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Sample records for fluorocarbon films deposited

  1. Selective Plasma Deposition of Fluorocarbon Films on SAMs

    NASA Technical Reports Server (NTRS)

    Crain, Mark M., III; Walsh, Kevin M.; Cohn, Robert W.

    2006-01-01

    A dry plasma process has been demonstrated to be useful for the selective modification of self-assembled monolayers (SAMs) of alkanethiolates. These SAMs are used, during the fabrication of semiconductor electronic devices, as etch masks on gold layers that are destined to be patterned and incorporated into the devices. The selective modification involves the formation of fluorocarbon films that render the SAMs more effective in protecting the masked areas of the gold against etching by a potassium iodide (KI) solution. This modification can be utilized, not only in the fabrication of single electronic devices but also in the fabrication of integrated circuits, microelectromechanical systems, and circuit boards. In the steps that precede the dry plasma process, a silicon mold in the desired pattern is fabricated by standard photolithographic techniques. A stamp is then made by casting polydimethylsiloxane (commonly known as silicone rubber) in the mold. The stamp is coated with an alkanethiol solution, then the stamp is pressed on the gold layer of a device to be fabricated in order to deposit the alkanethiol to form an alkanethiolate SAM in the desired pattern (see figure). Next, the workpiece is exposed to a radio-frequency plasma generated from a mixture of CF4 and H2 gases. After this plasma treatment, the SAM is found to be modified, while the exposed areas of gold remain unchanged. This dry plasma process offers the potential for forming masks superior to those formed in a prior wet etching process. Among the advantages over the wet etching process are greater selectivity, fewer pin holes in the masks, and less nonuniformity of the masks. The fluorocarbon films formed in this way may also be useful as intermediate layers for subsequent fabrication steps and as dielectric layers to be incorporated into finished products.

  2. Electrowetting on plasma-deposited fluorocarbon hydrophobic films for biofluid transport in microfluidics

    SciTech Connect

    Bayiati, P.; Tserepi, A.; Petrou, P. S.; Kakabakos, S. E.; Misiakos, K.; Gogolides, E.

    2007-05-15

    The present work focuses on the plasma deposition of fluorocarbon (FC) films on surfaces and the electrostatic control of their wettability (electrowetting). Such films can be employed for actuation of fluid transport in microfluidic devices, when deposited over patterned electrodes. Here, the deposition was performed using C{sub 4}F{sub 8} and the plasma parameters that permit the creation of films with optimized properties desirable for electrowetting were established. The wettability of the plasma-deposited surfaces was characterized by means of contact angle measurements (in the static and dynamic mode). The thickness of the deposited films was probed in situ by means of spectroscopic ellipsometry, while the surface roughness was provided by atomic force microscopy. These plasma-deposited FC films in combination with silicon nitride, a material of high dielectric constant, were used to create a dielectric structure that requires reduced voltages for successful electrowetting. Electrowetting experiments using protein solutions were conducted on such optimized dielectric structures and were compared with similar structures bearing commercial spin-coated Teflon registered amorphous fluoropolymer (AF) film as the hydrophobic top layer. Our results show that plasma-deposited FC films have desirable electrowetting behavior and minimal protein adsorption, a requirement for successful transport of biological solutions in 'digital' microfluidics.

  3. Surface-Morphology-Induced Hydrophobicity of Fluorocarbon Films Grown by a Simultaneous Etching and Deposition Process

    NASA Astrophysics Data System (ADS)

    Fang, J. S.; Lin, C. S.; Huang, Y. Y.; Chin, T. S.

    2015-08-01

    Development of facile methods to prepare hydrophobic films is of great important. We report fluorocarbon films deposited by a simple plasma-assisted chemical vapor deposition method using C3F8 and C2H2 with extra Ar and/or O2 gases. The surface characteristics of the films were examined by scanning electron microscopy, atomic force microscopy, and x-ray photoelectron spectroscopy. The hydrophobic and oleophobic properties of the films were evaluated by measurements of static contact angle. The results showed that the film deposited with C3F8, C2H2, Ar, and O2 exhibited a water contact angle of 114°, hexadecane contact angle of 45°, and transmittance of 94.5%. Photoelectron spectra further revealed that the films contained mainly CF and CF2 bonds and thus a high F/C ratio. Introduction of O2 increased the F/C ratio, which combined with the stripe-like surface of the films achieved better hydrophobicity.

  4. The effects of changing deposition conditions on the similarity of sputter-deposited fluorocarbon thin films to bulk PTFE

    NASA Astrophysics Data System (ADS)

    Zandona, Philip

    Solid lubrication of space-borne mechanical components is essential to their survival and the continued human exploration of space. Recent discoveries have shown that PTFE when blended with alumina nanofillers exhibits greatly improved physical performance properties, with wear rates being reduced by several orders of magnitude. The bulk processes used to produce the PTFE-alumina blends are limiting. Co-sputter deposition of PTFE and a filler material overcomes several of these limitations by enabling the reduction of particle size to the atomic level and also by allowing for the even coating of the solid lubricant on relatively large areas and components. The goal of this study was to establish a baseline performance of the sputtered PTFE films as compared to the bulk material, and to establish deposition conditions that would result in the most bulk-like film possible. In order to coax change in the structure of the sputtered films, sputtering power and deposition temperature were increased independently. Further, post-deposition annealing was applied to half of the deposited film in an attempt to affect change in the film structure. Complications in the characterization process due to increasing film thickness were also examined. Bulk-like metrics for characterization processes the included Fourier transform infrared spectroscopy (FTIR), X-ray spectroscopy (XPS), nanoindentation via atomic force microscopy, and contact angle of water on surface measurements were established. The results of the study revealed that increasing sputtering power and deposition temperature resulted in an increase in the similarity between the fluorocarbon films and the bulk PTFE, at a cost of affecting the potential of the film thicknesses, either by affecting the deposition process directly, or by decreasing the longevity of the sputtering targets.

  5. Plasma-deposited fluorocarbon polymer films on titanium for preventing cell adhesion: a surface finishing for temporarily used orthopaedic implants

    NASA Astrophysics Data System (ADS)

    Finke, B.; Testrich, H.; Rebl, H.; Walschus, U.; Schlosser, M.; Zietz, C.; Staehlke, S.; Nebe, J. B.; Weltmann, K. D.; Meichsner, J.; Polak, M.

    2016-06-01

    The design of a titanium implant surface should ideally support its later application in clinical use. Temporarily used implants have to fulfil requirements different from permanent implants: they should ensure the mechanical stabilization of the bone stock but in trauma surgery they should not be integrated into the bone because they will be removed after fracture healing. Finishing of the implant surface by a plasma-fluorocarbon-polymer (PFP) coating is a possible approach for preventing cell adhesion of osteoblasts. Two different low pressure gas-discharge plasma processes, microwave (MW 2.45 GHz) and capacitively coupled radio frequency (RF 13.56 MHz) plasma, were applied for the deposition of the PFP film using a mixture of the precursor octafluoropropane (C3F8) and hydrogen (H2). The thin films were characterized by x-ray photoelectron spectroscopy, Fourier transform infrared reflection absorption spectroscopy, and water contact angle measurements. Cell culture experiments show that cell adhesion and spreading of MG-63 osteoblasts were clearly reduced or nonexistent on these surfaces, also after 24 h of storage in the cell culture medium. In vivo data demonstrated that the local inflammatory tissue response for the PFP films deposited in MW and RF plasma were comparable to uncoated controls.

  6. Contributions of CF and CF2 Species to fluorocarbon film composition and properties for C(x)F(y) plasma-enhanced chemical vapor deposition.

    PubMed

    Cuddy, Michael F; Fisher, Ellen R

    2012-03-01

    Inductively-coupled C(x)F(y) (y/x = 2.0-4.0) plasma systems were investigated to determine relationships between precursor chemistry, CF(n) radical-surface reactivities, and surface properties of deposited films. The contributions of CF(n) (n = 1, 2) radicals to film properties were probed via gas-phase diagnostics and the imaging of radicals interacting with surfaces (IRIS) technique. Time-resolved radical emission data elucidate CF(g) and CF(2)(g) production kinetics from the C(x)F(y) source gases and demonstrate that CF(4) plasmas inherently lag in efficacy of film formation when compared to C(2)F(6), C(3)F(8), and C(3)F(6) systems. IRIS data show that as the precursor y/x ratio decreases, the propensity for CF(n) scatter concomitantly declines. Analyses of the composition and characteristics of fluorocarbon films deposited on Si wafers demonstrate that surface energies of the films decrease markedly with increasing film fluorine content. In turn, increased surface energies correspond with significant decreases in the observed scatter coefficients for both CF and CF(2). These data improve our molecular-level understanding of CF(n) contributions to fluorocarbon film deposition, which promises advancements in the ability to tailor FC films to specific applications.

  7. Plasma-deposited fluorocarbon films: insulation material for microelectrodes and combined atomic force microscopy-scanning electrochemical microscopy probes.

    PubMed

    Wiedemair, Justyna; Balu, Balamurali; Moon, Jong-Seok; Hess, Dennis W; Mizaikoff, Boris; Kranz, Christine

    2008-07-01

    Pinhole-free insulation of micro- and nanoelectrodes is the key to successful microelectrochemical experiments performed in vivo or in combination with scanning probe experiments. A novel insulation technique based on fluorocarbon insulation layers deposited from pentafluoroethane (PFE, CF3CHF2) plasmas is presented as a promising electrical insulation approach for microelectrodes and combined atomic force microscopy-scanning electrochemical microscopy (AFM-SECM) probes. The deposition allows reproducible and uniform coating, which is essential for many analytical applications of micro- and nanoelectrodes such as, e.g., in vivo experiments and SECM experiments. Disk-shaped microelectrodes and frame-shaped AFM tip-integrated electrodes have been fabricated by postinsulation focused ion beam (FIB) milling. The thin insulation layer for combined AFM-SECM probes renders this fabrication technique particularly useful for submicro insulation providing radius ratios of the outer insulation versus the disk electrode (RG values) suitable for SECM experiments. Characterization of PFE-insulated AFM-SECM probes will be presented along with combined AFM-SECM approach curves and imaging.

  8. Amorphous fluorocarbon polymer (a-C:F) films obtained by plasma enhanced chemical vapor deposition from perfluoro-octane (C8F18) vapor I: Deposition, morphology, structural and chemical properties

    NASA Astrophysics Data System (ADS)

    Biloiu, Costel; Biloiu, Ioana Arabela; Sakai, Yosuke; Suda, Yoshiyuki; Ohta, Akitsugu

    2004-01-01

    The method of obtaining amorphous fluorocarbon polymer (a-C:F) films by plasma enhanced chemical vapor deposition in a capacitively coupled, 13.56 MHz reactor, from a new monomer, namely perfluoro-octane (C8F18) vapor, is presented. For monomer pressure ranging from 0.2 to 1 Torr and input power density from 0.15 to 0.85 W/cm3, the maximum deposition rate reached 300 nm/min, while 10% monomer dilution with argon led to a deposition rate of 200 nm/min. The film surface and bulk morphologies, chemical and structural compositions were investigated using scanning electron microscopy, x-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. It was revealed that the films have a dense and compact structure. The fluorine to carbon ratio (F/C) of the films was between 1.57 and 1.75, and the degree of cross-linking was between 55% and 58%. The relative amount of perfluoroalkyl (CF2) groups in the films was 29%. The FTIR spectra showed absorption bands corresponding to the different vibrational modes of CF, CF2, and CF3 moieties. .

  9. Gas Adsorption Properties of Fluorocarbon Thin Films Prepared Using Three Different Types of RF Magnetron Sputtering Systems

    NASA Astrophysics Data System (ADS)

    Satoru Iwamori,; Norihiko Hasegawa,; Satoshi Yano,; Kazutoshi Noda,

    2010-04-01

    Fluorocarbon thin films were deposited onto a quartz crystal with a poly(tetrafluoroethylene) target using three different types of RF magnetron sputtering systems with strong, weak, and unbalanced magnetic fields. The adsorption properties of these thin films for water, ethanol, acetone, acetaldehyde, toluene, and methyl salicylate were evaluated using the quartz crystal microbalance (QCM) method in order to characterize the surface properties of these thin films. These thin films have low sensitivities to non-polar solvents that contain methyl and aromatic groups, and high sensitivities to polar solvents that contain carbonyl and hydroxyl groups. Chemical structures, especially, polar moieties in these fluorocarbon thin films would affect the gas adsorption properties.

  10. Plasma polymerization and deposition of linear, cyclic and aromatic fluorocarbons on (100)-oriented single crystal silicon substrates

    NASA Astrophysics Data System (ADS)

    Yang, G. H.; Oh, S. W.; Kang, E. T.; Neoh, K. G.

    2002-11-01

    Fluoropolymer films were deposited on the Ar plasma-pretreated Si(100) surfaces by plasma polymerization of perfluorohexane (PFH, a linear fluorocarbon), perfluoro(methylcyclohexane) (MCH, a cyclic fluorocarbon), and hexafluorobenzene (HFB, an aromatic fluorocarbon) under different glow discharge conditions. The effects of the radio-frequency plasma power on the chemical composition and structure of the plasma-polymerized fluoropolymer films were studied by x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, time-of-flight secondary ion mass spectrometry, and water contact angle measurements. The changes in structure and composition of the three types of the plasma-deposited films from those of the respective fluorocarbons were compared. Under similar glow discharge conditions: (i) the extent of defluorination was highest for the PFH polymer, (ii) the deposition rate was highest for the HFB polymer, (iii) the cyclic structure of MCH was less well preserved than the aromatic structure of HFB, (iv) aliphatic structures appeared in the plasma-deposited MCH polymer, and (v) the plasma-polymerized HFB has the highest thermal stability due to the preservation of the aromatic rings. The adhesive tape peel test results revealed that the plasma-polymerized and deposited fluoropolymer layers were strongly bonded to the Ar plasma-pretreated Si(100) surfaces.

  11. Metal doped fluorocarbon polymer films prepared by plasma polymerization using an RF planar magnetron target

    NASA Astrophysics Data System (ADS)

    Biederman, H.; Holland, L.

    1983-07-01

    Fluorocarbon films have been prepared by plasma polymerization of CF4 using an RF planar magnetron with an aluminium target. More than one order of magnitude higher deposition rate has been achieved in comparison with an r.f. diode system operated under similar conditions of monomer pressure and flow rate and power input. A glow discharge in a CF4[25%]-argon [75%] mixture was used to incorporate aluminium from a target electrode into the polymer films. The foregoing mixture and another based on CF4 [87%]-argon [13%] were used in the RF discharge with a copper target. Some experiments with a gold target and pure CF4 as the inlet gas were also made. The film structure was examined by SEM and TEM and characteristic micrographs are presented here. The composition of the films was estimated from an AES study. The sheet resistivity of the metal/polymer film complexes was determined.

  12. Comparative study of plasma-deposited fluorocarbon coatings on different substrates

    NASA Astrophysics Data System (ADS)

    Farsari, E.; Kostopoulou, M.; Amanatides, E.; Mataras, D.; Rapakoulias, D. E.

    2011-05-01

    The deposition of hydrophobic fluorocarbon coatings from C2F6 and C2F6-H2 rf discharges on different substrates was examined. Polyester textile, glass and two different ceramic compounds were used as substrates. The effect of the total gas pressure, the rf power dissipation and the deposition time on the hydrophobic character of the samples was investigated. Films deposited on polyester textiles at low pressure (0.03 mbar) and power consumption (16 mW cm-2) using pure C2F6 presented the highest water contact angles (~150°). On the other hand, the addition of hydrogen was necessary in order to deposit stable hydrophobic coatings on glass and ceramic substrates. Coatings deposited on glass at intermediate deposition rates (~100 Å min-1) and pressures presented the highest angles (~105°). Concerning the heavy clay ceramics, samples treated in low-pressure (0.05 mbar) and low-power (16 mW cm-2) discharges showed the highest contact angles. The deposition time was found to play an important role in the hydrophobicity and long-term behaviour of porous and rough substrates.

  13. Properties of solid polymer electrolyte fluorocarbon film. [used in hydrogen/oxygen fuel cells

    NASA Technical Reports Server (NTRS)

    Alston, W. B.

    1973-01-01

    The ionic fluorocarbon film used as the solid polymer electrolyte in hydrogen/oxygen fuel cells was found to exhibit delamination failures. Polarized light microscopy of as-received film showed a lined region at the center of the film thickness. It is shown that these lines were not caused by incomplete saponification but probably resulted from the film extrusion process. The film lines could be removed by an annealing process. Chemical, physical, and tensile tests showed that annealing improved or sustained the water contents, spectral properties, thermo-oxidative stability, and tensile properties of the film. The resistivity of the film was significantly decreased by the annealing process.

  14. 157 nm Pellicles (Thin Films) for Photolithography: Mechanistic Investigation of the VUV and UV-C Photolysis of Fluorocarbons

    SciTech Connect

    Lee, Kwangjoo; Jockusch, Steffen; Turro, Nicholas J.; French, Roger H.; Wheland, Robert C.; Lemon, M F.; Braun, Andre M.; Widerschpan, Tatjana; Dixon, David A.; Li, Jun; Ivan, Marius; Zimmerman, Paul

    2005-06-15

    The use of 157 nm as the next lower wavelength for photolithography for the production of semiconductors has created a need for transparent and radiation-durable polymers for use in soft pellicles, the polymer films which protect the chip from particle deposition. The most promising materials for pellicles are fluorinated polymers, but currently available fluorinated polymers undergo photodegradation and/or photodarkening upon long term exposure to 157 nm irradiation. To understand the mechanism of the photodegradation and photodarkening of fluorinated polymers, mechanistic studies on the photolysis of liquid model fluorocarbons, including perfluorobutylethyl ether and perfluoro-2 H-3-oxa-heptane, were performed employing UV, NMR, FTIR, GC, and GC/MS analyses. All hydrogen-containing compounds showed decreased photostability compared to the fully perfluorinated compounds. Irradiation in the presence of atmospheric oxygen showed reduced photostability compared to deoxygenated samples. Photolysis of the samples was performed at 157, 172, 185, and 254 nm and showed only minor wavelength dependence. Mechanisms for photodegradation of the fluorocarbons are proposed, which involve Rydberg excited states. Time-dependent density functional theory has been used to predict the excitation spectra of model compounds.

  15. Assembly and Structure of alpha-helical Peptide Films on Hydrophobic Fluorocarbon Surfaces

    SciTech Connect

    Weidner, T.; Samual, N; McCrea, K; Gamble, L; Ward, R; Castner, D

    2010-01-01

    The structure, orientation, and formation of amphiphilic {alpha}-helix model peptide films on fluorocarbon surfaces has been monitored with sum frequency generation (SFG) vibrational spectroscopy, near-edge x-ray absorption fine structure (NEXAFS) spectroscopy, and x-ray photoelectron spectroscopy (XPS). The {alpha}-helix peptide is a 14-mer of hydrophilic lysine and hydrophobic leucine residues with a hydrophobic periodicity of 3.5. This periodicity yields a rigid amphiphilic peptide with leucine and lysine side chains located on opposite sides. XPS composition analysis confirms the formation of a peptide film that covers about 75% of the surface. NEXAFS data are consistent with chemically intact adsorption of the peptides. A weak linear dichroism of the amide {pi}* is likely due to the broad distribution of amide bond orientations inherent to the {alpha}-helical secondary structure. SFG spectra exhibit strong peaks near 2865 and 2935 cm{sup -1} related to aligned leucine side chains interacting with the hydrophobic surface. Water modes near 3200 and 3400 cm{sup -1} indicate ordering of water molecules in the adsorbed-peptide fluorocarbon surface interfacial region. Amide I peaks observed near 1655 cm{sup -1} confirm that the secondary structure is preserved in the adsorbed peptide. A kinetic study of the film formation process using XPS and SFG showed rapid adsorption of the peptides followed by a longer assembly process. Peptide SFG spectra taken at the air-buffer interface showed features related to well-ordered peptide films. Moving samples through the buffer surface led to the transfer of ordered peptide films onto the substrates.

  16. Correlation of elastohydrodynamic film thickness measurements for fluorocarbon type 2 ester, and polyphenyl ether lubricants

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.; Parker, R. J.; Zaretsky, E. V.

    1974-01-01

    A minimum films thickness correlation applicable to heavily loaded elastohydrodynamic (EHD) contacts was formulated from experimental data obtained by an X-ray transmission technique. The correlation, based on data generated with fluorocarbon, type II ester, and polyphenyl ether lubricants, extends a previous analysis developed from data for a synthetic paraffinic oil. The resulting correlation represents the data of the four lubricants reasonably well over a large range of operating conditions. Contained within the derived relation is a factor to account for the high-load dependence displayed by the measurements beyond that which is provided for by the theory. Thermal corrections applied to a commonly used film thickness formula showed little improvement to the general disagreement that exists between theory and test. Choice of contact geometry and material are judged to have a relatively mild influence on the form of the semiempirical model.

  17. Influence of the 316 L stainless steel interface on the stability and barrier properties of plasma fluorocarbon films.

    PubMed

    Lewis, François; Cloutier, Maxime; Chevallier, Pascale; Turgeon, Stéphane; Pireaux, Jean-Jacques; Tatoulian, Michael; Mantovani, Diego

    2011-07-01

    Coatings are known to be one of the more suited strategies to tailor the interface between medical devices and the surrounding cells and tissues once implanted. The development of coatings and the optimization of their adhesion and stability are of major importance. In this work, the influence of plasma etching of the substrate on a plasma fluorocarbon ultrathin coating has been investigated with the aim of improving the stability and the corrosion properties of coated medical devices. The 316 L stainless steel interface was subjected to two different etching sequences prior to the plasma deposition. These plasma etchings, with H(2) and C(2)F(6) as gas precursors, modified the chemical composition and the thickness of the oxide layer and influenced the subsequent polymerization. The coating properties were evaluated using flat substrates submitted to deformation, aging into aqueous medium and corrosion tests. X-ray photoelectron spectroscopy (XPS), time of flight-secondary ion mass spectrometry (ToF-SIMS), ellipsometry, and atomic force microscopy (AFM) were performed to determine the effects of the deformation and the aging on the chemistry and morphology of the coated samples. Analyses showed that plasma etchings were essential to promote reproducible polymerization and film growth. However, the oxide layer thinning due to the etching lowered the corrosion resistance of the substrate and affected the stability of the interface. Still, the deformed samples did not exhibited adhesion and cohesion failure before and after the aging.

  18. Biomimetic thin film deposition

    SciTech Connect

    Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

    1995-09-01

    Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

  19. Surface films of short fluorocarbon-hydrocarbon diblocks studied by molecular dynamics simulations: Spontaneous formation of elongated hemimicelles.

    PubMed

    Piñeiro, Angel; Prieto, Gerardo; Ruso, Juan M; Verdes, Pedro V; Sarmiento, Félix

    2009-01-15

    Using grazing incidence small-angle X-ray scattering (GISAXS), and atomic force microscopy (AFM) it has been recently demonstrated that linear fluorocarbon-hydrocarbon diblocks (FnHm) self-assemble in water/air interfaces forming elongated and circular hemimicelles. Those structures have been observed for diblocks with at least eight fluorinated carbons. Based on the lack of a collapse pressure for F6H16, and due to the fact that no stable surface pressure values are reached under compression, it has been concluded that these molecules do not form stable monolayers. It has been also suggested that F6H16 and shorter diblocks desorb from the water surface under compression. It is not easy to accept that a significant concentration of so hydrophobic molecules can be stable in aqueous solution even when the employed experimental techniques were not able to clearly detect a well defined structure on the interface. In the present work the adsorption and arrangement of F6H16 and F6H10 at the water surface are studied by molecular dynamics (MD) simulations as a function of the available area per molecule. Starting from a random mixture, the spontaneous formation of elongated hemimicelles is observed for both systems when the area per molecule is higher than approximately 50 A(2). For intermediate areas two pseudo-phases, one rich in hydrocarbons and the other with higher fluorocarbon concentration, are formed. For the systems with less than approximately 30 A(2) available per molecule the formation of multilayers is observed. This is the first time that the dynamics and structure of perfluoroalkane (PFA) films, and in particular of hemimicelles on a liquid surface, are observed and characterized at atomic level.

  20. Impact of etching kinetics on the roughening of thermal SiO{sub 2} and low-k dielectric coral films in fluorocarbon plasmas

    SciTech Connect

    Yin Yunpeng; Sawin, Herbert H.

    2007-07-15

    The impact of etching kinetics and etching chemistries on surface roughening was investigated by etching thermal silicon dioxide and low-k dielectric coral materials in C{sub 4}F{sub 8}/Ar plasma beams in an inductive coupled plasma beam reactor. The etching kinetics, especially the angular etching yield curves, were measured by changing the plasma pressure and the feed gas composition which influence the effective neutral-to-ion flux ratio during etching. At low neutral-to-ion flux ratios, the angular etching yield curves are sputteringlike, with a peak around 60 deg. -70 deg. off-normal angles; the surface at grazing ion incidence angles becomes roughened due to ion scattering related ion-channeling effects. At high neutral-to-ion flux ratios, ion enhanced etching dominates and surface roughening at grazing angles is mainly caused by the local fluorocarbon deposition induced micromasking mechanism. Interestingly, the etched surfaces at grazing angles remain smooth for both films at intermediate neutral-to-ion flux ratio regime. Furthermore, the oxygen addition broadens the region over which the etching without roughening can be performed.

  1. Fluorocarbon emulsions--the stability issue.

    PubMed

    Postel, M; Riess, J G; Weers, J G

    1994-01-01

    Long-term room temperature stability of ready-to-use concentrated fluorocarbon emulsions is necessary in order to fully exploit the therapeutic potential of fluorocarbons. Consequently, considerable efforts have been directed at investigating the physical nature of such emulsions, the mechanisms which lead to their degradation and the means of counteracting these. The particles which constitute typical fluorocarbon/egg yolk phospholipid emulsions have been identified to be surfactant-coated fluorocarbon droplets and lipid vesicles. Better understanding has been gained on the formation, structure and evolution of these particles during processing and storage. This has led to optimized formulations and processing, better control of emulsion characteristics and significantly improved stability. Molecular diffusion (Ostwald ripening or transcondensation) has been shown to be the maun mechanism of degradation when particles are less than 1 micron in diameter, even for the highly concentrated (volume fraction of fluorocarbon up to 50%) second generation fluorocarbon emulsions. Significant emulsion stabilization has been accomplished by adding fluorochemicals which are both less volatile and less water soluble, and nevertheless have an organ dwell time acceptable for intravascular use. The rate of molecular diffusion can also be reduced by decreasing the fluorocarbon/water interfacial tension; this was effectively achieved with appropriate, well-defined fluorinated surfactants. A further, novel means of stabilizing fluorocarbon-in-water emulsions makes use of mixed fluorocarbon-hydrocarbon amphiphiles which act as molecular dowels to reinforce the adhesion between the fluorocarbon phase and the lipophilic zone of the surfactant film. Both long-term room temperature stability, and particle-size control over a large range of diameter, have been achieved by applying this principle. All in all it can be said that the challenge of producing injectable fluorocarbon emulsions

  2. Etching characteristics of high-k dielectric HfO{sub 2} thin films in inductively coupled fluorocarbon plasmas

    SciTech Connect

    Takahashi, Kazuo; Ono, Kouichi; Setsuhara, Yuichi

    2005-11-15

    Inductively coupled fluorocarbon (CF{sub 4}/Ar and C{sub 4}F{sub 8}/Ar) plasmas were used to etch HfO{sub 2}, which is a promising high-dielectric-constant material for the gate of complementary metal-oxide-semiconductor devices. The etch rates of HfO{sub 2} in CF{sub 4}/Ar plasmas exceeded those in C{sub 4}F{sub 8}/Ar plasmas. The tendency for etch rates to become higher in fluorine-rich (high F/C ratio) conditions indicates that HfO{sub 2} can be chemically etched by fluorine-containing species. In C{sub 4}F{sub 8}/Ar plasmas with a high Ar dilution ratio, the etch rate of HfO{sub 2} increased with increasing bias power. The etch rate of Si, however, decreased with bias power, suggesting that the deposition of carbon-containing species increased with increasing the power and inhibited the etching of Si. The HfO{sub 2}/Si selectivity monotonically increased with increasing power, then became more than 5 at the highest tested bias power. The carbon-containing species to inhibit etching of Si play an important role in enhancing the HfO{sub 2}/Si selectivity in C{sub 4}F{sub 8}/Ar plasmas.

  3. Metals plated on fluorocarbon polymers

    NASA Technical Reports Server (NTRS)

    Ford, H.; Krasinsky, J. B.; Vango, S. P.

    1964-01-01

    Electroplating lead on fluorocarbon polymer parts is accomplished by etching the parts to be plated with sodium, followed by successive depositions of silver and lead from ultrasonically agitated plating solutions. Metals other than lead may be electroplated on the silvered parts.

  4. Variable temperature semiconductor film deposition

    DOEpatents

    Li, Xiaonan; Sheldon, Peter

    1998-01-01

    A method of depositing a semiconductor material on a substrate. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  5. Variable temperature semiconductor film deposition

    DOEpatents

    Li, X.; Sheldon, P.

    1998-01-27

    A method of depositing a semiconductor material on a substrate is disclosed. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  6. Vapor deposition of thin films

    DOEpatents

    Smith, David C.; Pattillo, Stevan G.; Laia, Jr., Joseph R.; Sattelberger, Alfred P.

    1992-01-01

    A highly pure thin metal film having a nanocrystalline structure and a process of preparing such highly pure thin metal films of, e.g., rhodium, iridium, molybdenum, tungsten, rhenium, platinum, or palladium by plasma assisted chemical vapor deposition of, e.g., rhodium(allyl).sub.3, iridium(allyl).sub.3, molybdenum(allyl).sub.4, tungsten(allyl).sub.4, rhenium(allyl).sub.4, platinum(allyl).sub.2, or palladium(allyl).sub.2 are disclosed. Additionally, a general process of reducing the carbon content of a metallic film prepared from one or more organometallic precursor compounds by plasma assisted chemical vapor deposition is disclosed.

  7. PRODUCTION OF FLUOROCARBONS

    DOEpatents

    Sarsfield, N.F.

    1949-06-21

    This patent pertains to a process for recovering fluorocarbons from a liquid mixture of hydrocarbons with partially and completely fluorinated products thereof. It consists of contacting the mxture in the cold with a liquid which is a solvent for the hydrocarbons and which is a nonsolvent for the fluorocarbons, extracting the hydrocarbons, separating the fluorocarbon-containing layer from the solvent-containing layer, and submitting the fluorocarbon layer to fractlonal distillation, to isolate the desired fluorocarbon fraction. Suitable solvents wnich may be used in the process include the lower aliphatic alcohols, and the lower aliphatic ketones.

  8. Deposited films with improved microstructures

    DOEpatents

    Patten, James W.; Moss, Ronald W.; McClanahan, Edwin D.

    1984-01-01

    Methods for improving microstructures of line-of-sight deposited films are described. Columnar growth defects ordinarily produced by geometrical shadowing during deposition of such films are eliminated without resorting to post-deposition thermal or mechanical treatments. The native, as-deposited coating qualities, including homogeneity, fine grain size, and high coating-to-substrate adherence, can thus be retained. The preferred method includes the steps of emitting material from a source toward a substrate to deposit a coating non-uniformly on the substrate surface, removing a portion of the coating uniformly over the surface, again depositing material onto the surface, but from a different direction, and repeating the foregoing steps. The quality of line-of-sight deposited films such as those produced by sputtering, progressively deteriorates as the angle of incidence between the flux and the surface becomes increasingly acute. Depositing non-uniformly, so that the coating becomes progressively thinner as quality deteriorates, followed by uniformly removing some of the coating, such as by resputtering, eliminates the poor quality portions, leaving only high quality portions of the coating. Subsequently sputtering from a different direction applies a high quality coating to other regions of the surface. Such steps can be performed either simultaneously or sequentially to apply coatings of a uniformly high quality, closed microstructure to three-dimensional or large planar surfaces.

  9. Ion beam sputter deposited diamond like films

    NASA Technical Reports Server (NTRS)

    Banks, B. A.; Rutledge, S. K.

    1982-01-01

    A single argon ion beam source was used to sputter deposit carbon films on fused silica, copper, and tantalum substrates under conditions of sputter deposition alone and sputter deposition combined with simultaneous argon ion bombardment. Simultaneously deposited and ion bombarded carbon films were prepared under conditions of carbon atom removal to arrival ratios of 0, 0.036, and 0.71. Deposition and etch rates were measured for films on fused silica substrates. Resulting characteristics of the deposited films are: electrical resistivity of densities of 2.1 gm/cu cm for sputter deposited films and 2.2 gm/cu cm for simultaneously sputter deposited and Ar ion bombarded films. For films approximately 1700 A thick deposited by either process and at 5550 A wavelength light the reflectance was 0.2, the absorptance was 0.7, the absorption coefficient was 67,000 cm to the -1 and the transmittance was 0.1.

  10. Chemical Vapor Deposition of Fluoroalkylsilane Monolayer Films for Adhesion Control in Microelectromechanical Systems

    SciTech Connect

    MAYER,THOMAS M.; DE BOER,MAARTEN P.; SHINN,NEAL D.; CLEWS,PEGGY J.; MICHALSKE,TERRY A.

    2000-01-26

    We have developed a new process for applying a hydrophobic, low adhesion energy coating to microelectromechanical (MEMS) devices. Monolayer films are synthesized from tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane (FOTS) and water vapor in a low-pressure chemical vapor deposition process at room temperature. Film thickness is self-limiting by virtue of the inability of precursors to stick to the fluorocarbon surface of the film once it has formed. We have measured film densities of {approx}3 molecules nm{sup 2} and film thickness of {approx}1 nm. Films are hydrophobic, with a water contact angle >110{sup o}. We have also incorporated an in-situ downstream microwave plasma cleaning process, which provides a clean, reproducible oxide surface prior to film deposition. Adhesion tests on coated and uncoated MEMS test structures demonstrate superior performance of the FOTS coatings. Cleaned, uncoated cantilever beam structures exhibit high adhesion energies in a high humidity environment. An adhesion energy of 100 mJ m{sup -2} is observed after exposure to >90% relative humidity. Fluoroalkylsilane coated beams exhibit negligible adhesion at low humidity and {<=} 20 {micro}J m{sup -2} adhesion energy at >90% relative humidity. No obvious film degradation was observed for films exposed to >90% relative humidity at room temperature for >24 hr.

  11. Depositing Adherent Ag Films On Ti Films On Alumina

    NASA Technical Reports Server (NTRS)

    Honecy, Frank S.

    1995-01-01

    Report discusses cleaning of ceramic (principally, alumina) substrates in preparation for sputter deposition of titanium intermediate films on substrates followed by sputter deposition of outer silver films. Principal intended application, substrates sliding parts in advanced high-temperature heat engines, and outer silver films serve as solid lubricants: lubricating properties described in "Solid Lubricant for Alumina" (LEW-15495).

  12. Chemical-Vapor-Deposited Diamond Film

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1999-01-01

    This chapter describes the nature of clean and contaminated diamond surfaces, Chemical-vapor-deposited (CVD) diamond film deposition technology, analytical techniques and the results of research on CVD diamond films, and the general properties of CVD diamond films. Further, it describes the friction and wear properties of CVD diamond films in the atmosphere, in a controlled nitrogen environment, and in an ultra-high-vacuum environment.

  13. Pulsed laser deposition: Prospects for commercial deposition of epitaxial films

    SciTech Connect

    Muenchausen, R.E.

    1999-03-01

    Pulsed laser deposition (PLD) is a physical vapor deposition (PVD) technique for the deposition of thin films. The vapor source is induced by the flash evaporation that occurs when a laser pulse of sufficient intensity (about 100 MW/cm{sup 2}) is absorbed by a target. In this paper the author briefly defines pulsed laser deposition, current applications, research directed at gaining a better understanding of the pulsed laser deposition process, and suggests some future directions to enable commercial applications.

  14. Mirrorlike pulsed laser deposited tungsten thin film

    SciTech Connect

    Mostako, A. T. T.; Khare, Alika; Rao, C. V. S.

    2011-01-15

    Mirrorlike tungsten thin films on stainless steel substrate deposited via pulsed laser deposition technique in vacuum (10{sup -5} Torr) is reported, which may find direct application as first mirror in fusion devices. The crystal structure of tungsten film is analyzed using x-ray diffraction pattern, surface morphology of the tungsten films is studied with scanning electron microscope and atomic force microscope. The film composition is identified using energy dispersive x-ray. The specular and diffuse reflectivities with respect to stainless steel substrate of the tungsten films are recorded with FTIR spectra. The thickness and the optical quality of pulsed laser deposition deposited films are tested via interferometric technique. The reflectivity is approaching about that of the bulk for the tungsten film of thickness {approx}782 nm.

  15. Mirrorlike pulsed laser deposited tungsten thin film.

    PubMed

    Mostako, A T T; Rao, C V S; Khare, Alika

    2011-01-01

    Mirrorlike tungsten thin films on stainless steel substrate deposited via pulsed laser deposition technique in vacuum (10(-5) Torr) is reported, which may find direct application as first mirror in fusion devices. The crystal structure of tungsten film is analyzed using x-ray diffraction pattern, surface morphology of the tungsten films is studied with scanning electron microscope and atomic force microscope. The film composition is identified using energy dispersive x-ray. The specular and diffuse reflectivities with respect to stainless steel substrate of the tungsten films are recorded with FTIR spectra. The thickness and the optical quality of pulsed laser deposition deposited films are tested via interferometric technique. The reflectivity is approaching about that of the bulk for the tungsten film of thickness ∼782 nm. PMID:21280810

  16. Polymer-assisted deposition of films

    DOEpatents

    McCleskey, Thomas M.; Burrell, Anthony K.; Jia, Quanxi; Lin, Yuan

    2008-04-29

    A polymer assisted deposition process for deposition of metal oxide films is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures to yield metal oxide films. Such films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  17. Polymer-assisted deposition of films

    DOEpatents

    McCleskey, Thomas M.; Burrell; Anthony K.; Jia; Quanxi; Lin; Yuan

    2009-10-20

    A polymer assisted deposition process for deposition of metal oxide films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures to yield metal oxide films and the like. Such films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  18. Deposition of thin films of multicomponent materials

    NASA Technical Reports Server (NTRS)

    Thakoor, Sarita (Inventor)

    1993-01-01

    Composite films of multicomponent materials, such as oxides and nitrides, e.g., lead zirconate titanate, are deposited by dc magnetron sputtering, employing a rotating substrate holder, which rotates relative to a plurality of targets, one target for each metal element of the multicomponent material. The sputtering is carried out in a reactive atmosphere. The substrates on which the layers are deposited are at ambient temperature. Following deposition of the composite film, the film is heated to a temperature sufficient to initiate a solid state reaction and form the final product, which is substantially single phase and substantially homogeneous.

  19. Polymer-assisted deposition of films

    DOEpatents

    McCleskey,Thomas M.; Burrell,Anthony K.; Jia,Quanxi; Lin,Yuan

    2012-02-28

    A polymer assisted deposition process for deposition of metal nitride films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures under a suitable atmosphere to yield metal nitride films and the like. Such films can be conformal on a variety of substrates including non-planar substrates. In some instances, the films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  20. Perovskite thin films via atomic layer deposition.

    PubMed

    Sutherland, Brandon R; Hoogland, Sjoerd; Adachi, Michael M; Kanjanaboos, Pongsakorn; Wong, Chris T O; McDowell, Jeffrey J; Xu, Jixian; Voznyy, Oleksandr; Ning, Zhijun; Houtepen, Arjan J; Sargent, Edward H

    2015-01-01

    A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3 NH3 PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm(-1) .

  1. Elastohydrodynamic film thickness measurements with advanced ester, fluorocarbon, and polyphenyl ether lubricants to 589 K (600 F)

    NASA Technical Reports Server (NTRS)

    Parker, R. J.; Kannel, J. W.

    1971-01-01

    Elastohydrodynamic (EHD) film thicknesses have been measured, by means of an X-ray technique, under conditions that closely simulate the ball-race contact in advanced turbine engine thrust bearings. The experiments were conducted with a rolling-disk machine using disks which yield a contact zone similar to that in the actual bearing. Both the rolling and spinning motions of the ball relative to the race were simulated by the apparatus. Four lubricants were evaluated at temperatures to 600 F and maximum Hertz stresses to 350,000 psi. The X-ray film thickness data correlated well with observations of surface distress (or lack thereof) in full-scale bearing tests with the same lubricants under similar conditions of temperature and load. The predicted variation of film thickness with speed and viscosity as verified, although the magnitude of measured film thickness was generally one-half to one-third of predicted values. An effect of stress greater than predicted was consistently observed in the higher stress range.

  2. Ion beam sputter deposited zinc telluride films

    NASA Technical Reports Server (NTRS)

    Gulino, D. A.

    1986-01-01

    Zinc telluride is of interest as a potential electronic device material, particularly as one component in an amorphous superlattice, which is a new class of interesting and potentially useful materials. Some structural and electronic properties of ZnTe films deposited by argon ion beam sputter deposition are described. Films (up to 3000 angstroms thick) were deposited from a ZnTe target. A beam energy of 1000 eV and a current density of 4 mA/sq cm resulted in deposition rates of approximately 70 angstroms/min. The optical band gap was found to be approximately 1.1 eV, indicating an amorphous structure, as compared to a literature value of 2.26 eV for crystalline material. Intrinsic stress measurements showed a thickness dependence, varying from tensile for thicknesses below 850 angstroms to compressive for larger thicknesses. Room temperature conductivity measurement also showed a thickness dependence, with values ranging from 1.86 x 10 to the -6th/ohm cm for 300 angstrom film to 2.56 x 10 to the -1/ohm cm for a 2600 angstrom film. Measurement of the temperature dependence of the conductivity for these films showed complicated behavior which was thickness dependent. Thinner films showed at least two distinct temperature dependent conductivity mechanisms, as described by a Mott-type model. Thicker films showed only one principal conductivity mechanism, similar to what might be expected for a material with more crystalline character.

  3. Post-Flight Analysis of Selected Fluorocarbon and Other Thin Film Polymer Specimens Flown on MISSE-5

    NASA Technical Reports Server (NTRS)

    DeGroh, Kim; Finckenor, Miria; Minton, Tim; Brunsvold, Amy; Pippin, Gary

    2007-01-01

    Twenty thin film specimens were flown on M1SSE-5 as a cooperative effort between several organizations. This presentation will report results of initial inspections and post-flight measurements of the optical properties and recession of these materials due to the approx.13 month exposure period on the exterior of the International Space Station. These specimens were located on the "anti-solar" side of the MISSE-5 container and received a low number of Equivalent Sun Hours of solar UV exposure. Profilometry and/or ATF measurements will be conducted to determine thickness changes and atomic oxygen-induced recession rates Six of the specimens were covered with thin Kapton films, 0.1 and 0.3 mil in thickness. The 0.1 mil Kapton was almost completely eroded, suggesting that the atomic oxygen fluence is <8 x 10(exp 19) atoms/sq cm, similar to levels experienced during Space Shuttle materials experiments in the 1980's and 1990's. A comparison of results from MISSE-5 and Space Shuttle experiments will be included for those materials common to both the short and long-term exposures.

  4. Ion beam sputter deposited zinc telluride films

    NASA Technical Reports Server (NTRS)

    Gulino, D. A.

    1985-01-01

    Zinc telluride is of interest as a potential electronic device material, particularly as one component in an amorphous superlattice, which is a new class of interesting and potentially useful materials. Some structural and electronic properties of ZnTe films deposited by argon ion beam sputter depoairion are described. Films (up to 3000 angstroms thick) were deposited from a ZnTe target. A beam energy of 1000 eV and a current density of 4 mA/sq. cm. resulted in deposition rates of approximately 70 angstroms/min. The optical band gap was found to be approximately 1.1 eV, indicating an amorphous structure, as compared to a literature value of 2.26 eV for crystalline material. Intrinsic stress measurements showed a thickness dependence, varying from tensile for thicknesses below 850 angstroms to compressive for larger thicknesses. Room temperature conductivity measurement also showed a thickness dependence, with values ranging from 1.86 x to to the -6/ohm. cm. for 300 angstrom film to 2.56 x 10 to the -1/ohm. cm. for a 2600 angstrom film. Measurement of the temperature dependence of the conductivity for these films showed complicated behavior which was thickness dependent. Thinner films showed at least two distinct temperature dependent conductivity mechanisms, as described by a Mott-type model. Thicker films showed only one principal conductivity mechanism, similar to what might be expected for a material with more crystalline character.

  5. Iron films deposited on porous alumina substrates

    NASA Astrophysics Data System (ADS)

    Yamada, Yasuhiro; Tanabe, Kenichi; Nishida, Naoki; Kobayashi, Yoshio

    2016-12-01

    Iron films were deposited on porous alumina substrates using an arc plasma gun. The pore sizes (120 - 250 nm) of the substrates were controlled by changing the temperature during the anodic oxidation of aluminum plates. Iron atoms penetrated into pores with diameters of less than 160 nm, and were stabilized by forming γ-Fe, whereas α-Fe was produced as a flat plane covering the pores. For porous alumina substrates with pore sizes larger than 200 nm, the deposited iron films contained many defects and the resulting α-Fe had smaller hyperfine magnetic fields. In addition, only a very small amount of γ-Fe was obtained. It was demonstrated that the composition and structure of an iron film can be affected by the surface morphology of the porous alumina substrate on which the film is grown.

  6. Ultrashort pulse laser deposition of thin films

    DOEpatents

    Perry, Michael D.; Banks, Paul S.; Stuart, Brent C.

    2002-01-01

    Short pulse PLD is a viable technique of producing high quality films with properties very close to that of crystalline diamond. The plasma generated using femtosecond lasers is composed of single atom ions with no clusters producing films with high Sp.sup.3 /Sp.sup.2 ratios. Using a high average power femtosecond laser system, the present invention dramatically increases deposition rates to up to 25 .mu.m/hr (which exceeds many CVD processes) while growing particulate-free films. In the present invention, deposition rates is a function of laser wavelength, laser fluence, laser spot size, and target/substrate separation. The relevant laser parameters are shown to ensure particulate-free growth, and characterizations of the films grown are made using several diagnostic techniques including electron energy loss spectroscopy (EELS) and Raman spectroscopy.

  7. Ultrasound-Assisted Deposition Of Dielectric Films

    NASA Astrophysics Data System (ADS)

    Hwangbo, C. K.; Jacobson, M. R.; Macleod, H. A.; Potoff, R. H.

    1986-12-01

    The effects of ultrasound-assisted deposition (UAD) of ZrOx , Ta0x , and MgFx films on their optical properties have been investigated. The direction of vibration is transverse to the direction of growing films on substrates that are glued to tubular piezoelectric transducers driven by a power amplifier. Results indicate that ultrasonic powers above 20 W/cm2 are required to induce detectable changes in UV absorption and vacuum-to-air shifts of spectral profiles. UAD is likely to induce oxygen and fluoride deficiencies in oxide and fluoride films and increase the packing density of films. No significant changes between UAD and conventional films were observed in x-ray diffraction analysis, humidity testing, and Nomarski microscopy.

  8. Semiconductor and ceramic nanoparticle films deposited by chemical bath deposition.

    PubMed

    Hodes, Gary

    2007-06-14

    Chemical bath deposition (CBD) has been used to deposit films of metal sulfides, selenides and oxides, together with some miscellaneous compounds, beginning nearly 140 years ago. While it is a well-known technique in a few specific areas (notably photoconductive lead salt detectors, photoelectrodes and more recently, thin film solar cells), it is by and large an under-appreciated technique. The more recent interest in all things 'nano' has provided a boost for CBD: since it is a low temperature, solution (almost always aqueous) technique, crystal size is often very small. This is evidenced by the existence of size quantization commonly found in CBD semiconductor films. The intention of this review is to provide readers, many of whom may not even be aware of the CBD technique, with an overview of how the technique has been used to fabricate nanocrystalline semiconductor (this terminology also includes oxides often classified as ceramics) films and some properties of these films. The review begins, after a short introduction, with a general description of the CBD method, designed to give the reader a basic knowledge of the technique. The rest of the review then focuses on nanocrystalline (or, in the few cases of amorphous deposits, nanoparticle) films. The various factors which determine crystal size are first discussed. This is followed by some of the many examples of size quantization observed in the films. Since CBD films are usually porous, surface effects can be very important, and various surface-dependent properties (light emission and surface states) as well as surface modification, are treated: (although some properties, like emission, can be strongly dependent on both surface and 'bulk'). Because of the fact that many CBD films have been made specifically for use as photoelectrodes in photoelectrochemical cells, there is next a chapter on this topic with a few examples of such photoelectrodes. Film structure and morphology follows with examples of

  9. Photobiomolecular deposition of metallic particles and films

    DOEpatents

    Hu, Zhong-Cheng

    2005-02-08

    The method of the invention is based on the unique electron-carrying function of a photocatalytic unit such as the photosynthesis system I (PSI) reaction center of the protein-chlorophyll complex isolated from chloroplasts. The method employs a photo-biomolecular metal deposition technique for precisely controlled nucleation and growth of metallic clusters/particles, e.g., platinum, palladium, and their alloys, etc., as well as for thin-film formation above the surface of a solid substrate. The photochemically mediated technique offers numerous advantages over traditional deposition methods including quantitative atom deposition control, high energy efficiency, and mild operating condition requirements.

  10. (Chemically vapor deposited diamond films)

    SciTech Connect

    Clausing, R.E.; Heatherly, L. Jr.

    1990-09-22

    The NATO-ASI on Diamond and Diamond-Like Films and Coatings'' was an opportunity for us to learn the latest research results from ongoing programs in the leading laboratories of the world and relate them to our work. Specific examples are given in the comprehensive report which follows. The meeting format provided an ideal environment to meet and interact with our international counterparts. It is clear that our studies are well regarded, and that we have established an excellent reputation in a short time. New opportunities for collaboration were identified. A panel discussion at the end of the meeting addressed the needs and opportunities in the synthesis of CVD diamond. The key scientific needs are those related to modeling the nucleation and growth processes and to elucidation of the critical roles of atomic hydrogen and the mechanisms of carbon addition to the growing surfaces. The development and more extensive use of in situ diagnostics for both surface and gas phases are important to solving these issues. The more immediate practical questions concern the identification of the growth-rate-limiting steps, the relation of growth parameters to the resulting film structure, and the dependence of properties on structure.

  11. Photochemical Deposition of Patterned Gold Thin Films

    NASA Astrophysics Data System (ADS)

    Kumaran, Abbu Udaiyar Senthil; Miyawaki, Tetsuya; Ichimura, Masaya

    2006-12-01

    We present a novel route for patterned gold thin-film deposition on glass substrates with the help of UV-light irradiation. Chloroauric acid (HAuCl4) is used as a source material and sodium sulfite (Na2SO3) acts as a reducing agent in an aqueous solution. Ethylene diamine (EDA) is added to increase the solution stability. The deposition solution is injected on the substrate. A patterned metal mask is placed 5 mm above the substrate, and the solution is illuminated for 15 min by an ultrahigh-pressure mercury arc lamp. A patterned Au film with a thickness of 0.1-0.2 μm is deposited.

  12. Effect of fluorocarbon self-assembled monolayer films on sidewall adhesion and friction of surface micromachines with impacting and sliding contact interfaces

    NASA Astrophysics Data System (ADS)

    Xiang, H.; Komvopoulos, K.

    2013-06-01

    A self-assembled monolayer film consisting of fluoro-octyltrichlorosilane (FOTS) was vapor-phase deposited on Si(100) substrates and polycrystalline silicon (polysilicon) surface micromachines. The hydrophobic behavior and structural composition of the FOTS film deposited on Si(100) were investigated by goniometry and X-ray photoelectron spectroscopy, respectively. The effects of contact pressure, relative humidity, temperature, and impact/sliding cycles on the adhesive and friction behavior of uncoated and FOTS-coated polysilicon micromachines (referred to as the Si and FOTS/Si micromachines, respectively) were investigated under controlled loading and environmental conditions. FOTS/Si micromachines demonstrated much lower and stable adhesion than Si micromachines due to the highly hydrophobic and conformal FOTS film. Contrary to Si micromachines, sidewall adhesion of FOTS/Si micromachines demonstrated a weak dependence on relative humidity, temperature, and impact cycles. In addition, FOTS/Si micromachines showed low and stable adhesion and low static friction for significantly more sliding cycles than Si micromachines. The adhesive and static friction characteristics of Si and FOTS/Si micromachines are interpreted in the context of physicochemical surface changes, resulting in the increase of the real area of contact and a hydrophobic-to-hydrophilic transition of the surface chemical characteristics caused by nanoscale surface smoothening and the removal of the organic residue (Si micromachines) or the FOTS film (FOTS/Si micromachines) during repetitive impact and oscillatory sliding of the sidewall surfaces.

  13. Effect of fluorocarbon self-assembled monolayer films on sidewall adhesion and friction of surface micromachines with impacting and sliding contact interfaces

    SciTech Connect

    Xiang, H.; Komvopoulos, K.

    2013-06-14

    A self-assembled monolayer film consisting of fluoro-octyltrichlorosilane (FOTS) was vapor-phase deposited on Si(100) substrates and polycrystalline silicon (polysilicon) surface micromachines. The hydrophobic behavior and structural composition of the FOTS film deposited on Si(100) were investigated by goniometry and X-ray photoelectron spectroscopy, respectively. The effects of contact pressure, relative humidity, temperature, and impact/sliding cycles on the adhesive and friction behavior of uncoated and FOTS-coated polysilicon micromachines (referred to as the Si and FOTS/Si micromachines, respectively) were investigated under controlled loading and environmental conditions. FOTS/Si micromachines demonstrated much lower and stable adhesion than Si micromachines due to the highly hydrophobic and conformal FOTS film. Contrary to Si micromachines, sidewall adhesion of FOTS/Si micromachines demonstrated a weak dependence on relative humidity, temperature, and impact cycles. In addition, FOTS/Si micromachines showed low and stable adhesion and low static friction for significantly more sliding cycles than Si micromachines. The adhesive and static friction characteristics of Si and FOTS/Si micromachines are interpreted in the context of physicochemical surface changes, resulting in the increase of the real area of contact and a hydrophobic-to-hydrophilic transition of the surface chemical characteristics caused by nanoscale surface smoothening and the removal of the organic residue (Si micromachines) or the FOTS film (FOTS/Si micromachines) during repetitive impact and oscillatory sliding of the sidewall surfaces.

  14. Studies of Niobium Thin Film Produced by Energetic Vacuum Deposition

    SciTech Connect

    Genfa Wu; Anne-Marie Valente; H. Phillips; Haipeng Wang; Andy Wu; T. J. Renk; P Provencio

    2004-05-01

    An energetic vacuum deposition system has been used to study deposition energy effects on the properties of niobium thin films on copper and sapphire substrates. The absence of working gas avoids the gaseous inclusions commonly seen with sputtering deposition. A biased substrate holder controls the deposition energy. Transition temperature and residual resistivity ratio of the niobium thin films at several deposition energies are obtained together with surface morphology and crystal orientation measurements by AFM inspection, XRD and TEM analysis. The results show that niobium thin films on sapphire substrate exhibit the best cryogenic properties at deposition energy around 123 eV. The TEM analysis revealed that epitaxial growth of film was evident when deposition energy reaches 163 eV for sapphire substrate. Similarly, niobium thin film on copper substrate shows that film grows more oriented with higher deposition energy and grain size reaches the scale of the film thickness at the deposition energy around 153 eV.

