE:3300B performance, its future enhancements and the recent progress in EUV source performance.

  15. Technology of alignment mark in electron beam lithography

    NASA Astrophysics Data System (ADS)

    Zhao, Min; Xu, Tang; Chen, Baoqin; Niu, Jiebin

    2014-08-01

    Electron beam direct wring lithography has been an indispensable approach by which all sorts of novel nano-scale devices include many kinds optical devices can be fabricated. Alignment accuracy is a key factor especially to those devices which need multi-level lithography. In addition to electron beam lithography system itself the quality of alignment mark directly influences alignment accuracy. This paper introduces fundamental of alignment mark detection and discusses some techniques of alignment mark fabrication along with considerations for obtaining highly accurate alignment taking JBX5000LS and JBX6300FS e-beam lithography systems for example. The fundamental of alignment mark detection is expounded first. Many kinds of factors which can impact on the quality of alignment mark are analyzed including mark materials, depth of mark groove and influence of multi-channel process. It has been proved from experiments that material used as metal mark with higher average atomic number is better beneficial for getting high alignment accuracy. Depth of mark groove is required to 1.5~5 μm on our experience. The more process steps alignment mark must pass through, the more probability of being damaged there will be. So the compatibility of alignment mark fabrication with the whole device process and the protection of alignment mark are both need to be considered in advance.

  16. Vertical Flow Lithography for Fabrication of 3D Anisotropic Particles.

    PubMed

    Habasaki, Shohei; Lee, Won Chul; Yoshida, Shotaro; Takeuchi, Shoji

    2015-12-22

    A microfluidics-based method for the 3D fabrication of anisotropic particles is reported. The method uses a vertical microchannel where tunable light patterns solidify photocurable resins for stacking multiple layers of the resins, thus enabling an application of stereolithography concepts to conventional flow lithography. Multilayered, tapered, and angular compartmental microparticles are demonstrated. PMID:26551590

  17. Lithography develop process electrostatic discharge effect mechanism study

    NASA Astrophysics Data System (ADS)

    Yang, Xiaosong; Ye, Yi Zhou; Zou, Yongxiang; Zhu, XiaoZheng

    2015-03-01

    Electrostatic discharge (ESD) problem resulting from charges on wafers is a serious concern in IC manufacturing. As is discovered in our paper, three types of defect, AA (active area) damage, IMD (Inter Metal Dielectric) crack and Via hole W corrosion that are confirmed to be induced by lithography process related ESD charging effect. We carefully studied the mechanism of these ESD charging effect by DOE splits and succeeded to dig out that these electric charge major comes from the lithography develop process. In the lithography coating and developing wafer process, the wafer will be at high spin speed at many of the steps which will easy help to store the electric charge on the wafer. In our study, the rinse step in developing process is the most key factor to store the electric charge on wafer. In generally, the higher rinse speed, the higher positive electric charge. Furthermore, we also discovered that the different step in develop rinse process have different impact on charge level, in which the acceleration and deceleration step has the highest charge voltage. As to minimize and eliminate the ESD damage in lithography process, we finally carry out the simplified recipe optimization solution which only need optimize for the develop rinse speed with different in-coming surface charge level and process application, so that can be easy implemented in the worldwide fabs.

  18. Diffractive element in extreme-UV lithography condenser

    DOEpatents

    Sweatt, William C.; Ray-Chaudhuri, Avijit

    2001-01-01

    Condensers having a mirror with a diffraction grating in projection lithography using extreme ultra-violet significantly enhances critical dimension control. The diffraction grating has the effect of smoothing the illumination at the camera's entrance pupil with minimum light loss. Modeling suggests that critical dimension control for 100 nm features can be improved from 3 nm to less than about 0.5 nm.

  19. Diffractive element in extreme-UV lithography condenser

    DOEpatents

    Sweatt, William C.; Ray-Chaudhurl, Avijit K.

    2000-01-01

    Condensers having a mirror with a diffraction grating in projection lithography using extreme ultra-violet significantly enhances critical dimension control. The diffraction grating has the effect of smoothing the illumination at the camera's entrance pupil with minimum light loss. Modeling suggests that critical dimension control for 100 nm features can be improved from 3 nm to less than about 0.5 nm.

  20. OPC modeling and correction solutions for EUV lithography

    NASA Astrophysics Data System (ADS)

    Word, James; Zuniga, Christian; Lam, Michael; Habib, Mohamed; Adam, Kostas; Oliver, Michael

    2011-11-01

    The introduction of EUV lithography into the semiconductor fabrication process will enable a continuation of Moore's law below the 22nm technology node. EUV lithography will, however, introduce new sources of patterning distortions which must be accurately modeled and corrected with software. Flare caused by scattered light in the projection optics result in pattern density-dependent imaging errors. The combination of non-telecentric reflective optics with reflective reticles results in mask shadowing effects. Reticle absorber materials are likely to have non-zero reflectivity due to a need to balance absorber stack height with minimization of mask shadowing effects. Depending upon placement of adjacent fields on the wafer, reflectivity along their border can result in inter-field imaging effects near the edge of neighboring exposure fields. Finally, there exists the ever-present optical proximity effects caused by diffractionlimited imaging and resist and etch process effects. To enable EUV lithography in production, it is expected that OPC will be called-upon to compensate for most of these effects. With the anticipated small imaging error budgets at sub-22nm nodes it is highly likely that only full model-based OPC solutions will have the required accuracy. The authors will explore the current capabilities of model-based OPC software to model and correct for each of the EUV imaging effects. Modeling, simulation, and correction methodologies will be defined, and experimental results of a full model-based OPC flow for EUV lithography will be presented.