  15. Excimer laser deposition of hydroxyapatite thin films.

    PubMed

    Singh, R K; Qian, F; Nagabushnam, V; Damodaran, R; Moudgil, B M

    1994-06-01

    We have demonstrated a new and simple in situ method to fabricate adherent and dense hydroxyapatite (HA) coatings at relatively low deposition temperatures (500-600 degrees C). Under optimum processing conditions, the HA coatings possess a nominal Ca:P ratio of 1.65 and exhibit a fully crystalline single-phase structure. This deposition technique is based on the application of a pulsed excimer laser (wavelength lambda = 248 nm, pulse duration tau = 25 x 10(-9) s) to ablate a dense stoichiometric HA target. The HA target was prepared by standard ceramic coprecipitation techniques followed by cold pressing and further sintering at 1200 degrees C in air. High substrate temperatures (> or = 600 degrees C) during film deposition led to phosphorus deficient coatings because of re-evaporation of phosphorus during the deposition process. The stabilization of various calcium and phosphorus phases in the film was controlled by a number of process parameters such as substrate temperature, chamber pressure and presence of water vapour in the chamber. This is particularly advantageous for production of HA coatings, since it is known that HA decomposes at high temperatures due to the uncertainty in the starting material stoichiometry. Rutherford backscattering spectrometry, energy dispersive X-ray analysis, transmission electron microscopy, scanning electron microscopy and X-ray diffraction techniques were employed to determine the structure-processing relationships. Qualitative scratch measurements were conducted to determine the adhesion strength of the films.

  16. Silicon carbide and other films and method of deposition

    NASA Technical Reports Server (NTRS)

    Mehregany, Mehran (Inventor); Zorman, Christian A. (Inventor); Fu, Xiao-An (Inventor); Dunning, Jeremy L. (Inventor)

    2007-01-01

    A method of depositing a ceramic film, particularly a silicon carbide film, on a substrate is disclosed in which the residual stress, residual stress gradient, and resistivity are controlled. Also disclosed are substrates having a deposited film with these controlled properties and devices, particularly MEMS and NEMS devices, having substrates with films having these properties.

  17. Silicon carbide and other films and method of deposition

    NASA Technical Reports Server (NTRS)

    Mehregany, Mehran (Inventor); Zorman, Christian A. (Inventor); Fu, Xiao-An (Inventor); Dunning, Jeremy (Inventor)

    2011-01-01

    A method of depositing a ceramic film, particularly a silicon carbide film, on a substrate is disclosed in which the residual stress, residual stress gradient, and resistivity are controlled. Also disclosed are substrates having a deposited film with these controlled properties and devices, particularly MEMS and NEMS devices, having substrates with films having these properties.

  18. water-soluble fluorocarbon coating

    NASA Technical Reports Server (NTRS)

    Nanelli, P.

    1979-01-01

    Water-soluble fluorocarbon proves durable nonpolluting coating for variety of substrates. Coatings can be used on metals, masonry, textiles, paper, and glass, and have superior hardness and flexibility, strong resistance to chemicals fire, and weather.

  19. Apparatus for laser assisted thin film deposition

    DOEpatents

    Warner, B.E.; McLean, W. II

    1996-02-13

    A pulsed laser deposition apparatus uses fiber optics to deliver visible output beams. One or more optical fibers are coupled to one or more laser sources, and delivers visible output beams to a single chamber, to multiple targets in the chamber or to multiple chambers. The laser can run uninterrupted if one of the deposition chambers ceases to operate because other chambers can continue their laser deposition processes. The laser source can be positioned at a remote location relative to the deposition chamber. The use of fiber optics permits multi-plexing. A pulsed visible laser beam is directed at a generally non-perpendicular angle upon the target in the chamber, generating a plume of ions and energetic neutral species. A portion of the plume is deposited on a substrate as a thin film. A pulsed visible output beam with a high pulse repetition frequency is used. The high pulse repetition frequency is greater than 500 Hz, and more preferably, greater than about 1000 Hz. Diamond-like-carbon (DLC) is one of the thin films produced using the apparatus. 9 figs.

  20. Apparatus for laser assisted thin film deposition

    DOEpatents

    Warner, Bruce E.; McLean, II, William

    1996-01-01

    A pulsed laser deposition apparatus uses fiber optics to deliver visible output beams. One or more optical fibers are coupled to one or more laser sources, and delivers visible output beams to a single chamber, to multiple targets in the chamber or to multiple chambers. The laser can run uninterrupted if one of the deposition chambers ceases to operate because other chambers can continue their laser deposition processes. The laser source can be positioned at a remote location relative to the deposition chamber. The use of fiber optics permits multi-plexing. A pulsed visible laser beam is directed at a generally non-perpendicular angle upon the target in the chamber, generating a plume of ions and energetic neutral species. A portion of the plume is deposited on a substrate as a thin film. A pulsed visible output beam with a high pulse repetition frequency is used. The high pulse repetition frequency is greater than 500 Hz, and more preferably, greater than about 1000 Hz. Diamond-like-carbon (DLC) is one of the thin films produced using the apparatus.

  1. Substrate heater for thin film deposition

    DOEpatents

    Foltyn, Steve R.

    1996-01-01

    A substrate heater for thin film deposition of metallic oxides upon a target substrate configured as a disk including means for supporting in a predetermined location a target substrate configured as a disk, means for rotating the target substrate within the support means, means for heating the target substrate within the support means, the heating means about the support means and including a pair of heating elements with one heater element situated on each side of the predetermined location for the target substrate, with one heater element defining an opening through which desired coating material can enter for thin film deposition and with the heating means including an opening slot through which the target substrate can be entered into the support means, and, optionally a means for thermal shielding of the heating means from surrounding environment is disclosed.

  2. Fluoropolymer Films Deposited by Argon Ion-Beam Sputtering of Polytetrafluoroethylene

    NASA Technical Reports Server (NTRS)

    Golub, Morton A.; Banks, Bruce A.; Kliss, Mark (Technical Monitor)

    1998-01-01

    The FT-IR, XPS and UV spectra of fluoropolymer films (SPTFE-I) deposited by argon ion-beam sputtering of polytetrafluoroethylene (PTFE) were obtained and compared with prior corresponding spectra of fluoropolymer films (SPTFE-P) deposited by argon rf plasma sputtering of PTFE. Although the F/C ratios for SPTFE-I and -P (1.63 and 1.51) were similar, their structures were quite different in that there was a much higher concentration of CF2 groups in SPTFE-I than in SPTFE-P, ca. 61 and 33% of the total carbon contents, respectively. The FT-IR spectra reflect that difference, that for SPTFE-I showing a distinct doublet at 1210 and 1150 per centimeter while that for SPTFE-P presents a broad, featureless band at ca. 1250 per centimeter. The absorbance of the 1210-per centimeter band in SPTFE-I was proportional to the thickness of the film, in the range of 50-400 nanometers. The SPTFE-I was more transparent in the UV than SPTFE-P at comparable thickness. The mechanism for SPTFE-I formation likely involves "chopping off" of oligomeric segments of PTFE as an accompaniment to "plasma" polymerization of TFE monomer or other fluorocarbon fragments generated in situ from PTFE on impact with energetic Ar ions. Data are presented for SPTFE-I deposits and the associated Ar(+) bombarded PTFE targets where a fresh target was used for each run or a single target was used for a sequence of runs.

  3. Study of fluorocarbon plasma in 60 and 100 MHz capacitively coupled discharges using mass spectrometry

    SciTech Connect

    Ushakov, Andrey; Volynets, Vladimir; Jeong, Sangmin; Sung, Dougyong; Ihm, Yongho; Woo, Jehun; Han, Moonhyeong

    2008-09-15

    The signals of positive ions and radicals formed in the fluorocarbon plasma of the capacitively coupled plasma reactor were measured using a quadrupole mass spectrometry and optical emission actinometry. The plasma was produced at 60 and 100 MHz frequencies for the same reactor configuration and gas mixtures. Experiments were performed at 25 mTorr with a SiO{sub 2} wafer on the grounded electrode. Mass spectra of ions were measured in C{sub 4}F{sub 8}/O{sub 2}/Ar and C{sub 4}F{sub 6}/O{sub 2}/Ar gas mixtures at 500-1500 W generator powers. For 60 and 100 MHz discharges production of fluorocarbon ions and radicals is discussed. It was found that the production of heavy species increases with frequency. The high mass signals such as C{sub 3}F{sub 3}{sup +}, C{sub 2}F{sub 4}{sup +}, C{sub 2}F{sub 5}{sup +}, C{sub 3}F{sub 5}{sup +}, C{sub 4}F{sub 7}{sup +} decrease when CHF{sub 3} is added to the gas mixture. However, the signals of CF{sub x}{sup +} (x=1,2,3) do not change significantly. These results are compared to the results of polymer film deposition on the wafer. It was suggested to control the polymerization film formation by adding small amount of CHF{sub 3} to the process mixture.

  4. Electro-deposition of superconductor oxide films

    SciTech Connect

    Bhattacharya, Raghu N.

    2001-01-01

    Methods for preparing high quality superconducting oxide precursors which are well suited for further oxidation and annealing to form superconducting oxide films. The method comprises forming a multilayered superconducting precursor on a substrate by providing an electrodeposition bath comprising an electrolyte medium and a substrate electrode, and providing to the bath a plurality of precursor metal salts which are capable of exhibiting superconducting properties upon subsequent treatment. The superconducting precursor is then formed by electrodepositing a first electrodeposited (ED) layer onto the substrate electrode, followed by depositing a layer of silver onto the first electrodeposited (ED) layer, and then electrodepositing a second electrodeposited (ED) layer onto the Ag layer. The multilayered superconducting precursor is suitable for oxidation at a sufficient annealing temperature in air or an oxygen-containing atmosphere to form a crystalline superconducting oxide film.

  5. Electrophoretically-deposited solid film lubricants

    SciTech Connect

    Dugger, M.T.; Panitz, J.K.J.; Vanecek, C.W.

    1995-04-01

    An aqueous-based process that uses electrophoresis to attract powdered lubricant in suspension to a charged target was developed. The deposition process yields coatings with low friction, complies with environmental safety regulations, requires minimal equipment, and has several advantages over processes involving organic binders or vacuum techniques. This work focuses on development of the deposition process, includes an analysis of the friction coefficient of the material in sliding contact with stainless steel under a range of conditions, and a functional evaluation of coating performance in a precision mechanical device application. Results show that solid lubricant films with friction coefficients as low as 0.03 can be produced. A 0.03 friction coefficient is superior to solid lubricants with binder systems and is comparable to friction coefficients generated with more costly vacuum techniques.

  6. Real-Time Deposition Monitor for Ultrathin Conductive Films

    NASA Technical Reports Server (NTRS)

    Hines, Jacqueline

    2011-01-01

    A device has been developed that can be used for the real-time monitoring of ultrathin (2 or more) conductive films. The device responds in less than two microseconds, and can be used to monitor film depositions up to about 60 thick. Actual thickness monitoring capability will vary based on properties of the film being deposited. This is a single-use device, which, due to the very low device cost, can be disposable. Conventional quartz/crystal microbalance devices have proven inadequate to monitor the thickness of Pd films during deposition of ultrathin films for hydrogen sensor devices. When the deposited film is less than 100 , the QCM measurements are inadequate to allow monitoring of the ultrathin films being developed. Thus, an improved, high-sensitivity, real-time deposition monitor was needed to continue Pd film deposition development. The new deposition monitor utilizes a surface acoustic wave (SAW) device in a differential delay-line configuration to produce both a reference response and a response for the portion of the device on which the film is being deposited. Both responses are monitored simultaneously during deposition. The reference response remains unchanged, while the attenuation of the sensing path (where the film is being deposited) varies as the film thickness increases. This device utilizes the fact that on high-coupling piezoelectric substrates, the attenuation of an SAW undergoes a transition from low to very high, and back to low as the conductivity of a film on the device surface goes from nonconductive to highly conductive. Thus, the sensing path response starts with a low insertion loss, and as a conductive film is deposited, the film conductivity increases, causing the device insertion loss to increase dramatically (by up to 80 dB or more), and then with continued film thickness increases (and the corresponding conductivity increases), the device insertion loss goes back down to the low level at which it started. This provides a

  7. Chemical vapor deposition of copper films

    NASA Astrophysics Data System (ADS)

    Borgharkar, Narendra Shamkant

    We have studied the kinetics of copper chemical vapor deposition (CVD) for interconnect metallization using hydrogen (Hsb2) reduction of the Cu(hfac)sb2 (copper(II) hexafluoroacetylacetonate) precursor. Steady-state deposition rates were measured using a hot-wall microbalance reactor. For base case conditions of 2 Torr Cu(hfac)sb2, 40 Torr Hsb2, and 300sp°C, a growth rate of 0.5 mg cmsp{-2} hrsp{-1} (ca. 10 nm minsp{-1}) is observed. Reaction order experiments suggest that the deposition rate passes through a maximum at partial pressure of 2 Torr of Cu(hfac)sb2. The deposition rate has an overall half-order dependence on Hsb2 partial pressure. A Langmuir-Hinshelwood rate expression is used to describe the observed kinetic dependencies on Cu(hfac)sb2, Hsb2, and H(hfac). Based on the rate expression a mechanism is proposed in which the overall rate is determined by the surface reaction of adsorbed Cu(hfac)sb2 and H species. Additionally, the role of alcohols in enhancing the deposition rate has been investigated. Addition of isopropanol results in a six fold enhancement to yield a deposition rate of 3.3 mg cmsp{-2} hrsp{-1} (ca. 60 nm minsp{-1}) at 5 Torr of isopropanol, 0.4 Torr Cu(hfac)sb2, 40 Torr Hsb2, and 300sp°C. Ethanol and methanol give lower enhancements of 1.75 and 1.1 mg cmsp{-2} hrsp{-1}, respectively. A mechanism based on the ordering of the aqueous pKsba values of the alcohols is proposed to explain the observed results. Lastly, we have built a warm-wall Pedestal reactor apparatus to demonstrate copper CVD on TiN/Si substrates. The apparatus includes a liquid injection system for transport of isopropanol-diluted precursor solutions. At optimized conditions of precursor and substrate pre-treatments, we have deposited uniform films of copper on TiN/Si substrates at an average deposition rate of 3.0 mg cmsp{-2} hrsp{-1} (ca. 60 nm minsp{-1}).

  8. Recrystallisation of electrophoretically deposited CdTe films

    NASA Astrophysics Data System (ADS)

    Pande, P. C.; Bocking, S.; Duke, S.; Miles, R. W.; Carter, M. J.; Latimer, I. D.; Hill, R.

    1996-02-01

    Films of CdTe have been produced by a novel low cost process based on electrophoretic deposition using polar organic solvents. The main advantage of this method is the high rate of deposition, greater than 20 μm/min. Details of the deposition process are given and the effects of post-deposition annealing of the samples have also been investigated using XRD, SEM and EDAX. Laser annealing resulted in melting of CdTe producing more compact and robust films.

  9. SnS2 Thin Film Deposition by Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Yahia Jaber, Abdallah; Noaiman Alamri, Saleh; Salah Aida, Mohammed

    2012-06-01

    Tin disulfide (SnS2) thin films have been synthesized using a simplified spray pyrolysis technique using a perfume atomizer. The films were deposited using two different solutions prepared by the dilution of SnCl2 and thiourea in distilled water and in methanol. The obtained films have a microcrystalline structure. The film deposited using methanol as the solvent is nearly stochiometric SnS2 with a spinel phase having a (001) preferential orientation. The film prepared with an aqueous solution is Sn-rich. Scanning electronic microscopy (SEM) images reveal that the film deposited with the aqueous solution is rough and is formed with large wires. However, the film deposited with methanol is dense and smooth. Conductivity measurements indicate that the aqueous solution leads to an n-type semiconductor, while methanol leads to a p-type semiconductor.

  10. Pulsed laser deposition of CdWO4 thin films

    NASA Astrophysics Data System (ADS)

    Kodu, M.; Avarmaa, T.; Jaaniso, R.; Leemets, K.; Mändar, H.; Nagirnyi, V.

    2016-10-01

    Thin CdWO4 films were produced on various substrates by pulsed laser deposition. A method of producing transparent films of high structural and optical quality on MgO substrate was developed. It is based on deposition of an amorphous film from a non-stoichiometric CdWO4-CdO target and a consequent crystallization of the film in oxygen atmosphere at 750 °C. The quality of the films produced was verified by x-ray diffraction, electron probe microanalysis, scanning electron microscopy, Raman and optical spectroscopy.

  11. Spraylon fluorocarbon encapsulation for silicon solar cell arrays, phase 3

    NASA Technical Reports Server (NTRS)

    Naes, L. G.

    1978-01-01

    The liquid transparent film-forming, fluorocarbon, Spraylon, a protective coating for terrestrial solar cell modules was evaluated. Two modules were completed and field tested. Problems developed early in the field testing which led to the shortened test period, specifically, lifting of the antireflection coating, followed in some areas by complete film delamination. It is believed that although these problems were certainly induced by the presence of the SPRAYLON film, they were not failures of the material per se. Instead, assembly procedures, module design, and cell coating quality should be evaluated to determine cause of failure.

  12. Precursors for the polymer-assisted deposition of films

    DOEpatents

    McCleskey, Thomas M.; Burrell, Anthony K.; Jia, Quanxi; Lin, Yuan

    2013-09-10

    A polymer assisted deposition process for deposition of metal oxide films is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures to yield metal oxide films. Such films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  13. Electrochromic lithium nickel oxide thin film by pulsed laser deposition

    SciTech Connect

    Wen, S.J.; Rottkay, K. von; Rubin, M.

    1996-10-01

    * Thin films of lithium nickel oxide were deposited by pulsed laser deposition (PLD) from targets of pressed LiNiO{sub 2} powder with layered structure. The composition, structure and surface air sensitivity of these films were analyzed using a variety of techniques, such as nuclear reaction analysis, Rutherford backscattering spectrometry (RBS), x-ray diffraction, infrared spectroscopy, and atomic force microscopy. Optical properties were measured using a combination of variable angle spectroscopic ellipsometry and IP spectroradiometry. Crystalline structure, surface morphology and chemical composition of Li{sub x}Ni{sub 1-x}O thin films depend strongly on deposition oxygen pressure, temperature as well as substrate target distance. The films produced at temperatures lower than 600 degrees C spontaneously absorb CO{sub 2} and H{sub 2}O at their surface once they are exposed to the air. The films deposited at 600 degrees C proved to be stable in air over a long period. Even when deposited at room temperature the PLD films are denser and more stable than sputtered films. RBS determined that the best electrochromic films had the stoichiometric composition L{sub 0.5}Ni{sub 0.5}O when deposited at 60 mTorr O{sub 2} pressure. Electrochemical tests show that the films exhibit excellent reversibility in the range 1.0 V to 3.4 V versus lithium and long cyclic life stability in a liquid electrolyte half cell. Electrochemical formatting which is used to develop electrochromism in other films and nickel oxide films is not needed for these stoichiometric films. The optical transmission range is almost 70% at 550 nm for 120 nm thick films.

  14. Properties of vaccum arc deposited amorphous hard carbon films

    SciTech Connect

    Anders, S.; Anders, A.; Raoux, S.

    1995-12-31

    Amorphous hard carbon films formed by vacuum arc deposition are, hydrogen-free, dense, and very hard. The properties of amorphous hard carbon films depend strongly on the energy of the incident ions. A technique which is called Plasma Immersion Ion Implantation can be applied to vacuum arc deposition of amorphous hard carbon films to influence the ion energy. We have studied the influence of the ion energy on the elastic modulus determined by an ultrasonic method, and have measured the optical gap for films with the highest sp{sup 3} content we have obtained so far with this deposition technique. The results show an elastic modulus close to that of diamond, and an optical gap of 2.1 eV which is much greater than for amorphous hard carbon films deposited by other techniques.

  15. Polyimide films from vapor deposition: toward high strength, NIF capsules

    SciTech Connect

    Cook, R C; Hsieh, E J; Letts, S A; Roberts, C C; Saculla, M

    1998-10-16

    The focus of recent efforts at LLNL has been to demonstrate that vapor deposition processing is a suitable technique to form polyimide fnms with sufficient strength for current national ignition facility target specifications. Production of polyimide films with controlled stoichiometry was acccomplished by: 1) depositing a novel co-functional monomer and 2) matching the vapor pressure of each monomer in PMDA/ODA co-depositions. The sublimation and deposition rate for the monomers was determined over a range of temperatures. Polyimide films with thicknesses up to 30 p.m were fabricated. Composition, structure and strength were assessed using FTIR, SEM and biaxial burst testing. The best films had a tensile strength of approximately 100 MPa. A qualitative relationship between the stoichiometry and tensile strength of the film was demonstrated. Thin films ({approximately}3.5 {micro}m) were typically smooth with an rms of 1.5 nm.

  16. Properties of vacuum arc deposited amorphous hard carbon films

    SciTech Connect

    Anders, S.; Anders, A.; Raoux, S.

    1995-04-01

    Amorphous hard carbon films formed by vacuum arc deposition are hydrogen-free, dense, and very hard. The properties of amorphous hard carbon films depend strongly on the energy of the incident ions. A technique which is called Plasma Immersion Ion Implantation can be applied to vacuum arc deposition of amorphous hard carbon films to influence the ion energy. The authors have studied the influence of the ion energy on the elastic modulus determined by an ultrasonic method, and have measured the optical gap for films with the highest sp{sup 3} content they have obtained so far with this deposition technique. The results show an elastic modulus close to that of diamond, and an optical gap of 2.1 eV which is much greater than for amorphous hard carbon films deposited by other techniques.

  17. Crystalline Indium Sulphide thin film by photo accelerated deposition technique

    NASA Astrophysics Data System (ADS)

    Dhanya, A. C.; Preetha, K. C.; Deepa, K.; Remadevi, T. L.

    2015-02-01

    Indium sulfide thin films deserve special attention because of its potential application as buffer layers in CIGS based solar cells. Highly transparent indium sulfide (InS) thin films were prepared using a novel method called photo accelerated chemical deposition (PCD). Ultraviolet source of 150 W was used to irradiate the solution. Compared to all other chemical methods, PCD scores its advantage for its low cost, flexible substrate and capable of large area of deposition. Reports on deposition of high quality InS thin films at room temperature are very rare in literature. The precursor solution was initially heated to 90°C for ten minutes and then deposition was carried out at room temperature for two hours. The appearance of the film changed from lemon yellow to bright yellow as the deposition time increased. The sample was characterized for its structural and optical properties. XRD profile showed the polycrystalline behavior of the film with mixed phases having crystallite size of 17 nm. The surface morphology of the films exhibited uniformly distributed honey comb like structures. The film appeared to be smooth and the value of extinction coefficient was negligible. Optical measurements showed that the film has more than 80% transmission in the visible region. The direct band gap energy was 2.47eV. This method is highly suitable for the synthesis of crystalline and transparent indium sulfide thin films and can be used for various photo voltaic applications.

  18. SnS thin films deposited by chemical bath deposition, dip coating and SILAR techniques

    NASA Astrophysics Data System (ADS)

    Chaki, Sunil H.; Chaudhary, Mahesh D.; Deshpande, M. P.

    2016-05-01

    The SnS thin films were synthesized by chemical bath deposition (CBD), dip coating and successive ionic layer adsorption and reaction (SILAR) techniques. In them, the CBD thin films were deposited at two temperatures: ambient and 70 °C. The energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and optical spectroscopy techniques were used to characterize the thin films. The electrical transport properties studies on the as-deposited thin films were done by measuring the I-V characteristics, DC electrical resistivity variation with temperature and the room temperature Hall effect. The obtained results are deliberated in this paper.

  19. Chemical deposition and characterization of copper indium disulphide thin films

    NASA Astrophysics Data System (ADS)

    Pathan, H. M.; Lokhande, C. D.

    2004-12-01

    A simple chemical deposition method was used to prepare copper indium disulphide thin films. The method is based on sequential immersion of substrate into different cationic and anionic precursor solutions and rinsing before every immersion with double distilled water. In the present investigation, CuInS 2 films have been deposited using chemical deposition method. These films were characterized for their structural, surface morphological, compositional and electrical properties by using X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Rutherford back scattering (RBS), electrical resistivity and thermoemf measurement techniques.

  20. Optical Films Deposited By A Reactive Ion Plating Process

    NASA Astrophysics Data System (ADS)

    Pulker, H. K.; BUhler, M.; Hora, R.

    1986-12-01

    Oxide films on glass substrates, both single and multilayers, were produced by a special reactive ion plating process in the new automatic plating system BALZERS BAP 800. Structure, optical and mechanical film properties have been examined as a function of the deposition parameters. Multilayer systems consisting of TiO2 and Si02 films were deposited, and tests were made concerning optical characteristics, reproducibility and stability. Because of the unique characteristics of the films ion plating promises to become the new technology for the production of optical coatings.

  1. Molecular beam deposition of high quality silicon oxide dielectric films

    NASA Astrophysics Data System (ADS)

    Chand, Naresh; Johnson, J. E.; Osenbach, J. W.; Liang, W. C.; Feldman, L. C.; Tsang, W. T.; Krautter, H. W.; Passlack, M.; Hull, R.; Swaminathan, V.

    1995-03-01

    We report a method for depositing clean, uniform and stable SiO x dielectric films with high control and reproducibility. The technique uses a molecular or chemical beam epitaxy system (MBE or CBE). The technique offers many advantages over the conventional methods such as load lock facility, accurate determination of the flux, low background contamination, in-situ process monitoring tools, and heating, rotation and tilting of the substrate. Rutherford backscattering (RBS) shows that the films deposited without oxygen are stoichiometric, 50% oxygen and 50% Si, irrespective of the deposition rate or temperature. Such SiO films have a resistivity of ≥10 13 Ω · cm and a nominal refractive index of 2 at 632.8 nm. The refractive index can be reduced by introducing a controlled amount of oxygen into the chamber to result in SiO x ( x = 1-2) films. The SiO films have uniform density and composition, and are free from voids, or any inclusions of different crystalline or amorphous phases. These SiO films are easy to pattern and their erosion rate is slower than that of SiO 2 deposited by plasma enhanced chemical vapor deposition (PECVD). During 192 h soak in 99°C deionized (DI) water, no moisture absorption was observed in SiO films deposited at a rate of 2 Å/s. Even in films deposited at 11 Å/s, the moisture content after 192 h soak in 99°C DI water was about one third the moisture content of an as-deposited typical PECVD SiO 2 film, indicating that the SiO films are highly resistant to moisture absorption and the film quality improves with reducing deposition rate. The insulating, mechanical and optical properties of SiO x films make them suitable for many applications such as surface passivation, mask for processing and facet coating of lasers. The process can be easily integrated with MBE/CBE which would greatly simplify and improve the III-V semiconductor processing. It may also be possible to deposit such dielectric films by CBE using gaseous compound sources.

  2. Helical structured thin films deposited at a glancing angle

    NASA Astrophysics Data System (ADS)

    Jen, Yi-Jun; Jheng, Ci-Yao; Chan, San; Tseng, Chien-Hoa

    2015-08-01

    Gold nanohelical structured thin films (NHFs) were tried to be deposited on a glass substrate using glancing angle deposition technique. At a deposition angle of 89°, gold NHFs were fabricated by introducing liquid nitrogen to flow under the backside of BK7 glass substrate holder. The temperature of substrate was reduced to be less than -140°C before deposition. The spin rate was controlled with respect to the deposition rate to grow three different sized nanohelices. The morphology and optical properties of Au NHFs were measured and compared between the three samples. The strong g-factor implies high sensitivity of deposited helixes in biosensing in the future.

  3. Surface treatment of nanocrystal quantum dots after film deposition

    DOEpatents

    Sykora, Milan; Koposov, Alexey; Fuke, Nobuhiro

    2015-02-03

    Provided are methods of surface treatment of nanocrystal quantum dots after film deposition so as to exchange the native ligands of the quantum dots for exchange ligands that result in improvement in charge extraction from the nanocrystals.

  4. Fluorinated diamond bonded in fluorocarbon resin

    DOEpatents

    Taylor, Gene W.

    1982-01-01

    By fluorinating diamond grit, the grit may be readily bonded into a fluorocarbon resin matrix. The matrix is formed by simple hot pressing techniques. Diamond grinding wheels may advantageously be manufactured using such a matrix. Teflon fluorocarbon resins are particularly well suited for using in forming the matrix.

  5. Atomic layer deposition of MoS2 thin films

    NASA Astrophysics Data System (ADS)

    Browning, Robert; Padigi, Prasanna; Solanki, Raj; Tweet, Douglas J.; Schuele, Paul; Evans, David

    2015-03-01

    Atomic layer deposition (ALD) was used to grow thin films of MoS2 over 5 × 5 cm areas of silicon oxide coated silicon wafers. Smooth, uniform, and continuous films were produced over a temperature range of 350 °C-450 °C. The as-grown films were analyzed using x-ray photoelectron spectroscopy, Raman spectroscopy, photoluminescence, and x-ray diffraction. Electrical characteristics of the films were evaluated by fabricating a back gated field effect transistor. These analyses indicate that ALD technique can produce large area, high quality MoS2 films.

  6. Pulsed Laser Deposition of High Temperature Protonic Films

    NASA Technical Reports Server (NTRS)

    Dynys, Fred W.; Berger, M. H.; Sayir, Ali

    2006-01-01

    Pulsed laser deposition has been used to fabricate nanostructured BaCe(0.85)Y(0.15)O3- sigma) films. Protonic conduction of fabricated BaCe(0.85)Y(0.15)O(3-sigma) films was compared to sintered BaCe(0.85)Y(0.15)O(3-sigma). Sintered samples and laser targets were prepared by sintering BaCe(0.85)Y(0.15)O(3-sigma) powders derived by solid state synthesis. Films 1 to 8 micron thick were deposited by KrF excimer laser on porous Al2O3 substrates. Thin films were fabricated at deposition temperatures of 700 to 950 C at O2 pressures up to 200 mTorr using laser pulse energies of 0.45 - 0.95 J. Fabricated films were characterized by X-ray diffraction, electron microscopy and electrical impedance spectroscopy. Single phase BaCe(0.85)Y(0.15)O(3-sigma) films with a columnar growth morphology are observed with preferred crystal growth along the [100] or [001] direction. Results indicate [100] growth dependence upon laser pulse energy. Electrical conductivity of bulk samples produced by solid state sintering and thin film samples were measured over a temperature range of 100 C to 900 C. Electrical conduction behavior was dependent upon film deposition temperature. Maximum conductivity occurs at deposition temperature of 900 oC; the electrical conductivity exceeds the sintered specimen. All other deposited films exhibit a lower electrical conductivity than the sintered specimen. Activation energy for electrical conduction showed dependence upon deposition temperature, it varied

  7. Deposition of diamond-like films by ECR microwave plasma

    NASA Technical Reports Server (NTRS)

    Shing, Yuh-Han (Inventor); Pool, Frederick S. (Inventor)

    1995-01-01

    Hard amorphous hydrogenated carbon, diamond-like films are deposited using an electron cyclotron resonance microwave plasma with a separate radio frequency power bias applied to a substrate stage. The electron cyclotron resonance microwave plasma yields low deposition pressure and creates ion species otherwise unavailable. A magnetic mirror configuration extracts special ion species from a plasma chamber. Different levels of the radio frequency power bias accelerate the ion species of the ECR plasma impinging on a substrate to form different diamond-like films. During the deposition process, a sample stage is maintained at an ambient temperature of less than 100.degree. C. No external heating is applied to the sample stage. The deposition process enables diamond-like films to be deposited on heat-sensitive substrates.

  8. Characterization of Nanoporous WO3 Films Grown via Ballistic Deposition

    SciTech Connect

    Smid, Bretislav; Li, Zhenjun; Dohnalkova, Alice; Arey, Bruce W.; Smith, R. Scott; Matolin, Vladimir; Kay, Bruce D.; Dohnalek, Zdenek

    2012-05-17

    We report on the preparation and characterization of high surface area, supported nanoporous tungsten oxide films prepared under different conditions on polished polycrystalline Ta and Pt(111) substrates via direct sublimation of monodispersed gas phase of cyclic (WO3)3 clusters. Scanning Electron Microscopy and Transmission Electron Microscopy were used to investigate the film morphology on a nanometer scale. The films consist of arrays of separated filaments that are amorphous. The chemical composition and the thermal stability of the films were investigated by means of X-ray Photoelectron Spectroscopy. The surface area and the distribution of binding sites on the films are measured as functions of growth temperature, deposition angle, and annealing conditions using temperature programmed desorption of Kr. Films deposited at 20 K and at an incident angle of 65{sup o} from substrate normal display the greatest specific surface area of {approx}560 m2/g.

  9. Polymer-assisted aqueous deposition of metal oxide films

    DOEpatents

    Li, DeQuan; Jia, Quanxi

    2003-07-08

    An organic solvent-free process for deposition of metal oxide thin films is presented. The process includes aqueous solutions of necessary metal precursors and an aqueous solution of a water-soluble polymer. After a coating operation, the resultant coating is fired at high temperatures to yield optical quality metal oxide thin films.

  10. Characterization of CdTe Films Deposited at Various Bath Temperatures and Concentrations Using Electrophoretic Deposition

    PubMed Central

    Daud, Mohd Norizam Md; Zakaria, Azmi; Jafari, Atefeh; Ghazali, Mohd Sabri Mohd; Abdullah, Wan Rafizah Wan; Zainal, Zulkarnain

    2012-01-01

    CdTe film was deposited using the electrophoretic deposition technique onto an ITO glass at various bath temperatures. Four batch film compositions were used by mixing 1 to 4 wt% concentration of CdTe powder with 10 mL of a solution of methanol and toluene. X-ray Diffraction analysis showed that the films exhibited polycrystalline nature of zinc-blende structure with the (111) orientation as the most prominent peak. From the Atomic Force Microscopy, the thickness and surface roughness of the CdTe film increased with the increase of CdTe concentration. The optical energy band gap of film decreased with the increase of CdTe concentration, and with the increase of isothermal bath temperature. The film thickness increased with respect to the increase of CdTe concentration and bath temperature, and following, the numerical expression for the film thickness with respect to these two variables has been established. PMID:22754325

  11. Resonant infrared pulsed laser deposition of cyclic olefin copolymer films

    NASA Astrophysics Data System (ADS)

    Singaravelu, S.; Klopf, J. M.; Schriver, K. E.; Park, H. K.; Kelley, M. J.; Haglund, R. F.

    2014-03-01

    Barrier materials on thin-film organic optoelectronic devices inhibit the uptake of water, oxygen, or environmental contaminants, and fabricating them is a major challenge. By definition, these barrier layers must be insoluble, so the usual routes to polymer- or organic-film deposition by spin coating are not problematic. In this paper, we report comparative studies of pulsed laser deposition of cyclic olefin copolymer (COC), an excellent moisture barrier and a model system for a larger class of protective materials that are potentially useful in organic electronic devices, such as organic light-emitting diodes (OLEDs). Thin films of COC were deposited by resonant and nonresonant infrared pulsed laser ablation of solid COC targets, using a free-electron laser tuned to the 3.43 μm C-H stretch of the COC, and a high-intensity nanosecond Q-switched laser operated at 1064 nm. The ablation craters and deposited films were characterized by scanning-electron microscopy, Fourier-transform infrared spectrometry, atomic-force microscopy, high-resolution optical microscopy, and surface profilometry. Thermal-diffusion calculations were performed to determine the temperature rise induced in the film at the C-H resonant wavelength. The results show that resonant infrared pulsed laser deposition (RIR-PLD) is an effective, low-temperature thin-film deposition technique that leads to evaporation and deposition of intact molecules in homogeneous, smooth films. Nonresonant PLD, on the other hand, leads to photothermal damage, degradation of the COC polymers, and to the deposition only of particulates.

  12. Resonant infrared pulsed laser deposition of cyclic olefin copolymer films

    SciTech Connect

    Singaravelu, Senthil R.; Klopf, John M.; Schriver, Kenneth E.; Park, HyeKyoung; Kelley, Michael J.; Haglund, Jr., Richard F.

    2013-08-01

    Barrier materials on thin-film organic optoelectronic devices inhibit the uptake of water, oxygen, or environmental contaminants, and fabricating them is a major challenge. By definition, these barrier layers must be insoluble, so the usual routes to polymer- or organic-film deposition by spin coating are not problematic. In this paper, we report comparative studies of pulsed laser deposition of cyclic olefin copolymer (COC), an excellent moisture barrier and a model system for a larger class of protective materials that are potentially useful in organic electronic devices, such as organic light-emitting diodes (OLEDs). Thin films of COC were deposited by resonant and nonresonant infrared pulsed laser ablation of solid COC targets, using a free-electron laser tuned to the 3.43 μm C–H stretch of the COC, and a high-intensity nanosecond Q-switched laser operated at 1064 nm. The ablation craters and deposited films were characterized by scanning-electron microscopy, Fourier-transform infrared spectrometry, atomic-force microscopy, high-resolution optical microscopy, and surface profilometry. Thermal-diffusion calculations were performed to determine the temperature rise induced in the film at the C–H resonant wavelength. The results show that resonant infrared pulsed laser deposition (RIR-PLD) is an effective, low-temperature thin-film deposition technique that leads to evaporation and deposition of intact molecules in homogeneous, smooth films. Nonresonant PLD, on the other hand, leads to photothermal damage, degradation of the COC polymers, and to the deposition only of particulates.

  13. Sputter deposition for multi-component thin films

    DOEpatents

    Krauss, Alan R.; Auciello, Orlando

    1990-01-01

    Ion beam sputter-induced deposition using a single ion beam and a multicomponent target is capable of reproducibly producing thin films of arbitrary composition, including those which are close to stoichiometry. Using a quartz crystal deposition monitor and a computer controlled, well-focused ion beam, this sputter-deposition approach is capable of producing metal oxide superconductors and semiconductors of the superlattice type such as GaAs-AlGaAs as well as layered metal/oxide/semiconductor/superconductor structures. By programming the dwell time for each target according to the known sputtering yield and desired layer thickness for each material, it is possible to deposit composite films from a well-controlled sub-monolayer up to thicknesses determined only by the available deposition time. In one embodiment, an ion beam is sequentially directed via a set of X-Y electrostatic deflection plates onto three or more different element or compound targets which are constituents of the desired film. In another embodiment, the ion beam is directed through an aperture in the deposition plate and is displaced under computer control to provide a high degree of control over the deposited layer. In yet another embodiment, a single fixed ion beam is directed onto a plurality of sputter targets in a sequential manner where the targets are each moved in alignment with the beam under computer control in forming a multilayer thin film. This controlled sputter-deposition approach may also be used with laser and electron beams.

  14. Sputter deposition for multi-component thin films

    DOEpatents

    Krauss, A.R.; Auciello, O.

    1990-05-08

    Ion beam sputter-induced deposition using a single ion beam and a multicomponent target is capable of reproducibly producing thin films of arbitrary composition, including those which are close to stoichiometry. Using a quartz crystal deposition monitor and a computer controlled, well-focused ion beam, this sputter-deposition approach is capable of producing metal oxide superconductors and semiconductors of the superlattice type such as GaAs-AlGaAs as well as layered metal/oxide/semiconductor/superconductor structures. By programming the dwell time for each target according to the known sputtering yield and desired layer thickness for each material, it is possible to deposit composite films from a well-controlled sub-monolayer up to thicknesses determined only by the available deposition time. In one embodiment, an ion beam is sequentially directed via a set of X-Y electrostatic deflection plates onto three or more different element or compound targets which are constituents of the desired film. In another embodiment, the ion beam is directed through an aperture in the deposition plate and is displaced under computer control to provide a high degree of control over the deposited layer. In yet another embodiment, a single fixed ion beam is directed onto a plurality of sputter targets in a sequential manner where the targets are each moved in alignment with the beam under computer control in forming a multilayer thin film. This controlled sputter-deposition approach may also be used with laser and electron beams. 10 figs.

  15. Ubiquitous pentacene monolayer on metals deposited onto pentacene films.

    PubMed

    Jaeckel, B; Sambur, J B; Parkinson, B A

    2007-11-01

    Photoelectron spectroscopy (XPS and UPS) was used to study the deposition of metal layers (Ag, Cu, and Au) onto pentacene films. Very low work functions were measured (PhiAg = 3.91 eV, PhiCu = 3.93 eV, and PhiAu = 4.3 eV) for all of the metals, in agreement with results from the literature. The intensities of the C 1s core-level signals from pentacene that were monitored during stepwise metal deposition leveled off at a value of about 30% of a thick pentacene film. This C 1s intensity is comparable to that of one monolayer of pentacene deposited onto the respective metal. The valence band spectra of metals deposited onto pentacene and spectra collected for pentacene deposited onto bare metal surfaces are very similar. These findings lead to the conclusion that approximately one monolayer of pentacene is always present on top of the freshly deposited metal film, which explains the very low work function of the metals when they are deposited onto organic films. We expect similar behavior with other nonreactive metals deposited onto stable organic layers.

  16. Vacuum deposition of stoichiometric crystalline PbS films: The effect of sulfurizing environment during deposition

    NASA Astrophysics Data System (ADS)

    Singh, B. P.; Kumar, R.; Kumar, A.; Tyagi, R. C.

    2015-10-01

    Thin film of lead sulfide (PbS) was deposited onto highly cleaned glass and quartz substrates using a vacuum thermal evaporation technique. The effect of the sulfurizing environment on the growth and properties of vacuum-deposited PbS thin film was studied. The ambient sulfurizing environment was created by thermal decomposition of thiourea inside the vacuum chamber during deposition to maintain the stoichiometry and quality of the PbS film. The sulfurizing gas H2S, produced in the thermal decomposition of the solid sulfur containing thiourea readily combines with the cations (Pb2+) without leaving any anions (S2-) at the substrates and also has not produced any excess of sulfur at the substrates. The deposited film was characterized by optical spectroscopy, x-ray diffraction patterns, scanning electron micrographs with energy dispersive analysis of x-rays, and atomic force micrographs. The physical characterization of the deposited PbS film revealed that the surface of film grown in the sulfurizing environment improved and contained more stoichiometric sulfur in comparison to film deposited without the sulfurizing environment.

  17. Anomalous hysteresis properties of iron films deposited on liquid surfaces

    SciTech Connect

    Ye Quanlin; Feng Chunmu; Xu Xiaojun; Jin Jinsheng; Xia Agen; Ye Gaoxiang

    2005-07-01

    A nearly free sustained iron film system, deposited on silicone oil surfaces by vapor-phase deposition method, has been fabricated and its crystal structure as well as magnetic properties has been studied. Both the temperature-dependent coercivity H{sub c}(T) and exchange anisotropy field H{sub E}(T) of the iron films possess a maximum peak around the critical temperature T{sub crit}=10-15 and 4 K, respectively. Our experimental results show that the anomalous hysteresis properties mainly result from the oxide surfaces of the films with spin-glass-like phase below freezing temperature T{sub f}=30-50 K.

  18. Anomalous hysteresis properties of iron films deposited on liquid surfaces

    NASA Astrophysics Data System (ADS)

    Ye, Quan-Lin; Feng, Chun-Mu; Xu, Xiao-Jun; Jin, Jin-Sheng; Xia, A.-Gen; Ye, Gao-Xiang

    2005-07-01

    A nearly free sustained iron film system, deposited on silicone oil surfaces by vapor-phase deposition method, has been fabricated and its crystal structure as well as magnetic properties has been studied. Both the temperature-dependent coercivity Hc(T) and exchange anisotropy field HE(T) of the iron films possess a maximum peak around the critical temperature Tcrit=10-15 and 4K, respectively. Our experimental results show that the anomalous hysteresis properties mainly result from the oxide surfaces of the films with spin-glass-like phase below freezing temperature Tf=30-50K.

  19. Development of a Co-deposition method for Deposition of Low-Contamination Pyrite Thin Films

    NASA Astrophysics Data System (ADS)

    Walimbe, Aditya

    Pyrite is a 0.95 eV bandgap semiconductor which is purported to have great potential in widespread, low--cost photovoltaic cells. A thorough material selection process was used in the design of a pyrite sequential vapor deposition chamber aimed at reducing and possibly eliminating contamination during thin film growth. The design process focused on identifying materials that do not produce volatile components when exposed to high temperatures and high sulfur pressures. Once the materials were identified and design was completed, the ultra--high vacuum growth system was constructed and tested. Pyrite thin films were deposited using the upgraded sequential vapor deposition chamber by varying the substrate temperature from 250°C to 420°C during deposition, keeping sulfur pressure constant at 1 Torr. Secondary Ion Mass Spectrometry (SIMS) results showed that all contaminants in the films were reduced in concentration by orders of magnitude from those grown with the previous system. Characterization techniques of Rutherford Back--scattering Spectrometry (RBS), X--Ray Diffraction (XRD), Raman Spectroscopy, Optical Profilometry and UV/Vis/Near--IR Spectroscopy were performed on the deposited thin films. The results indicate that stoichiometric ratio of S:Fe, structural--quality (epitaxy), optical roughness and percentage of pyrite in the deposited thin films improve with increase in deposition temperature. A Tauc plot of the optical measurements indicates that the pyrite thin films have a bandgap of 0.94 eV.

  20. Measuring Thicknesses Of Vacuum-Deposited Organic Thin Films

    NASA Technical Reports Server (NTRS)

    David, Carey E.

    1996-01-01

    Method of measuring thickness of thin organic liquid film deposited in vacuum involves use of quartz-crystal monitor (QCM) calibrated by use of witness plate that has, in turn, calibrated by measurement of absorption of infrared light in deposited material. Present procedure somewhat tedious, but once calibration accomplished, thicknesses of organic liquid deposits monitored in real time and in situ by use of QCM.

  1. Chemical vapor deposition reactor. [providing uniform film thickness

    NASA Technical Reports Server (NTRS)

    Chern, S. S.; Maserjian, J. (Inventor)

    1977-01-01

    An improved chemical vapor deposition reactor is characterized by a vapor deposition chamber configured to substantially eliminate non-uniformities in films deposited on substrates by control of gas flow and removing gas phase reaction materials from the chamber. Uniformity in the thickness of films is produced by having reactive gases injected through multiple jets which are placed at uniformally distributed locations. Gas phase reaction materials are removed through an exhaust chimney which is positioned above the centrally located, heated pad or platform on which substrates are placed. A baffle is situated above the heated platform below the mouth of the chimney to prevent downdraft dispersion and scattering of gas phase reactant materials.

  2. Plasma deposition of polymer composite films incorporating nanocellulose whiskers

    NASA Astrophysics Data System (ADS)

    Samyn, P.; Airoudj, A.; Laborie, M.-P.; Mathew, A. P.; Roucoules, V.

    2011-11-01

    In a trend for sustainable engineering and functionalization of surfaces, we explore the possibilities of gas phase processes to deposit nanocomposite films. From an analysis of pulsed plasma polymerization of maleic anhydride in the presence of nanocellulose whiskers, it seems that thin nanocomposite films can be deposited with various patterns. By specifically modifying plasma parameters such as total power, duty cycle, and monomer gas pressure, the nanocellulose whiskers are either incorporated into a buckled polymer film or single nanocellulose whiskers are deposited on top of a polymeric film. The density of the latter can be controlled by modifying the exact positioning of the substrate in the reactor. The resulting morphologies are evaluated by optical microscopy, AFM, contact angle measurements and ellipsometry.

  3. Deposition and investigation of lanthanum-cerium hexaboride thin films

    SciTech Connect

    Kuzanyan, A.S. . E-mail: akuzan@ipr.sci.am; Harutyunyan, S.R.; Vardanyan, V.O.; Badalyan, G.R.; Petrosyan, V.A.; Kuzanyan, V.S.; Petrosyan, S.I.; Karapetyan, V.E.; Wood, K.S.; Wu, H.-D.

    2006-09-15

    Thin films of lanthanum-cerium hexaboride, the promising thermoelectric material for low-temperature applications, are deposited on various substrates by the electron-beam evaporation, pulsed laser deposition and magnetron sputtering. The influence of the deposition conditions on the films X-ray characteristics, composition, microstructure and physical properties, such as the resistivity and Seebeck coefficient, is studied. The preferred (100) orientation of all films is obtained from XRD traces. In the range of 780-800 deg. C deposition temperature the highest intensity of diffractions peaks and the highest degree of the preferred orientation are observed. The temperature dependence of the resistivity and the Seebeck coefficient of films are investigated in the temperature range of 4-300 K. The features appropriate to Kondo effect in the dependences {rho}(T) and S(T) are detected at temperatures below 20 K. Interplay between the value of the Seebeck coefficient, metallic parameters and Kondo scattering of investigated films is discussed. - Graphical abstract: Kondo scattering in (La,Ce)B{sub 6} films: temperature dependence of the resistivity of (La,Ce)B{sub 6} films on various substrates and the ceramics La{sub 0.99}Ce{sub 0.01}B{sub 6}.

  4. UV laser deposition of metal films by photogenerated free radicals

    NASA Technical Reports Server (NTRS)

    Montgomery, R. K.; Mantei, T. D.

    1986-01-01

    A novel photochemical method for liquid-phase deposition of metal films is described. In the liquid phase deposition scheme, a metal containing compound and a metal-metal bonded carbonyl complex are dissolved together in a polar solvent and the mixture is irradiated using a UV laser. The optical arrangement consists of a HeCd laser which provides 7 mW of power at a wavelength of 325 nm in the TEM(OO) mode. The beam is attenuated and may be expanded to a diameter of 5-20 mm. Experiments with photochemical deposition of silver films onto glass and quartz substrates are described in detail. Mass spectrometric analysis of deposited silver films indicated a deposition rate of about 1 A/s at incident power levels of 0.01 W/sq cm. UV laser-induced copper and palladium films have also been obtained. A black and white photograph showing the silver Van Der Pauw pattern of a solution-deposited film is provided.

  5. thin films by an hybrid deposition configuration: pulsed laser deposition and thermal evaporation

    NASA Astrophysics Data System (ADS)

    Escobar-Alarcón, L.; Solís-Casados, D. A.; Perez-Alvarez, J.; Romero, S.; Morales-Mendez, J. G.; Haro-Poniatowski, E.

    2014-10-01

    The aim of this work was to report the application of an hybrid deposition configuration to deposit Titanium dioxide (TiO2) thin films modified with different amounts of bismuth (Bi:TiO2). The samples were synthesized combining a TiO2 laser ablation plasma with a flux of vapor of bismuth produced by thermal evaporation. By varying the deposition rate of Bi it was possible to control the amount of Bi incorporated in the film and consequently the film properties. A detailed compositional, structural, and optical characterization by XPS, RBS, Raman spectroscopy, and UV-Vis spectrometry techniques is discussed. Photocatalytic response of the deposited thin films was studied through the degradation of a malachite green solution.

  6. SEM Analysis of Electrophoretically-Deposited Nanoparticle Films

    NASA Astrophysics Data System (ADS)

    Verma, Neil

    Cobalt ferrite nanoparticles (20 nm) were synthesized and electrophoretically deposited onto aluminum foil, graphite paper, and carbon felt in order to study its potential as a cost-effective electrocatalyst for the oxidation of ammonium sulfite to ammonium sulfate in a proposed sulfur ammonia thermochemical cycle. Scanning electron microscopy and linear sweep voltammetry were used to characterize the deposited films and investigate their electrochemical activity. Furthermore, the effects of electrophoretic deposition conditions on deposit morphology and subsequently the effects of deposit morphology on electrochemical activity in 2 M ammonium sulfite were studied to better understand how to improve electrocatalysts. It was found that there is a critical deposit thickness for each substrate, where additional deposited particles reduce overall electrocatalytic activity of the deposits. For graphite paper, this thickness was estimated to be 3 particle layers for the EPD conditions studied. The 3 particle layer film on graphite paper resulted in a 5.5 fold increase in current density from a blank graphite paper substrate. For carbon felt, the deposit thickness threshold was calculated to be 0.13 of a particle layer for the EPD conditions studied. Moreover, this film was found to have a 4.3 fold increase in current density from a blank carbon felt substrate.

  7. Chromium carbide thin films deposited by ultra-short pulse laser deposition

    NASA Astrophysics Data System (ADS)

    Teghil, R.; Santagata, A.; De Bonis, A.; Galasso, A.; Villani, P.

    2009-06-01

    Pulsed laser deposition performed by a laser with a pulse duration of 250 fs has been used to deposit films from a Cr 3C 2 target. Due to the different processes involved in the laser ablation when it is performed by an ultra-short pulse source instead of a conventional short pulse one, it has been possible to obtain in vacuum films containing only one type of carbide, Cr 3C 2, as shown by X-ray photoelectron spectroscopy. On the other hand, Cr 3C 2 is not the only component of the films, since a large amount of amorphous carbon is also present. The films, deposited at room temperature, are amorphous and seem to be formed by the coalescence of a large number of particles with nanometric size. The film composition can be explained in terms of thermal evaporation from particles ejected from the target.

  8. Chemical vapour deposition of zeolitic imidazolate framework thin films

    NASA Astrophysics Data System (ADS)

    Stassen, Ivo; Styles, Mark; Grenci, Gianluca; Gorp, Hans Van; Vanderlinden, Willem; Feyter, Steven De; Falcaro, Paolo; Vos, Dirk De; Vereecken, Philippe; Ameloot, Rob

    2016-03-01

    Integrating metal-organic frameworks (MOFs) in microelectronics has disruptive potential because of the unique properties of these microporous crystalline materials. Suitable film deposition methods are crucial to leverage MOFs in this field. Conventional solvent-based procedures, typically adapted from powder preparation routes, are incompatible with nanofabrication because of corrosion and contamination risks. We demonstrate a chemical vapour deposition process (MOF-CVD) that enables high-quality films of ZIF-8, a prototypical MOF material, with a uniform and controlled thickness, even on high-aspect-ratio features. Furthermore, we demonstrate how MOF-CVD enables previously inaccessible routes such as lift-off patterning and depositing MOF films on fragile features. The compatibility of MOF-CVD with existing infrastructure, both in research and production facilities, will greatly facilitate MOF integration in microelectronics. MOF-CVD is the first vapour-phase deposition method for any type of microporous crystalline network solid and marks a milestone in processing such materials.

  9. Modified chemical route for deposition of molybdenum disulphide thin films

    SciTech Connect

    Vyas, Akshay N. Sartale, S. D.

    2014-04-24

    Molybdenum disulphide (MoS{sub 2}) thin films were deposited on quartz substrates using a modified chemical route. Sodium molybdate and sodium sulphide were used as precursors for molybdenum and sulphur respectively. The route involves formation of tetrathiomolybdate ions (MoS{sub 4}{sup 2−}) and further reduction by sodium borohydride to form MoS{sub 2}. The deposition was performed at room temperature. The deposited films were annealed in argon atmosphere at 1073 K for 1 hour to improve its crystallinity. The deposited films were characterized using scanning electron microscopy (SEM) for morphology, UV-Vis absorption spectroscopy for optical studies and X-ray diffraction (XRD) for structure determination.

  10. Chemical and Magnetic Order in Vapor-Deposited Metal Films

    NASA Astrophysics Data System (ADS)

    Rooney, Peter Wiliam

    1995-01-01

    A stochastic Monte Carlo model of vapor deposition and growth of a crystalline, binary, A_3 B metallic alloy with a negative energy of mixing has been developed which incorporates deposition and surface diffusion in a physically correct manner and allows the simulation of deposition rates that are experimentally realizable. The effects of deposition rate and growth temperature on the development of short range order (SRO) in vapor-deposited films have been examined using this model. SRO in the simulated films increases with growth temperature up to the point at which the temperature corresponds to the energy of mixing, but we see no corresponding development of anisotropic SRO (preferential ordering of A-B pairs along the growth direction). Epitaxial (100) and (111) CoPt_3 films have been deposited over a range of growth temperatures from -50^circ C to 800^circC. Curie temperature (T_{rm c}) and saturation magnetization are dramatically enhanced in those films grown near 400^circ C over the values expected for the chemically homogeneous alloy. Magnetization data indicates that the high T _{rm c} films are inhomogeneous. These phenomena are interpreted as evidence of a previously unobserved magnetically driven miscibility gap in the Co-Pt phase diagram. Films grown near 400^circ C exhibit large uniaxial perpendicular magnetic anisotropy that cannot be accounted for by strain. The observed anisotropy coincides with the chemical phase separation and it seems likely that these two phenomena are related. Long range order (LRO) in the as-deposited films peaks at a growth temperature of 630^circC and then decreases with decreasing growth temperature. The decrease in LRO is either due to kinetic frustration or to competition from magnetically induced Co clustering. Theoretical phase diagrams based on the appropriate Blume-Emery-Griffiths Hamiltonian suggest the latter.

  11. Sputter deposited Terfenol-D thin films for multiferroic applications

    NASA Astrophysics Data System (ADS)

    Mohanchandra, K. P.; Prikhodko, S. V.; Wetzlar, K. P.; Sun, W. Y.; Nordeen, P.; Carman, G. P.

    2015-09-01

    In this paper, we study the sputter deposition and crystallization process to produce high quality Terfenol-D thin film (100 nm) with surface roughness below 1.5 nm. The Terfenol-D thin film was produced using DC magnetron sputtering technique with various sputtering parameters and two different crystallization methods, i.e. substrate heating and post-annealing. Several characterization techniques including WDS, XRD, TEM, AFM, SQUID and MOKE were used to determine the physical and magnetic properties of the Terfenol-D films. TEM studies reveal that the film deposited on the heated substrate has large grains grown along the film thickness producing undesirable surface roughness while the film crystallized by post-annealing method shows uniformly distributed small grains producing a smooth surface. The Terfenol-D film was also deposited onto (011) cut PMN-PT single crystal substrate. With the application of an electric field the film exhibited a 1553 Oe change in coercivity with an estimated saturation magnetostriction of λs = 910 x 10-6.

  12. Heat treatment of cathodic arc deposited amorphous hard carbon films

    SciTech Connect

    Anders, S.; Ager, J.W. III; Brown, I.G.

    1997-02-01

    Amorphous hard carbon films of varying sp{sup 2}/sp{sup 3} fractions have been deposited on Si using filtered cathodic are deposition with pulsed biasing. The films were heat treated in air up to 550 C. Raman investigation and nanoindentation were performed to study the modification of the films caused by the heat treatment. It was found that films containing a high sp{sup 3} fraction sustain their hardness for temperatures at least up to 400 C, their structure for temperatures up to 500 C, and show a low thickness loss during heat treatment. Films containing at low sp{sup 3} fraction graphitize during the heat treatment, show changes in structure and hardness, and a considerable thickness loss.

  13. Electrophoretic deposition of tannic acid-polypyrrolidone films and composites.

    PubMed

    Luo, Dan; Zhang, Tianshi; Zhitomirsky, Igor

    2016-05-01

    Thin films of polyvinylpyrrolidone (PVP)-tannic acid (TA) complexes were prepared by a conceptually new strategy, based on electrophoretic deposition (EPD). Proof of concept investigations involved the analysis of the deposition yield, FTIR and UV-vis spectroscopy of the deposited material, and electron microscopy studies. The analysis of the deposition mechanism indicated that the limitations of the EPD in the deposition of small phenolic molecules, such as TA, and electrically neutral polymers, similar to PVP, containing hydrogen-accepting carbonyl groups, can be avoided. The remarkable adsorption properties of TA and film forming properties of the PVP-TA complexes allowed for the EPD of materials of different types, such as huntite mineral platelets and hydrotalcite clay particles, TiO2 and MnO2 oxide nanoparticles, multiwalled carbon nanotubes, TiN and Pd nanoparticles. Moreover, PVP-TA complexes were used for the co-deposition of different materials and formation of composite films. In another approach, TA was used as a capping agent for the hydrothermal synthesis of ZnO nanorods, which were then deposited by EPD using PVP-TA complexes. The fundamental adsorption and interaction mechanisms of TA involved chelation of metal atoms on particle surfaces with galloyl groups, π-π interactions and hydrogen bonding. The films prepared by EPD can be used for various applications, utilizing functional properties of TA, PVP, inorganic and organic materials of different types and their composites.

  14. Electrophoretic deposition of tannic acid-polypyrrolidone films and composites.

    PubMed

    Luo, Dan; Zhang, Tianshi; Zhitomirsky, Igor

    2016-05-01

    Thin films of polyvinylpyrrolidone (PVP)-tannic acid (TA) complexes were prepared by a conceptually new strategy, based on electrophoretic deposition (EPD). Proof of concept investigations involved the analysis of the deposition yield, FTIR and UV-vis spectroscopy of the deposited material, and electron microscopy studies. The analysis of the deposition mechanism indicated that the limitations of the EPD in the deposition of small phenolic molecules, such as TA, and electrically neutral polymers, similar to PVP, containing hydrogen-accepting carbonyl groups, can be avoided. The remarkable adsorption properties of TA and film forming properties of the PVP-TA complexes allowed for the EPD of materials of different types, such as huntite mineral platelets and hydrotalcite clay particles, TiO2 and MnO2 oxide nanoparticles, multiwalled carbon nanotubes, TiN and Pd nanoparticles. Moreover, PVP-TA complexes were used for the co-deposition of different materials and formation of composite films. In another approach, TA was used as a capping agent for the hydrothermal synthesis of ZnO nanorods, which were then deposited by EPD using PVP-TA complexes. The fundamental adsorption and interaction mechanisms of TA involved chelation of metal atoms on particle surfaces with galloyl groups, π-π interactions and hydrogen bonding. The films prepared by EPD can be used for various applications, utilizing functional properties of TA, PVP, inorganic and organic materials of different types and their composites. PMID:26878711

  15. Fluorocarbon-enhanced mutagenesis of polyaromatic hydrocarbons

    SciTech Connect

    Mahurin, R.G.; Bernstein, R.L.

    1988-02-01

    The widely used fluorocarbon refrigerant and cleaning solvent 1,1,2-trichloro-1,2,2-trifluoroethane (Freon TF), though generally considered biologically inert, enhances the metabolic activation of chemical carcinogens. Liver microsomal extracts from mice given single intraperitoneal injections of this fluorocarbon showed significant increases in their ability to activate carcinogenic polyaromatic hydrocarbons to form mutagens, compared to control mice injected with saline. Polyaromatic hydrocarbons aminofluorene and acetylaminofluorene were activated in this way. Mutagenicity was measured by a microbial assay. Both commercial grade and redistilled fluorocarbons gave similar results, that is, more highly active liver extracts after administration of the fluorocarbon preparation to mice. Neither industrial grade nor redistilled preparation was itself mutagenic. A combined liver microsomal extract from mice breathing Freon TF at 20,000 ppm in air for 8 hr also had enhanced ability to activate aminofluorene as a mutagen. Exposing mice to Freon TF by inhalation more closely matches the normal route of human exposure to fluorocarbons. The results of this study imply that low-molecular-weight fluorocarbons may pose a carcinogenic risk by acting as cocarcinogenic enhancers of carcinogen activation. The possibility that fluorocarbons are cocarcinogens in this way has apparently not been heretofore considered.

  16. Pulsed laser deposition of ITO thin films and their characteristics

    SciTech Connect

    Zuev, D. A. Lotin, A. A.; Novodvorsky, O. A.; Lebedev, F. V.; Khramova, O. D.; Petuhov, I. A.; Putilin, Ph. N.; Shatohin, A. N.; Rumyanzeva, M. N.; Gaskov, A. M.

    2012-03-15

    The indium tin oxide (ITO) thin films are grown on quartz glass substrates by the pulsed laser deposition method. The structural, electrical, and optical properties of ITO films are studied as a function of the substrate temperature, the oxygen pressure in the vacuum chamber, and the Sn concentration in the target. The transmittance of grown ITO films in the visible spectral region exceeds 85%. The minimum value of resistivity 1.79 Multiplication-Sign 10{sup -4} {Omega} cm has been achieved in the ITO films with content of Sn 5 at %.

  17. Large-Scale Graphene Film Deposition for Monolithic Device Fabrication

    NASA Astrophysics Data System (ADS)

    Al-shurman, Khaled

    Since 1958, the concept of integrated circuit (IC) has achieved great technological developments and helped in shrinking electronic devices. Nowadays, an IC consists of more than a million of compacted transistors. The majority of current ICs use silicon as a semiconductor material. According to Moore's law, the number of transistors built-in on a microchip can be double every two years. However, silicon device manufacturing reaches its physical limits. To explain, there is a new trend to shrinking circuitry to seven nanometers where a lot of unknown quantum effects such as tunneling effect can not be controlled. Hence, there is an urgent need for a new platform material to replace Si. Graphene is considered a promising material with enormous potential applications in many electronic and optoelectronics devices due to its superior properties. There are several techniques to produce graphene films. Among these techniques, chemical vapor deposition (CVD) offers a very convenient method to fabricate films for large-scale graphene films. Though CVD method is suitable for large area growth of graphene, the need for transferring a graphene film to silicon-based substrates is required. Furthermore, the graphene films thus achieved are, in fact, not single crystalline. Also, graphene fabrication utilizing Cu and Ni at high growth temperature contaminates the substrate that holds Si CMOS circuitry and CVD chamber as well. So, lowering the deposition temperature is another technological milestone for the successful adoption of graphene in integrated circuits fabrication. In this research, direct large-scale graphene film fabrication on silicon based platform (i.e. SiO2 and Si3N4) at low temperature was achieved. With a focus on low-temperature graphene growth, hot-filament chemical vapor deposition (HF-CVD) was utilized to synthesize graphene film using 200 nm thick nickel film. Raman spectroscopy was utilized to examine graphene formation on the bottom side of the Ni film

  18. Passivation properties of aluminum oxide films deposited by mist chemical vapor deposition for solar cell applications

    NASA Astrophysics Data System (ADS)

    Miki, Shohei; Iguchi, Koji; Kitano, Sho; Hayakashi, Koki; Hotta, Yasushi; Yoshida, Haruhiko; Ogura, Atsushi; Satoh, Shin-ichi; Arafune, Koji

    2015-08-01

    Aluminum oxide (AlOx) films were deposited by mist chemical vapor deposition (MCVD) in air for p-type crystalline silicon, and the effects of the deposition temperature (Tdep) and AlOx film thickness on the maximum surface recombination velocities (Smax) were evaluated. It was found that Smax was improved with increasing Tdep. The AlOx film deposited at 400 °C exhibited the best Smax value of 2.8 cm/s, and the passivation quality was comparable to that of AlOx deposited by other vacuum-based techniques. Smax was also improved with increasing film thickness. When the film thickness was above 10 nm, Smax was approximately 10 cm/s. From the Fourier transform infrared spectra, it was found that the AlOx films deposited by MCVD consisted of an AlOx layer and a Si-diffused AlOx layer. In addition, it is important for the layers to be thick enough to obtain high-quality passivation.

  19. Parametric study on electrochemical deposition of copper nanoparticles on an ultrathin polypyrrole film deposited on a gold film electrode.

    PubMed

    Zhou, X J; Harmer, A J; Heinig, N F; Leung, K T

    2004-06-01

    Monoshaped and monosized copper nanostructured particles have been prepared by potentiostatic electrochemical deposition on an ultrathin polypyrrole (PPY) film, electrochemically grown on a Si(100) substrate sputter-coated with a thin gold film or gold-film electrode (GFE). The crystal size and the number density of the copper nanocrystals have been examined by varying several deposition parameters, including the thickness of the gold film, the PPY film thickness, the applied potential, and the Cu2+ and the electrolyte concentrations for copper deposition. Optimal conditions for uniform growth ofnanocrystals well-dispersed on the GFE have been determined, along with insight into the mechanism of crystal growth. A minimum gold film thickness of 80 nm is required to eliminate the effects of the gold-silicon interface. The PPY film thickness and homogeneity principally affect the shape uniformity of the nanocrystals, while the copper deposition potential could be used to regulate the size and number density of the nanocrystals. Both the Cu2+ and electrolyte concentrations are also found to play important roles in controlling the electrodeposition of nanocrystal growth.

  20. Methods for making deposited films with improved microstructures

    DOEpatents

    Patten, James W.; Moss, Ronald W.; McClanahan, Edwin D.

    1982-01-01

    Methods for improving microstructures of line-of-sight deposited films are described. Columnar growth defects ordinarily produced by geometrical shadowing during deposition of such films are eliminated without resorting to post-deposition thermal or mechanical treatments. The native, as-deposited coating qualities, including homogeneity, fine grain size, and high coating-to-substrate adherence, can thus be retained. The preferred method includes the steps of emitting material from a source toward a substrate to deposit a coating non-uniformly on the substrate surface, removing a portion of the coating uniformly over the surface, again depositing material onto the surface, but from a different direction, and repeating the foregoing steps. The quality of line-of-sight deposited films such as those produced by sputtering, progressively deteriorates as the angle of incidence between the flux and the surface becomes increasingly acute. Depositing non-uniformly, so that the coating becomes progressively thinner as quality deteriorates, followed by uniformly removing some of the coating, such as by resputtering, eliminates the poor quality portions, leaving only high quality portions of the coating. Subsequently sputtering from a different direction applies a high quality coating to other regions of the surface. Such steps can be performed either simultaneously or sequentially to apply coatings of a uniformly high quality, closed microstructure to three-dimensional or larger planar surfaces.

  1. Aerosol chemical vapor deposition of metal oxide films

    DOEpatents

    Ott, Kevin C.; Kodas, Toivo T.

    1994-01-01

    A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said FIELD OF THE INVENTION The present invention relates to the field of film coating deposition techniques, and more particularly to the deposition of multicomponent metal oxide films by aerosol chemical vapor deposition. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

  2. Pulsed laser deposition of niobium nitride thin films

    SciTech Connect

    Farha, Ashraf Hassan Elsayed-Ali, Hani E.; Ufuktepe, Yüksel; Myneni, Ganapati

    2015-12-04

    Niobium nitride (NbN{sub x}) films were grown on Nb and Si(100) substrates using pulsed laser deposition. NbN{sub x} films were deposited on Nb substrates using PLD with a Q-switched Nd:YAG laser (λ = 1064 nm, ∼40 ns pulse width, and 10 Hz repetition rate) at different laser fluences, nitrogen background pressures and deposition substrate temperatures. When all the fabrication parameters are fixed, except for the laser fluence, the surface roughness, nitrogen content, and grain size increase with increasing laser fluence. Increasing nitrogen background pressure leads to a change in the phase structure of the NbN{sub x} films from mixed β-Nb{sub 2}N and cubic δ-NbN phases to single hexagonal β-Nb{sub 2}N. The substrate temperature affects the preferred orientation of the crystal structure. The structural and electronic, properties of NbN{sub x} deposited on Si(100) were also investigated. The NbN{sub x} films exhibited a cubic δ-NbN with a strong (111) orientation. A correlation between surface morphology, electronic, and superconducting properties was found. The observations establish guidelines for adjusting the deposition parameters to achieve the desired NbN{sub x} film morphology and phase.

  3. Pulsed laser deposition of niobium nitride thin films

    NASA Astrophysics Data System (ADS)

    Farha, Ashraf Hassan; Ufuktepe, Yüksel; Myneni, Ganapati; Elsayed-Ali, Hani E.

    2015-12-01

    Niobium nitride (NbNx) films were grown on Nb and Si(100) substrates using pulsed laser deposition. NbNx films were deposited on Nb substrates using PLD with a Q-switched Nd:YAG laser (λ = 1064 nm, ˜40 ns pulse width, and 10 Hz repetition rate) at different laser fluences, nitrogen background pressures and deposition substrate temperatures. When all the fabrication parameters are fixed, except for the laser fluence, the surface roughness, nitrogen content, and grain size increase with increasing laser fluence. Increasing nitrogen background pressure leads to a change in the phase structure of the NbNx films from mixed β-Nb2N and cubic δ-NbN phases to single hexagonal β-Nb2N. The substrate temperature affects the preferred orientation of the crystal structure. The structural and electronic, properties of NbNx deposited on Si(100) were also investigated. The NbNx films exhibited a cubic δ-NbN with a strong (111) orientation. A correlation between surface morphology, electronic, and superconducting properties was found. The observations establish guidelines for adjusting the deposition parameters to achieve the desired NbNx film morphology and phase.

  4. Chemical vapor deposition and characterization of titanium dioxide thin films

    NASA Astrophysics Data System (ADS)

    Gilmer, David Christopher

    1998-12-01

    The continued drive to decrease the size and increase the speed of micro-electronic Metal-Oxide-Semiconductor (MOS) devices is hampered by some of the properties of the SiOsb2 gate dielectric. This research has focused on the CVD of TiOsb2 thin films to replace SiOsb2 as the gate dielectric in MOS capacitors and transistors. The relationship of CVD parameters and post-deposition anneal treatments to the physical and electrical properties of thin films of TiOsb2 has been studied. Structural and electrical characterization of TiOsb2 films grown from the CVD precursors tetraisopropoxotitanium (IV) (TTIP) and TTIP plus Hsb2O is described in Chapter 3. Both types of deposition produced stoichiometric TiOsb2 films comprised of polycrystalline anatase, but the interface properties were dramatically degraded when water vapor was added. Films grown with TTIP in the presence of Hsb2O contained greater than 50% more hydrogen than films grown using only TTIP and the hydrogen content of films deposited in both wet and dry TTIP environments decreased sharply with a post deposition Osb2 anneal. A significant thickness variation of the dielectric constant was observed which could be explained by an interfacial oxide and the finite accumulation thickness. Fabricated TiOsb2 capacitors exhibited electrically equivalent SiOsb2 gate dielectric thicknesses and leakage current densities as low as 38, and 1×10sp{-8} Amp/cmsp2 respectively. Chapter 4 discusses the low temperature CVD of crystalline TiOsb2 thin films deposited using the precursor tetranitratotitanium (IV), TNT, which produces crystalline TiOsb2 films of the anatase phase in UHV-CVD at temperatures as low as 184sp°C. Fabricated TiOsb2 capacitors exhibited electrically equivalent SiOsb2 gate dielectric thicknesses and leakage current densities as low as 17, and 1×10sp{-8} Amp/cmsp2 respectively. Chapter 5 describes the results of a comparison of physical and electrical properties between TiOsb2 films grown via LPCVD using

  5. Vapor-deposited porous films for energy conversion

    DOEpatents

    Jankowski, Alan F.; Hayes, Jeffrey P.; Morse, Jeffrey D.

    2005-07-05

    Metallic films are grown with a "spongelike" morphology in the as-deposited condition using planar magnetron sputtering. The morphology of the deposit is characterized by metallic continuity in three dimensions with continuous and open porosity on the submicron scale. The stabilization of the spongelike morphology is found over a limited range of the sputter deposition parameters, that is, of working gas pressure and substrate temperature. This spongelike morphology is an extension of the features as generally represented in the classic zone models of growth for physical vapor deposits. Nickel coatings were deposited with working gas pressures up 4 Pa and for substrate temperatures up to 1000 K. The morphology of the deposits is examined in plan and in cross section views with scanning electron microscopy (SEM). The parametric range of gas pressure and substrate temperature (relative to absolute melt point) under which the spongelike metal deposits are produced appear universal for other metals including gold, silver, and aluminum.

  6. Deposition of moisture barrier films by catalytic CVD using hexamethyldisilazane

    NASA Astrophysics Data System (ADS)

    Ohdaira, Keisuke; Matsumura, Hideki

    2014-01-01

    Hexamethyldisilazane (HMDS) is utilized to deposit moisture barrier films by catalytic chemical vapor deposition (Cat-CVD). An increase in the thickness of silicon oxynitride (SiOxNy) films leads to a better water-vapor transmission rate (WVTR), indicating that Cat-CVD SiOxNy films deposited using HMDS do not severely suffer from cracking. A WVTR on the order of 10-3 g m-2 day-1 can be realized by a Cat-CVD SiOxNy film formed using HMDS on a poly(ethylene terephthalate) (PET) substrate without any stacking structures at a substrate temperature of as low as 60 °C. X-ray reflectivity (XRR) measurement reveals that a film density of >2.0 g/cm3 is necessary for SiOxNy films to demonstrate an effective moisture barrier ability. The use of HMDS will give us safer production of moisture barrier films because of its non-explosive and non-toxic nature.

  7. Film synthesis on powders by cathodic arc plasma deposition

    SciTech Connect

    Anders, A.; Anders, S.; Brown, I.G.; Ivanov, I.C.

    1995-04-01

    Cathodic arc plasma deposition was used to coat Al{sub 2}O{sub 3} powder (mesh size 60) with platinum. The power particles were moved during deposition using a mechanical system operating at a resonance frequency of 20 Hz. Scanning electron microscopy and Auger electron microscopy show that all particles are completely coated with a platinum film having a thickness of about 100 nm. The actual deposition time was only 20 s, thus the deposition rate was very high (5 nm/s).

  8. Property transformation of graphene with Al2O3 films deposited directly by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Zheng, Li; Cheng, Xinhong; Cao, Duo; Wang, Zhongjian; Xia, Chao; Yu, Yuehui; Shen, Dashen

    2014-01-01

    Al2O3 films are deposited directly onto graphene by H2O-based atomic layer deposition (ALD), and the films are pinhole-free and continuously cover the graphene surface. The growth process of Al2O3 films does not introduce any detective defects in graphene, suppresses the hysteresis effect and tunes the graphene doping to n-type. The self-cleaning of ALD growth process, together with the physically absorbed H2O and oxygen-deficient ALD environment consumes OH- bonds, suppresses the p-doping of graphene, shifts Dirac point to negative gate bias and enhances the electron mobility.

  9. Combustion chemical vapor deposition: A novel thin-film deposition technique

    SciTech Connect

    Hunt, A.T.; Carter, W.B.; Cochran, J.K. Jr. )

    1993-07-12

    A new open-atmosphere chemical vapor deposition (CVD) technique has been developed that we term combustion chemical vapor deposition (CCVD). During CCVD a flame provides the necessary environment for the deposition of a dense film whose elemental constituents are derived from solution, vapor, or gas sources. Ag, YSZ, BaTiO[sub 3], YIG, YBa[sub 2]Cu[sub 3]O[sub [ital x

  10. Fractal structure of films deposited in a tokamak

    NASA Astrophysics Data System (ADS)

    Budaev, V. P.; Khimchenko, L. N.

    2007-04-01

    The surface of amorphous films deposited in the T-10 tokamak was studied in a scanning tunnel microscope. The surface relief on a scale from 10 nm to 100 μm showed a stochastic surface topography and revealed a hierarchy of grains. The observed variety of irregular structures of the films was studied within the framework of the concept of scale invariance using the methods of fractal geometry and statistical physics. The experimental probability density distribution functions of the surface height variations are close in shape to the Cauchy distribution. The stochastic surface topography of the films is characterized by a Hurst parameter of H = 0.68-0.85, which is evidence of a nontrivial self-similarity of the film structure. The fractal character and porous structure of deposited irregular films must be considered as an important issue related to the accumulation of tritium in the ITER project. The process of film growth on the surface of tokamak components exposed to plasma has been treated within the framework of the general concept of inhomogeneous surface growth. A strong turbulence of the edge plasma in tokamaks can give rise to fluctuations in the incident flux of particles, which leads to the growth of fractal films with grain dimensions ranging from nano-to micrometer scale. The shape of the surface of some films found in the T-10 tokamak has been interpreted using a model of diffusion-limited aggregation (DLA). The growth of films according to the discrete DLA model was simulated using statistics of fluctuations observed in a turbulent edge plasma of the T-10 tokamak. The modified DLA model reproduces well the main features of the surface of some films deposited in tokamaks.

  11. Biocompatible interface films deposited within porous polymers by Atomic Layer Deposition (ALD).

    PubMed

    Liang, Xinhua; Lynn, Aaron D; King, David M; Bryant, Stephanie J; Weimer, Alan W

    2009-09-01

    Ultrathin ceramic films were deposited throughout highly porous poly(styrene-divinylbenzene) (PS-DVB) particles using a low-temperature atomic layer deposition (ALD) process. Alumina and titania films were deposited by alternating reactions of trimethylaluminum and H2O at 33 degrees C and of titanium tetrachloride and H2O2 (50 wt % in H2O) at 100 degrees C, respectively. Analytical characterization revealed that conformal alumina and titania films were grown on internal and external polymer surfaces. The improved bioactivity of the polymer substrates was revealed on the basis of the formation of hydroxyapatite (HA) in simulated body fluid. The accelerated formation of HA on the ALD-modified polymer surface was caused by the negatively charged surface provided by the ultrathin ceramic interface. The potential for ALD films to support cell attachment was demonstrated.

  12. Ultraviolet laser deposition of graphene thin films without catalytic layers

    NASA Astrophysics Data System (ADS)

    Sarath Kumar, S. R.; Alshareef, H. N.

    2013-01-01

    In this letter, the formation of nanostructured graphene by ultraviolet laser ablation of a highly ordered pyrolytic graphite target under optimized conditions is demonstrated, without a catalytic layer, and a model for the growth process is proposed. Previously, graphene film deposition by low-energy laser (2.3 eV) was explained by photo-thermal models, which implied that graphene films cannot be deposited by laser energies higher than the C-C bond energy in highly ordered pyrolytic graphite (3.7 eV). Here, we show that nanostructured graphene films can in fact be deposited using ultraviolet laser (5 eV) directly over different substrates, without a catalytic layer. The formation of graphene is explained by bond-breaking assisted by photoelectronic excitation leading to formation of carbon clusters at the target and annealing out of defects at the substrate.

  13. Atomic Layer Deposition of Ir−Pt Alloy Films;

    SciTech Connect

    Christensen, S. T.; Elam, J. W.

    2010-01-01

    Atomic layer deposition (ALD) was used to prepare thin-film mixtures of iridium and platinum. By controlling the ratio between the iridium(III) acetylacetonate/oxygen cycles for Ir ALD and the (trimethyl)methylcyclopentadienyl platinum(IV)/oxygen cycles for Pt ALD, the Ir/Pt ratio in the films could be controlled precisely. We first examined the growth mechanisms for the pure Ir and Pt ALD films, as well as the mixed-metal Ir-Pt ALD films, using in situ quartz crystal microbalance and quadrupole mass spectrometer measurements. These studies revealed that the nucleation and growth of each of the noble metals proceeds smoothly, with negligible perturbation caused by the presence of the other metal. As a consequence of this mutual compatibility, the composition, as well as the growth per cycle for the Ir-Pt films, followed rule-of-mixtures formulas that were based on the ratio of the metal ALD cycles and the growth rates of pure Ir and Pt ALD. X-ray diffraction (XRD) measurements revealed that the films deposit as single-phase alloys in which the lattice parameter varies linearly with the composition. Similar to the pure noble-metal films, the Ir-Pt alloy films grow conformally on high-aspect-ratio trenches. This capability should open up new opportunities in microelectronics, catalysis, and other applications.

  14. Laser deposition of large-area thin films

    SciTech Connect

    Kuzanyan, A S; Petrosyan, V A; Pilosyan, S Kh; Nesterov, V M

    2011-03-31

    A new method for fabricating large-area thin films of uniform thickness on a rotating substrate is proposed. Its distinctive features are (i) the presence of a diaphragm, partially transmitting the evaporated material, between the target and substrate and (ii) the translatory motion of the rotating substrate with respect to the target at a certain velocity. The method proposed makes it possible to obtain thin films of uniform thickness on substrates with sizes limited by only the deposition chamber size. The method is experimentally verified by depositing thin CuO films on silicon substrates placed over the radius of a disk 300 mm in diameter. The deviation of the film thickness from the average value does not exceed {+-}3% throughout the entire radius, which confirms good prospects of this method for microelectronics, optical industry, and other modern technologies. (laser technology)

  15. A new approach to the deposition of nanostructured biocatalytic films

    NASA Astrophysics Data System (ADS)

    Troitsky, V. I.; Berzina, T. S.; Pastorino, L.; Bernasconi, E.; Nicolini, C.

    2003-06-01

    In the present work, monolayer engineering was used to fabricate biocatalytic nanostructured thin films based on the enzyme penicillin G acylase. The biocatalytic films with enhanced characteristics were produced by the deposition of alternate-layer assemblies with a predetermined structure using a combination of Langmuir-Blodgett and adsorption techniques. The value of enzyme activity and the level of protein detachment were measured in dependence on the variation of film composition and on the sequence of layer alternation. As a result, highly active and stable structures were found, which could be promising candidates for practical applications. The method of modification of the deposition method to provide continuous film formation on large-area supports is discussed.

  16. Final report of ''Fundamental Surface Reaction Mechanisms in Fluorocarbon Plasma-Based Processing''

    SciTech Connect

    Gottlieb S. Oehrlein; H. Anderson; J. Cecchi; D. Graves

    2004-09-21

    This report provides a summary of results obtained in research supported by contract ''Fundamental Surface Reaction Mechanisms in Fluorocarbon Plasma-Based Processing'' (Contract No. DE-FG0200ER54608). In this program we advanced significantly the scientific knowledge base on low pressure fluorocarbon plasmas used for patterning of dielectric films and for producing fluorocarbon coatings on substrates. We characterized important neutral and ionic gas phase species that are incident at the substrate, and the processes that occur at relevant surfaces in contact with the plasma. The work was performed through collaboration of research groups at three universities where significantly different, complementary tools for plasma and surface characterization, computer simulation of plasma and surface processes exist. Exchange of diagnostic tools and experimental verification of key results at collaborating institutions, both experimentally and by computer simulations, was an important component of the approach taken in this work.

  17. Supercritical Fluid Immersion Deposition: A New Process for Selective Deposition of Metal Films on Silicon Substrates

    SciTech Connect

    Ye, Xiangrong; Wai, Chien M.; Lin, Yuehe; Young, James S.; Engelhard, Mark H.

    2005-01-01

    Supercritical CO2 is used as a new solvent for immersion deposition, a galvanic displacement process traditionally carried out in aqueous HF solutions containing metal ions, to selectively develop metal films on featured or non-featured silicon substrates. Components of supercritical fluid immersion deposition (SFID) solutions for fabricating Cu and Pd films on silicon substrates are described along with the corresponding experimental setup and procedure. Only silicon substrates exposed and reactive to SFID solutions can be coated. The highly pressurized and gas-like supercritical CO2, combined with the galvanic displacement property of immersion deposition, enables the SFID technique to selectively deposit metal films in small features. SFID may also provide a new method to fabricate palladium silicide in small features or to metallize porous silicon.

  18. Substrates suitable for deposition of superconducting thin films

    DOEpatents

    Feenstra, Roeland; Boatner, Lynn A.

    1993-01-01

    A superconducting system for the lossless transmission of electrical current comprising a thin film of superconducting material Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x epitaxially deposited upon a KTaO.sub.3 substrate. The KTaO.sub.3 is an improved substrate over those of the prior art since the it exhibits small lattice constant mismatch and does not chemically react with the superconducting film.

  19. Stress control of silicon nitride films deposited by plasma enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Li, Dong-ling; Feng, Xiao-fei; Wen, Zhi-yu; Shang, Zheng-guo; She, Yin

    2016-07-01

    Stress controllable silicon nitride (SiNx) films deposited by plasma enhanced chemical vapor deposition (PECVD) are reported. Low stress SiNx films were deposited in both high frequency (HF) mode and dual frequency (HF/LF) mode. By optimizing process parameters, stress free (-0.27 MPa) SiNx films were obtained with the deposition rate of 45.5 nm/min and the refractive index of 2.06. Furthermore, at HF/LF mode, the stress is significantly influenced by LF ratio and LF power, and can be controlled to be 10 MPa with the LF ratio of 17% and LF power of 150 W. However, LF power has a little effect on the deposition rate due to the interaction between HF power and LF power. The deposited SiNx films have good mechanical and optical properties, low deposition temperature and controllable stress, and can be widely used in integrated circuit (IC), micro-electro-mechanical systems (MEMS) and bio-MEMS.

  20. Deposition of YBCO films by high temperature spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Shields, T. C.; Abell, J. S.; Button, T. W.; Chakalov, R. A.; Chakalova, R. I.; Cai, C.; Haessler, W.; Eickemeyer, J.; de Boer, B.

    2002-08-01

    The fabrication of YBCO coated conductors on flexible textured metallic substrates requires the deposition of biaxially textured buffer layers and superconducting films. In this study we have prepared YBCO thin films on single crystal SrTiO 3 substrates and cube textured Ni substrates by spray pyrolysis. The Ni substrates have been pre-buffered with CeO 2/YSZ/CeO 2, layers deposited by pulsed laser deposition. Spray pyrolysis of nitrate solutions has been performed directly on heated substrates at temperatures between 800 and 900 °C without need for a subsequent annealing step. YBCO films deposited on both types of substrate are biaxially textured. Full width half maximum values determined from φ-scans are 8° and 20° for films on SrTiO 3 and buffered Ni substrates respectively. A transport Jc value of 1.2×10 5 A/cm 2 at 77 K and zero field has been achieved on SrTiO 3 ( T c onset=91 K, ΔTc=6 K). χ ac susceptibility measurements of films on buffered Ni substrates show Tc onsets of 88 K with ΔTc=18 K.

  1. Liquid phase deposition synthesis of hexagonal molybdenum trioxide thin films

    SciTech Connect

    Deki, Shigehito; Beleke, Alexis Bienvenu; Kotani, Yuki; Mizuhata, Minoru

    2009-09-15

    Hexagonal molybdenum trioxide thin films with good crystallinity and high purity have been fabricated by the liquid phase deposition (LPD) technique using molybdic acid (H{sub 2}MoO{sub 4}) dissolved in 2.82% hydrofluoric acid (HF) and H{sub 3}BO{sub 3} as precursors. The crystal was found to belong to a hexagonal hydrate system MoO{sub 3}.nH{sub 2}O (napprox0.56). The unit cell lattice parameters are a=10.651 A, c=3.725 A and V=365.997 A{sup 3}. Scanning electron microscope (SEM) images of the as-deposited samples showed well-shaped hexagonal rods nuclei that grew and where the amount increased with increase in reaction time. X-ray photon electron spectroscopy (XPS) spectra showed a Gaussian shape of the doublet of Mo 3d core level, indicating the presence of Mo{sup 6+} oxidation state in the deposited films. The deposited films exhibited an electrochromic behavior by lithium intercalation and deintercalation, which resulted in coloration and bleaching of the film. Upon dehydration at about 450 deg. C, the hexagonal MoO{sub 3}.nH{sub 2}O was transformed into the thermodynamically stable orthorhombic phase. - Abstract: SEM photograph of typical h-MoO{sub 3}.nH{sub 2}O thin film nuclei obtained after 36 h at 40 deg. C by the LPD method. Display Omitted

  2. Pulsed Nd:YAG laser deposition of ruthenium thin films

    NASA Astrophysics Data System (ADS)

    Wai Keat, Lee

    Ruthenium (Ru) is one of the noble air-stable transition metals, which has excellent thermal chemical stability, low electrical resistivity, and relatively high work function near the valence band edge of Si. Recently, Ru has been introduced into the semiconductor industries as a result of the interesting chemical, physical, and electrical properties it possessed. So far, investigations of ruthenium films have been centered on material properties of Ru layers, growth using direct current/radiofrequency (DC/RF) magnetron sputtering, and chemical vapor deposition. However, comparatively little work has been carried out using the pulsed laser deposition (PLD) technique. In this research work, the growth of Ru film using PLD was investigated. The Ru films were deposited on silicon (Si) substrates employing 355 nm pulsed Nd:YAG laser source. Laser fluence ranged from 2 to 8 J/cm2 was employed, with deposition duration from 5 to 180 minutes under high vacuum condition. Optical emission spectroscopy (OES) was employed to study the species and purity of the plasma during the deposition. It was observed that intensity of the Ru species spectra increased with increasing laser fluence and more prominent after laser fluence of 4 J/cm2. No impurities were observed. Film thicknesses ranging from 15 to 280 nm were obtained. As the deposition duration and the laser fluence increased, the thickness of the deposited Ru films increased. It is observed that there was a critical deposition duration value, and this value increases as the laser fluence increased. X-ray diffraction (XRD) spectra showed Ru with crystalline orientation of (101), (100), and (002) peaks. The XRD results revealed an enhanced diffraction peak when film thickness increased, under all laser fluences. Grain sizes were deduced from the XRD data by using the Scherrer's formula and the values fall in the range of 20 to 35 nm for the film thickness covering from 50 nm to 250 nm. Besides, the electrical properties of

  3. Deposition Of Pinhole-Free CoSi2 Film

    NASA Technical Reports Server (NTRS)

    Lin, True-Lon; Fathauer, Robert N.; Grunthaner, Paula J.

    1989-01-01

    New fabrication method produces pinhole-free film of cobalt silicide on silicon substrate. In new method, cobalt and silicon evaporated from electron-beam sources onto substrate of silicon having <111> crystal orientation. Materials deposited in stoichiometric ratio of two silicon atoms to one of cobalt, yielding single-crystal CoSi2 film 5 to 10 nm thick. Layer of amorphous silicon 1 to 2 nm thick deposited on CoSi2. Specimen then annealed at 550 degree C for 10 min. Absence of pinholes critical to operation of multilayer devices employing CoSi2 layers, such as metal base transistor.

  4. Studies on atomic layer deposition of IRMOF-8 thin films

    SciTech Connect

    Salmi, Leo D. Heikkilä, Mikko J.; Vehkamäki, Marko; Puukilainen, Esa; Ritala, Mikko; Sajavaara, Timo

    2015-01-15

    Deposition of IRMOF-8 thin films by atomic layer deposition was studied at 260–320 °C. Zinc acetate and 2,6-naphthalenedicarboxylic acid were used as the precursors. The as-deposited amorphous films were crystallized in 70% relative humidity at room temperature resulting in an unknown phase with a large unit cell. An autoclave with dimethylformamide as the solvent was used to recrystallize the films into IRMOF-8 as confirmed by grazing incidence x-ray diffraction. The films were further characterized by high temperature x-ray diffraction (HTXRD), field emission scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), time-of-flight elastic recoil detection analysis (TOF-ERDA), nanoindentation, and energy-dispersive x-ray spectroscopy. HTXRD measurements revealed similar behavior to bulk IRMOF-8. According to TOF-ERDA and FTIR, composition of the films was similar to IRMOF-8. Through-porosity was confirmed by loading the films with palladium using Pd(thd){sub 2} (thd = 2,2,6,6-tetramethyl-3,5-heptanedionato) as the precursor.

  5. Pulsed laser deposition of anatase thin films on textile substrates

    NASA Astrophysics Data System (ADS)

    Krämer, André; Kunz, Clemens; Gräf, Stephan; Müller, Frank A.

    2015-10-01

    Pulsed laser deposition (PLD) is a highly versatile tool to prepare functional thin film coatings. In our study we utilised a Q-switched CO2 laser with a pulse duration τ ≈ 300 ns, a laser wavelength λ = 10.59 μm, a repetition frequency frep = 800 Hz and a peak power Ppeak = 15 kW to deposit crystalline anatase thin films on carbon fibre fabrics. For this purpose, preparatory experiments were performed on silicon substrates to optimise the anatase deposition conditions including the influence of different substrate temperatures and oxygen partial pressures. Processing parameters were then transferred to deposit anatase on carbon fibres. Scanning electron microscopy, X-ray diffraction analyses, Raman spectroscopy and tactile profilometry were used to characterise the samples and to reveal the formation of phase pure anatase without the occurrence of a secondary rutile phase. Methanol conversion test were used to prove the photocatalytic activity of the coated carbon fibres.

  6. Discovery during Hydrogen Annealing: Formation of Nanoscale Fluorocarbon Tubular Structures

    NASA Astrophysics Data System (ADS)

    Hao, Xiuchun; Tanaka, Sinya; Masuda, Atsuhiko; Maenaka, Kazusuke; Higuchi, Kohei

    2013-09-01

    A novel fabrication method for nanoscale tubular structures is presented in this paper. The tubular structures can be obtained by heating single-crystal silicon trenches or pillars formed by the inductively coupled plasma reactive-ion etching (ICP-RIE) Bosch process in hydrogen ambient. The importance of initial vacuum in the reaction chamber for tube formation and the tube formation mechanism were discussed. The components and sidewall size of the tubular structure were also studied to verify that the tube is made of the fluorocarbon (CF) passivation layer deposited by the Bosch process. The CF tubular structure would be a promising structure for BioMEMS.

  7. Process for thin film deposition of cadmium sulfide

    DOEpatents

    Muruska, H. Paul; Sansregret, Joseph L.; Young, Archie R.

    1982-01-01

    The present invention teaches a process for depositing layers of cadmium sulfide. The process includes depositing a layer of cadmium oxide by spray pyrolysis of a cadmium salt in an aqueous or organic solvent. The oxide film is then converted into cadmium sulfide by thermal ion exchange of the O.sup.-2 for S.sup.-2 by annealing the oxide layer in gaseous sulfur at elevated temperatures.

  8. Oxide films: low-temperature deposition and crystallization

    NASA Astrophysics Data System (ADS)

    Park, Sangmoon; Herman, Gregory S.; Keszler, Douglas A.

    2003-10-01

    Thin films of CeO 2 and (Ce,Sm)O 2 have been prepared by using the SILAR method of deposition in conjunction with hydrothermal and high-temperature annealing. Low-temperature, low-pressure hydrothermal annealing of amorphous Mn:Zn 2GeO 4 films has lead to the growth of grains having edge lengths near 1 μm. Thick films of crystalline Zn 2SiO 4 exhibiting limited cracking have been prepared by a doctor-blade method also in conjunction with hydrothermal dehydration and annealing.

  9. Multichamber Integrated Deposition System For Silicon Based Dielectric Films

    NASA Astrophysics Data System (ADS)

    Lucovsky, Gerald; Tsu, David V.; Parsons, Gregory N.; Kim, Sang S.

    1989-03-01

    This paper discusses the design and operation of a multichamber integrated processing system with in situ surface analysis capabilities. The system has been designed specifically for the deposition of silicon based dielectric thin films by the process of remote plasma-enhanced chemical-vapor deposition (Remote PECVD), and for the formation of microelectronic device heterostructures. In order to achieve these objectives the system includes the following: (1) two substrate-introduction load-lock chambers; (2) a semiconductor substrate processing chamber; (3) a dielectric deposition chamber, specifically configured for the remote PECVD process; (4) a surface analysis chamber including Reflection High Energy Electron Diffraction (RHEED) and Auger Electron Spectroscopy (AES); and (5) inter-chamber substrate transfer in a UHV compatible environment. We will discuss the deposition chamber in some detail and describe the way in which it is designed to meet the requirements for the Remote PECVD process reactions. We also describe an auxiliary deposition/analysis system, which provides both deposition process diagnostics, Mass Spectrometry (MS) and Optical Emission Spectroscopy (OES), and thin film deposition by Remote PECVD. These two systems taken together have provided a research capability for: (1) identifying the deposition process reactions; and (2) fabricating elementary microelectronic device structures, such as MOS and/or MIS capacitors.

  10. Deposition and characterization of aluminum magnesium boride thin film coatings

    NASA Astrophysics Data System (ADS)

    Tian, Yun

    Boron-rich borides are a special group of materials possessing complex structures typically comprised of B12 icosahedra. All of the boron-rich borides sharing this common structural unit exhibit a variety of exceptional physical and electrical properties. In this work, a new ternary boride compound AlMgB14, which has been extensively studied in bulk form due to its novel mechanical properties, was fabricated into thin film coatings by pulsed laser deposition (PLD) technology. The effect of processing conditions (laser operating modes, vacuum level, substrate temperature, and postannealing, etc.) on the composition, microstructure evolution, chemical bonding, and surface morphology of AlMgB14 thin film coatings has been investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectrometry; the mechanical, electrical, and optical properties of AlMgB14 thin films have been characterized by nanoindentation, four-point probe, van der Pauw Hall measurement, activation energy measurement, and UV-VIS-NIR spectrophotometer. Experimental results show that AlMgB14 films deposited in the temperature range of 300 K - 873 K are amorphous. Depositions under a low vacuum level (5 x 10-5 Torr) can introduce a significant amount of C and O impurities into AlMgB14 films and lead to a complex oxide glass structure. Orthorhombic AlMgB14 phase cannot be obtained by subsequent high temperature annealing. By contrast, the orthorhombic AlMgB 14 crystal structure can be attained via high temperature-annealing of AlMgB14 films deposited under a high vacuum level (< 3 x 10-6 Torr), accompanied by strong texture formation. Low vacuum level-as deposited AlMgB14 films have low hardness (10 GPa), but high vacuum level-as deposited AlMgB14 films exhibit an extremely high hardness (45 GPa - 51 GPa), and the higher deposition temperature results in still higher hardness

  11. Coaxial carbon plasma gun deposition of amorphous carbon films

    NASA Technical Reports Server (NTRS)

    Sater, D. M.; Gulino, D. A.; Rutledge, S. K.

    1984-01-01

    A unique plasma gun employing coaxial carbon electrodes was used in an attempt to deposit thin films of amorphous diamond-like carbon. A number of different structural, compositional, and electrical characterization techniques were used to characterize these films. These included scanning electron microscopy, scanning transmission electron microscopy, X ray diffraction and absorption, spectrographic analysis, energy dispersive spectroscopy, and selected area electron diffraction. Optical absorption and electrical resistivity measurements were also performed. The films were determined to be primarily amorphous, with poor adhesion to fused silica substrates. Many inclusions of particulates were found to be present as well. Analysis of these particulates revealed the presence of trace impurities, such as Fe and Cu, which were also found in the graphite electrode material. The electrodes were the source of these impurities. No evidence of diamond-like crystallite structure was found in any of the film samples. Details of the apparatus, experimental procedure, and film characteristics are presented.

  12. Formation of ultrasmooth thin silver films by pulsed laser deposition

    SciTech Connect

    Kuznetsov, I. A.; Garaeva, M. Ya.; Mamichev, D. A. Grishchenko, Yu. V.; Zanaveskin, M. L.

    2013-09-15

    Ultrasmooth thin silver films have been formed on a quartz substrate with a buffer yttrium oxide layer by pulsed laser deposition. The dependence of the surface morphology of the film on the gas (N{sub 2}) pressure in the working chamber and laser pulse energy is investigated. It is found that the conditions of film growth are optimal at a gas pressure of 10{sup -2} Torr and lowest pulse energy. The silver films formed under these conditions on a quartz substrate with an initial surface roughness of 0.3 nm had a surface roughness of 0.36 nm. These films can be used as a basis for various optoelectronics and nanoplasmonics elements.

  13. Friction and wear of plasma-deposited diamond films

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa; Wu, Richard L. C.; Garscadden, Alan; Barnes, Paul N.; Jackson, Howard E.

    1993-01-01

    Reciprocating sliding friction experiments in humid air and in dry nitrogen and unidirectional sliding friction experiments in ultrahigh vacuum were conducted with a natural diamond pin in contact with microwave-plasma-deposited diamond films. Diamond films with a surface roughness (R rms) ranging from 15 to 160 nm were produced by microwave-plasma-assisted chemical vapor deposition. In humid air and in dry nitrogen, abrasion occurred when the diamond pin made grooves in the surfaces of diamond films, and thus the initial coefficients of friction increased with increasing initial surface roughness. The equilibrium coefficients of friction were independent of the initial surface roughness of the diamond films. In vacuum the friction for diamond films contacting a diamond pin arose primarily from adhesion between the sliding surfaces. In these cases, the initial and equilibrium coefficients of friction were independent of the initial surface roughness of the diamond films. The equilibrium coefficients of friction were 0.02 to 0.04 in humid air and in dry nitrogen, but 1.5 to 1.8 in vacuum. The wear factor of the diamond films depended on the initial surface roughness, regardless of environment; it increased with increasing initial surface roughness. The wear factors were considerably higher in vacuum than in humid air and in dry nitrogen.

  14. Germanium films by polymer-assisted deposition

    DOEpatents

    Jia, Quanxi; Burrell, Anthony K.; Bauer, Eve; Ronning, Filip; McCleskey, Thomas Mark; Zou, Guifu

    2013-01-15

    Highly ordered Ge films are prepared directly on single crystal Si substrates by applying an aqueous coating solution having Ge-bound polymer onto the substrate and then heating in a hydrogen-containing atmosphere. A coating solution was prepared by mixing water, a germanium compound, ethylenediaminetetraacetic acid, and polyethyleneimine to form a first aqueous solution and then subjecting the first aqueous solution to ultrafiltration.

  15. Diamond deposition on polycrystalline films of cubic boron nitride

    SciTech Connect

    Friedmann, T.A.; Bernardez, L.J.; McCarty, K.F.; Klaus, E.J.; Ottesen, D.K.; Johnsen, H.A.; Clift, W.M. )

    1993-09-06

    We have grown diamond films on films of cubic boron nitride (cBN). The cBN films were grown on Si(100) substrates using ion-assisted pulsed laser deposition. Fourier transform infrared (FTIR) spectroscopy indicated that the BN films contained [similar to]75% [ital sp][sup 3]-bonded cBN. The as-grown cBN films were inserted with no surface pretreatment (e.g., abrading or scratching) into a conventional hot filament diamond reactor. [ital In] [ital situ] Raman spectroscopy was used to confirm diamond synthesis during growth. The nucleation density of the diamond films was estimated at 1[times]10[sup 9]/cm[sup 2], equivalent to or higher than the best values for scratched silicon substrates. In addition, we found that the cBN films were etched in the diamond reactor; a film thickness [approx gt]1500 A was required to prevent total film loss before diamond nucleation occurred. The presence of cBN under the diamond was established using FTIR spectroscopy and Auger electron spectroscopy.

  16. The Effect of Deposition Temperature to Photoconductivity Properties of Amorphous Carbon Thin Films Deposited By Thermal CVD

    NASA Astrophysics Data System (ADS)

    Mohamad, F.; Suriani, A. B.; Noor, U. M.; Rusop, M.

    2010-07-01

    Amorphous carbon (a-C) thin films were deposited by thermal chemical vapor deposition (CVD) using camphor oil on quartz substrates. The photoconductivity and optical properties of the thin films were studied with varying the deposition temperatures ranging from 650 to 900 °C. The film deposited at 750 °C shows large photoconductivity compare to other films. The optical characterization shows that the optical band gap of the thin films decreased from 0.65 to ˜0.0eV with increasing the deposition temperature due to the increase of sp2 bonded carbon configuration. The electrical conductivity of the thin films grown at higher temperature is much higher compared with the thin films deposited at low temperature.

  17. Effect of Deposition Temperature on the Properties of TIO2 Thin Films Deposited by Mocvd

    NASA Astrophysics Data System (ADS)

    Khalifa, Zaki S.

    2016-02-01

    Crystal structure, microstructure, and optical properties of TiO2 thin films deposited on quartz substrates by metal-organic chemical vapor deposition (MOCVD) in the temperature range from 250∘C to 450∘C have been studied. The crystal structure, thickness, microstructure, and optical properties have been carried out using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), atomic force microscope (AFM), and UV-visible transmittance spectroscopy, respectively. XRD patterns show that the obtained films are pure anatase. Simultaneously, the crystal size calculated using XRD peaks, and the grain size measured by AFM decrease with the increase in deposition temperature. Moreover, the texture of the films change and roughness decrease with the increase in deposition temperature. The spectrophotometric transmittance spectra have been used to calculate the refractive index, extinction coefficient, dielectric constant, optical energy gap, and porosity of the deposited films. While the refractive index and dielectric constant decrease with the increase of deposition temperature, the porosity shows the opposite.

  18. Chemical vapor deposition and atomic layer deposition of metal oxide and nitride thin films

    NASA Astrophysics Data System (ADS)

    Barton, Jeffrey Thomas

    Processes for depositing thin films with various electronic, optical, mechanical, and chemical properties are indispensable in many industries today. Of the many deposition methods available, chemical vapor deposition (CVD) has proved over time to be one of the most flexible, efficient, and cost-effective. Atomic layer deposition (ALD) is a newer process that is gaining favor as a method for depositing films with excellent properties and unparalleled precision. This work describes the development of novel CVD and ALD processes to deposit a variety of materials. Hafnium oxide and zirconium oxide show promise as replacements for SiO 2 as gate dielectrics in future-generation transistors. These high-k materials would provide sufficient capacitance with layers thick enough to avoid leakage from tunneling. An ALD method is presented here for depositing conformal hafnium oxide from tetrakis-(diethylamido)hafnium and oxygen gas. A CVD method for depositing zirconium oxide from tetrakis-(dialkylamido)zirconium and either oxygen gas or water vapor is also described. The use of copper for interconnects in integrated circuits requires improved diffusion barrier materials, given its high diffusivity compared to the previously-used aluminum and tungsten. Tungsten nitride has a low resistivity among barrier materials, and can be deposited in amorphous films that are effective diffusion barriers in layers as thin as a few nanometers. Here we demonstrate CVD and plasma-enhanced CVD methods to deposit tungsten nitride films from bis-(dialkylamido)bis-( tert-butylimido)tungsten precursors and ammonia gas. Recent findings had shown uniform copper growth on tantalum silicate films, without the dewetting that usually occurs on oxide surfaces. Tantalum and tungsten silicates were deposited by a CVD reaction from the reaction of either tris-(diethylamido)ethylimido tantalum or bis-(ethylmethylamido)-bis-( tert-butylimido)tungsten with tris-(tert-butoxy)silanol. The ability of evaporated

  19. Combustion chemical vapor deposition - A novel thin-film deposition technique

    NASA Astrophysics Data System (ADS)

    Hunt, A. T.; Carter, W. B.; Cochran, J. K., Jr.

    1993-07-01

    A new open-atmosphere chemical vapor deposition (CVD) technique has been developed that we term combustion chemical vapor deposition (CCVD). During CCVD a flame provides the necessary environment for the deposition of a dense film whose elemental constituents are derived from solution, vapor, or gas sources. Ag, YSZ, BaTiO3, YIG, YBa2Cu3O(x), and Y2BaCuO5 have been deposited via CCVD with the combustion of a sprayed, cation-containing, organic solution as the sole heat source. CCVD could, for some applications, be less expensive and more flexible than conventional CVD.

  20. Chemical Vapor Deposition of Aluminum Oxide Thin Films

    ERIC Educational Resources Information Center

    Vohs, Jason K.; Bentz, Amy; Eleamos, Krystal; Poole, John; Fahlman, Bradley D.

    2010-01-01

    Chemical vapor deposition (CVD) is a process routinely used to produce thin films of materials via decomposition of volatile precursor molecules. Unfortunately, the equipment required for a conventional CVD experiment is not practical or affordable for many undergraduate chemistry laboratories, especially at smaller institutions. In an effort to…

  1. Spatial atomic layer deposition of zinc oxide thin films.

    PubMed

    Illiberi, A; Roozeboom, F; Poodt, P

    2012-01-01

    Zinc oxide thin films have been deposited at high growth rates (up to ~1 nm/s) by spatial atomic layer deposition technique at atmospheric pressure. Water has been used as oxidant for diethylzinc (DEZ) at deposition temperatures between 75 and 250 °C. The electrical, structural (crystallinity and morphology), and optical properties of the films have been analyzed by using Hall, four-point probe, X-ray diffraction, scanning electron microscopy, spectrophotometry, and photoluminescence, respectively. All the films have c-axis (100) preferential orientation, good crystalline quality and high transparency (∼ 85%) in the visible range. By varying the DEZ partial pressure, the electrical properties of ZnO can be controlled, ranging from heavily n-type conductive (with 4 mOhm.cm resistivity for 250 nm thickness) to insulating. Combining the high deposition rates with a precise control of functional properties (i.e., conductivity and transparency) of the films, the industrially scalable spatial ALD technique can become a disruptive manufacturing method for the ZnO-based industry.

  2. Biomimetic lithography and deposition kinetics of iron oxyhydroxide thin films

    SciTech Connect

    Rieke, P.C.; Wood, L.L.; Marsh, B.M.; Fryxell, G.E.; Engelhard, M.H.; Baer, D.R.; Tarasevich, B.J. |; John, C.M.

    1993-12-01

    Heterogeneous nucleation and crystal growth on functionalized organic substrates is a critical step in biological hard tissue formation. Self assembled monolayers can be derivatized with various organic functional groups to mimic the ``nucleation proteins`` for induction of mineral growth. Studies of nucleation and growth on SAMs can provide a better understanding of biomineralization and can also form the basis of a superior thin film deposition process. We demonstrate that micron-scale, electron and ion beam, lithographic techniques can be used to pattern SAMs with functional organic groups that either inhibit or promote mineral deposition. Patterned films of iron oxyhydroxide were deposited on the areas patterned with nucleation sites. Studies of the deposition kinetic of these films show that indeed the surface induces heterogeneous nucleation and that film formation does not occur via absorption of polymers or colloidal material formed homogeneously in solution. The nucleus interfacial free energy was calculated to be 24 mJ/m2 on a SAM surface composed entirely of sulfonate groups.

  3. Electron cyclotron resonance deposition of diamond-like films

    NASA Technical Reports Server (NTRS)

    Shing, Y. H.; Pool, F. S.

    1990-01-01

    Electron cyclotron resonance (ECR) microwave plasma CVD has been developed at low pressures (0.0001 - 0.01 torr) and at ambient and high substrate temperatures (up to 750 C), to achieve large-area (greater than 4 in. diameter) depositions of diamondlike amorphous carbon (a - C:H) films. The application of a RF bias to the substrate stage, which induces a negative self-bias voltage, is found to play a critical role in determining carbon bonding configurations and in modifying the film morphology. There are two distinct types of ECR-deposited diamondlike films. One type of diamondlike film exhibits a Raman spectrum consisting of broad and overlapping, graphitic D (1360/cm, line width = 280/cm) and G (1590/cm, line width 140/cm) lines, and the other type has a broad Raman peak centered at appoximately 1500/cm. Examination of plasma species by optical emission spectroscopy shows no correlation between the CH-asterisk emission intensity and the deposition rate of diamondklike films.

  4. Microenergetic Shock Initiation Studies on Deposited Films of PETN

    NASA Astrophysics Data System (ADS)

    Tappan, Alexander S.; Wixom, Ryan R.; Trott, Wayne M.; Long, Gregory T.; Knepper, Robert; Brundage, Aaron L.; Jones, David A.

    2009-06-01

    Films of the high explosive PETN (pentaerythritol tetranitrate) up to 500-μm thick have been deposited through physical vapor deposition, with the intent of creating well-defined samples for shock-initiation studies. PETN films were characterized with surface profilometry, scanning electron microscopy, x-ray diffraction, and focused ion beam nanotomography. These high-density films were subjected to strong shocks in both the in-plane and out-of-plane orientations. Initiation behavior was monitored with high-speed framing and streak camera photography. Direct initiation with a donor explosive (either RDX with binder, or CL-20 with binder) was possible in both orientations, but with the addition of a thin aluminum buffer plate (in-plane configuration only), initiation proved to be difficult due to the attenuated shock and the high density of the PETN films. Mesoscale models of microenergetic samples were created using the shock physics code CTH and compared with experimental results. The results of these experiments will be discussed in the context of small sample geometry, deposited film morphology, and density.

  5. Control of Thin Liquid Film Morphology During Solvent-Assisted Film Deposition

    SciTech Connect

    Evmenenko, G.; Stripe, B; Dutta, P

    2010-01-01

    Liquid films of different silicate esters were deposited from volatile solvents on hydroxylated and hydrogen-passivated silicon surfaces. We show that adsorption of silicate ester molecules and the resulting structural morphology of the liquid films not only are determined by attractive van der Waals forces with contributions from electrostatic interactions between the silicone ester moieties and oxide surface sites but also can be tuned by modifying the substrate surface or by changing the liquid-solvent interactions. Our results also show the importance of the conformational properties of liquid molecules and their rearrangements at the liquid/solid interface for controlled solvent-assisted film deposition.

  6. YBCO thin film evaporation on as-deposited silver film on MgO

    NASA Astrophysics Data System (ADS)

    Azoulay, J.

    1999-11-01

    YBa 2Cu 3O 7- δ (YBCO) thin film was evaporated on as-deposited Ag buffer layer on MgO substrate. A simple, inexpensive vacuum system equipped with one resistively heated source was used. The subsequent heat treatment was carried out under low oxygen partial pressure at a relatively low temperature and short dwelling time. The films thus obtained were characterized for electrical properties using DC four-probe electrical measurements and inspected for structural properties and chemical composition by scanning electron microscopy (SEM). It is shown that YBCO thin film can grow on as-deposited thin silver layer on MgO substrate.

  7. Vacuum deposited polymer/metal films for optical applications

    SciTech Connect

    Affinito, J.D.; Martin, P.M.; Gross, M.E.; Coronado, C.; Greenwell, E.

    1995-04-01

    Vacuum deposited Polymer/Silver/Polymer reflectors and Tantalum/Polymer/Aluminum Fabry-Perot interference filters were fabricated in a vacuun web coating operation on polyester substrates with a new, high speed deposition process. Reflectivities were measured in the wavelength range from 0.3 to 0.8{mu}m. This new vacuum processing technique has been shown to be capable of deposition line speeds in excess of 500 linear meters/minute. Central to this technique is a new position process for the high rate deposition of polymer films. This polymer process involves the flash evaporation of an acrylic monomer onto a moving substrate. The monomer is subsequently cured by an electron beam or ultraviolet light. This high speed polymer film deposition process has been named the PML process -- for Polymer Multi-Layer. Also, vacuum deposited, index matched, polymer/CaF{sub 2} composites were fabricated from monomer slurries that were subsequently cured with LTV light. This second technique is called the Liquid Multi-Layer (or LML) process. Each of these polymer processes is compatible with each other and with conventional vacuum deposition processes such as sputtering or evaporation.

  8. Deposition of Thin Film Using a Surface Acoustic Wave Device

    NASA Astrophysics Data System (ADS)

    Murochi, Nobuaki; Sugimoto, Mitsunori; Matsui, Yoshikazu; Kondoh, Jun

    2007-07-01

    When a Rayleigh surface acoustic wave (SAW) propagates at a liquid/solid interface, it radiates its energy into the adjacent liquid. If a liquid droplet is loaded on the SAW propagation surface, droplet vibration, streaming, jetting, and atomization are observed. These phenomena are called SAW streaming. In this paper, a novel thin-film deposition method based on the atomization of SAW streaming phenomena is proposed. The liquid with film material is loaded on the SAW propagation surface and the liquid is atomized. The atomization direction depends on the Rayleigh angle, which is determined by the sound velocity in the liquid and the SAW velocity. For easy fabrication of a thin uniform film, the atomization direction is controlled in the perpendicular direction. Using the developed system, the deposition of pigments in ink is carried out. The results observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) indicate that a pigment layer is formed on a glass plate.

  9. Supercapacitors using carbon nanotubes films by electrophoretic deposition

    NASA Astrophysics Data System (ADS)

    Du, Chunsheng; Pan, Ning

    Multi-walled carbon nanotube (MWNT) thin films have been fabricated by electrophoretic deposition technique in this study. The supercapacitors built from such thin film electrodes have exhibited near-ideal rectangular cyclic voltammograms even at a scan rate as high as 1000 mV s -1 and a high specific power density over 20 kW kg -1. More importantly, the supercapacitors showed superior frequency response, with a frequency 'knee' at about 7560 Hz, which is more than 70 times higher than the highest 'knee' frequency (100 Hz) so far reported for such supercapacitors. Our study also demonstrated that these carbon nanotube thin films can serve as a coating layer over ordinary current collectors to drastically enhance the electrode performance, indicating the huge potential in supercapacitor and battery manufacturing. Finally, it is clear that electrophoretic deposition is a promising technique for massive fabrication of carbon nanotube electrodes for various electronic devices.

  10. Thermodynamics of deposition flux-dependent intrinsic film stress

    PubMed Central

    Saedi, Amirmehdi; Rost, Marcel J.

    2016-01-01

    Vapour deposition on polycrystalline films can lead to extremely high levels of compressive stress, exceeding even the yield strength of the films. A significant part of this stress has a reversible nature: it disappears when the deposition is stopped and re-emerges on resumption. Although the debate on the underlying mechanism still continues, insertion of atoms into grain boundaries seems to be the most likely one. However, the required driving force has not been identified. To address the problem we analyse, here, the entire film system using thermodynamic arguments. We find that the observed, tremendous stress levels can be explained by the flux-induced entropic effects in the extremely dilute adatom gas on the surface. Our analysis justifies any adatom incorporation model, as it delivers the underlying thermodynamic driving force. Counterintuitively, we also show that the stress levels decrease, if the barrier(s) for adatoms to reach the grain boundaries are decreased. PMID:26888311

  11. Thermodynamics of deposition flux-dependent intrinsic film stress

    NASA Astrophysics Data System (ADS)

    Saedi, Amirmehdi; Rost, Marcel J.

    2016-02-01

    Vapour deposition on polycrystalline films can lead to extremely high levels of compressive stress, exceeding even the yield strength of the films. A significant part of this stress has a reversible nature: it disappears when the deposition is stopped and re-emerges on resumption. Although the debate on the underlying mechanism still continues, insertion of atoms into grain boundaries seems to be the most likely one. However, the required driving force has not been identified. To address the problem we analyse, here, the entire film system using thermodynamic arguments. We find that the observed, tremendous stress levels can be explained by the flux-induced entropic effects in the extremely dilute adatom gas on the surface. Our analysis justifies any adatom incorporation model, as it delivers the underlying thermodynamic driving force. Counterintuitively, we also show that the stress levels decrease, if the barrier(s) for adatoms to reach the grain boundaries are decreased.

  12. Novel solutions for thin film layer deposition for organic materials

    NASA Astrophysics Data System (ADS)

    Keiper, Dietmar; Long, Michael; Schwambera, Markus; Gersdorff, Markus; Kreis, Juergen; Heuken, Michael

    2011-03-01

    Innovative systems for carrier-gas enhanced vapor phase deposition of organic layers offer advanced methods for the precise deposition of complex thin-film layer stacks. The approach inherently avoids potential short-comings from solvent-based polymer deposition and offers new opportunities. The process operates at low pressure (thus avoiding complex vacuum setups), and, by employing AIXTRON's extensive experience in freely scalable solutions, can be adapted to virtually any production process and allows for R&D and production systems alike. Deposition of organic layers and stacks recommends the approach for a wide range of organic small molecule and polymer materials (including layers with gradual change of the composition), for conductive layers, for dielectric layers, for barrier systems, for OLED materials, and surface treatments such as oleophobic / hydrophobic coatings. With the combination of other vapor phase deposition solutions, hybrid systems combining organic and inorganic materials and other advanced stacks can be realized.

  13. Chemically Deposited Thin-Film Solar Cell Materials

    NASA Technical Reports Server (NTRS)

    Raffaelle, R.; Junek, W.; Gorse, J.; Thompson, T.; Harris, J.; Hehemann, D.; Hepp, A.; Rybicki, G.

    2005-01-01

    We have been working on the development of thin film photovoltaic solar cell materials that can be produced entirely by wet chemical methods on low-cost flexible substrates. P-type copper indium diselenide (CIS) absorber layers have been deposited via electrochemical deposition. Similar techniques have also allowed us to incorporate both Ga and S into the CIS structure, in order to increase its optical bandgap. The ability to deposit similar absorber layers with a variety of bandgaps is essential to our efforts to develop a multi-junction thin-film solar cell. Chemical bath deposition methods were used to deposit a cadmium sulfide (CdS) buffer layers on our CIS-based absorber layers. Window contacts were made to these CdS/CIS junctions by the electrodeposition of zinc oxide (ZnO). Structural and elemental determinations of the individual ZnO, CdS and CIS-based films via transmission spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy and energy dispersive spectroscopy will be presented. The electrical characterization of the resulting devices will be discussed.

  14. Dual ion beam deposition of carbon films with diamondlike properties

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.; Swec, D. M.; Angus, J. C.

    1984-01-01

    A single and dual ion beam system was used to generate amorphous carbon films with diamond like properties. A methane/argon mixture at a molar ratio of 0.28 was ionized in the low pressure discharge chamber of a 30-cm-diameter ion source. A second ion source, 8 cm in diameter was used to direct a beam of 600 eV Argon ions on the substrates (fused silica or silicon) while the deposition from the 30-cm ion source was taking place. Nuclear reaction and combustion analysis indicate H/C ratios for the films to be 1.00. This high value of H/C, it is felt, allowed the films to have good transmittance. The films were impervious to reagents which dissolve graphitic and polymeric carbon structures. Although the measured density of the films was approximately 1.8 gm/cu cm, a value lower than diamond, the films exhibited other properties that were relatively close to diamond. These films were compared with diamondlike films generated by sputtering a graphite target.

  15. In situ measurement of conductivity during nanocomposite film deposition

    NASA Astrophysics Data System (ADS)

    Blattmann, Christoph O.; Pratsinis, Sotiris E.

    2016-05-01

    Flexible and electrically conductive nanocomposite films are essential for small, portable and even implantable electronic devices. Typically, such film synthesis and conductivity measurement are carried out sequentially. As a result, optimization of filler loading and size/morphology characteristics with respect to film conductivity is rather tedious and costly. Here, freshly-made Ag nanoparticles (nanosilver) are made by scalable flame aerosol technology and directly deposited onto polymeric (polystyrene and poly(methyl methacrylate)) films during which the resistance of the resulting nanocomposite is measured in situ. The formation and gas-phase growth of such flame-made nanosilver, just before incorporation onto the polymer film, is measured by thermophoretic sampling and microscopy. Monitoring the nanocomposite resistance in situ reveals the onset of conductive network formation by the deposited nanosilver growth and sinternecking. The in situ measurement is much faster and more accurate than conventional ex situ four-point resistance measurements since an electrically percolating network is detected upon its formation by the in situ technique. Nevertheless, general resistance trends with respect to filler loading and host polymer composition are consistent for both in situ and ex situ measurements. The time lag for the onset of a conductive network (i.e., percolation) depends linearly on the glass transition temperature (Tg) of the host polymer. This is attributed to the increased nanoparticle-polymer interaction with decreasing Tg. Proper selection of the host polymer in combination with in situ resistance monitoring therefore enable the optimal preparation of conductive nanocomposite films.

  16. Synthesis of silicon nitride films by ion beam enhanced deposition

    NASA Astrophysics Data System (ADS)

    Xianghuai, Liu; Bin, Xue; Zhihong, Zheng; Zuyao, Zhou; Shichang, Zou

    1989-03-01

    Silicon nitride films with stoichiometric ratio of Si 3N 4 have been synthesized by concurrent electron beam evaporation of silicon and bombardment with nitrogen ions. The results show that the component ratio of nitrogen to silicon in IBED silicon nitride films can be controlled and predicted by the atomic arrival rate ratio of nitrogen to silicon. IR measurement shows that the characteristic absorption peak of IBED Si 3N 4 is located at a wavenumber of 840 cm -1. The refractive index ranges from 2.2 to 2.6. RBS, AES, TEM, SEM, ED and spreading resistance measurement were used for investigation of the depth profiles of composition and structure of silicon nitride films synthesized by IBED. An intermixed layer is formed at the interface by the knock on effect, and a silicon enriched layer is observed at the surface region of the film. Normally the films were found to be amorphous, but electron diffraction patterns taken from deposited layer showed a certain crystallinity. The silicon nitride films prepared by IBED have dramatically less oxygen content than that formed by non-ion-assisted deposition.

  17. Enhanced Deposition Efficiency of Epitaxial Si Film from SiHCl3 by Mesoplasma Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Wu, Sudong; Kambara, Makoto; Yoshida, Toyonobu

    Epitaxial Si thick films have been deposited by mesoplasma chemical vapor deposition with SiHCl3-H2-Ar gas mixtures at high efficiency. Addition of hydrogen has been revealed to increase the deposition efficiency by removing Cl as a form of HCl. It also promotes the surface migration of deposition precursors for the attainment of epitaxial Si films. As a result, epitaxial Si films with a production yield of about 60% and a deposition rate of 430 nm/s were deposited at a H2/TCS ratio of 2-3.

  18. X-ray reflectivity measurements of vacuum deposited thin films

    SciTech Connect

    Chason, M.; Chason, E.

    1992-12-31

    X-ray reflectivity using energy dispersive X-ray detection, a nondestructive probe of surface roughness over the region of {approximately} 1--50 {Angstrom}, has been used to investigate the characteristicsof vacuum deposited thin films. With a surface roughness sensitivity better than 1 {Angstrom} X-ray reflectivity is sensitive to interfaces between different materials for sample thicknesses up to approximately2000 {Angstrom} (depending on material density). We have investigated discrete Cr/Al deposits on quartz substrates and determined the surface roughness at the interfaces. We have also monitored the evolution ofthe Cr/Al interface following annealing. The experimental data is presented and discussed. The use of the technique for studying thin film deposits is addressed.

  19. X-ray reflectivity measurements of vacuum deposited thin films

    SciTech Connect

    Chason, M. ); Chason, E. )

    1992-01-01

    X-ray reflectivity using energy dispersive X-ray detection, a nondestructive probe of surface roughness over the region of [approximately] 1--50 [Angstrom], has been used to investigate the characteristicsof vacuum deposited thin films. With a surface roughness sensitivity better than 1 [Angstrom] X-ray reflectivity is sensitive to interfaces between different materials for sample thicknesses up to approximately2000 [Angstrom] (depending on material density). We have investigated discrete Cr/Al deposits on quartz substrates and determined the surface roughness at the interfaces. We have also monitored the evolution ofthe Cr/Al interface following annealing. The experimental data is presented and discussed. The use of the technique for studying thin film deposits is addressed.

  20. Deposition of device quality low H content, amorphous silicon films

    DOEpatents

    Mahan, A.H.; Carapella, J.C.; Gallagher, A.C.

    1995-03-14

    A high quality, low hydrogen content, hydrogenated amorphous silicon (a-Si:H) film is deposited by passing a stream of silane gas (SiH{sub 4}) over a high temperature, 2,000 C, tungsten (W) filament in the proximity of a high temperature, 400 C, substrate within a low pressure, 8 mTorr, deposition chamber. The silane gas is decomposed into atomic hydrogen and silicon, which in turn collides preferably not more than 20--30 times before being deposited on the hot substrate. The hydrogenated amorphous silicon films thus produced have only about one atomic percent hydrogen, yet have device quality electrical, chemical, and structural properties, despite this lowered hydrogen content. 7 figs.

  1. Thin Film Nanomorphology Tailored by Physical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Suzuki, Motofumi

    Shadowing growth by glancing angle deposition (GLAD) has been providing self-assembled nanostructures over much larger area for much lower costs since much earlier than the recent advanced top down processes do. In these two decades, significant progress has been made in the development of the well-controlled 3D nanomorphologies such as zigzag and helix. Much effort for theoretical and numerical understanding of the growth mechanism has been also paid in order to improve the morphology. Many researches in academia have been investigating useful properties of nanocolumnar thin films in their laboratory. On the other hand, most companies seem hesitate to introduce GLAD technique into the factory due to the prejudice that the obliquely deposited thin films are not durable and reproducible. In this article, we discuss the progress in glancing angle deposition technology for the practical applications.

  2. Deposition of device quality low H content, amorphous silicon films

    DOEpatents

    Mahan, Archie H.; Carapella, Jeffrey C.; Gallagher, Alan C.

    1995-01-01

    A high quality, low hydrogen content, hydrogenated amorphous silicon (a-Si:H) film is deposited by passing a stream of silane gas (SiH.sub.4) over a high temperature, 2000.degree. C., tungsten (W) filament in the proximity of a high temperature, 400.degree. C., substrate within a low pressure, 8 mTorr, deposition chamber. The silane gas is decomposed into atomic hydrogen and silicon, which in turn collides preferably not more than 20-30 times before being deposited on the hot substrate. The hydrogenated amorphous silicon films thus produced have only about one atomic percent hydrogen, yet have device quality electrical, chemical, and structural properties, despite this lowered hydrogen content.

  3. Deposition of thermal and hot-wire chemical vapor deposition copper thin films on patterned substrates.

    PubMed

    Papadimitropoulos, G; Davazoglou, D

    2011-09-01

    In this work we study the hot-wire chemical vapor deposition (HWCVD) of copper films on blanket and patterned substrates at high filament temperatures. A vertical chemical vapor deposition reactor was used in which the chemical reactions were assisted by a tungsten filament heated at 650 degrees C. Hexafluoroacetylacetonate Cu(I) trimethylvinylsilane (CupraSelect) vapors were used, directly injected into the reactor with the aid of a liquid injection system using N2 as carrier gas. Copper thin films grown also by thermal and hot-wire CVD. The substrates used were oxidized silicon wafers on which trenches with dimensions of the order of 500 nm were formed and subsequently covered with LPCVD W. HWCVD copper thin films grown at filament temperature of 650 degrees C showed higher growth rates compared to the thermally ones. They also exhibited higher resistivities than thermal and HWCVD films grown at lower filament temperatures. Thermally grown Cu films have very uniform deposition leading to full coverage of the patterned substrates while the HWCVD films exhibited a tendency to vertical growth, thereby creating gaps and incomplete step coverage. PMID:22097561

  4. Annealing dependence of residual stress and optical properties of TiO2 thin film deposited by different deposition methods.

    PubMed

    Chen, Hsi-Chao; Lee, Kuan-Shiang; Lee, Cheng-Chung

    2008-05-01

    Titanium oxide (TiO(2)) thin films were prepared by different deposition methods. The methods were E-gun evaporation with ion-assisted deposition (IAD), radio-frequency (RF) ion-beam sputtering, and direct current (DC) magnetron sputtering. Residual stress was released after annealing the films deposited by RF ion-beam or DC magnetron sputtering but not evaporation, and the extinction coefficient varied significantly. The surface roughness of the evaporated films exceeded that of both sputtered films. At the annealing temperature of 300 degrees C, anatase crystallization occurred in evaporated film but not in the RF ion-beam or DC magnetron-sputtered films. TiO(2) films deposited by sputtering were generally more stable during annealing than those deposited by evaporation.

  5. Annealing dependence of residual stress and optical properties of TiO2 thin film deposited by different deposition methods.

    PubMed

    Chen, Hsi-Chao; Lee, Kuan-Shiang; Lee, Cheng-Chung

    2008-05-01

    Titanium oxide (TiO(2)) thin films were prepared by different deposition methods. The methods were E-gun evaporation with ion-assisted deposition (IAD), radio-frequency (RF) ion-beam sputtering, and direct current (DC) magnetron sputtering. Residual stress was released after annealing the films deposited by RF ion-beam or DC magnetron sputtering but not evaporation, and the extinction coefficient varied significantly. The surface roughness of the evaporated films exceeded that of both sputtered films. At the annealing temperature of 300 degrees C, anatase crystallization occurred in evaporated film but not in the RF ion-beam or DC magnetron-sputtered films. TiO(2) films deposited by sputtering were generally more stable during annealing than those deposited by evaporation. PMID:18449260

  6. Combinatorial thin film composition mapping using three dimensional deposition profiles

    NASA Astrophysics Data System (ADS)

    Suram, Santosh K.; Zhou, Lan; Becerra-Stasiewicz, Natalie; Kan, Kevin; Jones, Ryan J. R.; Kendrick, Brian M.; Gregoire, John M.

    2015-03-01

    Many next-generation technologies are limited by material performance, leading to increased interest in the discovery of advanced materials using combinatorial synthesis, characterization, and screening. Several combinatorial synthesis techniques, such as solution based methods, advanced manufacturing, and physical vapor deposition, are currently being employed for various applications. In particular, combinatorial magnetron sputtering is a versatile technique that provides synthesis of high-quality thin film composition libraries. Spatially addressing the composition of these thin films generally requires elemental quantification measurements using techniques such as energy-dispersive X-ray spectroscopy or X-ray fluorescence spectroscopy. Since these measurements are performed ex-situ and post-deposition, they are unable to provide real-time design of experiments, a capability that is required for rapid synthesis of a specific composition library. By using three quartz crystal monitors attached to a stage with translational and rotational degrees of freedom, we measure three-dimensional deposition profiles of deposition sources whose tilt with respect to the substrate is robotically controlled. We exhibit the utility of deposition profiles and tilt control to optimize the deposition geometry for specific combinatorial synthesis experiments.

  7. Optimized chemical vapor deposition of borophosphosilicate glass films

    NASA Astrophysics Data System (ADS)

    Kern, W.; Kurylo, W. A.; Tino, C. J.

    1985-06-01

    The optimization of atmospheric-pressure chemical vapor deposition (APCVD) of borophosphosilicate glass (BPSG) to produce glass films with few particle containments is discussed. The tests that were conducted in order to determine the optimum deposition temperature and proper oxygen/hydride ratio are explained. A decrease in deposition temperature and an increase in the oxygen/hydride ratio maximized the APCVD reaction. The techniques used to analyze the composition of BPSG after densification are described; the tests revealed that the elemental composition of BPSG was not altered by APCVD. An explanation of the film profiling technique used to determine the stability of BPSG films during processing is provided; BPSG films remain stable if they are densified or fused prior to the application of wet treatments. A comparison of conventional tube-furnace heating with rapid isothermal heating for fusion flow of BPSG is presented; fusion tapering by rapid heating was attained in 30 seconds at 175 C versus 30 minutes for tube heating.

  8. Molecular layer deposition of alucone films using trimethylaluminum and hydroquinone

    SciTech Connect

    Choudhury, Devika; Sarkar, Shaibal K.; Mahuli, Neha

    2015-01-01

    A hybrid organic–inorganic polymer film grown by molecular layer deposition (MLD) is demonstrated here. Sequential exposures of trimethylaluminum [Al(CH{sub 3}){sub 3}] and hydroquinone [C{sub 6}H{sub 4}(OH){sub 2}] are used to deposit the polymeric films, which is a representative of a class of aluminum oxide polymers known as “alucones.” In-situ quartz crystal microbalance (QCM) studies are employed to determine the growth characteristics. An average growth rate of 4.1 Å per cycle at 150 °C is obtained by QCM and subsequently verified with x-ray reflectivity measurements. Surface chemistry during each MLD-half cycle is studied in depth by in-situ Fourier transform infrared (FTIR) vibration spectroscopy. Self limiting nature of the reaction is confirmed from both QCM and FTIR measurements. The conformal nature of the deposit, typical for atomic layer deposition and MLD, is verified with transmission electron microscopy imaging. Secondary ion mass spectroscopy measurements confirm the uniform elemental distribution along the depth of the films.

  9. Poly-para-xylylene thin films: A study of the deposition chemistry, kinetics, film properties, and film stability

    NASA Astrophysics Data System (ADS)

    Fortin, Jeffrey Bernard

    Poly-para-xylylene, or parylene, thin films are chemically vapor deposited (CVD), conformal, pin-hole free polymeric thin films. They have found many industrial uses since there invention in 1947 and continue to find new applications in micro-electronics, biotechnology, and micro-electro-mechanical systems. In this study the deposition chemistry, deposition kinetics, film properties, and film stability were investigated. A differentially pumped quadrupole mass spectrometer was used to analyze the vapor species present during the CVD process. The identity of dimer contamination and its impact on the CVD process and film properties was studied. The quantitative conversion of dimer to monomer was investigated and it was found that conversion begins at around 385°C and by 565°C 100% conversion is obtained. The kinetics of the CVD process was analyzed for a range of substrate temperatures and chamber pressures. A new kinetic model based on a two-step adsorption was developed and fit the kinetic data well. This model should be appropriate for use with all parylene family polymers. Many of the properties of the films deposited in this study were analyzed. This includes a detailed study of surface morphology using atomic force microscopy which shows the interface width increases as a power law of film thickness. Other properties analyzed were the thermal stability, electrical properties, index of refraction, birefringence, hardness, and elastic modulus. The effect of ultraviolet (UV) radiation of lambda ≥ 250 nm on the thermal stability, electrical, and optical properties of thin parylene films was studied. The thermal stability and electrical properties of UV treated films were seen to deteriorate as the radiation dose increased. The stability of parylene thin films receiving plasma etching was analyzed. The dielectric constant, dissipation factor, and leakage current of plasma etched thin parylene films were investigated and found to be stable for the range of

  10. Novel doped hydroxyapatite thin films obtained by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Duta, L.; Oktar, F. N.; Stan, G. E.; Popescu-Pelin, G.; Serban, N.; Luculescu, C.; Mihailescu, I. N.

    2013-01-01

    We report on the synthesis of novel ovine and bovine derived hydroxyapatite thin films on titanium substrates by pulsed laser deposition for a new generation of implants. The calcination treatment applied to produce the hydroxyapatite powders from ovine/bovine bones was intended to induce crystallization and to prohibit the transmission of diseases. The deposited films were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy. Pull-off adherence and profilometry measurements were also carried out. X-ray diffraction ascertained the polycrystalline hydroxyapatite nature of the powders and films. Fourier transform infrared spectroscopy evidenced the vibrational bands characteristic to a hydroxyapatite material slightly carbonated. The micrographs of the films showed a uniform distribution of spheroidal particulates with a mean diameter of ∼2 μm. Pull-off measurements demonstrated excellent bonding strength values between the hydroxyapatite films and the titanium substrates. Because of their physical-chemical properties and low cost fabrication from renewable resources, we think that these new coating materials could be considered as a prospective competitor to synthetic hydroxyapatite used for implantology applications.

  11. [Effect of Helium on Diamond Films Deposited Using Microwave PCVD].

    PubMed

    Cao, Wei; Ma, Zhi-bin; Tao, Li-ping; Gao, Pan; Li, Yi-cheng; Fu, Qiu-ming

    2015-03-01

    Optical emission spectroscopy (OES) was used to in situ diagnose the CH4-H2-He plasma in order to know the effect of helium on the diamond growth by microwave plasma chemical vapor deposition (MPCVD). The spatial distribution of radicals in the plasma as a function of helium addition was studied. The diamond films deposited in different helium volume fraction were investigated using scanning electron microscope (SEM) and Raman spectroscopy. The results show that the spectra intensity of radicals of H(α), H(β), H(γ), CH and C2 increases with the increasing of helium volume fraction, especially, that of radical H(α) has the most improvement. The spectrum space diagnosis results show that the uniformity of C2, CH radicals in the plasma tends to poor due to the helium addition and resulted in a different thickness along the radial direction The measurement of deposition rate shows that the addition of helium is useful for the improvement of the growth rate of diamond films, due to relative concentration of carbon radicals was increased. The deposition rate increases by 24% when the volume fraction of He was increased from 0 vol. % to 4.7 vol.%. The micrographs of SEM reveal that with the increasing of helium volume fraction, the diamond films' crystallite orientation changes from (111) to disorder and a twins growth becomes obvious. The secondary nucleation density during growth increases because the high relatively concentration of C2 radicals under higher helium volume fraction (4.7 vol. %). In addition, the substrate was etched and sputtered by the plasma, which introduced metallic atoms into the plasma during the deposition of diamond films. Eventually, the existing of secondary nucleation and impurity atoms lead to the appearance of twins and results in the compressive dress.

  12. [Effect of Helium on Diamond Films Deposited Using Microwave PCVD].

    PubMed

    Cao, Wei; Ma, Zhi-bin; Tao, Li-ping; Gao, Pan; Li, Yi-cheng; Fu, Qiu-ming

    2015-03-01

    Optical emission spectroscopy (OES) was used to in situ diagnose the CH4-H2-He plasma in order to know the effect of helium on the diamond growth by microwave plasma chemical vapor deposition (MPCVD). The spatial distribution of radicals in the plasma as a function of helium addition was studied. The diamond films deposited in different helium volume fraction were investigated using scanning electron microscope (SEM) and Raman spectroscopy. The results show that the spectra intensity of radicals of H(α), H(β), H(γ), CH and C2 increases with the increasing of helium volume fraction, especially, that of radical H(α) has the most improvement. The spectrum space diagnosis results show that the uniformity of C2, CH radicals in the plasma tends to poor due to the helium addition and resulted in a different thickness along the radial direction The measurement of deposition rate shows that the addition of helium is useful for the improvement of the growth rate of diamond films, due to relative concentration of carbon radicals was increased. The deposition rate increases by 24% when the volume fraction of He was increased from 0 vol. % to 4.7 vol.%. The micrographs of SEM reveal that with the increasing of helium volume fraction, the diamond films' crystallite orientation changes from (111) to disorder and a twins growth becomes obvious. The secondary nucleation density during growth increases because the high relatively concentration of C2 radicals under higher helium volume fraction (4.7 vol. %). In addition, the substrate was etched and sputtered by the plasma, which introduced metallic atoms into the plasma during the deposition of diamond films. Eventually, the existing of secondary nucleation and impurity atoms lead to the appearance of twins and results in the compressive dress. PMID:26117884

  13. RBS study of amorphous silicon carbide films deposited by PECVD

    NASA Astrophysics Data System (ADS)

    Huran, J.; Hotovy, I.; Kobzev, A. P.; Balalykin, N. I.

    2004-03-01

    We present properties of nitrogen-doped amorphous silicon carbide films that were grown by a plasma enhanced chemical vapour deposition (PECVD) technique and annealed by pulsed electron beam. Samples with different amounts of N were achieved by a small addition of ammonia NH3 into the gas mixture of silane SiH4 and methane CH4, which were directly introduced into the reaction chamber. The actual amount of nitrogen in the SiC films was determined by Rutherford backscattering spectrometry (RBS). A simulation of the RBS spectra was used to calculate the concentration of carbon, silicon and nitrogen.

  14. Fluorocarbon Adsorption in Hierarchical Porous Frameworks

    SciTech Connect

    Motkuri, Radha K.; Annapureddy, Harsha V.; Vijayakumar, M.; Schaef, Herbert T.; Martin, P F.; McGrail, B. Peter; Dang, Liem X.; Krishna, Rajamani; Thallapally, Praveen K.

    2014-07-09

    The adsorption behavior of a series of fluorocarbon derivatives was examined on a set of microporous metal organic framework (MOF) sorbents and another set of hierarchical mesoporous MOFs. The microporous M-DOBDC (M = Ni, Co) showed a saturation uptake capacity for R12 of over 4 mmol/g at a very low relative saturation pressure (P/Po) of 0.02. In contrast, the mesoporous MOF MIL-101 showed an exceptionally high uptake capacity reaching over 14 mmol/g at P/Po of 0.4. Adsorption affinity in terms of mass loading and isosteric heats of adsorption were found to generally correlate with the polarizability of the refrigerant with R12 > R22 > R13 > R14 > methane. These results suggest the possibility of exploiting MOFs for separation of azeotropic mixtures of fluorocarbons and use in eco-friendly fluorocarbon-based adsorption cooling and refrigeration applications.

  15. Femtosecond pulsed laser deposition of amorphous, ultrahard boride thin films

    NASA Astrophysics Data System (ADS)

    Stock, Michael; Molian, Pal

    2004-05-01

    Amorphous thin films (300-500 nm) of ultrahard AlMgB10 with oxygen and carbon impurities were grown on Si (100) substrates at 300 K using a solid target of AlMgB14 containing a spinel phase (MgAl2O4) and using a 120 fs pulsed, 800 nm wavelength Ti:sapphire laser. The films were subsequently annealed in argon gas up to 1373 K for 2 h. Scanning electron microscopy (SEM) was used to examine the particulate formation, atomic force microscopy was employed to characterize the film surface topography, x-ray diffraction and transmission electron microscopy were used to determine the microstructure, x-ray photoelectron spectroscopy was performed to examine the film composition, and nanoindentation was employed to study the hardness of thin films. The as-deposited and postannealed films (up to 1273 K) had a stochiometry of AlMgB10 with a significant amount of oxygen and carbon impurities and exhibited amorphous structures for a maximum hardness of 40+/-3 GPa. However, postannealing at higher temperatures led to crystallization and transformation of the film to SiB6 with a substantial loss in hardness. Results are also compared with our previous study on 23 ns, 248 nm wavelength (KrF excimer) pulsed laser deposition of AlMgB14 reported in this journal [Y. Tian, A. Constant, C. C. H. Lo, J. W. Anderegg, A. M. Russell, J. E. Snyder, and P. A. Molian, J. Vac. Sci. Technol. A 21, 1055 (2003)]. .

  16. Thin films of barium fluoride scintillator deposited by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Kirlin, P. S.; Binder, R.; Winn, D. R.; O'Hare, J.; LaPierre, C.; Whitmore, M.

    1990-04-01

    We have used metal-organic chemical vapor deposition (MOCVD) technology to coat optical substrates with thin (˜1-10 μm thick) films of inorganic BaF 2 scintillator. Scanning electron microscope (SEM) photographs indicate that high-quality epitaxial crystalline film growth was achieved, with surface defects typically smaller than optical wavelengths. The scintillation light created by the deposition of ionizing radiation in the scintillating films was measured with a photomultiplier and shown to be similar to bulk melt-grown crystals. The results demonstrate the potential of these composite optical materials for planar and fiber scintillation radiation detectors in high energy and nuclear physics, synchrotron radiation research, and in radiation and X-ray imaging and monitoring.

  17. Effects of Ar plasma treatment for deposition of ruthenium film by remote plasma atomic layer deposition

    SciTech Connect

    Park, Taeyong; Lee, Jaesang; Park, Jingyu; Jeon, Heeyoung; Jeon, Hyeongtag; Lee, Ki-Hoon; Cho, Byung-Chul; Kim, Moo-Sung; Ahn, Heui-Bok

    2012-01-15

    Ruthenium thin films were deposited on argon plasma-treated SiO{sub 2} and untreated SiO{sub 2} substrates by remote plasma atomic layer deposition using bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp){sub 2}] as a Ru precursor and ammonia plasma as a reactant. The results of in situ Auger electron spectroscopy (AES) analysis indicate that the initial transient region of Ru deposition was decreased by Ar plasma treatment at 400 deg. C, but did not change significantly at 300 deg. C The deposition rate exhibited linearity after continuous film formation and the deposition rates were about 1.7 A/cycle and 0.4 A/cycle at 400 deg. C and 300 deg. C, respectively. Changes of surface energy and polar and dispersive components were measured by the sessile drop test. The quantity of surface amine groups was measured from the surface nitrogen concentration with AES. Furthermore, the Ar plasma-treated SiO{sub 2} contained more amine groups and less hydroxyl groups on the surface than on untreated SiO{sub 2}. Auger spectra exhibited chemical shifts by Ru-O bonding, and larger shifts were observed on untreated substrates due to the strong adhesion of Ru films.

  18. Deposition of nanocrystalline SiC films using helicon wave plasma enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Lu, Wanbing; Yu, Wei; Ma, Luo; Wu, Liping; Fu, Guangsheng

    2008-11-01

    Hydrogenated nanocrystalline SiC films have been deposited by using helicon wave plasma enhanced chemical vapor deposition (HW-PECVD) in H2, SiH4 and CH4 gas mixtures at different RF powers. Their structural and optical properties have been investigated by Fourier transform infrared absorption (FTIR), atomic force microscopy (AFM) and ultraviolet-visible (UV-VIS) transmission spectra. The results indicate that RF power has an important influence on properties of the deposited films. It is found that in a 300 °C low substrate temperature, only amorphous SiC can be deposited at the radio frequency (RF) power of lower than 400 W, while nanocrystalline SiC can be grown at the RF power of equal to or higher than 400 W. The analyses show that the high plasma density of helicon wave plasma source and the high hydrogen dilution condition are two key factors for depositing nanocrystalline SiC films at a low temperature.

  19. Atomic layer deposition of sodium and potassium oxides: evaluation of precursors and deposition of thin films.

    PubMed

    Østreng, E; Sønsteby, H H; Øien, S; Nilsen, O; Fjellvåg, H

    2014-11-28

    Thin films of sodium and potassium oxides have for the first time been deposited using atomic layer deposition. Sodium and potassium complexes of tert-butanol, trimethylsilanol and hexamethyldisilazide have been evaluated as precursors by characterising their thermal properties as well as tested in applications for thin film depositions. Out of these, sodium and potassium tert-butoxide and sodium trimethylsilanolate and hexamethyldisilazide were further tested as precursors together with the Al(CH3)3 + H2O/O3 process to form aluminates and together with ozone to form silicates. Sodium and potassium tert-butoxide and sodium trimethylsilanolate showed self-limiting growth and proved useable at deposition temperatures from 225 to 375 or 300 °C, respectively. The crystal structures of NaO(t)Bu and KO(t)Bu were determined by single crystal diffraction revealing hexamer- and tetramer structures, respectively. The current work demonstrates the suitability of the ALD technique to deposit thin films containing alkaline elements even at 8'' wafer scale.

  20. Optical Characterization Of Chemically Deposited Nanostructured CdS Films

    NASA Astrophysics Data System (ADS)

    Goswami, Y. C.; Kansal, Archana

    2009-06-01

    Newly modified hot chemical deposition method was used to grow Cadmium sulfide films. Substrates were kept at relatively higher temperature than the bath using local heating. The bath was consisting of aqueous solutions of Cadmium chloride, Thiourea and complexed by TEA. The Ph of the bath was maintained around 8-10 by adding ammonia solution. The soda lime glass slides were used as substrates. Good thick films were obtained few minutes. Air annealing was used to study the effect of heat treatment on quality of the films. All films were analyzed using optical spectrophotometer. The step like nature in transmission spectra and band gap curves could be due to discrete energy levels, which exist in nanomaterials. Blue shift is observed in samples. Band gap shift from higher value to lower value suggest that films are either of thickness of few nanometer range and/or grain size is of the nanometer range. This paper includes details about new modified dipping technique and optical, structural studies of these films.

  1. Apparatus and process for deposition of hard carbon films

    DOEpatents

    Nyaiesh, Ali R.; Garwin, Edward L.

    1989-01-03

    A process and an apparatus for depositing thin, amorphous carbon films having extreme hardness on a substrate is described. An enclosed chamber maintained at less than atmospheric pressure houses the substrate and plasma producing elements. A first electrode is comprised of a cavity enclosed within an RF coil which excites the plasma. A substrate located on a second electrode is excited by radio frequency power applied to the substrate. A magnetic field confines the plasma produced by the first electrode to the area away from the walls of the chamber and focuses the plasma onto the substrate thereby yielding film deposits having higher purity and having more rapid buildup than other methods of the prior art.

  2. Pulsed laser deposition and characterization of cellulase thin films

    NASA Astrophysics Data System (ADS)

    Cicco, N.; Morone, A.; Verrastro, M.; Viggiano, V.

    2013-08-01

    Thin films of cellulase were obtained by pulsed laser deposition (PLD) on an appropriate substrate. Glycoside hydrolase cellulase has received our attention because it emerges among the antifouling enzymes (enzymes being able to remove and prevent the formation of micro-organism biofilms) used in industry and medicine field. Pressed cellulase pellets, used as target material, were ablated with pulses of a Nd-YAG laser working at wavelength of 532 nm. In this work, we evaluated the impact of PLD technique both on molecular structure and hydrolytic activity of cellulase. Characteristic chemical bonds and morphology of deposited layers were investigated by FTIR spectroscopy and SEM respectively. The hydrolytic activity of cellulase thin films was detected by a colorimetric assay.

  3. Apparatus and process for deposition of hard carbon films

    DOEpatents

    Nyaiesh, Ali R.; Garwin, Edward L.

    1989-01-01

    A process and an apparatus for depositing thin, amorphous carbon films having extreme hardness on a substrate is described. An enclosed chamber maintained at less than atmospheric pressure houses the substrate and plasma producing elements. A first electrode is comprised of a cavity enclosed within an RF coil which excites the plasma. A substrate located on a second electrode is excited by radio frequency power applied to the substrate. A magnetic field confines the plasma produced by the first electrode to the area away from the walls of the chamber and focuses the plasma onto the substrate thereby yielding film deposits having higher purity and having more rapid buildup than other methods of the prior art.

  4. Drop size stability assessment of fluorocarbon emulsions.

    PubMed

    Krafft, M P; Postel, M; Riess, J G; Ni, Y; Pelura, T J; Hanna, G K; Song, D

    1992-01-01

    The aging of fluorocarbon emulsions prepared with natural egg yolk phospholipids (EYP) has been studied and a linear variation (r2 greater than 0.95) of the mean average volume of the droplets with time has been observed. The slope of the experimental lines, called "Stability Parameter, S" can thus be taken as a representation of the rate of aging of the emulsions. Examples are given of use of parameter S to assess the effect of formulation and processing parameters on the stability of diverse fluorocarbon emulsions. S is a useful tool to compare emulsions and ascertain any factors of stabilization/destabilization. PMID:1391525

  5. Influence of POST Annealing on Sol-Gel Deposited ZnO Thin Films

    NASA Astrophysics Data System (ADS)

    Bhadane, Hemalata; Samuel, Edmund; Gautam, Dinesh Kumar

    2014-05-01

    The effect of annealing temperature on sol-gel deposited ZnO thin films have been studied. The average crystallite size determined from XRD shows that the deposited films are nanocrystalline. FTIR confirms deposition of ZnO thin films. The transmittance of annealed ZnO thin films is greater than 80% in visible region with bandgap ranging from 3.25-3.19 eV. The films annealed at 450°C temperature shows lower resistivity value of 527.241 Ωm. The deposited nanocrystalline films are suitable for biosensing applications due to its higher surface area.

  6. Effect of two hydrocarbon and one fluorocarbon surfactant mixtures on the surface tension and wettability of polymers.

    PubMed

    Szymczyk, Katarzyna; González-Martín, Maria Luisa; Bruque, Jose Morales; Jańczuk, Bronisław

    2014-03-01

    The advancing contact angle of water, formamide and diiodomethane on polytetrafluoroethylene (PTFE) and polymethyl methacrylate (PMMA) surfaces covered with the film of ternary mixtures of surfactants including p-(1,1,3,3-tetramethylbutyl) phenoxypoly(ethyleneglycols), Triton X-100 (TX100) and Triton X-165 (TX165) and the fluorocarbon surfactants, Zonyl FSN-100 (FSN100) or Zonyl FSO-100 (FSO100) was measured. The obtained results were used for the surface tension of PTFE and PMMA covered with this film determination from the Young equation on the basis of van Oss et al. and Neumann et al. approaches to the interfacial tension. The surface tension of PTFE and PMMA was also determined using the Neumann et al. equation and the contact angle values for the aqueous solutions of the above mentioned ternary surfactants mixtures which were taken from the literature. As follows from our calculations mainly the presence of the fluorocarbon surfactant in the mixture considerably changes the surface properties of PTFE and PMMA causing that in contrast to hydrocarbon surfactants and their mixtures there is no linear dependence between adhesion and surface tension in the whole range of concentration of the ternary mixtures of surfactants including the fluorocarbon one. The behavior of fluorocarbon surfactants at the polymer-air and polymer-water interfaces is quite different from those of hydrocarbons. In the case of fluorocarbon surfactants not only adsorption but also sorption can occur on the polymer surface.

  7. Electrochemical deposition of conductive and adhesive polypyrrole-dopamine films.

    PubMed

    Kim, Semin; Jang, Lindy K; Park, Hyun S; Lee, Jae Young

    2016-01-01

    Electrode surfaces have been widely modified with electrically conductive polymers, including polypyrrole (PPY), to improve the performance of electrodes. To utilize conductive polymers for electrode modification, strong adhesion between the polymer films and electrode substrates should be ensured with high electrical/electrochemical activities. In this study, PPY films were electrochemically polymerized on electrodes (e.g., indium tin oxide (ITO)) with dopamine as a bio-inspired adhesive molecule. Efficient and fast PPY electrodeposition with dopamine (PDA/PPY) was found; the resultant PDA/PPY films exhibited greatly increased adhesion strengths of up to 3.7 ± 0.8 MPa and the modified electrodes had electrochemical impedances two to three orders of magnitude lower than that of an unmodified electrode. This electrochemical deposition of adhesive and conductive PDA/PPY offers a facile and versatile electrode modification for various applications, such as biosensors and batteries.

  8. Electrochemical deposition of highly-conducting metal dithiolene films.

    PubMed

    Allwright, Emily; Silber, Georg; Crain, Jason; Matsushita, Michio M; Awaga, Kunio; Robertson, Neil

    2016-05-31

    Electrochemical deposition has been used to prepare a thin film of neutral 4',4-(3-alkyl)-thiophene-5',5-hydogen-nickel and copper dithiolenes (Ni-C2, Cu-C2). The application of molecular electrodeposition provides a means to solution process molecular semiconductors of poor solubility, which results from the strong intermolecular interaction required for charge transport. Both Ni-C2 and Cu-C2 form continuous thin films that show intense NIR absorptions, extending to 1800 nm and 2000 nm respectively giving evidence for the strong intermolecular interactions in the solid state. Both films are highly conducting and temperature dependence of resistance gave an activation energy of 0.42 eV and 0.072 eV respectively, with the near-metallic behaviour of Cu-C2 attributed to the additional presence of an unpaired electron. PMID:27184422

  9. Electrochemical deposition of conductive and adhesive polypyrrole-dopamine films

    PubMed Central

    Kim, Semin; Jang, Lindy K.; Park, Hyun S.; Lee, Jae Young

    2016-01-01

    Electrode surfaces have been widely modified with electrically conductive polymers, including polypyrrole (PPY), to improve the performance of electrodes. To utilize conductive polymers for electrode modification, strong adhesion between the polymer films and electrode substrates should be ensured with high electrical/electrochemical activities. In this study, PPY films were electrochemically polymerized on electrodes (e.g., indium tin oxide (ITO)) with dopamine as a bio-inspired adhesive molecule. Efficient and fast PPY electrodeposition with dopamine (PDA/PPY) was found; the resultant PDA/PPY films exhibited greatly increased adhesion strengths of up to 3.7 ± 0.8 MPa and the modified electrodes had electrochemical impedances two to three orders of magnitude lower than that of an unmodified electrode. This electrochemical deposition of adhesive and conductive PDA/PPY offers a facile and versatile electrode modification for various applications, such as biosensors and batteries. PMID:27459901

  10. Superhydrophobicity of polytetrafluoroethylene thin film fabricated by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Kwong, H. Y.; Wong, M. H.; Wong, Y. W.; Wong, K. H.

    2007-09-01

    Superhydrophobic polytetrafluoroethylene (PTFE) thin films were obtained by pulsed laser deposition (PLD) technique carried out with KrF excimer laser ( λ = 248 nm) of about 1 J/cm 2 at a pressure of 1.33 Pa. The samples exhibit high water contact angle of about 170° and the sliding angle smaller than 2°. From studying the surface morphology of the prepared films, it is believed that the nano-scale surface roughness has enhanced the hydrophobic property of the PTFE. The increase of trapping air and reducing liquid-solid contact area due to the rough surface, as suggested by the Cassie-Baxter's model, should be responsible for superhydrophobicity of the PLD prepared films. This study thus provides a convenient one-step method without using wet-process to produce a superhydrophobic surface with good self-cleaning properties.

  11. Low Temperature Chemical Vapor Deposition Of Thin Film Magnets

    DOEpatents

    Miller, Joel S.; Pokhodnya, Kostyantyn I.

    2003-12-09

    A thin-film magnet formed from a gas-phase reaction of tetracyanoetheylene (TCNE) OR (TCNQ), 7,7,8,8-tetracyano-P-quinodimethane, and a vanadium-containing compound such as vanadium hexcarbonyl (V(CO).sub.6) and bis(benzene)vanalium (V(C.sub.6 H.sub.6).sub.2) and a process of forming a magnetic thin film upon at least one substrate by chemical vapor deposition (CVD) at a process temperature not exceeding approximately 90.degree. C. and in the absence of a solvent. The magnetic thin film is particularly suitable for being disposed upon rigid or flexible substrates at temperatures in the range of 40.degree. C. and 70.degree. C. The present invention exhibits air-stable characteristics and qualities and is particularly suitable for providing being disposed upon a wide variety of substrates.

  12. Electrochemical deposition of conductive and adhesive polypyrrole-dopamine films.

    PubMed

    Kim, Semin; Jang, Lindy K; Park, Hyun S; Lee, Jae Young

    2016-01-01

    Electrode surfaces have been widely modified with electrically conductive polymers, including polypyrrole (PPY), to improve the performance of electrodes. To utilize conductive polymers for electrode modification, strong adhesion between the polymer films and electrode substrates should be ensured with high electrical/electrochemical activities. In this study, PPY films were electrochemically polymerized on electrodes (e.g., indium tin oxide (ITO)) with dopamine as a bio-inspired adhesive molecule. Efficient and fast PPY electrodeposition with dopamine (PDA/PPY) was found; the resultant PDA/PPY films exhibited greatly increased adhesion strengths of up to 3.7 ± 0.8 MPa and the modified electrodes had electrochemical impedances two to three orders of magnitude lower than that of an unmodified electrode. This electrochemical deposition of adhesive and conductive PDA/PPY offers a facile and versatile electrode modification for various applications, such as biosensors and batteries. PMID:27459901

  13. Electrochemical deposition of conductive and adhesive polypyrrole-dopamine films

    NASA Astrophysics Data System (ADS)

    Kim, Semin; Jang, Lindy K.; Park, Hyun S.; Lee, Jae Young

    2016-07-01

    Electrode surfaces have been widely modified with electrically conductive polymers, including polypyrrole (PPY), to improve the performance of electrodes. To utilize conductive polymers for electrode modification, strong adhesion between the polymer films and electrode substrates should be ensured with high electrical/electrochemical activities. In this study, PPY films were electrochemically polymerized on electrodes (e.g., indium tin oxide (ITO)) with dopamine as a bio-inspired adhesive molecule. Efficient and fast PPY electrodeposition with dopamine (PDA/PPY) was found; the resultant PDA/PPY films exhibited greatly increased adhesion strengths of up to 3.7 ± 0.8 MPa and the modified electrodes had electrochemical impedances two to three orders of magnitude lower than that of an unmodified electrode. This electrochemical deposition of adhesive and conductive PDA/PPY offers a facile and versatile electrode modification for various applications, such as biosensors and batteries.

  14. Properties of zirconia thin films deposited by laser ablation

    SciTech Connect

    Cancea, V. N.; Filipescu, M.; Colceag, D.; Dinescu, M.; Mustaciosu, C.

    2013-11-13

    Zirconia thin films have been deposited by laser ablation of a ceramic ZrO{sub 2} target in vacuum or in oxygen background at 0.01 mbar. The laser beam generated by an ArF laser (λ=193 nm, ν=40 Hz) has been focalized on the target through a spherical lens at an incident angle of 45°. The laser fluence has been established to a value from 2.0 to 3.4 Jcm{sup −2}. A silicon (100) substrate has been placed parallel to the target, at a distance of 4 cm, and subsequently has been heated to temperatures ranging between 300 °C and 600 °C. Thin films morphology has been characterized by atomic force microscopy and secondary ion mass spectrometry. Biocompatibility of these thin films has been assessed by studying the cell attachment of L929 mouse fibroblasts.

  15. Electrochemical deposition of highly-conducting metal dithiolene films.

    PubMed

    Allwright, Emily; Silber, Georg; Crain, Jason; Matsushita, Michio M; Awaga, Kunio; Robertson, Neil

    2016-05-31

    Electrochemical deposition has been used to prepare a thin film of neutral 4',4-(3-alkyl)-thiophene-5',5-hydogen-nickel and copper dithiolenes (Ni-C2, Cu-C2). The application of molecular electrodeposition provides a means to solution process molecular semiconductors of poor solubility, which results from the strong intermolecular interaction required for charge transport. Both Ni-C2 and Cu-C2 form continuous thin films that show intense NIR absorptions, extending to 1800 nm and 2000 nm respectively giving evidence for the strong intermolecular interactions in the solid state. Both films are highly conducting and temperature dependence of resistance gave an activation energy of 0.42 eV and 0.072 eV respectively, with the near-metallic behaviour of Cu-C2 attributed to the additional presence of an unpaired electron.

  16. Supercritical fluid molecular spray film deposition and powder formation

    DOEpatents

    Smith, Richard D.

    1986-01-01

    Solid films are deposited, or fine powders formed, by dissolving a solid material into a supercritical fluid solution at an elevated pressure and then rapidly expanding the solution through a short orifice into a region of relatively low pressure. This produces a molecular spray which is directed against a substrate to deposit a solid thin film thereon, or discharged into a collection chamber to collect a fine powder. Upon expansion and supersonic interaction with background gases in the low pressure region, any clusters of solvent are broken up and the solvent is vaporized and pumped away. Solute concentration in the solution is varied primarily by varying solution pressure to determine, together with flow rate, the rate of deposition and to control in part whether a film or powder is produced and the granularity of each. Solvent clustering and solute nucleation are controlled by manipulating the rate of expansion of the solution and the pressure of the lower pressure region. Solution and low pressure region temperatures are also controlled.

  17. Pulsed laser deposition of nanostructured indium-tin-oxide film

    NASA Astrophysics Data System (ADS)

    Yong, Thian Kok; Nee, Chen Hon; Yap, Seong Shan; Siew, Wee Ong; Sáfran, György; Yap, Yoke Kin; Tou, Teck Yong

    2010-08-01

    Effects of O2, N2, Ar and He on the formation of micro- and nanostructured indium tin oxide (ITO) thin films were investigated in pulsed Nd:YAG laser deposition on glass substrate. For O2 and Ar, ITO resistivity of <= 4 × 10-4 Ωcm and optical transmittance of > 90% were obtained with substrate temperature of 250 °C. For N2 and He, low ITO resisitivity could be obtained but with poor optical transmittance. SEM images show nano-structured ITO thin films for all gases, where dense, larger and highly oriented, microcrystalline structures were obtained for deposition in O2 and He, as revealed from the XRD lines. EDX results indicated the inclusion of Ar and N2 at the expense of reduced tin (Sn) content. When the ITO films were applied for fabrication of organic light emitting devices (OLED), only those deposited in Ar and O2 produced comparable performance to single-layer OLED fabricated on the commercial ITO.

  18. Atomic layer deposition of superparamagnetic and ferrimagnetic magnetite thin films

    SciTech Connect

    Zhang, Yijun; Liu, Ming E-mail: wren@mail.xjtu.edu.cn Ren, Wei E-mail: wren@mail.xjtu.edu.cn; Zhang, Yuepeng; Chen, Xing; Ye, Zuo-Guang E-mail: wren@mail.xjtu.edu.cn

    2015-05-07

    One of the key challenges in realizing superparamagnetism in magnetic thin films lies in finding a low-energy growth way to create sufficiently small grains and magnetic domains which allow the magnetization to randomly and rapidly reverse. In this work, well-defined superparamagnetic and ferrimagnetic Fe{sub 3}O{sub 4} thin films are successfully prepared using atomic layer deposition technique by finely controlling the growth condition and post-annealing process. As-grown Fe{sub 3}O{sub 4} thin films exhibit a conformal surface and poly-crystalline nature with an average grain size of 7 nm, resulting in a superparamagnetic behavior with a blocking temperature of 210 K. After post-annealing in H{sub 2}/Ar at 400 °C, the as-grown α−Fe{sub 2}O{sub 3} sample is reduced to Fe{sub 3}O{sub 4} phase, exhibiting a ferrimagnetic ordering and distinct magnetic shape anisotropy. Atomic layer deposition of magnetite thin films with well-controlled morphology and magnetic properties provides great opportunities for integrating with other order parameters to realize magnetic nano-devices with potential applications in spintronics, electronics, and bio-applications.

  19. Structural and electrical properties of electric field assisted spray deposited pea structured ZnO film

    NASA Astrophysics Data System (ADS)

    Chaturvedi, Neha; Swami, Sanjay Kumar; Dutta, Viresh

    2016-05-01

    Spray deposition of ZnO film was carried out. The uneven growth of ZnO nanostructures is resulted for spray deposited ZnO film. Application of DC voltage (1000V) during spray deposition provides formation of pea like structures with uniform coverage over the substrate. Electric field assisted spray deposition provides increased crystallinity with reduced resistivity and improved mobility of the ZnO film as compared to spray deposited ZnO film without electric field. This with large area deposition makes the process more efficient than other techniques.

  20. On the evolution of film roughness during magnetron sputtering deposition

    SciTech Connect

    Turkin, A. A.; Pei, Y. T.; Shaha, K. P.; Chen, C. Q.; Vainshtein, D. I.; De Hosson, J. Th. M.

    2010-11-15

    The effect of long-range screening on the surface morphology of thin films grown with pulsed-dc (p-dc) magnetron sputtering is studied. The surface evolution is described by a stochastic diffusion equation that includes the nonlocal shadowing effects in three spatial dimensions. The diffusional relaxation and the angular distribution of the incident particle flux strongly influence the transition to the shadowing growth regime. In the magnetron sputtering deposition the shadowing effect is essential because of the configuration of the magnetron system (finite size of sputtered targets, rotating sample holder, etc.). A realistic angular distribution of depositing particles is constructed by taking into account the cylindrical magnetron geometry. Simulation results are compared with the experimental data of surface roughness evolution during 100 and 350 kHz p-dc deposition, respectively.

  1. Plasma deposited diamond-like carbon films for large neutralarrays

    SciTech Connect

    Brown, I.G.; Blakely, E.A.; Bjornstad, K.A.; Galvin, J.E.; Monteiro, O.R.; Sangyuenyongpipat, S.

    2004-07-15

    To understand how large systems of neurons communicate, we need to develop methods for growing patterned networks of large numbers of neurons. We have found that diamond-like carbon thin films formed by energetic deposition from a filtered vacuum arc carbon plasma can serve as ''neuron friendly'' substrates for the growth of large neural arrays. Lithographic masks can be used to form patterns of diamond-like carbon, and regions of selective neuronal attachment can form patterned neural arrays. In the work described here, we used glass microscope slides as substrates on which diamond-like carbon was deposited. PC-12 rat neurons were then cultured on the treated substrates and cell growth monitored. Neuron growth showed excellent contrast, with prolific growth on the treated surfaces and very low growth on the untreated surfaces. Here we describe the vacuum arc plasma deposition technique employed, and summarize results demonstrating that the approach can be used to form large patterns of neurons.

  2. High growth rate homoepitaxial diamond film deposition at high temperatures by microwave plasma-assisted chemical vapor deposition

    NASA Technical Reports Server (NTRS)

    Vohra, Yogesh K. (Inventor); McCauley, Thomas S. (Inventor)

    1997-01-01

    The deposition of high quality diamond films at high linear growth rates and substrate temperatures for microwave-plasma chemical vapor deposition is disclosed. The linear growth rate achieved for this process is generally greater than 50 .mu.m/hr for high quality films, as compared to rates of less than 5 .mu.m/hr generally reported for MPCVD processes.

  3. Photonic crystal engineering in glancing angle deposition thin films

    NASA Astrophysics Data System (ADS)

    Jensen, Hans Martin Overgaard

    2005-11-01

    From living rooms to operating rooms, our world is becoming dependent on information technology. For half a century a transformation in computing and communications has been borne by semiconductor microelectronics, but to serve us tomorrow, new materials transcending the performance and cost of current technology must be developed. An emerging optical material is the photonic bandgap crystal, which so fundamentally manipulates the emission and propagation of light that photons may be harnessed to eclipse what electronics accomplish today. However, the crystals consist of intricate, sub micrometre structures that are complex to fabricate, and even harder to engineer for technological applications. Indeed, fabrication challenges have inhibited photonic crystal progress. This thesis responds by enabling photonic crystal engineering through a chiral thin film fabrication technique known as glancing angle deposition. By oblique vapour deposition onto rotating substrates, the approach creates tetragonal lattices of square spirals with widths of a few hundred nanometres, predicted to yield strong photonic bandgaps at useful optical wavelengths. Within the scope of the thesis research, high resolution, high density direct write lithography is developed to deliver large area crystal substrates with extensive design freedom. The evolution of square spiral photonic crystal thin films on such substrates is analyzed, and new deposition methods are devised to allow engineering of the photonic bandgap by reducing the dimensions and enhancing the fine structure of the square spirals. Optical characterization is performed to evaluate the presence of a complete, three dimensional photonic bandgap, confirm an engineered bandgap at 1.65 mum, and quantify the improvement in crystal quality to a bandgap width of 10.9%. With a potential for use as photonic waveguides, the engineering of embedded, functional air and dielectric defects is also established. Furthermore, the thesis develops

  4. Pulsed laser deposition and characterizations of pyrochlore iridate thin films

    NASA Astrophysics Data System (ADS)

    Starr, Matthew; Aviles-Acosta, Jaime; Xie, Yuantao; Zhu, Wenka; Li, Zhen; Chen, Aiping; Li, Nan; Tao, Chenggang; Jia, Quanxi; Heremans, J. J.; Zhang, S. X.

    Pyrochlore iridates have attracted growing interest in recent years because of their potential to realize novel topological phases. While most of the previous studies have focused on polycrystalline and single crystalline bulk samples, epitaxial thin films offer a unique platform for controllable tuning of material parameters such as oxygen stoichiometry and elastic strain to achieve new electronic states. In this talk, we will present the growth and characterizations of epitaxial thin films of pyrochlore Y2Ir2O7 and Bi2Ir2O7 that are predicted to host topologically non-trivial states. The iridate thin films were grown by pulsed laser deposition at different conditions, and a narrow window for epitaxial growth was determined. Characterizations of crystalline structures were performed using X-ray diffraction and transmission electron microscopy to establish a growth parameter-structure phase diagram. The compositions of thin films were determined by energy dispersive X-ray spectroscopy, and the surface morphologies were characterized using atomic force microscopy and scanning tunneling microscopy. Magneto-transport studies indicate a strong dependence of transport properties on the oxygen stoichiometry and the film thickness.

  5. Properties of pulsed laser deposited fluorinated hydroxyapatite films on titanium

    SciTech Connect

    Rau, J.V.; Smirnov, V.V.; Laureti, S.; Generosi, A.; Varvaro, G.; Fosca, M.; Ferro, D.; Cesaro, S. Nunziante; Albertini, V. Rossi; Barinov, S.M.

    2010-09-15

    Fluorinated hydroxyapatite coated titanium was investigated for application as implant coating for bone substitute materials in orthopaedics and dentistry. Pulsed laser deposition technique was used for films preparation. Fluorinated hydroxyapatite target composition, Ca{sub 10}(PO{sub 4}){sub 6}F{sub 1.37}(OH){sub 0.63}, was maintained at 2 J/cm{sup 2} of laser fluence and 500-600 {sup o}C of the substrate temperature. Prepared films had a compact microstructure, composed of spherical micrometric-size aggregates. The average surface roughness resulted to be of 3 nm for the film grown at 500 {sup o}C and of 10 nm for that grown at 600 {sup o}C, showing that the temperature increase did not favour the growth of a more fine granulated surface. The films were polycrystalline with no preferential growth orientation. The films grown at 500-600 {sup o}C were about 8 {mu}m thick and possessed a hardness of 12-13 GPa. Lower or higher substrate temperature provides the possibility to obtain coatings with different fine texture and roughness, thus tayloring them for various applications.

  6. Development of Thick-Film Thermoelectric Microcoolers Using Electrochemical Deposition

    NASA Technical Reports Server (NTRS)

    Fleurial, J.-P.; Borshchevsky, A.; Ryan, M. A.; Phillips, W. M.; Snyder, J. G.; Caillat, T.; Kolawa, E. A.; Herman, J. A.; Mueller, P.; Nicolet, M.

    2000-01-01

    Advanced thermoelectric microdevices integrated into thermal management packages and low power, electrical source systems are of interest for a variety of space and terrestrial applications. By shrinking the size of the thermoelements, or legs, of these devices, it becomes possible to handle much higher heat fluxes, as well as operate at much lower currents and higher voltages that are more compatible with electronic components. The miniaturization of state-of-the-art thermoelectric module technology based on Bi2Te3 alloys is limited due to mechanical and manufacturing constraints for both leg dimensions (100-200 gm thick minimum) and the number of legs (100-200 legs maximum). We are investigating the development of novel microdevices combining high thermal conductivity substrate materials such as diamond, thin film metallization and patterning technology, and electrochemical deposition of thick thermoelectric films. It is anticipated that thermoelectric microcoolers with thousands of thermocouples and capable of pumping more than 200 W/sq cm over a 30 to 60 K temperature difference can be fabricated. In this paper, we report on our progress in developing an electrochemical deposition process for obtaining 10-50 microns thick films of Bi2Te3 and its solid solutions. Results presented here indicate that good quality n-type Bi2Te3, n-type Bi2Te(2.95)Se(0.05) and p-type Bi(0.5)Sb(1.5)Te3 thick films can be deposited by this technique. Some details about the fabrication of the miniature thermoelements are also described.

  7. Y-Ba-Cu-O film deposition by metal organic chemical vapor deposition on buffered metal substrates.

    SciTech Connect

    Selvamanickam, V.; Galinski, G.; DeFrank, J.; Trautwein, C.; Haldar, P.; Balachandran, U.; Lanagan, M.; Chudzik, M.

    1999-10-12

    YBa{sub 2}Cu{sub 3}O{sub 2} (YBCO) films have been deposited on buffered metal substrates by Metal Organic Chemical Vapor Deposition (MOCVD). Cube-textured nickel substrates were fabricated by a thermomechanical process. Epitaxial CeO{sub 2}films were deposited on these substrates by thermal evaporation. Nickel alloy substrates with biaxially-textured Yttria-Stabilized Zirconia (YSZ) buffer layers deposited by Ion Beam Assisted Deposition were also prepared. Highly biaxially-textured YBCO films were deposited by MOCVD on both types of metal substrates. A critical current density greater than 10{sup 5} A/cm{sup 2} at 77 K has been achieved in YBCO films on metal substrates.

  8. Fluorocarbon nanodrops as acoustic temperature probes.

    PubMed

    Mountford, Paul A; Smith, William S; Borden, Mark A

    2015-10-01

    This work investigated the use of superheated fluorocarbon nanodrops for ultrasound thermal imaging and the use of mixed fluorocarbons for tuning thermal and acoustic thresholds for vaporization. Droplets were fabricated by condensing phospholipid-coated microbubbles containing C3F8 and C4F10 mixed at various molar ratios. Vaporization temperatures first were measured in a closed system by optical transmission following either isothermal pressure release or isobaric heating. The vaporization temperature was found to depend linearly on the percentage of C4F10 in the droplet core, indicating excellent tunability under these fluorocarbon-saturated conditions. Vaporization temperatures were then measured in an open system using contrast-enhanced ultrasound imaging, where it was found that the mixed droplets behaved like pure C4F10 drops. Additionally, the critical mechanical index for vaporization was measured at the limits of therapeutic hyperthermia (37 and 60 °C), and again the mixed droplets were found to behave like pure C4F10 drops. These results suggested that C3F8 preferentially dissolves out of the droplet core in open systems, as shown by a simple mass transfer model of multicomponent droplet dissolution. Finally, proof-of-concept was shown that pure C4F10 nanodrops can be used as an acoustic temperature probe. Overall, these results not only demonstrate the potential of superheated fluorocarbon emulsions for sonothermetry but also point to the limits of tunability for fluorocarbon mixtures owing to preferential release of the more soluble species to the atmosphere.

  9. Cation Engineering of Cu-ferrite Films Deposited by Alternating Target Laser Ablation Deposition

    SciTech Connect

    Yang,A.; Chen, Z.; Islam, S.; Vittoria, C.; Harris, V.

    2008-01-01

    Epitaxial copper ferrite thin films were deposited on MgO substrates by the alternating target laser ablation deposition method. A series of films was studied to explore the impact of oxygen operating pressure, substrate temperature, and the ratio of laser shots incident on each target upon the magnetic, structural, and atomic structural properties. The highest saturation magnetization, 2800?G, was achieved at a 90?mTorr oxygen pressure and at 650? C for the substrate temperature. This value is 65% higher than the room temperature magnetization for bulk equilibrium samples. The inversion parameter was measured by extended x-ray absorption fine structure analysis. The sample having the highest saturation magnetization had a corresponding inversion parameter (percentage of Cu ion octahedral site occupancy) of 51.5% compared with the bulk value of 85%.

  10. Formation and post-deposition compression of smooth and processable silicon thin films from nanoparticle suspensions

    NASA Astrophysics Data System (ADS)

    Jafferis, Noah T.; Sturm, James C.

    2012-03-01

    We report the formation of smooth and processable silicon thin-films from single-crystal silicon-nanoparticle suspensions. Single-crystal Si-nanoparticles (1-4 nm) are produced and suspended in various solvents. Films deposited from the suspension are mechanically stable and can be patterned and processed upon deposition. Physical compression of the films is presented as a mechanism to reduce porosity and global roughness. These thin-films, ˜100 nm thick and deposited from a single droplet, contain significant levels of hydrogen, carbon, and oxygen. Resistivities of the as-deposited films are ˜7.107 Ω.cm—comparable to intrinsic nanocrystalline-Si.

  11. (abstract) Optical Scattering and Surface Microroughness of Ion Beam Deposited Au and Pt Thin Films

    NASA Technical Reports Server (NTRS)

    Al-Jumaily, Ghanim A.; Raouf, Nasrat A.; Edlou, Samad M.; Simons, John C.

    1994-01-01

    Thin films of gold and platinum have been deposited onto superpolished fused silica substrates using thermal evaporation, ion assisted deposition (IAD), and ion assisted sputtering. The influence of ion beam flux, thin film material, and deposition rate on the films microroughness have been investigated. Short range surface microroughness of the films has been examined using scanning tunneling microscopy (STM) and atomic force microscopy (AFM). Long range surface microroughness has been characterized using an angle resolved optical scatterometer. Results indicate that ion beam deposited coatings have improved microstructure over thermally evaporated films.

  12. Microenergetic Shock Initiation Studies on Deposited Films of Petn

    NASA Astrophysics Data System (ADS)

    Tappan, Alexander S.; Wixom, Ryan R.; Trott, Wayne M.; Long, Gregory T.; Knepper, Robert; Brundage, Aaron L.; Jones, David A.

    2009-12-01

    Films of the high explosive PETN (pentaerythritol tetranitrate) up to 500-μm thick have been deposited through physical vapor deposition, with the intent of creating well-defined samples for shock-initiation studies. PETN films were characterized with microscopy, x-ray diffraction, and focused ion beam nanotomography. These high-density films were subjected to strong shocks in both the out-of-plane and in-plane orientations. Initiation behavior was monitored with high-speed framing and streak camera photography. Direct initiation with a donor explosive (either RDX with binder, or CL-20 with binder) was possible in both orientations, but with the addition of a thin aluminum buffer plate (in-plane configuration only), initiation proved to be difficult. Initiation was possible with an explosively-driven 0.13-mm thick Kapton flyer and direct observation of initiation behavior was examined using streak camera photography at different flyer velocities. Models of this configuration were created using the shock physics code CTH.

  13. Texture evolution in nanocrystalline iron films deposited using biased magnetron sputtering

    SciTech Connect

    Vetterick, G.; Taheri, M. L.; Baldwin, J. K.; Misra, A.

    2014-12-21

    Fe thin films were deposited on sodium chloride (NaCl) substrates using magnetron sputtering to investigate means of texture control in free standing metal films. The Fe thin films were studied using transmission electron microscopy equipped with automated crystallographic orientation microscopy. Using this technique, the microstructure of each film was characterized in order to elucidate the effects of altering deposition parameters. The natural tendency for Fe films grown on (100) NaCl is to form a randomly oriented nanocrystalline microstructure. By careful selection of substrate and deposition conditions, it is possible to drive the texture of the film toward a single (100) orientation while retaining the nanocrystalline microstructure.

  14. Structural, morphological, optical and photoluminescent properties of spray-deposited ZnSe thin film

    NASA Astrophysics Data System (ADS)

    Lohar, G. M.; Shinde, S. K.; Fulari, V. J.

    2014-11-01

    ZnSe thin films are successfully deposited by spray pyrolysis deposition technique. Deposited thin films are characterized by X-ray diffraction study, and it reveals that spray-deposited ZnSe thin films are polycrystalline with hexagonal crystal structure. Surface morphology is carried out by scanning electron microscopy. It shows cotton-like morphology, and optical properties, such as absorbance, transmittance, reflectance, band gap, refractive index, extinction coefficient are studied. Photoluminescence shows strong emission at 497 nm. Also, spray-deposited ZnSe thin films are hydrophilic in nature, which is shown by contact angle meter.

  15. Vacuum deposited polymer films: Past, present, and future applications

    SciTech Connect

    Affinito, J.; Martin, P.; Gross, M.; Bennett, W.

    1994-11-01

    Two extremely high rate processes have been developed for the vacuum deposition of polymer thin films. Dubbed the PML (for Polymer Multi-Layer) and LML (for Liquid Multi-Layer) processes, the PML technique was originally developed for the manufacture of polymer/aluminum surface mount capacitors while the LML method arose from a need to fabricate lithium polymer batteries. These processes have since been found to be compatible with most other vacuum deposition techniques in, integrated, in-line coating processes. Battelle has developed an extensive program, and a great deal of hardware, to pursue a wide variety of PML and LML applications which integrate these two process technologies with other, conventional, vacuum deposition methods. The historical development of the technologies is reviewed and the Battelle PML/LML facilities are described. Current Battelle work involving solar thermal control films, PML QWOTs, and polymer/metal high reflectors are also discussed. Battelle PML work that is just starting, involving non-linear optical materials/devices, lithium polymer battery fabrication, electrochromic devices, and polymer/oxide multilayers, is discussed as well.

  16. CuInS2 Films Deposited by Aerosol-Assisted Chemical Vapor Deposition Using Ternary Single-Source Precursors

    NASA Technical Reports Server (NTRS)

    Jin, Michael H.-C.; Banger, Kulbinder K.; Harris, Jerry D.; Hepp, Aloysius F.

    2004-01-01

    Polycrystalline CuInS2 films were deposited by aerosol-assisted chemical vapor deposition using both solid and liquid ternary single-source precursors (SSPs) prepared in-house. Films with either (112) or (204/220) preferred orientation were obtained, and compositional analysis showed that (112)-oriented films contained more copper than (204/220)-oriented films. Using X-ray diffraction, the signature of chalcopyrite structure was often confirmed for (112)-oriented films. The preferred orientation of the film is likely related to the decomposition and reaction kinetics associated with the molecular structure of the precursors at the substrate. Interestingly, the (204/220)-oriented films were always accompanied by a secondary phase, which was identified as an unknown In-rich compound from the results of post-growth annealing, etching experiments, and Raman spectroscopic data. By increasing Cu to In ratio in the film, (112)-oriented films were obtained with a maximum grain size of about 0.5 micrometers, and their X-ray diffractions did not show any observable signature of the In secondary phase. Electrical and optical properties of all the films grown were characterized. They all showed p-type conduction with an electrical resistivity between 0.1 omega cm and 30 omega cm, and an optical band gap of 1.46eV +/- 0.02, as deposited. The material properties of deposited films revealed this methodology of using SSPs for fabricating chalcopyrite-based solar cells to be highly promising.

  17. Pulsed laser deposition of organic semiconductor rubrene thin films

    NASA Astrophysics Data System (ADS)

    Grochowska, K.; Majumdar, S.; Laukkanen, P.; Majumdar, H. S.; Sawczak, M.; Śliwiński, G.

    2015-01-01

    Pulsed Laser Deposition (PLD) technique is applied to produce organic semiconductor (OS) rubrene thin film for spintronics applications. The use of organic material for spintronics is motivated by the advantages such as long spin diffusion length due to low spin-orbit and hyperfine coupling1,2, chemical tuning of electronic functionality, easy structural modifications, ability of self-assembly and mechanical flexibility3 etc. However, a major drawback of OS is its low mobility compared to inorganic semiconductors. The PLD growth of rubrene aims on fabricating OS films under more controlled environment to achieve higher crystalline order to improve its mobility and spin coherence length. Among organic materials, rubrene reveals the highest hole mobility - up to 40 cm2/(V•s) and can be exploited in organic light-emitting diodes (OLEDs) or field-effect transistors (OFETs) 4. In this work the rubrene thin films are produced from hardened pellets in vacuum using Nd:YAG pulsed laser operated at 1064 nm, 2 Hz and energy fluence around 0.2 J/cm2. For the reference rubrene samples on SiO2 glass the AFM data reveal continuous 5-7 nm thick films. The amorphous structures are confirmed by XRD measurements and also Raman spectra which show signatures of both tetracene and phenyl bands and a broadband at 1373 cm-1. The obtained results indicate that continuous, defect-free rubrene films can be prepared by means of PLD for investigation of the spin polarization properties of organic-inorganic hybrids. Further studies are on the way to improve crystalline qualities of the rubrene films for less grain boundary related defects and improved mobility and spin diffusion length.

  18. Pulsed laser deposition of Tl-Ca-Ba-Cu-O films

    NASA Technical Reports Server (NTRS)

    Ianno, N. J.; Liou, S. H.; Woollam, John A.; Thompson, D.; Johs, B.

    1990-01-01

    Pulsed laser deposition is a technique commonly used to deposit high quality thin films of high temperature superconductors. This paper discusses the results obtained when this technique is applied to the deposition of Tl-Ca-Ba-Cu-O thin films using a frequency doubled Nd:YAG laser operating at 532 nm and an excimer laser operating at 248 nm. Films with onset temperatures of 125 K and zero resistance temperatures of 110 K deposited on (100) oriented MgO from a composite Tl2Ca2Ba2Cu3Ox target were obtained at both wavelengths upon appropriate post deposition annealing. Films deposited at 532 nm exhibit a rough surface, while those deposited at 248 nm are smooth and homogeneous. Upon annealing, films deposited at both wavelengths are single phase Tl2Ca2Ba2Cu3Ox.

  19. Aerosol chemical vapor deposition of metal oxide films

    DOEpatents

    Ott, K.C.; Kodas, T.T.

    1994-01-11

    A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said substrate.

  20. Investigation of silicon surface passivation by silicon nitride film deposition

    NASA Technical Reports Server (NTRS)

    Olsen, L. C.

    1984-01-01

    The use of Sin sub x grown by plasma enhanced chemical vapor deposition (PECVO) for passivating silicon surfaces was studied. The application of PECVO SiN sub x films for passivations of silicon N+/P or P+/N solar cells is of particular interest. This program has involved the following areas of investigation: (1) Establishment of PECVO system and development of procedures for growth of SiN sub x; (2) Optical characterization of SiN sub x films; (3) Characterization of the SiN sub x/Si interface; (4) Surface recombination velocity deduced from photoresponse; (5) Current-Voltage analyses of silicon N+/P cells; and (6) Gated diode device studies.

  1. Homogeneity analysis of sculptured thin films deposited in symmetric style through glancing angle deposition technique

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Qi, Hong-Ji; Sun, Wei; He, Jun; Zhao, Jiao-Ling; Wang, Hu; Hou, Yong-Qiang

    2014-11-01

    The symmetric deposition technique is often used to improve the uniformity of sculptured thin film (STF). In this paper, optical properties of STF with the columnar angles ±β are analyzed theoretically, based on the characteristic matrix method for extraordinary waves. Then, the transmittances of uniformity monolayer and bilayer STF in symmetrical style are calculated to show the effect of the bilayer structure on the optical properties of STF. The inhomogeneity of STF is involved in analyzing the differences in transmittance and phase retardation between monolayer and bilayer STF deposited in symmetric style. The results show that optical homogeneity of STF can be improved by depositing in symmetric style at the normal incidence, but it is not the same case as the oblique incidence.

  2. Optical and Scratch Resistant Properties of Diamondlike Carbon Films Deposited with Single and Dual Ion Beams

    NASA Technical Reports Server (NTRS)

    Kussmaul, Michael T.; Bogdanski, Michael S.; Banks, Bruce A.; Mirtich, Michael J.

    1993-01-01

    Amorphous diamond-like carbon (DLC) films were deposited using both single and dual ion beam techniques utilizing filament and hollow cathode ion sources. Continuous DLC films up to 3000 A thick were deposited on fused quartz plates. Ion beam process parameters were varied in an effort to create hard, clear films. Total DLC film absorption over visible wavelengths was obtained using a Perkin-Elmer spectrophotometer. An ellipsometer, with an Ar-He laser (wavelength 6328 A) was used to determine index of refraction for the DLC films. Scratch resistance, frictional, and adherence properties were determined for select films. Applications for these films range from military to the ophthalmic industries.

  3. Optical and scratch resistant properties of diamondlike carbon films deposited with single and dual ion beams

    NASA Technical Reports Server (NTRS)

    Kussmaul, Michael T.; Bogdanski, Michael S.; Banks, Bruce A.; Mirtich, Michael J.

    1993-01-01

    Amorphous diamondlike carbon (DLC) films were deposited using both single and dual ion beam techniques utilizing filament and hollow cathode ion sources. Continuous DLC films up to 3000 A thick were deposited on fused quartz plates. Ion beam process parameters were varied in an effort to create hard, clear films. Total DLC film absorption over visible wavelengths was obtained using a Perkin-Elmer spectrophotometer. An ellipsometer, with an Ar-He laser (wavelength 6328 A) was used to determine index of refraction for the DLC films. Scratch resistance and frictional and adherence properties were determined for select films. Applications for these films range from military to the ophthalmic industries.

  4. Nanostructured films of Boron suboxide by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Yu, Shengwen; Wang, Guanghou; Yin, Shuangye; Zhang, Yunxiang; Liu, Zhiguo

    2000-04-01

    We have prepared nanofilms of boron suboxide by the method of pulsed laser deposition (PLD) for the first time. Boron powder with purity of 99%+ was mixed with B 2O 3. The mixture was milled and then pressed into a pellet which was heated at 1200°C for one day. The heated pellet was used as the target for the experiment of PLD in preparing nanocluster-based films. Structural studies indicate that nanofilms contain the crystallized nanoclusters of B 6O with six-fold symmetry and icosahedron-like structure, which is the result of long range order packing.

  5. Ripple dislocation slip in wrinkled gold film deposited on polydimethylsiloxane

    NASA Astrophysics Data System (ADS)

    Lin, C. B.; Chuang, Y. F.; Liu, Y. H.; Lee, Sanboh; Chou, Y. T.

    2011-07-01

    The motion of ripple dislocations in a wrinkled thin film of gold deposited on polydimethylsiloxane (PDMS) was investigated. The deposition was made under tensile load along the first direction on the PDMS plate. After the tensile load was released, a ripple pattern and ripple dislocations were formed on the surface. Upon reloading in the second direction, these ripple dislocations were able to slip. At a given tensile load, the speed of slip decreased as the loading time increased, and finally reached a constant value, which was increasing with the applied load. The measured data were interpreted with a dynamic model based on Newton's law of motion. Interaction of ripple dislocations was also observed. It was shown that a pair of positive and negative ripple dislocations of equal strength could annihilate each other or form a dipole, depending on the magnitude of the applied load.

  6. Effect of substrate temperature and film thickness on the characteristics of silver thin films deposited by DC magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Mashaiekhy, Jahanbakhsh; Shafieizadeh, Zahra; Nahidi, Hossein

    2012-11-01

    Silver (Ag) films were prepared by DC magnetron sputtering deposition at different substrate temperatures (25-450 °C) and film thicknesses (100-800 nm) and their morphological, optical, electrical and structural properties were investigated. Atomic force microscopy (AFM) was employed to study the surface topography of the thin films. The grain size as well as surface roughness of the films is strongly dependent on the temperature and the film thickness. X-ray diffraction experiments showed the intensity enhancement by increasing substrate temperature, also by increasing film thickness. The optical properties were determined by means of spectrophotometric analysis. It is found that the optical reflection is not affected significantly with substrate temperature and film thickness. The electrical resistivities of films were determined by four-point probe measurements. The experimental results indicate that the films with higher thickness and deposition temperature have the lowest resistivity.

  7. Improvement in mechanical and barrier properties of polyethylene blown films using atomic layer deposition

    SciTech Connect

    Lee, Gyeong Beom; Hak Song, Seung; Wook Moon, Sung; Woo Kim, Jun; Hyung Shim, Joon; Choi, Byoung-Ho; Moo Heo, Young

    2014-01-15

    Recently, thin films deposited on polymer substrates have been widely utilized as encapsulation barriers in electronic applications such as flexible displays, packaging films, and organic light-emitting diodes. The barrier and mechanical properties of these films are critical aspects when using them for protecting the inner modules of electronic devices from environmental factors such as moisture, oxygen, and sunlight. In particular, polymers can be degraded or decomposed more easily than other materials under such environmental conditions. Therefore, polymer films can be deposited using thin functional materials; however, suitable deposition methods for polymers are scarce owing to many limitations such as low melting/glass transition temperature, thermal degradation, and oxidation. In this study, a thin alumina oxide film was deposited on a high-density polyethylene blown film by using atomic layer deposition. The mechanical and barrier properties of the alumina oxide film deposited on the polyethylene film were characterized by a microtensile test and water vapor transmission rate test. Process conditions such as process temperature, plasma surface treatment, and number of cycles were varied to ascertain the reliability of the thin alumina oxide film deposited on the high-density polyethylene blown film. The results showed that the barrier property of the deposited film improved upon the application of plasma surface treatment, and that its mechanical properties varied under different process conditions.

  8. Nano-oxide thin films deposited via atomic layer deposition on microchannel plates.

    PubMed

    Yan, Baojun; Liu, Shulin; Heng, Yuekun

    2015-01-01

    Microchannel plate (MCP) as a key part is a kind of electron multiplied device applied in many scientific fields. Oxide thin films such as zinc oxide doped with aluminum oxide (ZnO:Al2O3) as conductive layer and pure aluminum oxide (Al2O3) as secondary electron emission (SEE) layer were prepared in the pores of MCP via atomic layer deposition (ALD) which is a method that can precisely control thin film thickness on a substrate with a high aspect ratio structure. In this paper, nano-oxide thin films ZnO:Al2O3 and Al2O3 were prepared onto varied kinds of substrates by ALD technique, and the morphology, element distribution, structure, and surface chemical states of samples were systematically investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS), respectively. Finally, electrical properties of an MCP device as a function of nano-oxide thin film thickness were firstly studied, and the electrical measurement results showed that the average gain of MCP was greater than 2,000 at DC 800 V with nano-oxide thin film thickness approximately 122 nm. During electrical measurement, current jitter was observed, and possible reasons were preliminarily proposed to explain the observed experimental phenomenon.

  9. Nano-oxide thin films deposited via atomic layer deposition on microchannel plates

    NASA Astrophysics Data System (ADS)

    Yan, Baojun; Liu, Shulin; Heng, Yuekun

    2015-04-01

    Microchannel plate (MCP) as a key part is a kind of electron multiplied device applied in many scientific fields. Oxide thin films such as zinc oxide doped with aluminum oxide (ZnO:Al2O3) as conductive layer and pure aluminum oxide (Al2O3) as secondary electron emission (SEE) layer were prepared in the pores of MCP via atomic layer deposition (ALD) which is a method that can precisely control thin film thickness on a substrate with a high aspect ratio structure. In this paper, nano-oxide thin films ZnO:Al2O3 and Al2O3 were prepared onto varied kinds of substrates by ALD technique, and the morphology, element distribution, structure, and surface chemical states of samples were systematically investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS), respectively. Finally, electrical properties of an MCP device as a function of nano-oxide thin film thickness were firstly studied, and the electrical measurement results showed that the average gain of MCP was greater than 2,000 at DC 800 V with nano-oxide thin film thickness approximately 122 nm. During electrical measurement, current jitter was observed, and possible reasons were preliminarily proposed to explain the observed experimental phenomenon.

  10. Nano-oxide thin films deposited via atomic layer deposition on microchannel plates.

    PubMed

    Yan, Baojun; Liu, Shulin; Heng, Yuekun

    2015-01-01

    Microchannel plate (MCP) as a key part is a kind of electron multiplied device applied in many scientific fields. Oxide thin films such as zinc oxide doped with aluminum oxide (ZnO:Al2O3) as conductive layer and pure aluminum oxide (Al2O3) as secondary electron emission (SEE) layer were prepared in the pores of MCP via atomic layer deposition (ALD) which is a method that can precisely control thin film thickness on a substrate with a high aspect ratio structure. In this paper, nano-oxide thin films ZnO:Al2O3 and Al2O3 were prepared onto varied kinds of substrates by ALD technique, and the morphology, element distribution, structure, and surface chemical states of samples were systematically investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS), respectively. Finally, electrical properties of an MCP device as a function of nano-oxide thin film thickness were firstly studied, and the electrical measurement results showed that the average gain of MCP was greater than 2,000 at DC 800 V with nano-oxide thin film thickness approximately 122 nm. During electrical measurement, current jitter was observed, and possible reasons were preliminarily proposed to explain the observed experimental phenomenon. PMID:25883544

  11. Smoothening in thin-film deposition on rough substrates.

    PubMed

    de Assis, T A; Reis, F D A Aarão

    2015-11-01

    The evolution of the surface roughness W of a thin film deposited on a rough substrate is studied with a model of temperature-activated adatom diffusion, irreversible lateral aggregation, and no step energy barrier, in which the main parameter is the ratio R of diffusion and deposition rates. At sufficiently low temperatures (R≲10), the average number of adatom steps after adsorption is very small, thus W monotonically increases with time t due to an approximately uncorrelated deposition at short times. If the temperature is not very low (R∼10(3) or larger), smoothening occurs at short times and the Villain-Lai-Das Sarma (VLDS) growth equation governs the long time roughening, which is attained after a crossover time t(c) that increases with the correlation length ξ(i) of the substrate. Scaling arguments predict the dependence of t(c) on temperature and on the substrate production time and the scaling relation for the difference between the roughness of films deposited on rough and flat substrates, in good agreement with numerical results. The effect of temperature is not a direct extension of previous results on flat substrates because the short wavelength fluctuations delay the formation of terraces. For this reason, the effective energy obtained from the dependence of t(c) on R is 40% of the energy of activated adatom diffusion. A scaling law for the initial smoothening is proposed as W/W(i)=Ψ(t/t(c1)), with a crossover time t(c1)≡R(-θ)ξ(i)(z), where W(i) is the substrate roughness, θ≈0.4, and z is the VLDS dynamical exponent. It provides good data collapse if W is not very small and is suggested to be tested experimentally. PMID:26651710

  12. Binary and ternary NiTi-based shape memory films deposited by simultaneous sputter deposition from elemental targets

    SciTech Connect

    Sanjabi, S.; Cao, Y.Z.; Sadrnezhaad, S.K.; Barber, Z.H.

    2005-09-15

    The most challenging requirement for depositing NiTi-based shape memory thin films is the control of film composition because a small deviation can strongly shift the transformation temperatures. This article presents a technique to control film composition via adjustment of the power supplied to the targets during simultaneous sputter deposition from separate Ni, Ti, and X (e.g., Hf) targets. After optimization of sputter parameters such as working gas pressure, target-substrate distance, and target power ratio, binary Ni{sub 100-x}Ti{sub x} thin films were fabricated and characterized by energy dispersive x-ray spectroscopy in a scanning electron microscope (to measure the film composition and uniformity), in situ x-ray diffraction (to identify the phase structures), and differential scanning calorimetry (to indicate the transformation and crystallization temperatures). To explore the possibility of depositing ternary shape memory NiTi-based thin films with a high temperature transformation >100 deg. C, a Hf target was added to the NiTi deposition system. Annealing was carried out in a high vacuum furnace slightly above the films' crystallization temperatures (500 and 550 deg. C for NiTi and NiTiHf films, respectively). Differential scanning calorimetry (DSC) results of free-standing films illustrated the dependence of transformation temperatures on film composition: Ap and Mp (referring to the austenitic and martensitic peaks in the DSC curve) were above room temperature in near equiatomic NiTi and Ti-rich films, but below it in Ni-rich films. In NiTiHf films, the transformation temperatures were a function of Hf content, reaching as high as 414 deg. C (Ap) at a Hf content of 24.4 at. %. Atomic force microscopy revealed nanostructure surface morphology of both NiTi and NiTiHf films. Detailed characterization showed that the film properties were comparable with those of NiTi and NiTiHf bulk alloys.

  13. A Study of Morphology and Magnetic Properties of Doped Barium Ferrite Films Formed by Aerosol Deposition

    NASA Astrophysics Data System (ADS)

    Johnson, Scooter; Gonzalez, Christopher; Robinson, Zachary; Ellsworth, David; Wu, Mingzhong

    Aerosol deposition is a room-temperature thick film deposition technique that produces polycrystalline films that have > 95% of theoretical density and are up to several hundred microns thick. In addition to depositing films at room temperature another distinct advantage of aerosol deposition is the ability to produce films with the same resulting stoichiometry as the starting material. For this work, we deposited a proprietary doped barium ferrite (BaFe12O19) film from powder produced by Temex Ceramics. This material is designed for microwave absorption near 18 GHz via ferromagnetic resonance. We compare the structural and magnetic properties of the as-deposited film, bulk material, and starting powder. For this purpose, we employed scanning electron microscopy, x-ray photoemission spectroscopy, x-ray diffraction, vibrating sample magnetometry, and broad-band ferromagnetic resonance characterization techniques.

  14. Oxygen partial pressure dependent optical properties of glancing angle deposited (GLAD) Ta2O5 films deposited by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Tripathi, S.; Haque, S. Maidul; Rao, K. Divakar; Misal, J. S.; Pratap, C.; Sahoo, N. K.

    2016-05-01

    Experiments were carried out on Ta2O5 oxide thin films by asymmetric bipolar pulsed DC magnetron sputtering using a new hybrid combination of conventional (normal incidence) deposition and glancing angle deposition (GLAD) geometries. The films were prepared with varying O2 partial pressure. The ellipsometry characterization reveals a systematic variation in refractive index, which decreased from 2.2 in the normal films to an average 1.78 in the GLAD films. The bandgap of these GLAD films is slightly higher as compared to normal films. Overall transmission of the GLAD films is increased is by ~ 15 % implying a reduction in the refractive index for potential optical filtering device applications. The results were further supported by X-ray reflectivity measurements which show an effective double layer structure in GLAD consisting of layers with different densities of the same Ta2O5 material.

  15. Electrochemical deposition of conducting ruthenium oxide films from solution

    SciTech Connect

    Anderson, D.P.; Warren, L.F.

    1984-02-01

    In the last decade, ruthenium oxide, RuO /sub x/ (x less than or equal to 2), has been used extensively as the active anode electrocatalyst constituent for Cl/sub 2/ and O/sub 2/ evolution reactions, in chlorate production, and in metal electrowinning from mixed chloride-sulfate solutions. More recently, this material has been incorporated in several light-induced water electrolysis schemes and apparently possesses the ability to inhibit CdS photocorrosion by acting as a hole scavenger. The numerous applications for this catalyst material certainly warrant further studies of its electrochemical properties on a variety of substrates, e.g., semiconductors. The lack of a simple technique for controlled deposition of ruthenium oxide onto conducting substrates prompted us to investigate an electrochemical approach to this problem. We describe here a new way to electrochemically deposit conducting films of hydrated ruthenium oxide from an aqueous solution of the benzeneruthenium (II)aqua complex. The films slowly dissolve in aqueous electrolytes upon potential cycling, yet appear to be catalytic with regards to water oxidation.

  16. Deposition of Nanostructured Thin Film from Size-Classified Nanoparticles

    NASA Technical Reports Server (NTRS)

    Camata, Renato P.; Cunningham, Nicholas C.; Seol, Kwang Soo; Okada, Yoshiki; Takeuchi, Kazuo

    2003-01-01

    Materials comprising nanometer-sized grains (approximately 1_50 nm) exhibit properties dramatically different from those of their homogeneous and uniform counterparts. These properties vary with size, shape, and composition of nanoscale grains. Thus, nanoparticles may be used as building blocks to engineer tailor-made artificial materials with desired properties, such as non-linear optical absorption, tunable light emission, charge-storage behavior, selective catalytic activity, and countless other characteristics. This bottom-up engineering approach requires exquisite control over nanoparticle size, shape, and composition. We describe the design and characterization of an aerosol system conceived for the deposition of size classified nanoparticles whose performance is consistent with these strict demands. A nanoparticle aerosol is generated by laser ablation and sorted according to size using a differential mobility analyzer. Nanoparticles within a chosen window of sizes (e.g., (8.0 plus or minus 0.6) nm) are deposited electrostatically on a surface forming a film of the desired material. The system allows the assembly and engineering of thin films using size-classified nanoparticles as building blocks.

  17. Facile deposition of YSZ-inverse photonic glass films.

    PubMed

    do Rosário, Jefferson J; Dyachenko, Pavel N; Kubrin, Roman; Pasquarelli, Robert M; Petrov, Alexander Yu; Eich, Manfred; Schneider, Gerold A

    2014-08-13

    An alternative all-colloidal and single-step deposition method of yttrium-stabilized zirconia (YSZ)-infiltrated polymeric photonic glass films is presented. Heterocoagulation of oppositely charged polystyrene (PS) microspheres and YSZ nanocrystals in aqueous dispersions created PS/YSZ core-shell spheres. These composite particles were deposited on glass substrates by a simple drop-coating process. Heterocoagulation impaired self-assembly of the particles, resulting in a disordered structure. Burn-out of the polymer yielded a random array of YSZ shells. The effect of the filling fraction of YSZ between these shells was explored. YSZ-inverse photonic glass films with a thickness below 40 μm achieved 70% reflectance of the incident radiation over a broad wavelength range between 0.4 and 2.2 μm. The YSZ structures demonstrated structural stability up to 1000 °C and maintained high reflectance up to 1200 °C for several hours, thus enabling applications as broadband reflectors at elevated temperatures.

  18. Formation of Cobalt Silicide Films by Ion Beam Deposition

    SciTech Connect

    Zhang, Yanwen; McCready, David E.; Wang, Chong M.; Young, James S.; Mckinley, Mathew I.; Whitlow, Harry J.; Razpet, Alenka; Possnert, Göran; Zhang, Tonghe; Wu, Yuguang

    2006-01-01

    Thin films of cobalt silicide are widely used as metallization in very large-scale integrated electronic circuits. In this study, Co ions were deposited on Si (111) wafers by a high beam current filter metal vacuum arc deposition (FMEVAD) system. Surface silicide films were formed after annealing from 500 to 700 C for 30 minutes. Cobalt depth profiles and contaminations were determined using Rutherford backscattering spectrometry (RBS) and time-of-flight energy elastic recoil detection analysis (ToF-E ERDA). The polycrystalline cobalt silicide phases formed were characterized by grazing-incidence x-ray diffraction (GIXRD). The surface topography development and interfaces have been investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results show that a thin CoSi2 surface layer with both a smooth surface topography and sharp interface can be achieved by annealing at 700 C. The CoSi phase and O contamination were observed in the samples that were annealed at lower temperatures.

  19. Development of vapor deposited thin films for bio-microsystems

    NASA Astrophysics Data System (ADS)

    Popat, Ketul Chandrakant

    Increasing demands for more biocompatible and sophisticated bio-microsystems in recent years has led to the development of a new technology called BioMEMS (biological micro-electro-mechanical systems). The foundation of this technology is the same as that of the traditional field of IC (integrated circuits), but an emphasis on developing new diagnostic and therapeutic modalities. Micro- and nano-fabrication techniques are currently being used to develop implants that can record, sense, stimulate and deliver to biological systems. Micromachined substrates can provide unique advantages over traditional implantable devices in terms of their ability to control surface micro-architecture, topography and feature size in micron and nano sizes. However, as BioMEMS technology is rapidly being developed, the practical use of these bio-microsystems is limited due to the inability to effectively interface with the biological system in non-immunogenic and stable manner. This is one of the most important considerations, and hence it is useful to focus on the fundamental scientific issues relating to material science, surface chemistry and immunology of silicon based bio-microsystems. This results in development of biomolecular interfaces that are compatible with both microfabrication processing and biological systems. The overall thrust of this research is to develop, characterize and integrate vapor deposited thin films with bio-microsystems in a manner that it is both reproducible and fully integrated with existing technologies. The main strategy is to use silane coatings precursor coatings on which poly (ethylene glycol) (PEG) will be coated in vapor phase. Silane has been coated user vapor phase, but its chemical and biological characterization and stability of the films under physiological conditions has not been investigated for biological applications. PEG has been coated in solution phase on silicon surface. However, it has not been coated under vapor phase. Here we are

  20. High rate chemical vapor deposition of carbon films using fluorinated gases

    DOEpatents

    Stafford, Byron L.; Tracy, C. Edwin; Benson, David K.; Nelson, Arthur J.

    1993-01-01

    A high rate, low-temperature deposition of amorphous carbon films is produced by PE-CVD in the presence of a fluorinated or other halide gas. The deposition can be performed at less than 100.degree. C., including ambient room temperature, with a radio frequency plasma assisted chemical vapor deposition process. With less than 6.5 atomic percent fluorine incorporated into the amorphous carbon film, the characteristics of the carbon film, including index of refraction, mass density, optical clarity, and chemical resistance are within fifteen percent (15%) of those characteristics for pure amorphous carbon films, but the deposition rates are high.

  1. Second harmonic generation in ZnO thin films fabricated by metalorganic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Liu, C. Y.; Zhang, B. P.; Binh, N. T.; Segawa, Y.

    2004-07-01

    Second harmonic generation (SHG) from ZnO thin films fabricated by metalorganic chemical vapor deposition (MOCVD) technique was carried out. By comparing the second harmonic signal generated in a series of ZnO films with different deposition temperatures, we conclude that a significant part of second harmonic signal is generated at the film deposited with appropriate temperature. The second-order susceptibility tensor χ(2)zzz=9.2 pm/V was deduced for a film deposited at 250 °C.

  2. Low temperature deposition of polycrystalline silicon thin films on a flexible polymer substrate by hot wire chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Lee, Sang-hoon; Jung, Jae-soo; Lee, Sung-soo; Lee, Sung-bo; Hwang, Nong-moon

    2016-11-01

    For the applications such as flexible displays and solar cells, the direct deposition of crystalline silicon films on a flexible polymer substrate has been a great issue. Here, we investigated the direct deposition of polycrystalline silicon films on a polyimide film at the substrate temperature of 200 °C. The low temperature deposition of crystalline silicon on a flexible substrate has been successfully made based on two ideas. One is that the Si-Cl-H system has a retrograde solubility of silicon in the gas phase near the substrate temperature. The other is the new concept of non-classical crystallization, where films grow by the building block of nanoparticles formed in the gas phase during hot-wire chemical vapor deposition (HWCVD). The total amount of precipitation of silicon nanoparticles decreased with increasing HCl concentration. By adding HCl, the amount and the size of silicon nanoparticles were reduced remarkably, which is related with the low temperature deposition of silicon films of highly crystalline fraction with a very thin amorphous incubation layer. The dark conductivity of the intrinsic film prepared at the flow rate ratio of RHCl=[HCl]/[SiH4]=3.61 was 1.84×10-6 Scm-1 at room temperature. The Hall mobility of the n-type silicon film prepared at RHCl=3.61 was 5.72 cm2 V-1s-1. These electrical properties of silicon films are high enough and could be used in flexible electric devices.

  3. Properties of RF sputtered cadmium telluride (CdTe) thin films: Influence of deposition pressure

    NASA Astrophysics Data System (ADS)

    Kulkarni, R. R.; Pawbake, A. S.; Waykar, R. G.; Rondiya, S. R.; Jadhavar, A. A.; Pandharkar, S. M.; Karpe, S. D.; Diwate, K. D.; Jadkar, S. R.

    2016-04-01

    Influence of deposition pressure on structural, morphology, electrical and optical properties of CdTe thin films deposited at low substrate temperature (100°C) by RF magnetron sputtering was investigated. The formation of CdTe was confirmed by low angle XRD and Raman spectroscopy. The low angle XRD analysis revealed that the CdTe films have zinc blende (cubic) structure with crystallites having preferred orientation in (111) direction. Raman spectra show the longitudinal optical (LO) phonon mode peak ˜ 165.4 cm-1 suggesting high quality CdTe film were obtained over the entire range of deposition pressure studied. Scanning electron microscopy analysis showed that films are smooth, homogenous, and crack-free with no evidence of voids. The EDAX data revealed that CdTe films deposited at low deposition pressure are high-quality stoichiometric. However, for all deposition pressures, films are rich in Cd relative to Te. The UV-Visible spectroscopy analysis show the blue shift in absorption edge with increasing the deposition pressure while the band gap show decreasing trend. The highest electrical conductivity was obtained for the film deposited at deposition pressure 1 Pa which indicates that the optimized deposition pressure for our sputtering unit is 1 Pa. Based on the experimental results, these CdTe films can be useful for the application in the flexible solar cells and other opto-electronic devices.

  4. Ion-assisted deposition of optical thin films. Doctoral thesis

    SciTech Connect

    Targove, J.D.

    1988-01-01

    The columnar microstructure of most thermally evaporated thin films detrimentally affects many of their properties through a reduction in packing density. In this work, the author investigated ion-assisted deposition as a means of disrupting this columnar growth for a number of coating materials. A Kaufman hot-cathode ion source bombarded thermally evaporated films with low-energy (<1000 eV) positive ions during deposition in a cryopumped box coater. The author investigated MgF/sub 2/, Na/sub 3/AlF/sub 6/, AlF/sub 3/, LaF/sub 3/,CeF/sub 3/,NdF/sub 3/,Al/sub 2/O/sub 3/, and AlN. Argon ion bombardment of the fluoride coatings increased their packing densities dramatically. He achieved packing densities near unity without significant absorption for MgF/sub 2/,LaF/sub 3/, and NdF/sub 3/, while Na/sub 3/AlF/sub 6/,AlF/sub 3/, and CeF/sub 3/ began to absorb before unity packing density could be achieved. Fluorine was preferentially sputtered by the ion bombardment, creating anion vacancies. The films adsorbed water vapor and hydroxyl radicals from the residual chamber atmosphere. These filled the vacancy sites, eliminating absorption in the visible, but the oxygen complexes caused increased absorption in the ultraviolet. For LaF/sub 3/ and NdF/sub 3/, a sufficient amount of oxygen caused a phase transformation from the fluoride phase to an oxyfluoride phase.

  5. CuInS2 Films Deposited by Aerosol-Assisted Chemical Vapor Deposition Using Ternary Single-Source Precursors

    NASA Technical Reports Server (NTRS)

    Jin, Michael; Banger, Kal; Harris, Jerry; Hepp, Aloysius

    2003-01-01

    Polycrystalline CuInS2 films were deposited by aerosol-assisted chemical vapor deposition using both solid and liquid ternary single-source precursors (SSPs) which were prepared in-house. Films with either (112) or (204/220) preferred orientation, had a chalcopyrite structure, and (112)-oriented films contained more copper than (204/220)-oriented films. The preferred orientation of the film is likely related to the decomposition and reaction kinetics associated with the molecular structure of the precursors at the substrate. Interestingly, the (204/220)-oriented films were always In-rich and were accompanied by a secondary phase. From the results of post-growth annealing, etching experiments, and Raman spectroscopic data, the secondary phase was identified as an In-rich compound. On the contrary, (112)-oriented films were always obtained with a minimal amount of the secondary phase, and had a maximum grain size of about 0.5 micron. Electrical and optical properties of all the films grown were characterized. They all showed p-type conduction with an electrical resistivity between 0.1 and 30 Omega-cm, and an optical band gap of approximately 1.46 eV +/- 0.02, as deposited. The material properties of deposited films revealed this methodology of using SSPs for fabricating chalcopyrite-based solar cells to be highly promising.

  6. Fluorocarbon adsorption in hierarchical porous frameworks

    NASA Astrophysics Data System (ADS)

    Motkuri, Radha Kishan; Annapureddy, Harsha V. R.; Vijaykumar, M.; Schaef, H. Todd; Martin, Paul F.; McGrail, B. Peter; Dang, Liem X.; Krishna, Rajamani; Thallapally, Praveen K.

    2014-07-01

    Metal-organic frameworks comprise an important class of solid-state materials and have potential for many emerging applications such as energy storage, separation, catalysis and bio-medical. Here we report the adsorption behaviour of a series of fluorocarbon derivatives on a set of microporous and hierarchical mesoporous frameworks. The microporous frameworks show a saturation uptake capacity for dichlorodifluoromethane of >4 mmol g-1 at a very low relative saturation pressure (P/Po) of 0.02. In contrast, the mesoporous framework shows an exceptionally high uptake capacity reaching >14 mmol g-1 at P/Po of 0.4. Adsorption affinity in terms of mass loading and isosteric heats of adsorption is found to generally correlate with the polarizability and boiling point of the refrigerant, with dichlorodifluoromethane >chlorodifluoromethane >chlorotrifluoromethane >tetrafluoromethane >methane. These results suggest the possibility of exploiting these sorbents for separation of azeotropic mixtures of fluorocarbons and use in eco-friendly fluorocarbon-based adsorption cooling.

  7. Fluorocarbon adsorption in hierarchical porous frameworks.

    PubMed

    Motkuri, Radha Kishan; Annapureddy, Harsha V R; Vijaykumar, M; Schaef, H Todd; Martin, Paul F; McGrail, B Peter; Dang, Liem X; Krishna, Rajamani; Thallapally, Praveen K

    2014-07-09

    Metal-organic frameworks comprise an important class of solid-state materials and have potential for many emerging applications such as energy storage, separation, catalysis and bio-medical. Here we report the adsorption behaviour of a series of fluorocarbon derivatives on a set of microporous and hierarchical mesoporous frameworks. The microporous frameworks show a saturation uptake capacity for dichlorodifluoromethane of >4 mmol g(-1) at a very low relative saturation pressure (P/Po) of 0.02. In contrast, the mesoporous framework shows an exceptionally high uptake capacity reaching >14 mmol g(-1) at P/Po of 0.4. Adsorption affinity in terms of mass loading and isosteric heats of adsorption is found to generally correlate with the polarizability and boiling point of the refrigerant, with dichlorodifluoromethane > chlorodifluoromethane > chlorotrifluoromethane > tetrafluoromethane > methane. These results suggest the possibility of exploiting these sorbents for separation of azeotropic mixtures of fluorocarbons and use in eco-friendly fluorocarbon-based adsorption cooling.

  8. Fluorocarbon adsorption in hierarchical porous frameworks

    SciTech Connect

    Motkuri, RK; Annapureddy, HVR; Vijaykumar, M; Schaef, HT; Martin, PF; McGrail, BP; Dang, LX; Krishna, R; Thallapally, PK

    2014-07-09

    Metal-organic frameworks comprise an important class of solid-state materials and have potential for many emerging applications such as energy storage, separation, catalysis and bio-medical. Here we report the adsorption behaviour of a series of fluorocarbon derivatives on a set of microporous and hierarchical mesoporous frameworks. The microporous frameworks show a saturation uptake capacity for dichlorodifluoromethane of >4 mmol g(-1) at a very low relative saturation pressure (P/P-o) of 0.02. In contrast, the mesoporous framework shows an exceptionally high uptake capacity reaching >14 mmol g(-1) at P/P-o of 0.4. Adsorption affinity in terms of mass loading and isosteric heats of adsorption is found to generally correlate with the polarizability and boiling point of the refrigerant, with dichlorodifluoromethane >chlorodifluoromethane >chlorotrifluoromethane >tetrafluoromethane >methane. These results suggest the possibility of exploiting these sorbents for separation of azeotropic mixtures of fluorocarbons and use in eco-friendly fluorocarbon-based adsorption cooling.

  9. Tribological characteristics of gold films deposited on metals by ion plating and vapor deposition

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Spalvins, T.; Buckley, D. H.

    1984-01-01

    The graded interface between an ion-plated film and a substrate is discussed as well as the friction and wear properties of ion-plated gold. X-ray photoelectron spectroscopy (XPS) depth profiling and microhardness depth profiling were used to investigate the interface. The friction and wear properties of ion-plated and vapor-deposited gold films were studied both in an ultra high vacuum system to maximize adhesion and in oil to minimize adhesion. The results indicate that the solubility of gold on the substrate material controls the depth of the graded interface. Thermal diffusion and chemical diffusion mechanisms are thought to be involved in the formation of the gold-nickel interface. In iron-gold graded interfaces the gold was primarily dispersed in the iron and thus formed a physically bonded interface. The hardness of the gold film was influenced by its depth and was also related to the composition gradient between the gold and the substrate. The graded nickel-gold interface exhibited the highest hardness because of an alloy hardening effect. The effects of film thickness on adhesion and friction were established.

  10. Formation Of Silicon-Based Heterostructures In Multichamber Integrated-Processing Thin-Film Deposition Systems

    NASA Astrophysics Data System (ADS)

    Lucovsky, Gerald; Kim, Sang S.; Tsu, David V.; Parsons, Gregory N.; Fitch, J. T.

    1990-02-01

    This paper describes the formation of heterostructure devices using multichamber, integrated-processing thin-film deposition systems with UHV-compatible inter-chamber transfer. We describe the application of remote plasma-enhanced chemical-vapor deposition (Remote PECVD) for deposition of semiconducting and dielectric thin films in representative device structures. Special attention is directed to: i) deposition conditions necessary for control of thin-film and interface chemistry; and ii) post-deposition-annealing for the stabilization of physical and electronic properties of the heterostructures, including the interfaces between the constituent layers.

  11. Understanding the deposition mechanism of pulsed laser deposited B-C films using dual-targets

    SciTech Connect

    Zhang, Song; He, Zhiqiang; Wang, Chuanbin; Shen, Qiang; Zhang, Lianmeng; Ji, Xiaoli; Lu, Wenzhong

    2014-04-21

    Boron carbide thin films with stoichiometry (boron-carbon atomic ratio) range of 0.1 ∼ 8.9 were fabricated via pulsed laser deposition by using boron-carbon dual-targets. However, this experimental data on stoichiometry were smaller than the computer simulation values. The discrepancy was investigated by studies on composition and microstructure of the thin films and targets by scanning electron microscopy, excitation laser Raman spectroscopy, and X-ray photoelectron spectroscopy. The results indicate that the boron liquid droplets were formed by phase explosion after laser irradiation on boron sector. Part of the boron droplets would be lost via ejection in the direction of laser beam, which is tilted 45° to the surface of substrate.

  12. Inkjet Deposition of Layer-by-Layer Assembled Films

    SciTech Connect

    Andres, C. M.; Kotov, Nicholas A.

    2010-09-23

    Layer-by-layer assembly (LBL) can create advanced composites with exceptional properties unavailable by other means, but the laborious deposition process and multiple dipping cycles hamper their utilization in microtechnologies and electronics. Multiple rinse steps provide both structural control and thermodynamic stability to LBL multilayers, but they significantly limit their practical applications and contribute significantly to the processing time and waste. Here we demonstrate that by employing inkjet technology one can deliver the necessary quantities of LBL components required for film buildup without excess, eliminating the need for repetitive rinsing steps. This feature differentiates this approach from all other recognized LBL modalities. Using a model system of negatively charged gold nanoparticles and positively charged poly(diallyldimethylammonium) chloride, the material stability, nanoscale control over thickness, and particle coverage offered by the inkjet LBL technique are shown to be equal or better than the case of multilayers made with traditional dipping cycles. The opportunity for fast deposition of complex metallic patterns using a simple inkjet printer is also shown. The additive nature of LBL deposition based on the formation of insoluble nanoparticle-polyelectrolyte complexes of various compositions provides an excellent opportunity for versatile, multicomponent, and noncontact patterning for the simple production of stratified patterns that are much needed in advanced devices.

  13. Inkjet Deposition of Layer by Layer Assembled Films

    PubMed Central

    Andres, Christine M.; Kotov, Nicholas A.

    2010-01-01

    Layer-by-layer assembly (LBL) can create advanced composites with exceptional properties unavailable by other means, but the laborious deposition process and multiple dipping cycles hamper their utilization in microtechnologies and electronics. Multiple rinse steps provide both structural control and thermodynamic stability to LBL multilayers but they significantly limit their practical applications and contribute significantly to the processing time and waste. Here we demonstrate that by employing inkjet technology one can deliver the necessary quantities of LBL components required for film build-up without excess, eliminating the need for repetitive rinsing steps. This feature differentiates this approach from all other recognized LBL modalities. Using a model system of negatively charged gold nanoparticles and positively charged poly(diallyldimethylammonium) chloride, the material stability, nanoscale control over thickness and particle coverage offered by the inkjet LBL technique are shown to be equal or better than the multilayers made with traditional dipping cycles. The opportunity for fast deposition of complex metallic patterns using a simple inkjet printer was also shown. The additive nature of LBL deposition based on the formation of insoluble nanoparticle-polyelectrolyte complexes of various compositions provides an excellent opportunity for versatile, multi-component, and non-contact patterning for the simple production of stratified patterns that are much needed in advanced devices. PMID:20863114

  14. Enhanced Bactericidal Activity of Silver Thin Films Deposited via Aerosol-Assisted Chemical Vapor Deposition.

    PubMed

    Ponja, Sapna D; Sehmi, Sandeep K; Allan, Elaine; MacRobert, Alexander J; Parkin, Ivan P; Carmalt, Claire J

    2015-12-30

    Silver thin films were deposited on SiO2-barrier-coated float glass, fluorine-doped tin oxide (FTO) glass, Activ glass, and TiO2-coated float glass via AACVD using silver nitrate at 350 °C. The films were annealed at 600 °C and analyzed by X-ray powder diffraction, X-ray photoelectron spectroscopy, UV/vis/near-IR spectroscopy, and scanning electron microscopy. All the films were crystalline, and the silver was present in its elemental form and of nanometer dimension. The antibacterial activity of these samples was tested against Escherichia coli and Staphylococcus aureus in the dark and under UV light (365 nm). All Ag-deposited films reduced the numbers of E. coli by 99.9% within 6 h and the numbers of S. aureus by 99.9% within only 2 h. FTO/Ag reduced bacterial numbers of E. coli to below the detection limit after 60 min and caused a 99.9% reduction of S. aureus within only 15 min of UV irradiation. Activ/Ag reduced the numbers of S. aureus by 66.6% after 60 min and TiO2/Ag killed 99.9% of S. aureus within 60 min of UV exposure. More remarkably, we observed a 99.9% reduction in the numbers of E. coli within 6 h and the numbers of S. aureus within 4 h in the dark using our novel TiO2/Ag system. PMID:26632854

  15. Crystallization of amorphous silicon thin films deposited by PECVD on nickel-metalized porous silicon

    PubMed Central

    2012-01-01

    Porous silicon layers were elaborated by electrochemical etching of heavily doped p-type silicon substrates. Metallization of porous silicon was carried out by immersion of substrates in diluted aqueous solution of nickel. Amorphous silicon thin films were deposited by plasma-enhanced chemical vapor deposition on metalized porous layers. Deposited amorphous thin films were crystallized under vacuum at 750°C. Obtained results from structural, optical, and electrical characterizations show that thermal annealing of amorphous silicon deposited on Ni-metalized porous silicon leads to an enhancement in the crystalline quality and physical properties of the silicon thin films. The improvement in the quality of the film is due to the crystallization of the amorphous film during annealing. This simple and easy method can be used to produce silicon thin films with high quality suitable for thin film solar cell applications. PMID:22901341

  16. Crystallization of amorphous silicon thin films deposited by PECVD on nickel-metalized porous silicon.

    PubMed

    Ben Slama, Sonia; Hajji, Messaoud; Ezzaouia, Hatem

    2012-01-01

    Porous silicon layers were elaborated by electrochemical etching of heavily doped p-type silicon substrates. Metallization of porous silicon was carried out by immersion of substrates in diluted aqueous solution of nickel. Amorphous silicon thin films were deposited by plasma-enhanced chemical vapor deposition on metalized porous layers. Deposited amorphous thin films were crystallized under vacuum at 750°C. Obtained results from structural, optical, and electrical characterizations show that thermal annealing of amorphous silicon deposited on Ni-metalized porous silicon leads to an enhancement in the crystalline quality and physical properties of the silicon thin films. The improvement in the quality of the film is due to the crystallization of the amorphous film during annealing. This simple and easy method can be used to produce silicon thin films with high quality suitable for thin film solar cell applications.

  17. Research on high-speed deposition thermodynamics characteristic for DLC thin film by RF-PECVD

    NASA Astrophysics Data System (ADS)

    Zhu, Mi; Xiong, Changxin; Yang, Changcheng

    2009-05-01

    Diamond-like carbon (DLC) thin film is often used on the surface of Infrared windows as the protecting film. PECVD method is one of the principal ways to obtain DLC film. The key factors, which affect the deposition rate of DLC film, and how to achieve high speed rate have been analyzed in this work. We prepared high-speed deposition DLC film samples on Germanium and Silicon by RF-PECVD, and the relationships between deposition rate, RF power, vacuum degree and dimension size of substrates, deposition temperature have been investigated. We found that when the deposition temperature rises, the deposition rate would rise correspondingly but fall down later. According to MIL-48616 environmental stability standards, the environmental and physical durability test results and the curve of spectrum are also presented in detail in the paper.

  18. AFM investigation and optical band gap study of chemically deposited PbS thin films

    NASA Astrophysics Data System (ADS)

    Zaman, S.; Mansoor, M.; Abubakar; Asim, M. M.

    2016-08-01

    The interest into deposition of nanocrystalline PbS thin films, the potential of designing and tailoring both the topographical features and the band gap energy (Eg) by controlling growth parameters, has significant technological importance. Nanocrystalline thin films of lead sulfide were grown onto glass substrates by chemical bath deposition (CBD) method. The experiments were carried out by varying deposition temperature. We report on the modification of structural and optical properties as a function of deposition temperature. The morphological changes of the films were analyzed by using SEM and AFM. AFM was also used to calculate average roughness of the films. XRD spectra indicated preferred growth of cubic phase of PbS films in (200) direction with increasing deposition time. Optical properties have been studied by UV-Spectrophotometer. From the diffused reflectance spectra we have calculated the optical Eg shift from 0.649-0.636 eV with increasing deposition time.

  19. Crystallization of bismuth titanate and bismuth silicate grown as thin films by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Harjuoja, Jenni; Väyrynen, Samuli; Putkonen, Matti; Niinistö, Lauri; Rauhala, Eero

    2006-01-01

    Bismuth silicate and bismuth titanate thin films were deposited by atomic layer deposition (ALD). A novel approach with pulsing of two Bi-precursors was studied to control the Si/Bi atomic ratio in bismuth silicate thin films. The crystallization of compounds formed in the Bi 2O 3-SiO 2 and Bi 2O 3-TiO 2 systems was investigated. Control of the stoichiometry of Bi-Si-O thin films was studied when deposited on Si(1 0 0) and crystallization was studied for films on sapphire and MgO-, ZrO 2- and YSZ-buffered Si(1 0 0). The Bi-Ti-O thin films were deposited on Si(1 0 0) substrate. Both Bi-Si-O and Bi-Ti-O thin films were amorphous after deposition. Highly a-axis oriented Bi 2SiO 5 thin films were obtained when the Bi-Si-O thin films deposited on MgO-buffered Si(1 0 0) were annealed at 800 °C in nitrogen. The full-width half-maximum values for 200 peak were also studied. An excess of bismuth was found to improve the crystallization of Bi-Ti-O thin films and the best crystallinity was observed with Ti/Bi atomic ratio of 0.28 for films annealed at nitrogen at 1000 °C. Roughness of the thin films as well as the concentration depth distribution were also examined.

  20. Thermochromic properties of Sn, W co-doped VO2 nanostructured thin film deposited by pulsed laser deposition.

    PubMed

    Hur, M G; Masaki, T; Yoon, D H

    2014-12-01

    Tin (Sn) and tungsten (W) co-doped vanadium dioxide (VO2) nanostructured thin films with 50-nm thickness were deposited by pulsed laser deposition (PLD) to reduce the transition temperature and improve the IR transmittance. The crystal structure of the nanostructured thin films and the presence of elements were evaluated by XRD and XPS analysis. The transition temperature (T(c)) of 1 at% Sn-1 at% W co-doped VO2 nanostructured thin film was decreased to about 22 degrees C (from 70.3 to 48.5 degrees C) compared with the undoped VO2 nanostructured thin film. The transmittance width in the IR range of the co-doped nanostructured thin film decreased from 37.5% to 27% compared with the undoped VO2 nanostructured thin film. Also, the width of hysteresis was narrowed by Sn doping. PMID:25970986

  1. Thermochromic properties of Sn, W co-doped VO2 nanostructured thin film deposited by pulsed laser deposition.

    PubMed

    Hur, M G; Masaki, T; Yoon, D H

    2014-12-01

    Tin (Sn) and tungsten (W) co-doped vanadium dioxide (VO2) nanostructured thin films with 50-nm thickness were deposited by pulsed laser deposition (PLD) to reduce the transition temperature and improve the IR transmittance. The crystal structure of the nanostructured thin films and the presence of elements were evaluated by XRD and XPS analysis. The transition temperature (T(c)) of 1 at% Sn-1 at% W co-doped VO2 nanostructured thin film was decreased to about 22 degrees C (from 70.3 to 48.5 degrees C) compared with the undoped VO2 nanostructured thin film. The transmittance width in the IR range of the co-doped nanostructured thin film decreased from 37.5% to 27% compared with the undoped VO2 nanostructured thin film. Also, the width of hysteresis was narrowed by Sn doping.

  2. Structural and optical properties of SrCu2O2 films deposited on sapphire substrates by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Tambunan, Octolia Togibasa; Tukiman, Hadiyawarman; Parwanta, Kadek Juliana; Jeong, Da Woon; Jung, Chang Uk; Rhee, Seuk Joo; Liu, Chunli

    2012-10-01

    We deposited SrCu2O2 (SCO) films on sapphire (Al2O3) (0 0 0 1) substrates by pulsed laser deposition. The crystallographic orientation of the SCO thin film showed clear dependence on the growth temperature. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis showed that the film deposited at 400 °C was mainly oriented in the SCO [2 0 0] direction, whereas when the growth temperature was increased to 600 °C, the SCO film showed a dominant orientation of SCO [1 1 2]. The SCO film deposited at 500 °C was obvious polycrystalline, showing multi peaks from (2 0 0), (1 1 2), and (2 1 1) diffraction in the XRD spectrum. The SCO film deposited at 600 °C showed a band gap energy of 3.3 eV and transparency up to 80% around 500 nm. The photoluminescence (PL) spectra of the SCO films grown at 500 °C and 600 °C mainly showed blue-green emission, which was attributed to the intra-band transition of the isolated Cu+ and Cu+-Cu+ pairs according to the temperature dependent-PL analysis.

  3. Soap-film coating: High-speed deposition of multilayer nanofilms

    PubMed Central

    Zhang, Renyun; Andersson, Henrik A.; Andersson, Mattias; Andres, Britta; Edlund, Håkan; Edström, Per; Edvardsson, Sverker; Forsberg, Sven; Hummelgård, Magnus; Johansson, Niklas; Karlsson, Kristoffer; Nilsson, Hans-Erik; Norgren, Magnus; Olsen, Martin; Uesaka, Tetsu; Öhlund, Thomas; Olin, Håkan

    2013-01-01

    The coating of thin films is applied in numerous fields and many methods are employed for the deposition of these films. Some coating techniques may deposit films at high speed; for example, ordinary printing paper is coated with micrometre-thick layers of clay at a speed of tens of meters per second. However, to coat nanometre thin films at high speed, vacuum techniques are typically required, which increases the complexity of the process. Here, we report a simple wet chemical method for the high-speed coating of films with thicknesses at the nanometre level. This soap-film coating technique is based on forcing a substrate through a soap film that contains nanomaterials. Molecules and nanomaterials can be deposited at a thickness ranging from less than a monolayer to several layers at speeds up to meters per second. We believe that the soap-film coating method is potentially important for industrial-scale nanotechnology. PMID:23503102

  4. Aerosol-assisted chemical vapor deposition (AACVD) of binary alloy films: Studies of film composition

    SciTech Connect

    Xu, C.; Hampden-Smith, M.J.; Kodas, T.T.

    1995-08-01

    The chemical vapor deposition (CVD) of Cu-Ag and Cu-Pd alloys using aerosol precursor delivery over a range of preheating temperatures, 70 {approximately} 80 C and substrate temperatures, 250 {approximately} 300 C is described. The precursors used include Cu(hfac){sub 2}, (hfac)Ag(SEt{sub 2}) and Pd(hfac){sub 2} dissolved in toluene and 10% H{sub 2} in Ar as carrier gas. The films were characterized by SEM, EDS and X-ray diffraction (XRD). The X-ray diffraction results showed the Cu/Ag films were composed of {alpha}- and {beta}-phases of Cu-Ag alloys, the Cu/Pd films were Cu-Pd and Pd-Ag alloy, solid solutions, under these conditions. Compositional variation studies in Cu-Pd and Pd-Ag alloy systems were also conducted by mixing Cu(hfac){sub 2}/Pd(hfac){sub 2} and (hfac) Ag(SEt{sub 2})/Pd(hfac){sub 2} in toluene solution in different ratios. The films were characterized by X-ray diffraction and the results showed the composition of films was affected by the solution stoichiometry.

  5. Tunable hydrophilicity on a hydrophobic fluorocarbon polymer coating on silicon

    SciTech Connect

    Kolari, K.; Hokkanen, A.

    2006-07-15

    An efficient, economic, reliable, and repeatable patterning procedure of hydrophobic surfaces was developed. A fluorocarbon polymer derived from the C{sub 4}F{sub 8} gas in an inductively coupled plasma etcher was used as the hydrophobic coating. For a subsequent patterning of hydrophilic apertures on the polymer, a short O{sub 2} plasma exposure through a silicon shadow mask was utilized. The overall hydrophilicity of the patterned surface can be tuned by the duration of the O{sub 2} plasma exposure, and also by the density and the size of the hydrophilic apertures. The laborious photolithography and tricky lift-off procedures are avoided. Optimization of the whole patterning process is explained thoroughly and supported with experimental data. The hydrophilic adhesion of the patterned polymer was evaluated with aqueous droplets, which were studied on matrices of the hydrophilic apertures of different sizes. The deposition parameters of the fluorocarbon polymer, the size of the droplet required to enable rolling on the patterned surface, and the duration of the O{sub 2} plasma exposure were considered as the main parameters. To determine the achievable resolution of the patterning procedure, the subsurface etching beneath the shadow mask was evaluated. The results show that a resolution of less than 10 {mu}m can be achieved. The simple hydrophilic patterning procedure described here can be used for the production of on-plane microfluidics, where a controlled adhesion or decohesion of 8-50 {mu}l droplets on the surface with a variable hydrophilicity from one location to another can be achieved.

  6. Phase, grain structure, stress, and resistivity of sputter-deposited tungsten films

    SciTech Connect

    Choi, Dooho; Wang, Bincheng; Chung, Suk; Liu Xuan; Darbal, Amith; Wise, Adam; Nuhfer, Noel T.; Barmak, Katayun; Warren, Andrew P.; Coffey, Kevin R.; Toney, Michael F.

    2011-09-15

    Sputter-deposited W films with nominal thicknesses between 5 and 180 nm were prepared by varying the base pressure prior to film deposition and by including or not including sputtered SiO{sub 2} encapsulation layers. X-ray and electron diffraction studies showed that single phase, polycrystalline {alpha}-W could be achieved in as-deposited films as thin as 5 nm. The stress state in the as-deposited films was found to be inhomogeneous. Annealing resulted in stress relaxation and reduction of resistivity for all films, except the thinnest, unencapsulated film, which agglomerated. In-plane film grain sizes measured for a subset of the annealed films with thicknesses between 5 and 180 nm surprisingly showed a near constant value (101-116 nm), independent of film thickness. Thick-film ({>=}120 nm) resistivity values as low as 8.6 {mu}{Omega} cm at 301 K were obtained after annealing at 850 deg. C for 2 h. Film resistivities were found to increase with decreasing film thicknesses below 120 nm, even for films which are fully A2 {alpha}-W with no metastable, A15 {beta}-W evident.

  7. Uses of ion bombardment in thin-film deposition

    SciTech Connect

    Erck, R.A.; Fenske, G.R.; Erdemir, A.

    1990-10-01

    Use of plasma- and ion-beam-modified surfaces and surface coatings in continually expanding in engineering disciplines. The purpose of these modifications and treatments is to impart favorable properties, such as wear resistance and lubricity, to the surfaces, while at the same time retaining the strength or toughness of the bulk materials. Energetic-ion bombardment can be used to modify the structural and chemical properties of surfaces or applied coatings. Ion-implantation has been used for many years, and recently, other surface-modification techniques, among them ion-beam mixing and ion-beam-assisted deposition, have attracted attention because they permit application of highly adherent lubricious and wear-resistant films. In this paper, ion-beam techniques are described from the viewpoint of ion-surface interactions, and some avenues for the engineering of tribological surfaces are presented. 100 refs., 4 figs.

  8. Thin-film deposition and characterization for neutron detection applications

    NASA Astrophysics Data System (ADS)

    Misiano, C.; Trucchi, D. M.; Renzelli, M.; Bemporad, E.; Santoni, A.; Pietropaolo, A.; Vannozzi, A.; Celentano, G.

    2015-10-01

    Solid state physics experimental techniques and characterization tools can provide a valuable contribution to the research and development activity on He-free neutron detection systems, for both detector assessment and performance improvement. Presently, a He replacement strategy relies on the use of 6Li - and/or 10B -based neutron-to-charged particle converters coupled to radiation detectors (solid state, gaseous and scintillators). These topics have been discussed during a devoted session within the HeRe (He- Replacement) in Italy Workshop held in Frascati at the ENEA Research Centre, and this paper aims at presenting a brief overview on possible deposition and characterization techniques of thin films that have been subject of discussion.

  9. Nanomechanical properties of platinum thin films synthesized by atomic layer deposition

    SciTech Connect

    Mamun, M.A.; Gu, D.; Baumgart, H.; Elmustafa, A.A.

    2015-03-01

    The nanomechanical properties of Pt thin films grown on Si (100) using atomic layer deposition (ALD) were investigated using nanoindentation. Recently, atomic layer deposition (ALD) has successfully demonstrated the capability to deposit ultra-thin films of platinum (Pt). Using (methylcyclopentadienyl) trimethylplatinum (MeCpPtMe3) as chemical platinum precursor and oxygen (O2) as the oxidizing agent, the ALD synthesis of Pt can be achieved with high conformity and excellent film uniformity. The ALD process window for Pt films was experimentally established in the temperature range between 270 °C and 320 °C, where the sheet conductance was constant over that temperature range, indicating stable ALD Pt film growth rate. ALD growth of Pt films exhibits very poor nucleation and adhesion characteristics on bare Si surfaces when the native oxide was removed by 2% HF etch. Pt adhesion improves for thermally oxidized Si wafers and for Si wafers covered with native oxide. Three ALD Pt films deposited at 800, 900, and 1000 ALD deposition cycles were tested for the structural and mechanical properties. Additionally, the sample with 900 ALD deposition cycles was further annealed in forming gas (95% N2 and 5% H2) at 450 °C for 30 min in order to passivate dangling bonds in the grain boundaries of the polycrystalline Pt film. Cross-sectional transmission electron microscopy (TEM), X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscope (SEM) were employed to characterize the films' surface structure and morphology. Nanoindentation technique was used to evaluate the hardness and modulus of the ALD Pt films of various film thicknesses. The results indicate that the films depict comparable hardness and modulus results; however, the 800 and 1000 ALD deposition cycles films without forming gas annealing experienced significant amount of pileup, whereas the 900 ALD deposition cycles sample annealed in forming gas resulted in a smaller pileup.

  10. A review of basic phenomena and techniques for sputter-deposition of high temperature superconducting films

    SciTech Connect

    Auciello, O. North Carolina State Univ., Raleigh, NC . Dept. of Materials Science and Engineering); Ameen, M.S.; Kingon, A.I.; Lichtenwalner, D.J. . Dept. of Materials Science and Engineering); Krauss, A.R. )

    1990-01-01

    The processes involved in plasma and ion beam sputter-deposition of high temperature superconducting thin films are critically reviewed. Recent advances in the development of these techniques are discussed in relation to basic physical phenomena, specific to each technique, which must be understood before high quality films can be produced. Control of film composition is a major issue in sputter-deposition of multicomponent materials. Low temperature processing of films is a common goal for each technique, particularly in relation to integrating high temperature superconducting films with the current microelectronics technology. It has been understood for some time that for Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} deposition, the most intensely studied high-{Tc} compound, incorporation of sufficient oxygen into the film during deposition is necessary to produce as-deposited superconducting films at relatively substrate temperatures. Recent results have shown that with the use of suitable buffer layers, high quality Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} sputtered films can be obtained on Si substrates without the need for post-deposition anneal processing. This review is mainly focussed on issues related to sputter-deposition of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} thin films, although representative results concerning the bismuth and thallium based compounds are included. 143 refs., 11 figs.

  11. High Pressure Chemical Vapor Deposition of Hydrogenated Amorphous Silicon Films and Solar Cells.

    PubMed

    He, Rongrui; Day, Todd D; Sparks, Justin R; Sullivan, Nichole F; Badding, John V

    2016-07-01

    Thin films of hydrogenated amorphous silicon can be produced at MPa pressures from silane without the use of plasma at temperatures as low as 345 °C. High pressure chemical vapor deposition may open a new way to low cost deposition of amorphous silicon solar cells and other thin film structures over very large areas in very compact, simple reactors. PMID:27174318

  12. High Pressure Chemical Vapor Deposition of Hydrogenated Amorphous Silicon Films and Solar Cells.

    PubMed

    He, Rongrui; Day, Todd D; Sparks, Justin R; Sullivan, Nichole F; Badding, John V

    2016-07-01

    Thin films of hydrogenated amorphous silicon can be produced at MPa pressures from silane without the use of plasma at temperatures as low as 345 °C. High pressure chemical vapor deposition may open a new way to low cost deposition of amorphous silicon solar cells and other thin film structures over very large areas in very compact, simple reactors.

  13. Molecular dynamics simulation about porous thin-film growth in secondary deposition

    NASA Astrophysics Data System (ADS)

    Chen, Huawei; Tieu, A. Kiet; Liu, Qiang; Hagiwara, Ichiro; Lu, Cheng

    2007-07-01

    The thin film growth has been confirmed to be assembled by an enormous number of clusters in experiments of CVD. Sequence of clusters' depositions proceeds to form the thin film at short time as gas fluids through surface of substrate. In order to grow condensed thin film using series of cluster deposition, the effect of initial velocity, substrate temperature and density of clusters on property of deposited thin film, especially appearance of nanoscale pores inside thin film must be investigated. In this simulation, three different cluster sizes of 203, 653, 1563 atoms with different velocities (0, 10, 100, 1000 and 3000 m/s) were deposited on a Cu(0 0 1) substrate whose temperatures were set between 300 and 1000 K. Four clusters and one cluster were used in primary deposition and secondary deposition, respectively. We have clarified that adhesion between clusters and substrate is greatly influenced by initial velocity. As a result, the exfoliation pattern of deposited thin film is dependent on initial velocity and different between them. One borderline dividing whole region into porous region and nonporous region are obtained to show the effect of growth conditions on appearance of nanoscale pores inside thin film. Moreover, we have also shown that the likelihood of porous thin film is dependent on the point of impact of a cluster relative to previously deposited clusters.

  14. Characterization Of Fe{sub 1-x}Co{sub x}Si Thin Films Deposited Via Pulsed Laser Deposition

    SciTech Connect

    Manyala, N.; Ngom, Balla; Kana-Kana, J. B.; Bucher, Remy; Maaza, M.; Di Tusa, J. F.

    2008-09-23

    We report on the structural and morphological characterization of B20 cubic structure Fe{sub 1-x}Co{sub x}Si thin films grown by pulsed laser deposition for the concentration range 0{<=}x{<=}0.3 deposited on Si (111) substrate. The x-ray diffraction, Rutherford back scattering (RBS), Scanning Electron microscopy (SEM) and Atomic force microscopy (AFM) of the films show that all the films are single phase B20 cubic structure with concentrations close to expected values, very smooth and dense with surface roughness less than 0.8 nm.

  15. Process for synthesizing a new series of fluorocarbon polymers

    NASA Technical Reports Server (NTRS)

    Toy, M. S.

    1970-01-01

    Two-step process for preparing fluorocarbon materials includes - /1/ adding gaseous fluorine to a polyperfluoropolyene to create fluorocarbon radicals, with reactive sites at unsaturated carbon atoms, and /2/ introducing a monomer, after evacuation of fluorine gas, and allowing copolymerization with the free radicals.

  16. Characterization of chemical-vapor-deposited low-k thin films using x-ray porosimetry

    NASA Astrophysics Data System (ADS)

    Lee, Hae-Jeong; Lin, Eric K.; Bauer, Barry J.; Wu, Wen-li; Hwang, Byung Keun; Gray, William D.

    2003-02-01

    Trimethylsilane-based carbon-doped silica films prepared with varying chemical-vapor-deposition process conditions were characterized using x-ray reflectivity and porosimetry to measure the film thickness, average film density, density depth profile, wall density, and porosity. Samples deposited under single or dual frequency conditions with either N2O or O2 as an oxidant were compared. The structural parameters were correlated with the chemical bond structure measured by Fourier transform infrared spectroscopy. The density profiles of the porous films were uniform with a slight densification at the film surface. The distribution of pores was also uniform through the film. Films prepared under a single frequency and/or N2O atmosphere had the lowest film density, wall density, and dielectric constant. The porosities of the films were similar and the pore sizes were less than 10 Å.

  17. Annealing of TiO2 Films Deposited on Si by Irradiating Nitrogen Ion Beams

    SciTech Connect

    Yokota, Katsuhiro; Yano, Yoshinori; Miyashita, Fumiyoshi

    2006-11-13

    Thin TiO2 films were deposited on Si at a temperature of 600 deg. C by an ion beam assisted deposition (IBAD) method. The TiO2 films were annealed for 30 min in Ar at temperatures below 700 deg. C. The as-deposited TiO2 films had high permittivities such 200 {epsilon}o and consisted of crystallites that were not preferentially oriented to the c-axis but had an expanded c-axis. On the annealed TiO2 films, permittivities became lower with increasing annealing temperature, and crystallites were oriented preferentially to the (110) plane.

  18. Computer modeling of Y-Ba-Cu-O thin film deposition and growth

    SciTech Connect

    Burmester, C.; Gronsky, R. ); Wille, L. . Dept. of Physics)

    1991-07-01

    The deposition and growth of epitaxial thin films of YBa{sub 2}Cu{sub 3}O{sub 7} are modeled by means of Monte Carlo simulations of the deposition and diffusion of Y, Ba, and Cu oxide particles. This complements existing experimental characterization techniques to allow the study of kinetic phenomena expected to play a dominant role in the inherently non-equilibrium thin film deposition process. Surface morphologies and defect structures obtained in the simulated films are found to closely resemble those observed experimentally. A systematic study of the effects of deposition rate and substrate temperature during in-situ film fabrication reveals that the kinetics of film growth can readily dominate the structural formation of the thin film. 16 refs., 4 figs.

  19. Deposition of thermoelectric strontium hexaboride thin films by a low pressure CVD method

    NASA Astrophysics Data System (ADS)

    Tynell, Tommi; Aizawa, Takashi; Ohkubo, Isao; Nakamura, Katsumitsu; Mori, Takao

    2016-09-01

    Thin films of SrB6 were deposited on sapphire substrates using a chemical vapor deposition method, with elemental strontium and decaborane, B10H14, used as the strontium and boron sources, respectively. The formation of highly crystalline, phase-pure SrB6 films was confirmed with X-ray diffraction and reflection high energy diffraction (RHEED) analysis, and the films' thermoelectric transport properties were measured. A relatively high deposition temperature of 850-950 °C was found to be optimal for obtaining well-crystallized films at an extremely high deposition rate. The thermoelectric transport properties of the SrB6 thin films were observed to be comparable to those reported for bulk materials, but an unexpectedly high electrical resistivity led to a reduced power factor value for the thin films.

  20. Preparation of cuxinygazsen precursor films and powders by electroless deposition

    DOEpatents

    Bhattacharya, Raghu N.; Batchelor, Wendi Kay; Wiesner, Holm; Ramanathan, Kannan; Noufi, Rommel

    1999-01-01

    A method for electroless deposition of Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3) precursor films and powders onto a metallic substrate comprising: preparing an aqueous bath solution of compounds selected from the group consisting of: I) a copper compound, a selenium compound, an indium compound and gallium compound; II) a copper compound, a selenium compound and an indium compound; III) a selenium compound, and indium compound and a gallium compound; IV) a selenium compound and a indium compound; and V) a copper compound and selenium compound; each compound being present in sufficient quantity to react with each other to produce Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3); adjusting the pH of the aqueous bath solution to an acidic value by the addition of a dilute acid; and initiating an electroless reaction with an oxidizing counterelectrode for a sufficient time to cause a deposit of Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3) from the aqueous bath solution onto a metallic substrate.

  1. Diverse Amorphous Carbonaceous Thin Films Obtained by Plasma Enhanced Chemical Vapor Deposition and Plasma Immersion Ion Implantation and Deposition

    NASA Astrophysics Data System (ADS)

    Santos, R. M.; Turri, R.; Rangel, E. C.; da Cruz, N. C.; Schreiner, W.; Davanzo, C. U.; Durrant, S. F.

    Diverse amorphous hydrogenated carbon and similar films containing additional elements were produced by Plasma Enhanced Chemical Vapor Deposition (PECVD) and by Plasma Immersion Ion Implantation and Deposition (PIIID). Thus a-C:H, a-C:H:F, a-C:H:N, a-C:H:Cl and a-C:H:O:Si were obtained, starting from the same feed gases, using both techniques. The same deposition system supplied with radiofrequency (RF) power was used to produce all the films. A cylindrical stainless steel chamber equipped with circular electrodes mounted horizontally was employed. RF power was fed to the upper electrode; substrates were placed on the lower electrode. For PIIID negative high tension pulses were also applied to the lower electrode. Raman spectroscopy confirmed that all the films are amorphous. Chemical characterization of each pair of films was undertaken using Infrared Reflection Absorption Spectroscopy and X-ray Photoelectron Spectroscopy. The former revealed the presence of specific structures, such as C-H, C-O, O-H. The latter allowed calculation of the ratio of hetero-atoms to carbon atoms in the films, e.g. F:C, N:C, and Si:C. Only relatively small differences in elemental composition were detected between films produced by the two methods. The deposition rate in PIIID is generally reduced in relation to that of PECVD; for a-C:H:Cl films the reduction factor is almost four.

  2. Surface Modification of Polymer Photoresists in Fluorocarbon Plasma Etching

    NASA Astrophysics Data System (ADS)

    Wang, Mingmei; Kushner, Mark

    2009-10-01

    In plasma etching of high aspect ratio (AR), nm sized features, erosion of polymer photoresist (PR) can perturb the feature profile (e.g., bowing). Although cross-linking of PR due to ion and VUV fluxes could make it more resistive to etching, typically the PR etch rate is too high to maintain the pattern when the AR is large (> 20). In dielectric plasma etching using fluorocarbon gases, one strategy to prevent PR erosion is to deposit a (CxFy)n polymer on its surface. This process may be enhanced in dc-augmented capacitively coupled plasmas (CCPs) by sputtering of Si and CxFy from the dc biased electrode. Dangling bonds generated on the PR surface by ion, photon or electron bombardment trap Si and CxFy radicals forming Si-C and C-C bonds. Sputtered Si atoms can also react with CxFy radicals to produce more reactive CxFy-1 radicals which are more easily incorporated into the PR. In this talk we discuss scaling laws for radical production derived from a computational investigation of a dc-augmented dual frequency CCP reactor sustained in Ar/C4F8/O2. Fluxes of Si radicals are produced by sputtering of the dc electrode. Rates of polymer deposition on and sputtering of PR, and consequences of PR erosion (and deposition) on feature profiles will be discussed.

  3. Pulsed laser deposition of carbon nanotube and polystyrene-carbon nanotube composite thin films

    NASA Astrophysics Data System (ADS)

    Stramel, A. A.; Gupta, M. C.; Lee, H. R.; Yu, J.; Edwards, W. C.

    2010-12-01

    In this work, we report on the fabrication of carbon nanotube thin films via pulsed laser deposition using a pulsed, diode pumped, Tm:Ho:LuLF laser with 2 μm wavelength. The thin films were deposited on silicon substrates using pure carbon nanotube targets and polystyrene-carbon nanotube composite targets. Raman spectra, scanning electron micrographs, and transmission electron micrographs show that carbon nanotubes are present in the deposited thin films, and that the pulsed laser deposition process causes minimal degradation to the quality of the nanotubes when using pure carbon nanotube targets.

  4. Solar-induced chemical vapor deposition of diamond-type carbon films

    DOEpatents

    Pitts, J. Roland; Tracy, C. Edwin; King, David E.; Stanley, James T.

    1994-01-01

    An improved chemical vapor deposition method for depositing transparent continuous coatings of sp.sup.3 -bonded diamond-type carbon films, comprising: a) providing a volatile hydrocarbon gas/H.sub.2 reactant mixture in a cold wall vacuum/chemical vapor deposition chamber containing a suitable substrate for said films, at pressure of about 1 to 50 Torr; and b) directing a concentrated solar flux of from about 40 to about 60 watts/cm.sup.2 through said reactant mixture to produce substrate temperatures of about 750.degree. C. to about 950.degree. C. to activate deposition of the film on said substrate.

  5. Solar-induced chemical vapor deposition of diamond-type carbon films

    DOEpatents

    Pitts, J.R.; Tracy, C.E.; King, D.E.; Stanley, J.T.

    1994-09-13

    An improved chemical vapor deposition method for depositing transparent continuous coatings of sp[sup 3]-bonded diamond-type carbon films, comprises: (a) providing a volatile hydrocarbon gas/H[sub 2] reactant mixture in a cold wall vacuum/chemical vapor deposition chamber containing a suitable substrate for said films, at pressure of about 1 to 50 Torr; and (b) directing a concentrated solar flux of from about 40 to about 60 watts/cm[sup 2] through said reactant mixture to produce substrate temperatures of about 750 C to about 950 C to activate deposition of the film on said substrate. 11 figs.

  6. Deposition of hydroxyapatite thin films by Nd:YAG laser ablation: a microstructural study

    SciTech Connect

    Nistor, L.C.; Ghica, C.; Teodorescu, V.S.; Nistor, S.V. . E-mail: snistor@alpha1.infim.ro; Dinescu, M.; Matei, D.; Frangis, N.; Vouroutzis, N.; Liutas, C.

    2004-11-02

    Hydroxyapatite (HA) thin films has been successfully deposited by Nd:YAG laser ablation at {lambda} = 532 nm. The morphology and microstructure of the deposited layers was studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). Polycrystalline HA films were directly obtained with the substrate at 300 deg. C and without introducing water vapors in the deposition chamber. Electron paramagnetic resonance (EPR) measurements show that the oxygen stoichiometry in the HA films is also maintained. Depositions performed at {lambda} = 335 nm laser wavelength and 300 deg. C substrate temperature resulted in polycrystalline layers of mixed composition of HA and tricalciumphosphate (TCP)

  7. Chromium Carbide Thin Films Synthesized by Pulsed Nd:YAG Laser Deposition

    NASA Astrophysics Data System (ADS)

    Suda, Yoshiaki; Kawasaki, Hiroharu; Terajima, Ryou; Emura, Masanari

    1999-06-01

    Chromium carbide thin films are synthesized on Si(100)substrates by a pulsed Nd:YAG laser deposition method at differentsubstrate temperatures. Glancing-angle X-ray diffraction shows that acrystalline chromium carbide film can be prepared at the substratetemperature of 700°C. Grain size of the films, examined witha field-emission secondary electron microscope, increases withincreasing substrate temperature.

  8. Thin-film ferrites vapor deposited by one-step process in vacuum

    NASA Technical Reports Server (NTRS)

    Hacskaylo, M.

    1966-01-01

    Thin-film ferrites are formed by vapor deposition of a mixture of powdered ferrites and powdered boron oxide at controlled temperatures in a vacuum chamber. These films are used in memory devices for computers and as thin-film inductors in communications and telemetry systems.

  9. Dynamical Structures in Phase-Separated Films Deposited under Ion Bombardment

    SciTech Connect

    He, J. H.; Carosella, C. A.; Hubler, G. K.; Knies, D. L.; Qadri, S. B.; Grabowski, K. S.

    2009-03-10

    We report our experimental observation of ion bombardment effect on the film structures generated by co-evaporation of Au and silica. Three states are identified depending on the incident ion energy and beam current. Moderate ion bombardment creates nanoscale compositional modulations along the film growth direction. Strong ion bombardment induces disappearance of the compositional modulations. At still higher energy and flux, energetic ions sputter away all deposited atoms. The observed phenomena reflect synergistic effects of ion bombardment on the film growth in phase separated systems. Our observations suggest that ion beams can be employed to control the film structures in the deposition of phase-separated films.

  10. X-ray absorption study of pulsed laser deposited boron nitride films

    SciTech Connect

    Chaiken, A.; Terminello, L.J.; Wong, J.; Doll, G.L.; Sato, T.

    1994-02-02

    B and N K-edge x-ray absorption spectroscopy measurements have been performed on three BN thin films grown on Si substrates using ion- assisted pulsed laser deposition. Comparison of the films` spectra to those of several single-phase BN powder standards shows that the films consist primarily of sp{sup 2} bonds. Other features in the films`s spectra suggest the presence of secondary phases, possibly cubic or rhombohedral BN. Films grown at higher deposition rates and higher ion-beam voltages are found to be more disordered, in agreement with previous work.

  11. Spoof-like plasmonic behavior of plasma enhanced atomic layer deposition grown Ag thin films

    SciTech Connect

    Prokes, S. M.; Glembocki, O. J.; Cleveland, Erin; Caldwell, Josh D.; Foos, Edward; Niinistoe, Jaakko; Ritala, Mikko

    2012-01-30

    The plasmonic behavior of Ag thin films produced by plasma enhanced atomic layer deposition (PEALD) has been investigated. We show that as-deposited flat PEALD Ag films exhibit unexpected plasmonic properties, and the plasmonic enhancement can differ markedly, depending on the microstructure of the Ag film. Electromagnetic field simulations indicate that this plasmonic behavior is due to air gaps that are an inherent property of the mosaic-like microstructure of the PEALD-grown Ag film, suggesting that this is a metamaterial with behavior very similar to what would be expected in spoof plasmonics where gaps are fabricated in films to create plasmonic-like resonances.

  12. Deposition and Characterization of Thin Films on Metallic Substrates

    NASA Technical Reports Server (NTRS)

    Gatica, Jorge E.

    2005-01-01

    A CVD method was successfully developed to produce conversion coatings on aluminum alloys surfaces with reproducible results with a variety of precursors. A well defined protocol to prepare the precursor solutions formulated in a previous research was extended to other additives. It was demonstrated that solutions prepared following such a protocol could be used to systematically generate protective coatings onto aluminum surfaces. Experiments with a variety of formulations revealed that a refined deposition protocol yields reproducible conversion coatings of controlled composition. A preliminary correlation between solution formulations and successful precursors was derived. Coatings were tested for adhesion properties enhancement for commercial paints. A standard testing method was followed and clear trends were identified. Only one precursors was tested systematically. Anticipated work on other precursors should allow a better characterization of the effect of intermetallics on the production of conversion/protective coatings on metals and ceramics. The significance of this work was the practical demonstration that chemical vapor deposition (CVD) techniques can be used to systematically generate protective/conversion coating on non-ferrous surfaces. In order to become an effective approach to replace chromate-based pre- treatment processes, namely in the aerospace or automobile industry, the process parameters must be defined more precisely. Moreover, the feasibility of scale-up designs necessitates a more comprehensive characterization of the fluid flow, transport phenomena, and chemical kinetics interacting in the process. Kinetic characterization showed a significantly different effect of magnesium-based precursors when compared to iron-based precursors. Future work will concentrate on refining the process through computer simulations and further experimental studies on the effect of other transition metals to induce deposition of conversion/protective films

  13. Deposition and characterization of molybdenum thin films using dc-plasma magnetron sputtering

    SciTech Connect

    Khan, Majid; Islam, Mohammad

    2013-12-15

    Molebdenum (Mo) thin films were deposited on well-cleaned soda-lime glass substrates using DC-plasma magnetron sputtering. In the design of experiment deposition was optimized for maximum beneficial characteristics by monitoring effect of process variables such as deposition power (100–200 W). Their electrical, structural and morphological properties were analyzed to study the effect of these variables. The electrical resistivity of Mo thin films could be reduced by increasing deposition power. Within the range of analyzed deposition power, Mo thin films showed a mono crystalline nature and the crystallites were found to have an orientation along [110] direction. The surface morphology of thin films showed that a highly dense micro structure has been obtained. The surface roughness of films increased with deposition power. The adhesion of Mo thin films could be improved by increasing the deposition power. Atomic force microscopy was used for the topographical study of the films and to determine the roughness of the films. X-ray diffractrometer and scanning electron microscopy analysis were used to investigate the crystallinity and surface morphology of the films. Hall effect measurement system was used to find resistivity, carrier mobility and carrier density of deposited films. The adhesion test was performed using scotch hatch tape adhesion test. Mo thin films prepared at deposition power of 200 W, substrate temperature of 23°C and Ar pressure of 0.0123 mbar exhibited a mono crystalline structure with an orientation along (110) direction, thickness of ∼550 nm and electrical resistivity value of 0.57 × 10{sup −4} Ω cm.

  14. Optical and mechanical properties of nanocrystalline ZrC thin films grown by pulsed laser deposition.

    DOE PAGES

    Craciun, D.; Socol, G.; Lambers, E.; McCumiskey, E. J.; Taylor, C. R.; Martin, C.; Argibay, Nicolas; Craciun, V.; Tanner, D. B.

    2015-01-17

    Thin ZrC films (<500 nm) were grown on (100) Si substrates at a substrate temperature of 500 °C by the pulsed laser deposition (PLD) technique using a KrF excimer laser under different CH4 pressures. Glancing incidence X-ray diffraction showed that films were nanocrystalline, while X-ray reflectivity studies found out films were very dense and exhibited a smooth surface morphology. Optical spectroscopy data shows that the films have high reflectivity (>90%) in the infrared region, characteristic of metallic behavior. Nanoindentation results indicated that films deposited under lower CH4 pressures exhibited slightly higher nanohardness and Young modulus values than films deposited undermore » higher pressures. As a result, tribological characterization revealed that these films exhibited relatively high wear resistance and steady-state friction coefficients on the order of μ = 0.4.« less

  15. Pulsed laser deposition of NiMnGa thin films on silicon

    NASA Astrophysics Data System (ADS)

    Hakola, A.; Heczko, O.; Jaakkola, A.; Kajava, T.; Ullakko, K.

    Thin films of the magnetic shape-memory (MSM) material NiMnGa have been deposited on Si(100) substrates using pulsed laser deposition. The --200 300nm-thick films were prepared at substrate temperatures ranging from 450 °C to 650 °C and at different background Ar pressures. Large saturation magnetizations, up to 60% of the bulk value, were measured for the films. Only the films deposited in vacuum or at Ar pressures below 10-3 mbar and at temperatures between 500 °C and 600 °C were ferromagnetic. The films are mainly crystallized in the austenitic phase and they have a smooth surface with a low droplet density (0.01 μm-2). The magnetization and surface quality are sufficient that the films could be utilized in the realization of thin-film MSM devices.

  16. Optical and mechanical properties of nanocrystalline ZrC thin films grown by pulsed laser deposition.

    SciTech Connect

    Craciun, D.; Socol, G.; Lambers, E.; McCumiskey, E. J.; Taylor, C. R.; Martin, C.; Argibay, Nicolas; Craciun, V.; Tanner, D. B.

    2015-01-17

    Thin ZrC films (<500 nm) were grown on (100) Si substrates at a substrate temperature of 500 °C by the pulsed laser deposition (PLD) technique using a KrF excimer laser under different CH4 pressures. Glancing incidence X-ray diffraction showed that films were nanocrystalline, while X-ray reflectivity studies found out films were very dense and exhibited a smooth surface morphology. Optical spectroscopy data shows that the films have high reflectivity (>90%) in the infrared region, characteristic of metallic behavior. Nanoindentation results indicated that films deposited under lower CH4 pressures exhibited slightly higher nanohardness and Young modulus values than films deposited under higher pressures. As a result, tribological characterization revealed that these films exhibited relatively high wear resistance and steady-state friction coefficients on the order of μ = 0.4.

  17. Research on titanium nitride thin films deposited by reactive magnetron sputtering for MEMS applications

    NASA Astrophysics Data System (ADS)

    Merie, Violeta; Pustan, Marius; Negrea, Gavril; Bîrleanu, Corina

    2015-12-01

    Titanium nitride can be used among other materials as diffusion barrier for MEMS (microelectromechanical systems) applications. The aim of this study is to elaborate and to characterize at nanoscale titanium nitride thin films. The thin films were deposited by reactive magnetron sputtering on silicon substrates using a 99.99% purity titanium target. Different deposition parameters were employed. The deposition temperature, deposition time, substrate bias voltage and the presence/absence of a titanium buffer layer are the parameters that were modified. The so-obtained films were then investigated by atomic force microscopy. A significant impact of the deposition parameters on the determined mechanical and tribological characteristics was highlighted. The results showed that the titanium nitride thin films deposited for 20 min at room temperature without the presence of a titanium buffer layer when a negative bias of -90 V was applied to the substrate is characterized by the best tribological and mechanical behavior.

  18. The deposit stress behavior and magnetic properties of electrodeposited Ni-Co-Fe ternary alloy films

    NASA Astrophysics Data System (ADS)

    Kim, Jin-Soo; Kwak, Jun-Ho; Na, Seong-Hun; Lim, Seung-Kyu; Suh, Su-Jeong

    2012-08-01

    Ni-Co-Fe ternary alloy films were electrodeposited from a sulfate bath. The effects of the saccharin concentration on the deposit stress behavior of these films were investigated. When the saccharin concentration was 0.004 M, the deposit stress was the lowest (61 MPa, tensile stress mode). Then, the relation between the deposit stress and the magnetic properties was investigated. As the deposit stress of the Ni-Co-Fe thin films decreased from 307 to 61 MPa, the coercivity and the squareness decreased from 6.17 to 1.35 Oe and from 0.65 to 0.18, respectively. The dependence of the deposit stress on the temperature in the plating bath was investigated. As the temperature in the plating bath was increased from 25 to 50 °C the deposit stress of the Ni-Co-Fe alloy films decreased from 61 to 32 MPa.

  19. The effect of bias voltage on the morphology and wettability of plasma deposited titanium oxide films

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Li, Yan; Guo, Kai; Zhang, Jing

    2008-02-01

    Hydrophobic and hydrophilic films with titanium oxide inside were grown by radio frequency plasma enhanced chemical vapor deposition (RF--PECVD) on glass substrates. Bias voltage was used as an assistant for the deposition process. And a comparison was made between with and without the bias voltage. Titanium tetraisopropoxide (TTIP-Ti (OC 3H 7) 4) was used as the precursor compound. Film wettability was tested by water contact angle measurement (CAM). The water contact angle (WAC) of the film deposited in plasma without biased voltage was greater than 145°, while the WAC of the film deposited in plasma with biased voltage was less than 30°. The morphology of the deposited films was observed by scanning electron microscope (SEM). It is found that the films grown without bias voltage were covered with lots of nano grain and pores, but the surface of the films deposition with bias voltage was much dense. The chemical structure and property of the deposited films were analyzed by Fourier-transformed infrared spectroscopy (FTIR), while the plasma phase was investigated by optical emission spectroscopy (OES).

  20. Calcium phosphate thin film processing by pulsed laser deposition and in situ assisted ultraviolet pulsed laser deposition.

    PubMed

    Nelea, V; Pelletier, H; Iliescu, M; Werckmann, J; Craciun, V; Mihailescu, I N; Ristoscu, C; Ghica, C

    2002-12-01

    Calcium orthophosphates (CaP) and hydroxyapatite (HA) were intensively studied in order to design and develop a new generation of bioactive and osteoconductive bone prostheses. The main drawback now in the CaP and HA thin films processing persists in their poor mechanical characteristics, namely hardness, tensile and cohesive strength, and adherence to the metallic substrate. We report here a critical comparison between the microstructure and mechanical properties of HA and CaP thin films grown by two methods. The films were grown by KrF* pulsed laser deposition (PLD) or KrF* pulsed laser deposition assisted by in situ ultraviolet radiation emitted by a low pressure Hg lamp (UV-assisted PLD). The PLD films were deposited at room temperature, in vacuum on Ti-5Al-2.5Fe alloy substrate previously coated with a TiN buffer layer. After deposition the films were annealed in ambient air at 500-600 degrees C. The UV-assisted PLD films were grown in (10(-2)-10(-1) Pa) oxygen directly on Ti-5Al-2.5Fe substrates heated at 500-600 degrees C. The films grown by classical PLD are crystalline and stoichiometric. The films grown by UV-assisted PLD were crystalline and exhibit the best mechanical characteristics with values of hardness and Young modulus of 6-7 and 150-170 GPa, respectively, which are unusually high for the calcium phosphate ceramics. To the difference of PLD films, in the case of UV-assisted PLD, the GIXRD spectra show the decomposition of HA in Ca(2)P(2)O(7), Ca(2)P(2)O(9) and CaO. The UV lamp radiation enhanced the gas reactivity and atoms mobility during processing, increasing the tensile strength of the film, while the HA structure was destroyed.

  1. Highly oriented polycrystalline Cu2O film formation using RF magnetron sputtering deposition for solar cells

    NASA Astrophysics Data System (ADS)

    Noda, S.; Shima, H.; Akinaga, H.

    2014-02-01

    Room temperature sputtering deposition and re-crystallization of the deposited thin films by rapid thermal annealing have been evaluating in detail as a formation method of Cu2O active layer for solar cells, which minimize thermal budget in fabrication processes. Single phase polycrystalline Cu2O films were obtained by a magnetron rf sputtering deposition and its crystallinity and electrical characteristics were controlled by the annealing. Hall mobility was improved up to 17 cm2V-1s-1 by the annealing at 600°C for 30s. Since this value was smaller than 47 cm2V-1s-1 of the film deposited under thermal equilibrium state using pulsed laser deposition at 600°C, some contrivances were necessary to compensate the deficiency. It was understood that the sputter-deposited Cu2O films on (111)-oriented Pt films were strongly oriented to (111) face also by the self-assembly and the crystallinity was improved by the annealing preserving its orientation. The sputter-deposited film quality was expected to become equivalent to the pulsed laser deposition film from the results of X-ray diffractometry and photoluminescence.

  2. In-situ post-deposition thermal annealing of co-evaporated Cu(InGa)Se2 thin films deposited at low temperatures

    SciTech Connect

    Wilson, James D.; McCandless, Brian E.; Birkmire, Robert W.; Shafarman, William N.

    2009-06-09

    The effects of deposition temperature and in-situ post-deposition annealing on the microstructure of coevaporated Cu(InGa)Se2 thin films and on the performance of the resulting solar cell devices have been characterized. Films were deposited at substrate temperatures of 150°C, 300°C and 400°C. Films were also deposited at these temperatures and then annealed in-situ at 550°C for 10 minutes. In as -deposited films without annealing, additional XRD reflections that may be due to a polytypic modification of the chalcopyrite phase were observed. Films deposited at 150°C were Se-rich. Post-deposition annealing caused microstructural changes in all films and improved the resulting solar cells. Only films deposited at 400°C, however, yielded high-efficiency devices after post-deposition annealing that were equivalent to devices made from films grown at 550°C. Films originally deposited at 300°C yielded devices after post-deposition annealing with VOC close to that of devices made from films grown at 550°C, despite smaller grain size.

  3. Thermal conductivity of nitride films of Ti, Cr, and W deposited by reactive magnetron sputtering

    SciTech Connect

    Jagannadham, Kasichainula

    2015-05-15

    Nitride films of Ti, Cr, and W were deposited using reactive magnetron sputtering from metal targets in argon and nitrogen plasma. TiN films with (200) orientation were achieved on silicon (100) at the substrate temperature of 500 and 600 °C. The films were polycrystalline at lower temperature. An amorphous interface layer was observed between the TiN film and Si wafer deposited at 600 °C. TiN film deposited at 600 °C showed the nitrogen to Ti ratio to be near unity, but films deposited at lower temperature were nitrogen deficient. CrN film with (200) orientation and good stoichiometry was achieved at 600 °C on Si(111) wafer but the film deposited at 500 °C showed cubic CrN and hexagonal Cr{sub 2}N phases with smaller grain size and amorphous back ground in the x-ray diffraction pattern. An amorphous interface layer was not observed in the cubic CrN film on Si(111) deposited at 600 °C. Nitride film of tungsten deposited at 600 °C on Si(100) wafer was nitrogen deficient, contained both cubic W{sub 2}N and hexagonal WN phases with smaller grain size. Nitride films of tungsten deposited at 500 °C were nonstoichiometric and contained cubic W{sub 2}N and unreacted W phases. There was no amorphous phase formed along the interface for the tungsten nitride film deposited at 600 °C on the Si wafer. Thermal conductivity and interface thermal conductance of all the nitride films of Ti, Cr, and W were determined by transient thermoreflectance technique. The thermal conductivity of the films as function of deposition temperature, microstructure, nitrogen stoichiometry and amorphous interaction layer at the interface was determined. Tungsten nitride film containing both cubic and hexagonal phases was found to exhibit much higher thermal conductivity and interface thermal conductance. The amorphous interface layer was found to reduce effective thermal conductivity of TiN and CrN films.

  4. Centrifugal Deposition of Microgels for the Rapid Assembly of Nonfouling Thin Films

    PubMed Central

    South, Antoinette B.; Whitmire, Rachel E.; García, Andrés J.; Lyon, L. Andrew

    2010-01-01

    Thin films assembled from microgel building blocks have been constructed using a simple, high-throughput, and reproducible centrifugation (or “active”) deposition technique. When compared to a common passive adsorption method (e.g., dip coating), microgels that are actively deposited onto a surface have smaller footprints and are more closely packed. Under both active and passive deposition conditions, the microgel footprint areas decrease during deposition. However, under active deposition, the microgel footprint appears to decrease continually and to a greater degree over the course of the deposition, forming a tightly packed, homogeneous film. Taking advantage of the rapid and uniform assembly of these films, we demonstrate the use of active deposition toward the fabrication of polyelectrolyte multilayers containing anionic microgels and a cationic linear polymer. Microgel multilayers successfully demonstrated effective blocking of the underlying substrate toward macrophage adhesion, which is a highly sought-after property for modulating the inflammatory response to an implanted biomaterial. PMID:20356152

  5. Control of composition and crystallinity in hydroxyapatite films deposited by electron cyclotron resonance plasma sputtering

    NASA Astrophysics Data System (ADS)

    Akazawa, Housei; Ueno, Yuko

    2014-01-01

    Hydroxyapatite (HAp) films were deposited by electron cyclotron resonance plasma sputtering under a simultaneous flow of H2O vapor gas. Crystallization during sputter-deposition at elevated temperatures and solid-phase crystallization of amorphous films were compared in terms of film properties. When HAp films were deposited with Ar sputtering gas at temperatures above 460 °C, CaO byproducts precipitated with HAp crystallites. Using Xe instead of Ar resolved the compositional problem, yielding a single HAp phase. Preferentially c-axis-oriented HAp films were obtained at substrate temperatures between 460 and 500 °C and H2O pressures higher than 1×10-2 Pa. The absorption signal of the asymmetric stretching mode of the PO43- unit (ν3) in the Fourier-transform infrared absorption (FT-IR) spectra was the narrowest for films as-crystallized during deposition with Xe, but widest for solid-phase crystallized films. While the symmetric stretching mode of PO43- (ν1) is theoretically IR-inactive, this signal emerged in the FT-IR spectra of solid-phase crystallized films, but was absent for as-crystallized films, indicating superior crystallinity for the latter. The Raman scattering signal corresponding to ν1 PO43- sensitively reflected this crystallinity. The surface hardness of as-crystallized films evaluated by a pencil hardness test was higher than that of solid-phase crystallized films.

  6. Apparatus and method for selective area deposition of thin films on electrically biased substrates

    DOEpatents

    Zuhr, Raymond A.; Haynes, Tony E.; Golanski, Andrzej

    1994-01-01

    An ion beam deposition process for selective area deposition on a polarized substrate uses a potential applied to the substrate which allows the ionized particles to reach into selected areas for film deposition. Areas of the substrate to be left uncoated are held at a potential that repells the ionized particles.

  7. Apparatus and method for selective area deposition of thin films on electrically biased substrates

    DOEpatents

    Zuhr, R.A.; Haynes, T.E.; Golanski, A.

    1994-10-11

    An ion beam deposition process for selective area deposition on a polarized substrate uses a potential applied to the substrate which allows the ionized particles to reach into selected areas for film deposition. Areas of the substrate to be left uncoated are held at a potential that repels the ionized particles. 3 figs.

  8. Apparatus and method for selective area deposition of thin films on electrically biased substrates

    DOEpatents

    Zuhr, R.A.; Haynes, T.E.; Golanski, A.

    1999-06-08

    An ion beam deposition process for selective area deposition on a polarized substrate uses a potential applied to the substrate which allows the ionized particles to reach into selected areas for film deposition. Areas of the substrate to be left uncoated are held at a potential that repels the ionized particles. 3 figs.

  9. Apparatus and method for selective area deposition of thin films on electrically biased substrates

    DOEpatents

    Zuhr, Raymond A.; Haynes, Tony E.; Golanski, Andrzej

    1999-01-01

    An ion beam deposition process for selective area deposition on a polarized substrate uses a potential applied to the substrate which allows the ionized particles to reach into selected areas for film deposition. Areas of the substrate to be left uncoated are held at a potential that repells the ionized particles.

  10. Effects of Buffer Salt Concentration on the Dominated Deposition Mechanism and Optical Characteristics of Chemically Deposited Cadmium Sulfide Thin Films

    NASA Astrophysics Data System (ADS)

    Kakhaki, Z. Makhdoumi; Youzbashi, A.; Sangpour, P.; Kazemzadeh, A.; Naderi, N.; Bazargan, A. M.

    2016-02-01

    Effects of buffer salt concentration on the rate of deposition, dominated deposition mechanism and subsequently the structural, morphological, and optical properties of cadmium sulfide (CdS) thin films deposited by chemical bath deposition (CBD) on glass substrate were investigated. The precursors were chosen to be cadmium chloride (CdCl2) as the cadmium source, thiourea (CS(NH2)2) as the sulfur source, ammonium nitrate (NH4NO3) as the buffer salt and ammonia as the complexing agent and the pH controller. The influence of the NH4NO3 concentration on the structure, morphology, film uniformity, stoichiometry and optical properties of CdS thin films was also studied by X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray (EDX) spectroscope, uv-visible and photoluminescence (PL) spectroscopes. The XRD studies revealed that all the deposited films exhibited a (002)h/(111)c preferred orientation. The crystallite size was increased from 20nm to 30nm by the increase of concentration of NH4NO3 from 0.5M to 2.5M. The morphology of CdS thin films were agglomerated spherical particles consisted of smaller particles. The surface of thin films deposited at the NH4NO3 concentration of 0.5M was compact and smooth. The increase of the concentration of NH4NO3 decreased the packing density of the films. The optical band gap was in the range of 2.25-2.4eV, which was decreased by the decrement of packing density. The PL spectra showed two peaks centered at 400nm and 500nm which are attributed to violet and band-to-band emissions, respectively.

  11. Influence of solution deposition rate on properties of V2O5 thin films deposited by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Abd-Alghafour, N. M.; Ahmed, Naser M.; Hassan, Zai; Mohammad, Sabah M.

    2016-07-01

    Vanadium oxide (V2O5) thin films were deposited on glass substrates by using a cost-efficient spray pyrolysis technique. The films were grown at 350° through thermal decomposition of VCl3 in deionized water with different solution spray rates. The high resolution X-ray diffraction results revealed the formation of nanocrystalline films having orthorhombic structures with preferential orientation along (101) direction. The spray rate influenced the surface morphology and crystallite size of the films. The crystallite size was found to increase whereas the micro-strain was decreased by increasing the spray deposition rates. The increase in crystallite size and decrease in the macrostrain resulted in an improvement in the films' crystallinity. The UV-Visible spectroscopy analysis indicated that the average transmittance of all films lies in the range 75-80 %. The band gap of V2O5 film was decreased from 2.65 to 2.46 eV with increase of the spray deposition rate from 5 ml/min to 10 ml/min. first, second, and third level headings (first level heading).

  12. Hard boron{endash}suboxide-based films deposited in a sputter-sourced, high-density plasma deposition system

    SciTech Connect

    Doughty, C.; Gorbatkin, S.M.; Tsui, T.Y.; Pharr, G.M.; Medlin, D.L.

    1997-09-01

    Boron{endash}suboxide-based thin films have been deposited on Si in an electron cyclotron resonance microwave plasma using a radio frequency (rf) magnetron as a source of boron. Variations of the oxygen fraction in the deposition ambient and of the rf bias applied to the substrate were related to film tribology. The best films have hardnesses of {approximately}28GPa and moduli of {approximately}240GPa and were deposited in oxygen fractions {lt}1{percent} at substrate temperatures {lt}350{degree}C. The films contain 4{percent}{endash}15{percent} O and {approximately}15{percent}C, with carbon originating from the sputter target. They are amorphous and have surface roughnesses of {approximately}0.2nm. Boron{endash}oxide films may form a self-generating lubricating layer of B(OH){sub 3} in ambient atmosphere. Compositional depth profiling of these films reveals an oxygen-enriched surface of {approximately}10nm thickness. Initial nanoscratch test results indicate that these films fail at high critical loads and have low friction coefficients relative to other hard coatings. {copyright} {ital 1997 American Vacuum Society.}

  13. NH3 sensing characteristics of nano-WO3 thin films deposited on porous silicon.

    PubMed

    Sun, Fengyun; Hu, Ming; Sun, Peng; Zhang, Jie; Liu, Bo

    2010-11-01

    The NH3 sensing characteristics of nano-tungsten trioxide (WO3) thin films deposited on porous silicon (PS) were investigated in the present study. Porous silicon layer was first prepared by electrochemical etching in an HF-based solution on a p(+)-type silicon substrate. Then, WO3 nano-films were deposited on the porous silicon layer by DC magnetron sputtering. Pt electrodes were deposited on the top surface of the WO3 films to obtain the WO3/PS gas sensor. The WO3 films deposited on PS were characterized by SEM, XRD and XPS. The NH3 sensing characteristics for WO3/PS gas sensor were tested at room temperature and 50 degrees C. The results showed that the NH3 sensing characteristics of WO3/PS were superior to WO3/Al2O3 at room temperature. The sensing mechanism of the nano-WO3 thin films based on PS was also discussed. PMID:21138022

  14. Deposition of highly textured AlN thin films by reactive high power impulse magnetron sputtering

    SciTech Connect

    Moreira, Milena A.; Törndahl, Tobias; Katardjiev, Ilia; Kubart, Tomas

    2015-03-15

    Aluminum nitride thin films were deposited by reactive high power impulse magnetron sputtering (HiPIMS) and pulsed direct-current on Si (100) and textured Mo substrates, where the same deposition conditions were used for both techniques. The films were characterized by x-ray diffraction and atomic force microscopy. The results show a pronounced improvement in the AlN crystalline texture for all films deposited by HiPIMS on Si. Already at room temperature, the HiPIMS films exhibited a strong preferred (002) orientation and at 400 °C, no contributions from other orientations were detected. Despite the low film thickness of only 200 nm, an ω-scan full width at half maximum value of 5.1° was achieved on Si. The results are attributed to the high ionization of sputtered material achieved in HiPIMS. On textured Mo, there was no significant difference between the deposition techniques.

  15. Synthesis and tribological properties of diamond-like carbon films by electrochemical anode deposition

    NASA Astrophysics Data System (ADS)

    Li, Yang; Zhang, GuiFeng; Hou, XiaoDuo; Deng, DeWei

    2012-06-01

    Diamond-like carbon films (DLC) are deposited on Ti substrate by electrochemical anodic deposition at room temperature in pure methanol solution using a pulsed DC voltage at a range from 200 V to 2000 V. Raman spectroscopy analysis of the films reveals two broaden characteristic absorption peaks centred at ˜1350 cm-1 and 1580 cm-1, relating to D- and G-band of typical DLC films, respectively. A broad peak centred at 1325-1330 cm-1 is observed when an applied potential is 1200 V, which can confirm that the deposited films contained diamond structure phase. Tribological properties of the coated Ti substrates have been measured by means of a ball-on-plate wear test machine. A related growth mechanism of DLC films by the anodic deposition mode has also been discussed.

  16. Electrochemical deposition of layered copper thin films based on the diffusion limited aggregation

    PubMed Central

    Wei, Chenhuinan; Wu, Guoxing; Yang, Sanjun; Liu, Qiming

    2016-01-01

    In this work layered copper films with smooth surface were successfully fabricated onto ITO substrate by electrochemical deposition (ECD) and the thickness of the films was nearly 60 nm. The resulting films were characterized by SEM, TEM, AFM, XPS, and XRD. We have investigated the effects of potential and the concentration of additives and found that 2D dendritic-like growth process leaded the formation of films. A suitable growth mechanism based on diffusion limited aggregation (DLA) mechanism for the copper films formation is presented, which are meaningful for further designing homogeneous and functional films. PMID:27734900

  17. Characterization of hydroxyapatite film with mixed interface by Ar+ ion beam enhanced deposition.

    PubMed

    Li, X; Weng, J; Tong, W; Zuo, C; Zhang, X; Wang, P; Liu, Z

    1997-11-01

    Ar+ ion beam enhanced deposition (IBED) was used to produce a hydroxyapatite (HA) film on polished titanium substrates. In this study, the HA ceramic target was sputtered by an argon-ion beam with an energy of 1.5 KeV, and the sputtered film was intermittently bombarded by energetic argon-ions at 60 KeV. An effective Ca-Ti mixed layer produced by the energetic argon-ion bombardment was confirmed by using Auger electron spectroscopy. The characteristics of the deposited films were evaluated by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. XRD analysis revealed that the as-deposited film was amorphous, and a hydroxyapatite-type structure was obtained from the post-heat treatment of the deposited films. SEM observations showed that no distinct difference in surface morphology was found between the as-deposited and heat-treated samples for Ar+ IBED films, suggesting a strongly bonded HA film on the titanium substrate. In comparison with the HA target, some chemistry alterations were brought about in the deposited films, such as the incorporation of CO3, the loss of the OH groups and some distortion of the phosphate lattice.

  18. Compositional study of silicon oxynitride thin films deposited using electron cyclotron resonance plasma-enhanced chemical vapor deposition technique

    SciTech Connect

    Baumann, H.; Sah, R.E.

    2005-05-01

    We have used backscattering spectrometry and {sup 15}N({sup 1}H,{alpha},{gamma}){sup 12}C nuclear reaction analysis techniques to study in detail the variation in the composition of silicon oxynitride films with deposition parameters. The films were deposited using 2.45 GHz electron cyclotron resonance plasma-enhanced chemical vapor deposition (PECVD) technique from mixtures of precursors argon, nitrous oxide, and silane at deposition temperature 90 deg. C. The deposition pressure and nitrous oxide-to-silane gas flow rates ratio have been found to have a pronounced influence on the composition of the films. When the deposition pressure was varied for a given nitrous oxide-to-silane gas flow ratio, the amount of silicon and nitrogen increased with the deposition pressure, while the amount of oxygen decreased. For a given deposition pressure, the amount of incorporated nitrogen and hydrogen decreased while that of oxygen increased with increasing nitrous oxide-to-silane gas flow rates ratio. For nitrous oxide-to-silane gas flow ratio of 5, we obtained films which contained neither chemically bonded nor nonbonded nitrogen atoms as revealed by the results of infrared spectroscopy, backscattering spectrometry, and nuclear reaction analysis. Our results demonstrate the nitrogen-free nearly stoichiometric silicon dioxide films can be prepared from a mixture of precursors argon, nitrous oxide, and silane at low substrate temperature using high-density PECVD technique. This avoids the use of a hazardous and an often forbidden pair of silane and oxygen gases in a plasma reactor.

  19. Nanosecond laser-induced phase transitions in pulsed laser deposition-deposited GeTe films

    SciTech Connect

    Sun, Xinxing Thelander, Erik; Lorenz, Pierre; Gerlach, Jürgen W.; Decker, Ulrich; Rauschenbach, Bernd

    2014-10-07

    Phase transformations between amorphous and crystalline states induced by irradiation of pulsed laser deposition grown GeTe thin films with nanosecond laser pulses at 248 nm and pulse duration of 20 ns are studied. Structural and optical properties of the Ge-Te phase-change films were studied by X-ray diffraction and optical reflectivity measurements as a function of the number of laser pulses between 0 and 30 pulses and of the laser fluence up to 195 mJ/cm². A reversible phase transition by using pulse numbers ≥ 5 at a fluence above the threshold fluence between 11 and 14 mJ/cm² for crystallization and single pulses at a fluence between 162 and 182 mJ/cm² for amorphization could be proved. For laser fluences from 36 up to 130 mJ/cm², a high optical contrast of 14.7% between the amorphous and crystalline state is measured. A simple model is used that allows the discussion on the distribution of temperature in dependency on the laser fluence.

  20. Metal semiconductor transition in undoped ZnO films deposited by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Kavasoglu, Nese; Sertap Kavasoglu, A.

    2008-08-01

    ZnO films were deposited on glass substrate by using spray pyrolysis method. Films were deposited at different solution molarities 0.02 and 0.1 M. The films are highly transparent in the visible range of the electromagnetic spectrum with a transmission reaching up values to 90%. Band gaps were calculated as 3.24 and 3.28 eV with the help of transmission spectrums. When the solution molarity of the sprayed solution is increased from 0.02 to 0.1 M, carrier concentrations of the films increase from 1.6×10 19 cm -3 to 5.1×10 19 cm -3. Temperature-dependent conductivity measurements of these conducting and transparent films also showed, for the first time, a metal-semiconductor transition (MST). The deposited ZnO films show metallic conductivity above ∼420 K and semiconducting behavior at temperatures below it.

  1. Nanocrystalline diamond thin films deposited from C60 monoenergetic fullerene ion beam.

    PubMed

    Pukha, V E; Stetsenko, A N; Dub, S N; Lee, J K

    2007-01-01

    Carbon films 250 division by 500 nm in thickness deposited on Si wafers from mass-selected flow of accelerated C60 ions with energies of 5.0 +/- 0.1 keV at temperatures of 300 K and 673 K are characterized by TEM and nanoindentation. On the TEM images of the films deposited at 673 K, nanocrystalline graphite with the typical grain size of -6 nm is observed. The films deposited at 300 K are transparent in visible light. TEM study of these films has revealed structural elements with lattice spacing close to that of diamond and the grain size of about 4 nm. Nanohardness and elastic modulus of the films prepared at a substrate temperature of 300 K were 23.1 +/- 0.2 GPa and 200 +/- 1 GPa, respectively. Possible mechanisms of the carbon films structure formation are suggested in the framework of a hydrodynamic shock wave model.

  2. Pulsed electron beam deposition of highly oriented thin films of polytetrafluoroethylene

    NASA Astrophysics Data System (ADS)

    Chandra, Vimlesh; Manoharan, Solomon S.

    2008-04-01

    Thin films of polytetrafluoroethylene (PTFE) were deposited by pulsed electron deposition (PED) technique. The transmission electron microscopy (TEM) image of the RT fabricated (20 Å thick) film on carbon coated copper grid shows crystalline nature. Infrared spectra show one to one correspondence between PED ablated film and the PTFE bulk target. The asymmetrical and symmetrical -CF 2- stretching modes were observed at 1220 and 1156 cm -1, respectively. The -CF 2- wagging and bending modes occur at 644 and 512 cm -1, respectively. X-ray diffraction patterns of the film deposited at room temperature (RT) show oriented film along (1 0 0) plane of hexagonal structure and the crystalline nature is retained up to 300 °C on vacuum annealing. The room temperature fabricated film shows smooth and pin hole free surface whereas post-annealing brings discontinuity, roughness and pin holes.

  3. Annealing effect on structural and optical properties of chemical bath deposited MnS thin film

    NASA Astrophysics Data System (ADS)

    Ulutas, Cemal; Gumus, Cebrail

    2016-03-01

    MnS thin film was prepared by the chemical bath deposition (CBD) method on commercial microscope glass substrate deposited at 30 °C. The as-deposited film was given thermal annealing treatment in air atmosphere at various temperatures (150, 300 and 450 °C) for 1 h. The MnS thin film was characterized by using X-ray diffraction (XRD), UV-vis spectrophotometer and Hall effect measurement system. The effect of annealing temperature on the structural, electrical and optical properties such as optical constants of refractive index (n) and energy band gap (Eg) of the film was determined. XRD measurements reveal that the film is crystallized in the wurtzite phase and changed to tetragonal Mn3O4 phase after being annealed at 300 °C. The energy band gap of film decreased from 3.69 eV to 3.21 eV based on the annealing temperature.

  4. SrCoO3-δ thin films by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Ahvenniemi, Esko; Matvejeff, Mikko; Karppinen, Maarit

    2014-11-01

    Novel atomic layer deposition (ALD) process to deposit high-quality SrCoO3-δ thin films is introduced. Linear film growth is demonstrated within the film-thickness range of 15-300 nm. Post-annealing at 600 °C (in O2 or N2 atmosphere) is required to crystallize the as-deposited amorphous films. The new ALD process produces SrCoO3-δ films with a precisely controlled cation stoichiometry (±2.5%) and an appreciably high growth rate (1.67 Å per supercycle), hence providing us with a prominent method of fabricating high-quality SrCoO3-δ thin films in a readily scalable manner e.g. for intermediate-temperature solid oxide fuel cell cathodes.

  5. Helicon wave plasma chemical vapor deposition of nanocrystalline silicon carbide films at low substrate temperature

    NASA Astrophysics Data System (ADS)

    Yu, Wei; Lu, Wanbing; Wang, Baozhu; Han, Li; Fu, Guangsheng

    2005-02-01

    Silicon carbide thin films have been deposited by helicon wave plasma enhanced chemical vapor deposition (HW-PECVD) technique under the conditions of variant deposition temperatures from 300 to 600°C. Silane, methane and hydrogen are used as reactive gas. The structural properties of the deposited films are characterized using Fourier transform infrared (FTIR), scan electron microscopy (SEM), transmission electron microscopy (TEM) and ultraviolet-visible optical absorption techniques. Detailed analysis of the FTIR spectra indicates that the onset of growing nanocrystalline SiC films at low substrate temperature is closed related with the high plasma ionization rate of helicon wave plasma and the condition of low working gas pressure and strong hydrogen dilution in experiment. The SEM and TEM measurements confirm that the structure of the deposited films is nanocrystalline SiC grains embedded in amorphous matrix and the size of the crystalline gains increases with substrate temperature.

  6. Mössbauer study of electrochemically deposited amorphous iron-sulfide-oxide thin films

    NASA Astrophysics Data System (ADS)

    Ichimura, Masaya; Kajima, Takahiro; Kawai, Shoichi; Mibu, Ko

    2016-03-01

    Iron-sulfide-oxide thin films, which are promising candidates for solar cell materials, were deposited by electrochemical deposition. As-deposited and annealed films were characterized by Mössbauer spectroscopy, X-ray diffraction (XRD), and Raman scattering at room temperature. The as-deposited film is amorphous, and the oxygen content is about 1/4 of the sulfur content (S/Fe ≈ 1.5, O/Fe ≈ 0.4). The Mössbauer spectrum for the as-deposited film is a doublet with a broad line profile having hyperfine parameters similar to those of FeS2 pyrite or marcasite. This indicates that Fe atoms are in the Fe2+ low-spin state, as in FeS2.

  7. Pulsed laser deposition of barium metaplumbate thin films for ferroelectric capacitors

    NASA Astrophysics Data System (ADS)

    Mardare, A. I.; Mardare, C. C.; Fernandes, J. R. A.; Vilarinho, P. M.; Joanni, E.

    2003-08-01

    Barium metaplumbate thin films were deposited in situ by pulsed laser deposition on Si/SiO2/Ti/Pt substrates with a high deposition rate. The temperatures used ranged between 400 ^circ C and 700 ^circ C. As the deposition temperature was increased, the films assumed a strong (222) preferential orientation. This orientation of the electrodes was reflected on the PZT films, having a very big influence on their ferroelectric behavior. The PZT films made over BPO deposited at high temperature presented high values of remanent polarization (43 μC/cm^2) but indications of high leakage currents could be observed in the hysteresis loops. By using BPO bottom electrodes, a 30% improvement in the fatigue behavior of PZT capacitors when compared with the normal platinum electrodes was observed.

  8. Modification and Wettability Study ITO Glass Coated with ZnO Film by Electrochemical Deposition and Hydrothermal Deposition.

    PubMed

    Fang, Mei; Zou, Changwei; Gong, Manfeng

    2016-03-01

    ITO glass is a substrate often utilized to construct various IT devices and sensors, favored for its excellent characteristics such as rapid electron transfer kinetics, non-toxicity, chemical stability, and high electron transmission. In this paper, film with ZnO-modified nanostructures on ITO glass was fabricated by both electrochemical deposition and hydrothermal deposition, respectively. The ZnO film as-deposited was then modified by surface modification reagent (FOTMS) to obtain a hydrophobic surface. SEM, XRD, and ZYGO were used to characterize their properties. The contact angles were then measured to characterize and compare the wettability of non-modified ITO glass and ITO glass modified by zinc oxide films.

  9. Effects of post-deposition argon implantation on the memory properties of plasma-deposited silicon nitride films

    NASA Astrophysics Data System (ADS)

    Shams, Q. A.; Brown, W. D.

    1989-10-01

    Post-deposition ion implantation has been used to introduce argon into plasma-enhanced chemically vapor deposited silicon nitride films in an attempt to influence the transfer, trapping, and emission of charge during write/erase exercising of the metal-silicon nitride-silicon oxide-silicon structure. Argon was implanted into the SiH4 -NH3 -N2 deposited films at energies ranging from 25 to 75 keV, current densities ranging from 0.1 to 75 μA/cm2 and fluences ranging from 1×1012 to 1×1016 ions/cm2. Physical properties of the films were studied by ellipsometry and infrared spectroscopy, while high frequency capacitance-voltage (C-V) curves were used to obtain programming, retention, and endurance characteristics.

  10. Modification and Wettability Study ITO Glass Coated with ZnO Film by Electrochemical Deposition and Hydrothermal Deposition.

    PubMed

    Fang, Mei; Zou, Changwei; Gong, Manfeng

    2016-03-01

    ITO glass is a substrate often utilized to construct various IT devices and sensors, favored for its excellent characteristics such as rapid electron transfer kinetics, non-toxicity, chemical stability, and high electron transmission. In this paper, film with ZnO-modified nanostructures on ITO glass was fabricated by both electrochemical deposition and hydrothermal deposition, respectively. The ZnO film as-deposited was then modified by surface modification reagent (FOTMS) to obtain a hydrophobic surface. SEM, XRD, and ZYGO were used to characterize their properties. The contact angles were then measured to characterize and compare the wettability of non-modified ITO glass and ITO glass modified by zinc oxide films. PMID:27455756

  11. Effects of Al Doping on the Properties of ZnO Thin Films Deposited by Atomic Layer Deposition.

    PubMed

    Zhai, Chen-Hui; Zhang, Rong-Jun; Chen, Xin; Zheng, Yu-Xiang; Wang, Song-You; Liu, Juan; Dai, Ning; Chen, Liang-Yao

    2016-12-01

    The tuning of structural, optical, and electrical properties of Al-doped ZnO films deposited by atomic layer deposition technique is reported in this work. With the increasing Al doping level, the evolution from (002) to (100) diffraction peaks indicates the change in growth mode of ZnO films. Spectroscopic ellipsometry has been applied to study the thickness, optical constants, and band gap of AZO films. Due to the increasing carrier concentration after Al doping, a blue shift of band gap and absorption edge can be observed, which can be interpreted by Burstein-Moss effect. The carrier concentration and resistivity are found to vary significantly among different doping concentration, and the optimum value is also discussed. The modulations and improvements of properties are important for Al-doped ZnO films to apply as transparent conductor in various applications.

  12. Effects of Al Doping on the Properties of ZnO Thin Films Deposited by Atomic Layer Deposition

    NASA Astrophysics Data System (ADS)

    Zhai, Chen-Hui; Zhang, Rong-Jun; Chen, Xin; Zheng, Yu-Xiang; Wang, Song-You; Liu, Juan; Dai, Ning; Chen, Liang-Yao

    2016-09-01

    The tuning of structural, optical, and electrical properties of Al-doped ZnO films deposited by atomic layer deposition technique is reported in this work. With the increasing Al doping level, the evolution from (002) to (100) diffraction peaks indicates the change in growth mode of ZnO films. Spectroscopic ellipsometry has been applied to study the thickness, optical constants, and band gap of AZO films. Due to the increasing carrier concentration after Al doping, a blue shift of band gap and absorption edge can be observed, which can be interpreted by Burstein-Moss effect. The carrier concentration and resistivity are found to vary significantly among different doping concentration, and the optimum value is also discussed. The modulations and improvements of properties are important for Al-doped ZnO films to apply as transparent conductor in various applications.

  13. Effects of Al Doping on the Properties of ZnO Thin Films Deposited by Atomic Layer Deposition.

    PubMed

    Zhai, Chen-Hui; Zhang, Rong-Jun; Chen, Xin; Zheng, Yu-Xiang; Wang, Song-You; Liu, Juan; Dai, Ning; Chen, Liang-Yao

    2016-12-01

    The tuning of structural, optical, and electrical properties of Al-doped ZnO films deposited by atomic layer deposition technique is reported in this work. With the increasing Al doping level, the evolution from (002) to (100) diffraction peaks indicates the change in growth mode of ZnO films. Spectroscopic ellipsometry has been applied to study the thickness, optical constants, and band gap of AZO films. Due to the increasing carrier concentration after Al doping, a blue shift of band gap and absorption edge can be observed, which can be interpreted by Burstein-Moss effect. The carrier concentration and resistivity are found to vary significantly among different doping concentration, and the optimum value is also discussed. The modulations and improvements of properties are important for Al-doped ZnO films to apply as transparent conductor in various applications. PMID:27639580

  14. Molecular dynamics simulation of energetic atom depositions of Au/Au(100) film

    NASA Astrophysics Data System (ADS)

    Qing-yu, Zhang; Zheng-ying, Pan; Jia-yong, Tang

    1999-04-01

    The energetic atom deposition of thin Au/Au(100) film has been studied by molecular dynamics simulation using the Au-Au interatomic interaction potential with embedded atom method. By investigating the variation of coverage curves and Bragg diffraction intensities during the film growth, the transition of Stranski-Kranstanov growth mode to Frank-van der Merwe growth mode was observed with the increase of the incident energy of deposition atoms. The role of energetic atoms in the film growth is discussed by analyzing the transport properties of deposited atoms and the evolution of incident energy and substrate temperatures.

  15. Nanoparticle film deposition using a simple and fast centrifuge sedimentation method

    NASA Astrophysics Data System (ADS)

    Markelonis, Andrew R.; Wang, Joanna S.; Ullrich, Bruno; Wai, Chien M.; Brown, Gail J.

    2015-04-01

    Colloidal nanoparticles (NPs) can be deposited uniformly on flat or rough and uneven substrate surfaces employing a standard centrifuge and common solvents. This method is suitable for depositing different types of nanoparticles on a variety of substrates including glass, silicon wafer, aluminum foil, copper sheet, polymer film, plastic, and paper, etc. The thickness of the films can be controlled by the amount of the colloidal nanoparticle solution used in the preparation. The method offers a fast and simple procedure compared to other currently known nanoparticle deposition techniques for studying the optical properties of nanoparticle films.

  16. Laser Plasma Vapour Deposition Of Photoconducting And High Tc Superconducting Films

    NASA Astrophysics Data System (ADS)

    Popescu, Mihai A.; Apostol, Ileana; Mihailescu, Ion N.; Botila, T.; Pentia, E.; Ciurea, M. L.; Dinescu, M.; Jaklovsky, J.; Aldica, Gheorghe V.; Miu, L.; Rusu, C.; Hening, Al. A.; Mihai, S.; Constantin, C.; Stoica, Mihaela; Pausescu, P.; Cruceanu, Eugen; Pompe, Wolfgang; Wuensch, R.; Richter, Asta; Scheibe, H. J.

    1989-05-01

    Device quality PbS photoconducting films were obtained by laser plasma vapour deposition on special glass substrates at room temperature and their structure was investigated by X-ray diffraction. High Tc superconducting films of composition Dy0.2Y0.8Ba2Cu3O~7 and YBa2Cu3O~7 were deposited on sapphire substrate. It was shown for laser deposited YBa2Cu3O~7 that a buffer layer of the same composition predeposited by rf sputtering allows for getting high quality superconducting films.

  17. Surface Acoustic Wave Monitor for Deposition and Analysis of Ultra-Thin Films

    NASA Technical Reports Server (NTRS)

    Hines, Jacqueline H. (Inventor)

    2015-01-01

    A surface acoustic wave (SAW) based thin film deposition monitor device and system for monitoring the deposition of ultra-thin films and nanomaterials and the analysis thereof is characterized by acoustic wave device embodiments that include differential delay line device designs, and which can optionally have integral reference devices fabricated on the same substrate as the sensing device, or on a separate device in thermal contact with the film monitoring/analysis device, in order to provide inherently temperature compensated measurements. These deposition monitor and analysis devices can include inherent temperature compensation, higher sensitivity to surface interactions than quartz crystal microbalance (QCM) devices, and the ability to operate at extreme temperatures.

  18. Plasma-deposited amorphous hydrogenated carbon films and their tribological properties

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa; Pouch, John J.; Alterovitz, Samuel A.

    1989-01-01

    Recent work on the properties of diamondlike carbon films and their dependence on preparation conditions are reviewed. The results of the study indicate that plasma deposition enables one to deposit a variety of amorphous hydrogenated carbon (a-C:H ) films exhibiting more diamondlike behavior to more graphitic behavior. The plasma-deposited a-C:H can be effectively used as hard, wear-resistant, and protective lubricating films on ceramic materials such as Si(sub 3)N(sub 4) under a variety of environmental conditions such as moist air, dry nitrogrn, and vacuum.

  19. Microstructural modification of nc-Si/SiOx films during plasma-enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Zhang, X. W.

    2005-07-01

    Nanocrystalline-silicon embedded silicon oxide films are prepared by plasma-enhanced chemical vapor deposition (PECVD) at 300 °C without post-heat treatment. Measurements of XPS, IR, XRD, and HREM are performed. Microstructural modifications are found occurring throughout the film deposition. The silica network with a high oxide state is suggested to be formed directly under the abduction of the former deposited layer, rather than processing repeatedly from the original low-oxide state of silica. Nanocrystalline silicon particles with a size of 6-10 nm are embedded in the SiOx film matrix, indicating the potential application in Si-based optoelectronic integrity.

  20. Plasma-deposited amorphous hydrogenated carbon films and their tribological properties

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Pouch, J. J.; Alterovitz, S. A.

    1989-01-01

    Recent work on the properties of diamondlike carbon films and their dependence on preparation conditions are reviewed. The results of the study indicate that plasma deposition enables one to deposit a variety of amorphous hydrogenated carbon (a-C:H) films exhibiting more diamondlike behavior to more graphitic behavior. The plasma-deposited a-C:H can be effectively used as hard, wear-resistant, and protective lubricating films on ceramic materials such as Si(sub 3)N(sub 4) under a variety of environmental conditions such as moist air, dry nitrogen, and vacuum.

  1. Atomic Layer Deposition Films as Diffusion Barriers for Silver Artifacts

    NASA Astrophysics Data System (ADS)

    Marquardt, Amy; Breitung, Eric; Drayman-Weisser, Terry; Gates, Glenn; Rubloff, Gary W.; Phaneuf, Ray J.

    2012-02-01

    Atomic layer deposition (ALD) was investigated as a means to create transparent oxide diffusion barrier coatings to reduce the rate of tarnishing for silver objects in museum collections. Accelerated aging by heating various thicknesses (5 to 100nm) of ALD alumina (Al2O3) thin films on sterling and fine silver was used to determine the effectiveness of alumina as a barrier to silver oxidation. The effect of aging temperature on the thickness of the tarnish layer (Ag2S) created at the interface of the ALD coating and the bulk silver substrate was determined by reflectance spectroscopy and X-Ray Photoelectric Spectroscopy (XPS). Reflectance spectroscopy was an effective rapid screening tool to determine tarnishing rates and the coating's visual impact. X-Ray Photoelectric Spectroscopy (XPS), and Time of Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) analysis showed a phase transformation in the Ag2S tarnish layer at 177 C and saturation in the thickness of the silver sulfide layer, indicating possible self-passivation of the tarnish layer.

  2. Deposition of Hydrogenated Microcrystalline Films of CdTe by Chemical Sputtering in Hydrogen

    NASA Astrophysics Data System (ADS)

    Saito, Koji; Nishibayashi, Yoshiki; Imura, Takeshi; Osaka, Yukio

    1988-07-01

    Films of CdTe are deposited by chemical sputtering of a CdTe target in hydrogen gas. X-ray diffraction patterns show that the films are composed of microcrystals of cubic CdTe with a grain size of 15˜30 nm. The films contain a trace amount of hydrogen in the form of the Cd-H (and presumably Te-H2) bonds. This hydrogen is evolved during the thermal treatment of the film above 100°C, as the grain size of the microcrystal grows. The deposition rate is also reduced when the substrate temperature increases up to 100°C or more.

  3. Rapid deposition process for zinc oxide film applications in pyroelectric devices

    NASA Astrophysics Data System (ADS)

    Hsiao, Chun-Ching; Yu, Shih-Yuan

    2012-10-01

    Aerosol deposition (AD) is a rapid process for the deposition of films. Zinc oxide is a low toxicity and environmentally friendly material, and it possesses properties such as semiconductivity, pyroelectricity and piezoelectricity without the poling process. Therefore, AD is used to accelerate the manufacturing process for applications of ZnO films in pyroelectric devices. Increasing the temperature variation rate in pyroelectric films is a useful method for enhancing the responsivity of pyroelectric devices. In the present study, a porous ZnO film possessing the properties of large heat absorption and high temperature variation rate is successfully produced by the AD rapid process and laser annealing for application in pyroelectric devices.

  4. Preparation of mixed bismuth and iron thin films by pulsed laser deposition using powder targets

    NASA Astrophysics Data System (ADS)

    Kawasaki, Hiroharu; Ohshima, Tamiko; Yagyu, Yoshihito; Ihara, Takeshi; Tanaka, Yuki; Suda, Yoshiaki

    2016-01-01

    Bismuth iron garnet (Bi3Fe5O12) thin films, for use in magnetic optics, were prepared by a pulsed laser deposition method using Bi and Fe mixed powder targets in oxygen gas. The deposition rate of the film strongly depended on the target mixture. The X-ray diffraction and X-ray photoelectron spectroscopy results suggest that the prepared films were not Bi3Fe5O12 but Bi-rich films, because of the lower melting temperature of Bi (544 K) compared with that of Fe (1811 K).

  5. Polymer film deposition on agar using a dielectric barrier discharge jet and its bacterial growth inhibition

    NASA Astrophysics Data System (ADS)

    Tsai, T.-C.; Cho, J.; Mcintyre, K.; Jo, Y.-K.; Staack, D.

    2012-08-01

    Polymer film deposition on agar in ambient air was achieved using the helium dielectric barrier discharge jet (DBD jet) fed with polymer precursors, and the bacterial growth inhibition due to the deposited film was observed. The DBD jet with precursor addition was more efficient at sterilization than a helium-only DBD jet. On the areas where polymer films cover the agar the bacterial growth was significantly inhibited. The inhibition efficacy showed dependence on the film thickness. The DBD jet without precursor also created a modified agar layer, which may slow the growth of some bacterial strains.

  6. Thickness Dependence of Infrared Reflection Absorption in Vacuum-Deposited Thin Film of Polyvinylidene Fluoride

    NASA Astrophysics Data System (ADS)

    Maki, Kunisuke; Terashima, Hidenobu; Kikuma, Kazuhiro

    1990-06-01

    Reflection absorption intensities for p-polarized infrared rays are shown as a function of thickness (d) of vacuum-deposited films of polyvinylidene fluoride (PVDF), which were deposited on Ag-covered mica substrates held at 25°C. Each absorption due to α-type polycrystalline film at 1412, 1215, 1185, 1150, 1070, 875 and 615 cm-1 increases linearly with increasing d. Some structural relaxation during the growth of PVDF film is discussed for interpretation of the result that absorption at 1215, 1185 and 875 cm-1 is not observed and the peak height at 882 cm-1 is seen clearly for films at d<15 nm.

  7. Investigation of thin films of organic-based magnets grown by physical vapor deposition

    SciTech Connect

    Kao, C. Y.; Lu, Y.; Li, B.; Yoo, J.-W.; Epstein, A. J.

    2014-10-06

    Thin films of organic-based magnet, V[TCNE]{sub x} (TCNE: tetracyanoethylene), were deposited by physical vapor deposition (PVD) based reactive evaporation. The growth conditions were studied in detail. A saturated composition of V[TCNE]{sub ∼1.9} was determined by optimizing the growth condition. Two sets of films with different V to TCNE ratios were characterized. Both films were magnetic ordered up to 400 K and held coercive field of 60 Oe at room temperature. With the presence of excess vanadium within the film, the increase of defects created by PVD results in significant change in electronic property.

  8. Effect of deposition pressure on the structural and magnetic properties of cobalt ferrite thin films

    SciTech Connect

    Nongjai, R.; Khan, S.; Ahmad, H.; Khan, I.; Asokan, K.

    2013-06-03

    We present the influence of deposition pressure on the structural and magnetic properties of cobalt ferrite thin films. Thin films of Co ferrite were deposited by rf sputtering on Si (100) substrate and characterized by X - Ray Diffraction (XRD), Atomic Force Microscopy (AFM) and Vibrating Sample Magnetometer (VSM). The XRD patterns showed the formation of crystalline single phase of the films. The particle size and surface roughness of the films were strongly influence by gas pressure. Hysteresis loops measured at room temperature showed the enhancement of magnetic properties with the increase of gas pressure which is attributed to the decrease of particle size.

  9. Adherent diamond film deposited on Cu substrate by carbon transport from nanodiamond buried under Pt interlayer

    NASA Astrophysics Data System (ADS)

    Liu, Xuezhang; Wei, Qiuping; Yu, Zhiming; Yang, Taiming; Zhai, Hao

    2013-01-01

    Diamond film deposited on Cu suffered from poor adhesion mainly due to the large mismatch of thermal expansion coefficients and the lack of affinity between carbon and Cu. Enhancing diamond nucleation by carbon transport from buried nanodiamond through a Pt ultrathin interlayer, adherent diamond film was then deposited on Cu substrate without distinctly metallic interlayer. This novel nucleation mechanism increased diamond nucleation density to 1011 cm-2, and developed diamond film with a composite structure of nano-crystalline diamond (NCD) layer and micro-crystalline diamond layer. Diamond film was characterized by the scanning electron microscope (SEM) and Raman spectroscope, respectively. The composition of diamond film/Cu substrate interface was examined by electron probe microanalysis (EPMA). The adhesion of diamond film was evaluated by indentation test. Those results show that a Pt ultrathin interlayer provides stronger chemically bonded interfaces and improve film adhesion.

  10. Structural and Electromagnetic Properties of Ni-Mn-Ga Thin Films Deposited on Si Substrates

    NASA Astrophysics Data System (ADS)

    Pereira, M. J.; Lourenço, A. A. C. S.; Amaral, V. S.

    2014-07-01

    Ni2MnGa thin films raise great interest due to their properties, which provide them with strong potential for technological applications. Ni2MnGa thin films were prepared by r.f. sputtering deposition on Si substrates at low temperature (400 ºC). Film thicknesses in the range 10-120 nm were obtained. A study of the structural, magnetic and electrical properties of the films is presented. We find that the deposited films show some degree of crystallinity, with coexisting cubic and tetragonal structural phases, the first one being preponderant over the latter, particularly in the thinner films. The films possess soft magnetic properties and their coercivity is thickness dependent in the range 15-200 Oe at 300K. Electrical resistivity measurements signal the structural transition and suggest the occurrence of avalanche and return-point memory effects, in temperature cycling through the magnetic/structural transition range.

  11. In situ analysis of adsorption process from residual gases during thin film deposition

    NASA Astrophysics Data System (ADS)

    Giedraitis, A.; Tamulevicius, S.; Slapikas, K.; Gudaitis, R.; Juraitis, A.

    2008-03-01

    In this work we present the developed experimental technique as well as results of optical control of adsorption processes during thin film deposition. Different metallic films: (silver) as a model material and barium getter films were studied. Thermal evaporation method has been used to deposit thin metallic films and films of barium getter on glass substrates. Kinetics of the optical absorbance of the growing film was registered in situ measuring transmission of the film-substrate structure. These measurements were done in parallel to the ex-situ absorption (UV-VIS) and reflection spectra as well as XRD analysis. Such complex measurements enabled us to follow adsorption process from the residual gases during thermal evaporation as well to control adsorption process after the evaporation.

  12. Microstructural comparisons of ultrathin Cu films deposited by ion-beam and dc-magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Prater, W. L.; Allen, E. L.; Lee, W.-Y.; Toney, M. F.; Kellock, A.; Daniels, J. S.; Hedstrom, J. A.; Harrell, T.

    2005-05-01

    We report and contrast both the electrical resistance and the microstructure of copper thin films deposited in an oxygen-containing atmosphere by ion-beam and dc-magnetron sputtering. For films with thicknesses of 5 nm or less, the resistivity of the Cu films is minimized at oxygen concentrations ranging from 0.2% to 1% for dc-magnetron sputtering and 6%-10% for ion-beam sputtering. Films sputtered under both conditions show a similar decrease of interface roughness with increasing oxygen concentration, although the magnetron-deposited films are smoother. The dc-magnetron-produced films have higher resistivity, have smaller Cu grains, and contain a higher concentration of cuprous oxide particles. We discuss the mechanisms leading to the grain refinement and the consequent reduced resistivity in both types of films.

  13. Effects of electron irradiation on the properties of GZO films deposited with RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Kim, Y. S.; Heo, S. B.; Lee, H. M.; Lee, Y. J.; Kim, I. S.; Kang, M. S.; Choi, D. H.; Lee, B. H.; Kim, M. G.; Kim, Daeil

    2012-02-01

    Transparent conductive GZO films were deposited on polycarbonate substrates by electron beam assisted radio frequency (RF) magnetron sputtering and then the influence of electron irradiation on the structural, optical and electrical properties of GZO films was investigated by using X-ray diffractometry, UV-vis spectrophotometry, four point probes, atomic force microscopy and UV photoelectron spectroscopy. Sputtering power was kept constant at 3 W/cm2 during deposition, while electron irradiation energy varied from 450 to 900 eV. Electron irradiated GZO films show larger grain sizes than those of films prepared without electron irradiation, and films irradiated at 900 eV show higher optical transmittance in the visible wavelength region and lower sheet resistance (120 Ω/□) than other films. The work-function is also increased with electron irradiation energy. The highest work-function of 4.4 eV was observed in films that were electron irradiated at 900 eV.

  14. Spray Deposition of High Quality CuInSe2 and CdTe Films: Preprint

    SciTech Connect

    Curtis, C. J.; van Hest, M.; Miedaner, A.; Leisch, J.; Hersh, P.; Nekuda, J.; Ginley, D. S.

    2008-05-01

    A number of different ink and deposition approaches have been used for the deposition of CuInSe2 (CIS), Cu(In,Ga)Se2 (CIGS), and CdTe films. For CIS and CIGS, soluble precursors containing Cu, In, and Ga have been developed and used in two ways to produce CIS films. In the first, In-containing precursor films were sprayed on Mo-coated glass substrates and converted by rapid thermal processing (RTP) to In2Se3. Then a Cu-containing film was sprayed down on top of the In2Se3 and the stacked films were again thermally processed to give CIS. In the second approach, the Cu-, In-, and Ga-containing inks were combined in the proper ratio to produce a mixed Cu-In-Ga ink that was sprayed on substrates and thermally processed to give CIGS films directly. For CdTe deposition, ink consisting of CdTe nanoparticles dispersed in methanol was prepared and used to spray precursor films. Annealing these precursor films in the presence of CdCl2 produced large-grained CdTe films. The films were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). Optimized spray and processing conditions are crucial to obtain dense, crystalline films.

  15. Morphology of Imidazolium-Based Ionic Liquids as Deposited by Vapor Deposition: Micro-/Nanodroplets and Thin Films.

    PubMed

    Costa, José C S; Mendes, Adélio; Santos, Luís M N B F

    2016-07-18

    The morphology of micro- and nanodroplets and thin films of ionic liquids (ILs) prepared through physical vapor deposition is presented. The morphology of droplets deposited on indium-tin-oxide-coated glass is presented for the extended 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Cn C1 im][Ntf2 ]; n=1-8) series, and the results show the nanostructuration of ILs. The use of in-vacuum energetic particles enhances/increases the nanodroplets mobility/coalescence mechanisms and can be a pathway to the fabrication of thin IL films. PMID:27028765

  16. Influence of the normalized ion flux on the constitution of alumina films deposited by plasma-assisted chemical vapor deposition

    SciTech Connect

    Kurapov, Denis; Reiss, Jennifer; Trinh, David H.; Hultman, Lars; Schneider, Jochen M.

    2007-07-15

    Alumina thin films were deposited onto tempered hot working steel substrates from an AlCl{sub 3}-O{sub 2}-Ar-H{sub 2} gas mixture by plasma-assisted chemical vapor deposition. The normalized ion flux was varied during deposition through changes in precursor content while keeping the cathode voltage and the total pressure constant. As the precursor content in the total gas mixture was increased from 0.8% to 5.8%, the deposition rate increased 12-fold, while the normalized ion flux decreased by approximately 90%. The constitution, morphology, impurity incorporation, and the elastic properties of the alumina thin films were found to depend on the normalized ion flux. These changes in structure, composition, and properties induced by normalized ion flux may be understood by considering mechanisms related to surface and bulk diffusion.

  17. Atomic layer deposition of ultrathin platinum films on tungsten atomic layer deposition adhesion layers: Application to high surface area substrates

    SciTech Connect

    Clancey, Joel W.; Cavanagh, Andrew S.; Kukreja, Ratandeep S.; Kongkanand, Anusorn; George, Steven M.

    2015-01-15

    Platinum (Pt) atomic layer deposition (ALD) usually yields Pt nanoparticles during initial film growth. In contrast, deposition of continuous and ultrathin Pt films is needed for many important applications, such as the oxygen reduction reaction in polymer electrolyte membrane (PEM) fuel cells. A continuous and high radius of curvature Pt film is more stable and has a higher area-specific activity than the Pt nanoparticles commonly used in PEM fuel cells. However, the Pt film must be ultrathin and have a large surface area to be cost effective. In this paper, a review of earlier Pt ALD studies on flat substrates is presented that demonstrates that tungsten, with a higher surface energy than platinum, can serve as an adhesion layer to achieve Pt ALD films that are continuous at ultrathin thicknesses of ∼1.5 nm. This work utilized MeCpPtMe{sub 3} and H{sub 2} plasma as the Pt ALD reactants. The deposition of continuous and ultrathin Pt ALD films using MeCpPtMe{sub 3} and H{sub 2} plasma as the reactants is then studied on two high surface area substrate materials: TiO{sub 2} nanoparticles and 3M nanostructured thin film (NSTF). Transmission electron microscopy (TEM) showed uniform and continuous Pt films with thicknesses of ∼4 nm on the TiO{sub 2} nanoparticles. TEM with electron energy loss spectroscopy analysis revealed W ALD and Pt ALD films with thicknesses of ∼3 nm that were continuous and conformal on the high aspect ratio NSTF substrates. These results demonstrate that cost effective use of Pt ALD on high surface area substrates is possible for PEM fuel cells.

  18. Nanoscale compositional analysis of NiTi shape memory alloy films deposited by DC magnetron sputtering

    SciTech Connect

    Sharma, S. K.; Mohan, S.; Bysakh, S.; Kumar, A.; Kamat, S. V.

    2013-11-15

    The formation of surface oxide layer as well as compositional changes along the thickness for NiTi shape memory alloy thin films deposited by direct current magnetron sputtering at substrate temperature of 300 °C in the as-deposited condition as well as in the postannealed (at 600 °C) condition have been thoroughly studied by using secondary ion mass spectroscopy, x-ray photoelectron spectroscopy, and scanning transmission electron microscopy-energy dispersive x-ray spectroscopy techniques. Formation of titanium oxide (predominantly titanium dioxide) layer was observed in both as-deposited and postannealed NiTi films, although the oxide layer was much thinner (8 nm) in as-deposited condition. The depletion of Ti and enrichment of Ni below the oxide layer in postannealed films also resulted in the formation of a graded microstructure consisting of titanium oxide, Ni{sub 3}Ti, and B2 NiTi. A uniform composition of B2 NiTi was obtained in the postannealed film only below a depth of 200–250 nm from the surface. Postannealed film also exhibited formation of a ternary silicide (Ni{sub x}Ti{sub y}Si) at the film–substrate interface, whereas no silicide was seen in the as-deposited film. The formation of silicide also caused a depletion of Ni in the film in a region ∼250–300 nm just above the film substrate interface.

  19. Biaxially aligned template films fabricated by inclined-substrate deposition for YBCO-coated conductor applications.

    SciTech Connect

    Ma, B.; Li, M.; Koritala, R. E.; Fisher, B. L.; Erck, R. A.; Dorris, S. E.; Miller, D. J.; Balachandran, U.

    2002-08-12

    Inclined substrate deposition (ISD) has the potential for rapid production of high-quality biaxially textured buffer layers, which are important for YBCO-coated conductor applications. We have grown biaxially textured MgO films by ISD at deposition rates of 20-100 {angstrom}/sec. Columnar grains with a roof-tile surface structure were observed in the ISD-MgO films. X-ray pole figure analysis revealed that the (002) planes of the ISD-MgO films are tilted at an angle from the substrate normal. A small {phi}-scan full-width at half maximum (FWHM) of {approx}9{sup o} was observed on MgO films deposited at an inclination angle of 55{sup o}. In-plane texture in the ISD MgO films developed in the first 0.5 {micro}m from the interface, then stabilized with further increases in film thickness. YBCO films deposited by pulsed laser deposition on ISD-MgO buffered Hastelloy C276 substrates were biaxially aligned with the c-axis parallel to the substrate normal. T{sub c} of 91 K with a sharp transition and transport J{sub c} of 5.5 x 10{sup 5} A/cm{sup 2} at 77 K in self-field were measured on a YBCO film that was 0.46-{micro}m thick, 4-mm wide, 10-mm long.

  20. Pulsed-laser deposition and growth studies of Bi3Fe5O12 thin films

    NASA Astrophysics Data System (ADS)

    Lux, Robert; Heinrich, Andreas; Leitenmeier, Stephan; Körner, Timo; Herbort, Michael; Stritzker, Bernd

    2006-12-01

    Magneto-optical garnets are attractive because of their high Faraday rotation and low optical loss in the near infrared. Therefore their use is generally in nonreciprocal devices, i.e., as optical isolators in optical communication. In this paper we present data concerning the deposition of Bi3Fe5O12 (BIG) thin films on (100) and (111) Gd3Ga5O12 substrates using pulsed-laser deposition. Laser-induced processes on the surface of the oxide target used for ablation were analyzed and numerous films were deposited. We found the BIG film quality to be strongly affected by oxygen pressure, laser energy density, and the Bi /Fe film ratio, whereas temperature had a minor influence. We also investigated the BIG-film deposition using a target pressed from metallic Bi and Fe powders and found information on the growth behavior of BIG. We report on details of the film deposition and film properties determined by environmental scanning electron microscopy, energy dispersive x-ray analysis, Rutherford backscattering spectroscopy, and x-ray diffraction. In addition, we determined the Faraday rotation of the films.

  1. Low temperature temporal and spatial atomic layer deposition of TiO{sub 2} films

    SciTech Connect

    Aghaee, Morteza Maydannik, Philipp S.; Johansson, Petri; Kuusipalo, Jurkka; Creatore, Mariadriana; Homola, Tomáš; Cameron, David C.

    2015-07-15

    Titanium dioxide films were grown by atomic layer deposition (ALD) using titanium tetraisopropoxide as a titanium precursor and water, ozone, or oxygen plasma as coreactants. Low temperatures (80–120 °C) were used to grow moisture barrier TiO{sub 2} films on polyethylene naphthalate. The maximum growth per cycle for water, ozone, and oxygen plasma processes were 0.33, 0.12, and 0.56 Å/cycle, respectively. X-ray photoelectron spectrometry was used to evaluate the chemical composition of the layers and the origin of the carbon contamination was studied by deconvoluting carbon C1s peaks. In plasma-assisted ALD, the film properties were dependent on the energy dose supplied by the plasma. TiO{sub 2} films were also successfully deposited by using a spatial ALD (SALD) system based on the results from the temporal ALD. Similar properties were measured compared to the temporal ALD deposited TiO{sub 2}, but the deposition time could be reduced using SALD. The TiO{sub 2} films deposited by plasma-assisted ALD showed better moisture barrier properties than the layers deposited by thermal processes. Water vapor transmission rate values lower than 5 × 10{sup −4} g day{sup −1} m{sup −2} (38 °C and 90% RH) was measured for 20 nm of TiO{sub 2} film deposited by plasma-assisted ALD.

  2. Temperature control for the gate workfunction engineering of TiC film by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Kim, Choong-Ki; Ahn, Hyun Jun; Moon, Jung Min; Lee, Sukwon; Moon, Dong-II; Park, Jeong Soo; Cho, Byung-Jin; Choi, Yang-Kyu; Lee, Seok-Hee

    2015-12-01

    The effects of the deposition temperature on titanium carbide film formed by atomic layer deposition are investigated for gate workfunction (WF) engineering. As the deposition temperature increases from 250 °C to 500 °C, the WF of the TiC decreases from 5.24 eV to 4.45 eV. This WF dependency on the deposition temperature is mainly attributed to the average WF of each orientation of the sub-planes of the TiC film. An investigation of a tunable WF is conducted through Auger electron spectroscopy, transmission electron microscopy, and X-ray diffraction.

  3. UV optical properties of thin film oxide layers deposited by different processes.

    PubMed

    Pellicori, Samuel F; Martinez, Carol L

    2011-10-01

    UV optical properties of thin film layers of compound and mixed oxide materials deposited by different processes are presented. Japan Electron Optics Laboratory plasma ion assisted deposition (JEOL PIAD), electron beam with and without IAD, and pulsed DC magnetron sputtering were used. Comparisons are made with published deposition process data. Refractive indices and absorption values to as short as 145 nm were measured by spectroscopic ellipsometry (SE). Electronic interband defect states are detected that are deposition-process dependent. SE might be effective in identifying UV optical film quality, especially in defining processes and material composition beneficial for high-energy excimer laser applications and environments requiring stable optical properties.

  4. Structural and gasochromic properties of WO3 films prepared by reactive sputtering deposition

    NASA Astrophysics Data System (ADS)

    Yamamoto, S.; Hakoda, T.; Miyashita, A.; Yoshikawa, M.

    2015-02-01

    The effects of deposition temperature and film thickness on the structural and gasochromic properties of tungsten trioxide (WO3) films used for the optical detection of diluted cyclohexane gas have been investigated. The WO3 films were prepared on SiO2 substrates by magnetron sputtering, with the deposition temperature ranging from 300 to 550 °C in an Ar and O2 gas mixture. The films were characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD), and Rutherford backscattering spectroscopy (RBS). The gasochromic properties of the WO3 films, coated with a catalytic Pt layer, were examined by exposing them to up to 5% cyclohexane in N2 gas. It was found that (001)-oriented monoclinic WO3 films, with a columnar structure, grew at deposition temperatures between 400 and 450 °C. Furthermore, (010)-oriented WO3 films were preferably formed at deposition temperatures higher than 500 °C. The gasochromic characterization of the Pt/WO3 films revealed that (001)-oriented WO3 films, with cauliflower-like surface morphology, were appropriate for the optical detection of cyclohexane gas.

  5. Electrophoretic deposition of PTFE particles on porous anodic aluminum oxide film and its tribological properties

    NASA Astrophysics Data System (ADS)

    Zhang, Dongya; Dong, Guangneng; Chen, Yinjuan; Zeng, Qunfeng

    2014-01-01

    Polytetrafluoroethylene (PTFE) composite film was successfully fabricated by depositing PTFE particles into porous anodic aluminum oxide film using electrophoretic deposition (EPD) process. Firstly, porous anodic aluminum oxide film was synthesized by anodic oxidation process in sulphuric acid electrolyte. Then, PTFE particles in suspension were directionally deposited into the porous substrate. Finally, a heat treatment at 300 °C for 1 h was utilized to enhance PTFE particles adhesion to the substrate. The influence of anodic oxidation parameters on the morphology and micro-hardness of the porous anodic aluminum oxide film was studied and the PTFE particles deposited into the pores were authenticated using energy-dispersive spectrometer (EDS) and scanning electron microscopy (SEM). Tribological properties of the PTFE composite film were investigated under dry sliding. The experimental results showed that the composite film exhibit remarkable low friction. The composite film had friction coefficient of 0.20 which deposited in 15% PTFE emulsion at temperature of 15 °C and current density of 3 A/dm2 for 35 min. In addition, a control specimen of porous anodic aluminum oxide film and the PTFE composite film were carried out under the same test condition, friction coefficient of the PTFE composite film was reduced by 60% comparing with the control specimen at 380 MPa and 100 mm/s. The lubricating mechanism was that PTFE particles embedded in porous anodic aluminum oxide film smeared a transfer film on the sliding path and the micro-pores could support the supplement of solid lubricant during the sliding, which prolonged the lubrication life of the aluminum alloys.

  6. Hydroxyapatite thin films grown by pulsed laser deposition and radio-frequency magnetron sputtering: comparative study

    NASA Astrophysics Data System (ADS)

    Nelea, V.; Morosanu, C.; Iliescu, M.; Mihailescu, I. N.

    2004-04-01

    Hydroxyapatite (HA) thin films for applications in the biomedical field were grown by pulsed laser deposition (PLD) and radio-frequency magnetron sputtering (RF-MS) techniques. The depositions were performed from pure hydroxyapatite targets on Ti-5Al-2.5Fe (TiAlFe) alloys substrates. In order to prevent the HA film penetration by Ti atoms or ions diffused from the Ti-based alloy during and after deposition, the substrates were pre-coated with a thin buffer layer of TiN. In both cases, TiN was introduced by reactive PLD from TiN targets in low-pressure N 2. The PLD films were grown in vacuum onto room temperature substrates. The RF-MS films were deposited in low-pressure argon on substrates heated at 550 °C. The initially amorphous PLD thin films were annealed at 550 °C for 1 h in ambient air in order to restore the initial crystalline structure of HA target. The thickness of the PLD and RF-MS films were ˜1 μm and ˜350 nm, respectively. All films were structurally studied by scanning electron microscopy (SEM), grazing incidence X-ray diffraction (GIXRD), energy dispersive X-ray spectrometry (EDS) and white light confocal microscopy (WLCM). The mechanical properties of the films were tested by Berkovich nano-indentation. Both PLD and RF-MS films mostly contain HA phase and exhibit good mechanical characteristics. Peaks of CaO were noticed as secondary phase in the GIXRD patterns only for RF-MS films. By its turn, the sputtered films were smoother as compared to the ones deposited by PLD (50 nm versus 250 nm average roughness). The RF-MS films were harder, more mechanically resistant and have a higher Young modulus.

  7. Sputter-Deposited AlTiO Thin Films for Semi-Transparent Silicon Thin Film Solar Cells

    NASA Astrophysics Data System (ADS)

    Lee, Seung-Yun; Bang, Ki Su; Lim, Jung Wook

    2014-09-01

    This paper reports on sputter-deposited AlTiO (ATO) thin films and their effects on the performance of semi-transparent silicon thin film solar cells. The electrical resistivity and the transparency of the ATO films depend significantly on the flow ratio of oxygen to argon during the reactive sputtering process. With highly transparent ATO films, transmittances of over 80% were obtained by increasing this flow ratio. When the ATO films were used on silicon substrates, they exhibited an anti-reflection property, where the minimum reflectance at visible light wavelength was decreased to 1.2%. The introduction of ATO thin film layers into solar cells resulted in a 24% increase in transmittance at wavelengths of around 700 nm, due to the film's anti-reflection characteristic. In addition, the color of the cells changed from green to bright red as the ATO layers were adopted. These beneficial effects of the sputter-deposited ATO films suggest an effective pathway towards the semi-transparent silicon thin film solar cells for building-integrated photovoltaic system applications.

  8. Pulsed laser deposition of AlMgB14 thin films

    SciTech Connect

    Britson, Jason Curtis

    2008-11-18

    Hard, wear-resistant coatings of thin film borides based on AlMgB14 have the potential to be applied industrially to improve the tool life of cutting tools and pump vanes and may account for several million dollars in savings as a result of reduced wear on these parts. Past work with this material has shown that it can have a hardness of up to 45GPa and be fabricated into thin films with a similar hardness using pulsed laser deposition. These films have already been shown to be promising for industrial applications. Cutting tools coated with AlMgB14 used to mill titanium alloys have been shown to substantially reduce the wear on the cutting tool and extend its cutting life. However, little research into the thin film fabrication process using pulsed laser deposition to make AlMgB14 has been conducted. In this work, research was conducted into methods to optimize the deposition parameters for the AlMgB14 films. Processing methods to eliminate large particles on the surface of the AlMgB14 films, produce films that were at least 1m thick, reduce the surface roughness of the films, and improve the adhesion of the thin films were investigated. Use of a femtosecond laser source rather than a nanosecond laser source was found to be effective in eliminating large particles considered detrimental to wear reduction properties from the films. Films produced with the femtosecond laser were also found to be deposited at a rate 100 times faster than those produced with the nanosecond laser. However, films produced with the femtosecond laser developed a relatively high RMS surface roughness around 55nm. Attempts to decrease the surface roughness were largely unsuccessful. Neither increasing the surface temperature of the substrate during deposition nor using a double pulse to ablate the material was found to be extremely successful to reduce the surface roughness. Finally, the adhesion of the thin films to M2 tool steel

  9. CW laser compaction of aqueous solution deposited metal oxide films

    SciTech Connect

    Exarhos, G.J.; Dennis, T.

    1997-12-01

    Zirconium dioxide films were spin cast onto silica or silicon substrates from an aqueous solution comprised of the precursor metal nitrate and an organic complexant such as glycine. The hydrated films so derived consist of an amorphous organic phase in which the metal cations and nitrate anions are homogeneously dispersed. Heating to temperatures above 200 {degrees}C leads to film dehydration followed by an auto-catalyzed oxidation reaction whereby the bound nitrate oxidizes the organic matrix leaving behind an intact stoichiometric and crystalline metal oxide film. Films are characterized using AFM, XRD, and optical methods. Transformation processes in these films have been studied in detail by means of spectroscopic ellipsometry and laser induced fluorescence from films doped with a suitable rare earth probe ion such as SM{sup +3}. In the latter case, the measured fluorescence emission spectra are used to identify the hydrated, dehydrated, amorphous and crystalline metal oxide phases which evolve during processing. These transformations also have been induced upon visible CW laser irradiation at fluences in excess of 1 MW/cm{sup 2}. Under these conditions, the film dehydrates and compacts within the footprint of the incident laser beam rendering this region of the film water insoluble. Post irradiation washing of the film with water removes all vestiges of the film outside of the beam footprint suggesting a possible use of this technique for lithography applications. Films subjected to laser irradiation and post irradiation heating have been characterized with respect to thickness, phase composition, crystallite size and optical constants.

  10. Deposition of biopolymer thin films by matrix assisted pulsed laser evaporation

    NASA Astrophysics Data System (ADS)

    Cristescu, R.; Mihaiescu, D.; Socol, G.; Stamatin, I.; Mihailescu, I. N.; Chrisey, D. B.

    We report on the successful deposition of high quality type I fibrilar collagen thin films by Matrix assisted pulsed laser evaporation (MAPLE). Thin films deposition was performed in a N2 ambient (20 Pa) using a KrF* laser source (λ=248 nm,τ>=20 ns) operated at a repetition rate of 3 Hz, the incident laser energy at a value within the range (20-35)mJ , and the laser spot area was (3.5-18.5)+/-0.1 mm2. The collagen films were deposited on double face polished <100> single crystalline Si wafers and characterized by Fourier transform infrared spectroscopy, atomic force microscopy and high-resolution transmission electron microscopy. We demonstrate that our thin films are composed of collagen, with no impurities and the roughness can be controlled by the deposition conditions.

  11. Improvement of copper plating adhesion on silane modified PET film by ultrasonic-assisted electroless deposition

    NASA Astrophysics Data System (ADS)

    Lu, Yinxiang

    2010-03-01

    Copper thin film on silane modified poly(ethylene terephthalate) (PET) substrate was fabricated by ultrasonic-assisted electroless deposition. The composition and topography of copper plating PET films were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. Peel adhesion strength, as high as 16.7 N/cm, was achieved for the planting copper layer to the modified PET substrate with ultrasonic-assisted deposition; however, a relative low value as 11.9 N/cm was obtained for the sample without ultrasonic vibration by the same measurement. The electrical conductivity of Cu film was changed from 7.9 × 10 4 to 2.1 × 10 5 S/cm by using ultrasonic technique. Ultrasonic operation has the significant merits of fast deposition and formation of good membranes for electroless deposition of Cu on PET film.

  12. The Effects of Sputtering Target Preparation and Deposition Temperature on ZnTe:Cu Film Properties

    SciTech Connect

    Faulkner, Brooke R.; Ohno, T. R.; Burst, James M.; Duenow, Joel N.; Perkins, Craig L.; To, Bobby; Gessert, Timothy A.

    2015-06-14

    A back contact containing a sputtered ZnTe:Cu interface layer can produce high-performing thin-film CdS/CdTe photovoltaic devices. We have found that varying the ZnTe:Cu sputtering target fabrication processes and deposition temperature can affect material properties of the ZnTe:Cu films and the resulting device performance. Two different target 'recipes' with various copper contents were used to study changes in the compositional, structural, optical, and electrical properties of ZnTe:Cu films. Substrate temperature during deposition was also varied to investigate the temperature dependence of the films. It was found that the target recipe, Cu concentration in the target, and deposition temperature affect the composition of the ZnTe:Cu films, which impacts their structural, optical, and electrical properties.

  13. Evaporation system and method for gas jet deposition of thin film materials

    DOEpatents

    Schmitt, Jerome J.; Halpern, Bret L.

    1994-01-01

    A method and apparatus for depositing thin films of materials such as metals, oxides and nitrides at low temperature relies on a supersonic free jet of inert carrier gas to transport vapor species generated from an evaporation source to the surface of a substrate. Film deposition vapors are generated from solid film precursor materials, including those in the form of wires or powders. The vapor from these sources is carried downstream in a low pressure supersonic jet of inert gas to the surface of a substrate where the vapors deposit to form a thin film. A reactant gas can be introduced into the gas jet to form a reaction product with the evaporated material. The substrate can be moved from the gas jet past a gas jet containing a reactant gas in which a discharge has been generated, the speed of movement being sufficient to form a thin film which is chemically composed of the evaporated material and reactant gases.

  14. Exchange bias in polycrystalline magnetite films made by ion-beam assisted deposition

    SciTech Connect

    Kaur, Maninder; Jiang, Weilin; Qiang, You; Burks, Edward; Liu, Kai; Namavar, Fereydoon; Mccloy, John S.

    2014-11-03

    Iron oxide films were deposited onto Si substrates using ion-beam-assisted deposition. The films were ~300 nm thick polycrystalline magnetite with an average crystallite size of ~6 nm. Additionally, incorporation of significant fractions of argon in the films from ion bombardment is evident from chemical analysis, and Fe/O ratios are lower than expected from pure magnetite. However, Raman spectroscopy and x-ray diffraction both indicate that the films are single-phase magnetite. Since no direct evidence of a second phase could be found, exchange bias likely arises due to defects at grain boundaries, possibly amorphous, creating frustrated spins. Since these samples have such small grains, a large fraction of the material consists of grain boundaries, where spins are highly disordered and reverse independently with external field. The high energy deposition process results in an oxygen-rich, argon-containing magnetite film with low temperature exchange bias due to defects at the high concentration of grain boundaries.

  15. Formation mechanism and ordered patterns in Cu films deposited on silicone oil surfaces

    NASA Astrophysics Data System (ADS)

    Chen, Miao-Gen; Xie, Jian-Ping; Ye, Gao-Xiang

    2006-12-01

    A copper (Cu) film system, deposited on silicone oil surfaces by vapor phase deposition method, has been fabricated and its formation mechanism as well as ordered patterns has been studied. The formation mechanism of the films obeys the two-stage growth model. The ordered patterns, which are composed of a large number of parallel keys with different width w but nearly uniform length L, are observed in the continuous Cu films. It is noted that, if the nominal film thickness d=120.0 nm, the value of α=L/(4w) reaches its maximum at the deposition rate f=0.05 nm/s. The experiment indicates that the ordered patterns mainly result from the ordered material aggregation, which depends closely on the internal stress in the nearly free sustained Cu film system.

  16. Frequency dependent FMR studies on pulsed laser ablated YIG films deposited on (111) GGG substrate

    NASA Astrophysics Data System (ADS)

    Bhoi, B.; Venkataramani, N.; Aiyar, R. P. R. C.; Prasad, Shiva; Kostylev, Mikhail; Stamps, R. L.

    2013-02-01

    Ferromagnetic Resonance (FMR) studies were carried out as a function of frequency on ex-situ post-annealed (Ta: 700 °C and 850 °C) YIG films. The films were deposited at TS: 750 °C on polished single crystal (111) GGG substrate using pulsed laser deposition. Both the films (Ta: 700 °C, 850 °C) shows a in-plane FMR line-width (ΔH) of 40 Oe and 50 Oe respectively which remains constant over a broad frequency range (8 GHz-20 GHz). On the other hand, a linear increment in in-plane resonance field (HR) has been observed with the increase in frequency of RF signal. The effective saturation magnetization (4πMeff) has been estimated for both the films using Kittel's equations and is found as 90% of the bulk value for the film deposited at 750 °C, annealed at 700 °C.

  17. Transparent ferrimagnetic semiconducting CuCr2O4 thin films by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Tripathi, T. S.; Yadav, C. S.; Karppinen, M.

    2016-04-01

    We report the magnetic and optical properties of CuCr2O4 thin films fabricated by atomic layer deposition (ALD) from Cu(thd)2, Cr(acac)3, and ozone; we deposit 200 nm thick films and anneal them at 700 °C in oxygen atmosphere to crystallize the spinel phase. A ferrimagnetic transition at 140 K and a direct bandgap of 1.36 eV are determined for the films from magnetic and UV-vis spectrophotometric measurements. Electrical transport measurements confirm the p-type semiconducting behavior of the films. As the ALD technique allows the deposition of conformal pin-hole-free coatings on complex 3D surfaces, our CuCr2O4 films are interesting material candidates for various frontier applications.

  18. Microstructure and optoelectronic properties of galliumtitanium-zinc oxide thin films deposited by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Chen, Shou-bu; Lu, Zhou; Zhong, Zhi-you; Long, Hao; Gu, Jin-hua; Long, Lu

    2016-07-01

    Gallium-titanium-zinc oxide (GTZO) transparent conducting oxide (TCO) thin films were deposited on glass substrates by radio frequency magnetron sputtering. The dependences of the microstructure and optoelectronic properties of GTZO thin films on Ar gas pressure were observed. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) results show that all the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. With the increment of Ar gas pressure, the microstructure and optoelectronic properties of GTZO thin films will be changed. When Ar gas pressure is 0.4 Pa, the deposited films possess the best crystal quality and optoelectronic properties.

  19. Atomic Oxygen Sensors Based on Nanograin ZnO Films Prepared by Pulse Laser Deposition

    SciTech Connect

    Wang Yunfei; Chen Xuekang; Li Zhonghua; Zheng Kuohai; Wang Lanxi; Feng Zhanzu; Yang Shengsheng

    2009-01-05

    High-quality nanograin ZnO thin films were deposited on c-plane sapphire (Al{sub 2}O{sub 3}) substrates by pulse laser deposition (PLD). Scanning electron microscopy (SEM) and x-ray diffraction (XRD) were used to characterize the samples. The structural and morphological properties of ZnO films under different deposition temperature have been investigated before and after atomic oxygen (AO) treatment. XRD has shown that the intensity of the (0 0 2) peak increases and its FWHM value decreases after AO treatment. The AO sensing characteristics of nano ZnO film also has been investigated in a ground-based atomic oxygen simulation facility. The results show that the electrical conductivity of nanograin ZnO films decreases with increasing AO fluence and that the conductivity of the films can be recovered by heating.

  20. Novel fabrication of an electrochromic antimony-doped tin oxide film using a nanoparticle deposition system

    NASA Astrophysics Data System (ADS)

    Kim, Hyungsub; Park, Yunchan; Choi, Dahyun; Ahn, Sung-Hoon; Lee, Caroline Sunyong

    2016-07-01

    Novel deposition method of Antimony-doped tin oxide (ATO) thin films was introduced using a nanoparticle deposition system (NPDS) to fabricate an electrochromic (EC) device. NPDS is a dry deposition method that simplifies the ATO deposition process by eliminating the need for solvents or binders. In this study, an ATO EC layer was deposited using NPDS. The surface morphology and electrochemical and optical transmittance properties were characterized. The optical transmittance change in the ATO EC device was ∼35% over the wavelength range of 350-800 nm, and the cyclic transmittance was stable. The ATO film deposited using NPDS, exhibited a coloration efficiency of 15.5 cm2 C-1. Therefore, our results suggest that ATO EC devices can be fabricated using a simple, cost-effective NPDS, which allows nanoparticles to be deposited directly without pre- or post-processing.

  1. Investigation on vanadium oxide thin films deposited by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Margoni, Mudaliar Mahesh; Mathuri, S.; Ramamurthi, K.; Babu, R. Ramesh; Sethuraman, K.

    2016-05-01

    Vanadium oxide thin films were deposited at 400 °C by spray pyrolysis technique using 0.1 M aqueous precursor solution of ammonium meta vanadate (AMV) with two different pH values. X-ray diffraction results showed that the film prepared using aqueous precursor AMV solution (solution A; pH 7) is amorphous in nature and the film prepared by adding HNO3 in the AMV aqua solution A (solution B; pH 3) is polycrystalline in nature. Vanadium oxide film prepared from the precursor solution B is in the mixed phases of V2O5 and V4O7. Crystallinity is improved for the film prepared using solution B when compared to film prepared from solution A. Crystallite size, strain and dislocation density calculated for the film prepared from solution B is respectively 72.1 nm, 0.4554 × 10-3 lin.-2m-4 and 1.7263 × 1014 lin.m-2. Morphology study revealed that the size of the flakes formed on the surface of the films is influenced by the pH of the precursor solution. Average Visible Transmittance and maximum transmittance of the deposited films exceed 70% and the direct optical band gap value calculated for the films deposited from A and B solution is 1.91 eV and 2.08 eV respectively.

  2. PROCESS FOR DECONTAMINATING LIQUID FLUOROCARBONS OF OIL SUSPENDED THEREIN

    DOEpatents

    Schneider, H.; Massey, B.J.

    1958-12-01

    Decontaminatlon of a bulk of liquld fluorocarbon contaminated with oil and water can be accomplished by passlng the contaminated material through a bed of either silica gel, activated alumina or activated carbon to absorb the contaminants.

  3. Deposition and characterization of far-infrared absorbing gold black films

    NASA Technical Reports Server (NTRS)

    Advena, Donna J.; Bly, Vincent T.; Cox, J. T.

    1993-01-01

    A process is described for producing gold black films with high absorptance in the far IR. The optical and electrical properties of these films have been studied with particular emphasis on the absorptance of films at wavelengths as long as 50 microns. A substantial decrease in absorptance near 50 microns has been observed for pure gold black films on aging in air. This degradation can be largely avoided by alloying the gold with a small percentage of copper during the deposition. Preliminary results on two methods for delineating gold black films are also presented.

  4. Antimicrobial oligo(p-phenylene-ethynylene) film deposited by resonant infrared matrix-assisted pulsed laser evaporation.

    PubMed

    Ge, Wangyao; Yu, Qian; López, Gabriel P; Stiff-Roberts, Adrienne D

    2014-04-01

    The antimicrobial oligomer, oligo(p-phenylene-ethynylene) (OPE), was deposited as thin films by resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) on solid substrates and exhibited light-induced biocidal activity. The biocidal activity of OPE thin films deposited by spin-coating and drop-casting was also investigated for comparison. Enhanced bacterial attachment and biocidal efficiency of the film deposited by RIR-MAPLE were observed and attributed to nanoscale surface topography of the thin film.

  5. Low temperature atmospheric pressure chemical vapor deposition of group 14 oxide films

    SciTech Connect

    Hoffman, D.M.; Atagi, L.M. |; Chu, Wei-Kan; Liu, Jia-Rui; Zheng, Zongshuang; Rubiano, R.R.; Springer, R.W.; Smith, D.C.

    1994-06-01

    Depositions of high quality SiO{sub 2} and SnO{sub 2} films from the reaction of homoleptic amido precursors M(NMe{sub 2})4 (M = Si,Sn) and oxygen were carried out in an atmospheric pressure chemical vapor deposition r. The films were deposited on silicon, glass and quartz substrates at temperatures of 250 to 450C. The silicon dioxide films are stoichiometric (O/Si = 2.0) with less than 0.2 atom % C and 0.3 atom % N and have hydrogen contents of 9 {plus_minus} 5 atom %. They are deposited with growth rates from 380 to 900 {angstrom}/min. The refractive indexes of the SiO{sub 2} films are 1.46, and infrared spectra show a possible Si-OH peak at 950 cm{sup {minus}1}. X-Ray diffraction studies reveal that the SiO{sub 2} film deposited at 350C is amorphous. The tin oxide films are stoichiometric (O/Sn = 2.0) and contain less than 0.8 atom % carbon, and 0.3 atom % N. No hydrogen was detected by elastic recoil spectroscopy. The band gap for the SnO{sub 2} films, as estimated from transmission spectra, is 3.9 eV. The resistivities of the tin oxide films are in the range 10{sup {minus}2} to 10{sup {minus}3} {Omega}cm and do not vary significantly with deposition temperature. The tin oxide film deposited at 350C is cassitterite with some (101) orientation.

  6. Crystallinity of inorganic films grown by atomic layer deposition: Overview and general trends

    NASA Astrophysics Data System (ADS)

    Miikkulainen, Ville; Leskelä, Markku; Ritala, Mikko; Puurunen, Riikka L.

    2013-01-01

    Atomic layer deposition (ALD) is gaining attention as a thin film deposition method, uniquely suitable for depositing uniform and conformal films on complex three-dimensional topographies. The deposition of a film of a given material by ALD relies on the successive, separated, and self-terminating gas-solid reactions of typically two gaseous reactants. Hundreds of ALD chemistries have been found for depositing a variety of materials during the past decades, mostly for inorganic materials but lately also for organic and inorganic-organic hybrid compounds. One factor that often dictates the properties of ALD films in actual applications is the crystallinity of the grown film: Is the material amorphous or, if it is crystalline, which phase(s) is (are) present. In this thematic review, we first describe the basics of ALD, summarize the two-reactant ALD processes to grow inorganic materials developed to-date, updating the information of an earlier review on ALD [R. L. Puurunen, J. Appl. Phys. 97, 121301 (2005)], and give an overview of the status of processing ternary compounds by ALD. We then proceed to analyze the published experimental data for information on the crystallinity and phase of inorganic materials deposited by ALD from different reactants at different temperatures. The data are collected for films in their as-deposited state and tabulated for easy reference. Case studies are presented to illustrate the effect of different process parameters on crystallinity for representative materials: aluminium oxide, zirconium oxide, zinc oxide, titanium nitride, zinc zulfide, and ruthenium. Finally, we discuss the general trends in the development of film crystallinity as function of ALD process parameters. The authors hope that this review will help newcomers to ALD to familiarize themselves with the complex world of crystalline ALD films and, at the same time, serve for the expert as a handbook-type reference source on ALD processes and film crystallinity.

  7. Structural properties of indium tin oxide thin films by glancing angle deposition method.

    PubMed

    Oh, Gyujin; Kim, Seon Pil; Lee, Kyoung Su; Kim, Eun Kyu

    2013-10-01

    We have studied the structural and optical properties of indium tin oxide (ITO) films deposited on sapphire substrates by electron beam evaporator with glancing angle deposition method. The ITO films were grown with different deposition angles of 0 degrees, 30 degrees, 45 degrees, 60 degrees at fixed deposition rate of 3 angstroms/s and with deposition rates of 2 angstroms/s, 3 angstroms/s, and 4angstroms/s at deposition angle of 45 degrees, respectively. From analysis of ellipsometry measurements, it appears that the void fraction of the films increased and their refractive indices decreased from 2.18 to 1.38 at the wavelength of 500 as increasing the deposition angle. The refractive index in the wavelength ranges of 550 nm-800 nm also depends on the deposition rates. Transmittance of ITO film with 235-nm-thickness grown at 60 degrees was covered about 20-80%, and then it was increased in visible wavelength range with increase of deposition angle. PMID:24245214

  8. Theoretical investigation about secondary deposition of thin-film formation by molecular dynamics simulation

    NASA Astrophysics Data System (ADS)

    Chen, Huawei; Hagiwara, Ichiro; Kiet Tieu, A.; Kishimoto, Kikuo; Liu, Qiang

    2007-05-01

    The thin-film growth has been confirmed to be assembled by an enormous number of clusters in experiments of CVD. Sequence of clusters' depositions proceeds to form the thin-film in short time as gas fluids through surface of substrate. Such growth mechanism has been mainly investigated on the basis of experiment. Due to immense cost of the experimental equipment and low level of current measurement technology, the comprehension about authentic effect of formation condition on properties of nanomaterial is limited in qualitative manner. Three quantitative items: flatness of primary deposition, adhesion between cluster and substrate, and degree of epitaxial growth were proposed to evaluate the property of thin-film. In this simulation, three different cluster sizes of 203, 653, and 1563 atoms with different velocities (0, 10, 100, 1000, and 3000 m/s) were deposited on a Cu(0 0 1) substrate whose temperatures were set between 300 and 1000 K. Four clusters and one cluster were used in primary deposition and secondary deposition, respectively. To increase initial velocity not only enhanced the speed of epitaxial growth, adhesion between clusters and substrate, but also increased the degree of epitaxy for primary deposition and secondary deposition. Exfoliation pattern of thin-film was profoundly dependent on initial velocity through comparison between adhesion of primary and secondary deposition. Moreover, the epitaxial growth became well as the temperature of substrate was raised, and the degree of epitaxy of small cluster was larger than that of larger cluster, no matter of primary and secondary deposition.

  9. Method for continuous control of composition and doping of pulsed laser deposited films

    DOEpatents

    Lowndes, Douglas H.; McCamy, James W.

    1995-01-01

    A method for growing a deposit upon a substrate of semiconductor material involves the utilization of pulsed laser deposition techniques within a low-pressure gas environment. The substrate and a target of a first material are positioned within a deposition chamber and a low-pressure gas atmosphere is developed within the chamber. The substrate is then heated, and the target is irradiated, so that atoms of the target material are ablated from the remainder of the target, while atoms of the gas simultaneously are adsorbed on the substrate/film surface. The ablated atoms build up upon the substrate, together with the adsorbed gas atoms to form the thin-film deposit on the substrate. By controlling the pressure of the gas of the chamber atmosphere, the composition of the formed deposit can be controlled, and films of continuously variable composition or doping can be grown from a single target of fixed composition.

  10. Method for continuous control of composition and doping of pulsed laser deposited films by pressure control

    DOEpatents

    Lowndes, Douglas H.; McCamy, James W.

    1996-01-01

    A method for growing a deposit upon a substrate of semiconductor material involves the utilization of pulsed laser deposition techniques within a low-pressure gas environment. The substrate and a target of a first material are positioned within a deposition chamber and a low-pressure gas atmosphere is developed within the chamber. The substrate is then heated, and the target is irradiated, so that atoms of the target material are ablated from the remainder of the target, while atoms of the gas simultaneously are adsorbed on the substrate/film surface. The ablated atoms build up upon the substrate, together with the adsorbed gas atoms to form the thin-film deposit on the substrate. By controlling the pressure of the gas of the chamber atmosphere, the composition of the formed deposit can be controlled, and films of continuously variable composition or doping can be grown from a single target of fixed composition.

  11. Low loss Nb2O5 films deposited by novel remote plasma sputtering

    NASA Astrophysics Data System (ADS)

    Liu, Zhe; Bu, Yi-kun

    2013-03-01

    We report the deposition of Nb2O5 films on unheated BK-7 glass substrates using remote plasma sputtering system. The remote plasma geometry allows pseudo separation of plasma and target bias parameters, which offers complete deposition rate control. Using appropriate oxygen flow rates, high-density and low-loss Nb2O5 films are deposited with rates up to 0.49 nm/s. Lower deposition rates (˜0.026 nm/s) can also be obtained by working at low target current and voltage and at low pressure. Nb2O5 films deposited at different rates have the refractive index of about 2.3 and the extinction coefficient as low as 6.9×10-5.

  12. Photoresponse in thin films of WO{sub 3} grown by pulsed laser deposition

    SciTech Connect

    Roy Moulik, Samik; Samanta, Sudeshna; Ghosh, Barnali

    2014-06-09

    We report, the photoresponse behaviour of Tungsten trioxide (WO{sub 3}) films of different surface morphology, grown by using pulsed laser deposition (PLD). The Growth parameters for PLD were changed for two substrates SiO{sub 2}/Si (SO) and SrTiO{sub 3} (STO), such a way which, result nanocrystalline film on SO and needle like structured film on STO. The photoresponse is greatly modified in these two films because of two different surface morphologies. The nanocrystalline film (film on SO) shows distinct photocurrent (PC) ON/OFF states when light was turned on/off, the enhancement of PC is ∼27%. Whereas, the film with needle like structure (film on STO) exhibits significantly enhanced persistent photocurrent even in light off condition, in this case, the enhancement of PC ∼ 50% at room temperature at lowest wavelength (λ = 360 nm) at a nominal bias voltage of 0.1 V.

  13. Fluorinated diamond particles bonded in a filled fluorocarbon resin matrix

    DOEpatents

    Taylor, G.W.; Roybal, H.E.

    1983-11-14

    A method of producing fluorinated diamond particles bonded in a filled fluorocarbon resin matrix. Simple hot pressing techniques permit the formation of such matrices from which diamond impregnated grinding tools and other articles of manufacture can be produced. Teflon fluorocarbon resins filled with Al/sub 2/O/sub 3/ yield grinding tools with substantially improved work-to-wear ratios over grinding wheels known in the art.

  14. Fluorinated diamond particles bonded in a filled fluorocarbon resin matrix

    DOEpatents

    Taylor, Gene W.; Roybal, Herman E.

    1985-01-01

    A method of producing fluorinated diamond particles bonded in a filled fluorocarbon resin matrix. Simple hot pressing techniques permit the formation of such matrices from which diamond impregnated grinding tools and other articles of manufacture can be produced. Teflon fluorocarbon resins filled with Al.sub.2 O.sub.3 yield grinding tools with substantially improved work-to-wear ratios over grinding wheels known in the art.

  15. Fluorocarbon compounds in MRI diagnostics and medical therapy

    NASA Astrophysics Data System (ADS)

    Pirogov, Yu

    2016-02-01

    The lecture describes the application of fluorocarbon compounds as blood substitutes and contrasting preparations in MRI diagnostics. A blood substitute product fluorocarbon Perfluorane® has shown effectiveness in oxygen delivery to the tissues of living organisms, and cardioprotective effect which does not depend on the patient's blood group. Inclusion of paramagnetic atoms (gadolinium, iron, etc.) to the Perfluorane® chemical formula creates a new compound with high MRI contrast efficiencies at Larmor frequencies of protons so and fluorine-19 nuclei.

  16. Evaluation of Interfacial Strength of Bnt Films Hydrothermally Deposited on Titanium Substrates

    NASA Astrophysics Data System (ADS)

    Kusukawa, Kazuhiro; Xu, Fangchao

    Lead-free piezoelectric (Bi1/2Na1/2)TiO3 (abbreviated as BNT) films were deposited on 0.2 mm thick pure titanium(Ti) substrates by a hydrothermal method. Scratch tests and Vickers indentation tests were performed to quantitatively assess the adhesion strength between BNT films and Ti substrates. Some of Ti substrates were pretreated by chemical polish and mechanical polish respectively prior to BNT film deposition with a view of investigating the effects of substrate surface pretreatments on the adhesion of BNT films. In the scratch test, the critical force was determined from the variations of the tangential force and the acoustic emission (AE) signals with the normal force. The scratch test results revealed that the chemical polish pretreatment effectively improved the adhesion of BNT films. In addition, the critical substrate strain inducing the adhesion failure of BNT films has been investigated by the Vickers indentation test combined with finite element analysis (FEM).

  17. Continuous Microreactor-Assisted Solution Deposition for Scalable Production of CdS Films

    SciTech Connect

    Ramprasad, Sudhir; Su, Yu-Wei; Chang, Chih-Hung; Paul, Brian; Palo, Daniel R.

    2013-06-13

    Solution deposition offers an attractive, low temperature option in the cost effective production of thin film solar cells. Continuous microreactor-assisted solution deposition (MASD) was used to produce nanocrystalline cadmium sulfide (CdS) films on fluorine doped tin oxide (FTO) coated glass substrates with excellent uniformity. We report a novel liquid coating technique using a ceramic rod to efficiently and uniformly apply reactive solution to large substrates (152 mm × 152 mm). This technique represents an inexpensive approach to utilize the MASD on the substrate for uniform growth of CdS films. Nano-crystalline CdS films have been produced from liquid phase at ~90°C, with average thicknesses of 70 nm to 230 nm and with a 5 to 12% thickness variation. The CdS films produced were characterized by UV-Vis spectroscopy, transmission electron microscopy, and X-Ray diffraction to demonstrate their suitability to thin-film solar technology.

  18. High sensitive formaldehyde graphene gas sensor modified by atomic layer deposition zinc oxide films

    SciTech Connect

    Mu, Haichuan; Zhang, Zhiqiang; Wang, Keke; Xie, Haifen; Zhao, Xiaojing; Liu, Feng

    2014-07-21

    Zinc oxide (ZnO) thin films with various thicknesses were fabricated by Atomic Layer Deposition on Chemical Vapor Deposition grown graphene films and their response to formaldehyde has been investigated. It was found that 0.5 nm ZnO films modified graphene sensors showed high response to formaldehyde with the resistance change up to 52% at the concentration of 9 parts-per-million (ppm) at room temperature. Meanwhile, the detection limit could reach 180 parts-per-billion (ppb) and fast response of 36 s was also obtained. The high sensitivity could be attributed to the combining effect from the highly reactive, top mounted ZnO thin films, and high conductive graphene base network. The dependence of ZnO films surface morphology and its sensitivity on the ZnO films thickness was also investigated.

  19. High sensitive formaldehyde graphene gas sensor modified by atomic layer deposition zinc oxide films

    NASA Astrophysics Data System (ADS)

    Mu, Haichuan; Zhang, Zhiqiang; Zhao, Xiaojing; Liu, Feng; Wang, Keke; Xie, Haifen

    2014-07-01

    Zinc oxide (ZnO) thin films with various thicknesses were fabricated by Atomic Layer Deposition on Chemical Vapor Deposition grown graphene films and their response to formaldehyde has been investigated. It was found that 0.5 nm ZnO films modified graphene sensors showed high response to formaldehyde with the resistance change up to 52% at the concentration of 9 parts-per-million (ppm) at room temperature. Meanwhile, the detection limit could reach 180 parts-per-billion (ppb) and fast response of 36 s was also obtained. The high sensitivity could be attributed to the combining effect from the highly reactive, top mounted ZnO thin films, and high conductive graphene base network. The dependence of ZnO films surface morphology and its sensitivity on the ZnO films thickness was also investigated.

  20. Interfacial development of electrophoretically deposited graphene oxide films on Al alloys

    SciTech Connect

    Jin, Sumin; Dickerson, James H.; Pham, Viet Hung; Brochu, Mathieu

    2015-07-28

    Adhesion between film and substrate is critical for electronic device and coating applications. Interfacial development between electrophoretically deposited graphene oxide films on Al 1100 and Al 5052 alloys were investigated using FT-IR and XPS depth profiling techniques. Obtained results suggest metal ion permeation from the substrates into deposited graphene oxide films. The interface between the films and the substrates were primarily composed of Al-O-C bonds from oxygenated defects on graphene oxide plane rather than expected Al-C formation. Films heat treated at 150 °C had change in microstructure and peak shifts in XPS spectra suggesting change in chemical structure of bonds between the films and the substrates.

  1. Interfacial development of electrophoretically deposited graphene oxide films on Al alloys

    DOE PAGES

    Jin, Sumin; Dickerson, James H.; Pham, Viet Hung; Brochu, Mathieu

    2015-07-28

    Adhesion between film and substrate is critical for electronic device and coating applications. Interfacial development between electrophoretically deposited graphene oxide films on Al 1100 and Al 5052 alloys were investigated using FT-IR and XPS depth profiling techniques. Obtained results suggest metal ion permeation from the substrates into deposited graphene oxide films. The interface between the films and the substrates were primarily composed of Al-O-C bonds from oxygenated defects on graphene oxide plane rather than expected Al-C formation. Films heat treated at 150 °C had change in microstructure and peak shifts in XPS spectra suggesting change in chemical structure of bondsmore » between the films and the substrates.« less

  2. Fundamental tribological properties of ion-beam-deposited boron nitride films

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1989-01-01

    The adhesion, friction, and micromechanical properties of ion-beam-deposited boron nitride (BN) films are reviewed. The BN films are examined in contact with BN metals and other harder materials. For simplicity of discussion, the tribological properties of concern in the processes are separated into two parts. First, the pull-off force (adhesion) and the shear force required to break the interfacial junctions between contacting surfaces are discussed. The effects of surface films, hardness of metals, and temperature on tribological response with respect to adhesion and friction are considered. The second part deals with the abrasion of the BN films. Elastic, plastic, and fracture behavior of the BN films in solid-state contact are discussed. The scratch technique of determining the critical load needed to fracture interfacial adhesive bonds of BN films deposited on substrates is also addressed.

  3. Investigation on single walled carbon nanotube thin films deposited by Langmuir Blodgett method

    SciTech Connect

    Vishalli, Dharamvir, Keya; Kaur, Ramneek; Raina, K. K.

    2015-05-15

    Langmuir Blodgett is a technique to deposit a homogeneous film with a fine control over thickness and molecular organization. Thin films of functionalized SWCNTs have been prepared by Langmuir Blodgett method. The good surface spreading properties of SWCNTs at air/water interface are indicated by surface pressure-area isotherm and the monolayer formed on water surface is transferred onto the quartz substrate by vertical dipping. A multilayer film is thus obtained in a layer by layer manner. The film is characterized by Atomic Force Microscope (AFM), UV-Vis-NIR spectroscopy and FTIR.AFM shows the surface morphology of the deposited film. UV-Vis-NIR spectroscopy shows the characteristic peaks of semiconducting SWCNTs. The uniformity of LB film can be used further in understanding the optical and electrical behavior of these materials.

  4. In situ monitoring of atomic layer deposition in nanoporous thin films using ellipsometric porosimetry.

    PubMed

    Dendooven, Jolien; Devloo-Casier, Kilian; Levrau, Elisabeth; Van Hove, Robbert; Sree, Sreeprasanth Pulinthanathu; Baklanov, Mikhail R; Martens, Johan A; Detavernier, Christophe

    2012-02-28

    Ellipsometric porosimetry (EP) is a handy technique to characterize the porosity and pore size distribution of porous thin films with pore diameters in the range from below 1 nm up to 50 nm and for the characterization of porous low-k films especially. Atomic layer deposition (ALD) can be used to functionalize porous films and membranes, e.g., for the development of filtration and sensor devices and catalytic surfaces. In this work we report on the implementation of the EP technique onto an ALD reactor. This combination allowed us to employ EP for monitoring the modification of a porous thin film through ALD without removing the sample from the deposition setup. The potential of in situ EP for providing information about the effect of ALD coating on the accessible porosity, the pore radius distribution, the thickness, and mechanical properties of a porous film is demonstrated in the ALD of TiO(2) in a mesoporous silica film.

  5. Protein Adsorption on Patterned Hydroxyapatite Thin Films Fabricated by Pulsed Laser Deposition

    NASA Astrophysics Data System (ADS)

    Kusunoki, Masanobu; Kawasima, Masami; Nishikawa, Hiroaki; Morimoto, Koichi; Hayami, Takashi; Hontsu, Shigeki; Kawai, Tomoji

    2005-02-01

    Protein adsorption on hydroxyapatite (HAP) thin film was investigated before and after patterning. Hydroxyapatite thin film 100 nm thick was deposited by pulsed laser deposition. The film was patterned by photolithography and wet etching with HCl solution. Proteins (phospholyrase b, bovine serum albumin, and others) labeled with fluorescein isothiocyanate (FITC) were used as the reagent. After the HAP film was soaked in the reagent and washed with pure water, a conspicuous contrast in FITC was observed between the HAP pattern and the glass substrate (or photoresist). This behavior showed that the biocompatibility of the HAP thin film was not influenced by the patterning process. Our technique for HAP thin film is adaptable for applications involving biosensors as electronic devices and scaffolds for tissue culture.

  6. Fundamental tribological properties of ion-beam-deposited boron nitride films

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.

    1990-01-01

    The adhesion, friction, and micromechanical properties of ion-beam-deposited boron nitride (BN) films are reviewed. The BN films are examined in contact with BN metals and other harder materials. For simplicity of discussion, the tribological properties of concern in the processes are separated into two parts. First, the pull-off force (adhesion) and the shear force required to break the interfacial junctions between contacting surfaces are discussed. The effects of surface films, hardness of metals, and temperature on tribological response with respect to adhesion and friction are considered. The second part deals with the abrasion of the BN films. Elastic, plastic, and fracture behavior of the BN films in solid-state contact are discussed. The scratch technique of determining the critical load needed to fracture interfacial adhesive bonds of BN films deposited on substrates is also addressed.

  7. [Optical Properties of ZnO Films Fabricated by Atomic Layer Deposition].

    PubMed

    Zhang, Chun-mei; Wang, Dong-dong; Fang, Ming; Zhang, Ao; Wang, Xiao-yu; Chen, Qiang; Meng, Tao

    2016-01-01

    The ZnO films were deposited by atomic layer deposition method using water and diethylzinc as precursors at different temperatures (110 and 190 degrees C). X-ray photoelectron spectroscopy, spectroscopic ellipsometry and photoluminescence spectra (PL) were used to investigate the elemental composition and optical properties of ZnO films. Our results showed that with the increasing of the growth temperature, the amount of -OH groups in the ZnO film decreased, which indicated that the reactions went to completion at high processing temperatures. The PL spectra of the ZnO film deposited at 110 degrees C exhibited two emission bands, one in the UV region and the other in the visible region. When the deposition temperature increased to 190 degrees C, the emission bands in the visible region disappeared, which indicated that the deep level defect in ZnO became less. The carrier mobility improved from 25 to 32 cm2 x (V x S)(-1) with the reduction of the defects in the ZnO film. The refractive index of the ZnO films decreased from 2.33 to 1.9 in the 375-800 nm region. The optical absorption edge (E(g)) values of the ZnO films deposited at different temperature were about 3.27 eV.

  8. Differing morphologies of textured diamond films with electrical properties made with microwave plasma chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Lai, Wen Chi; Wu, Yu-Shiang; Chang, Hou-Cheng; Lee, Yuan-Haun

    2010-12-01

    This study investigates the orientation of textured diamond films produced through microwave plasma chemical vapor deposition (MPCVD) at 1200 W, 110 Torr, CH 4/H 2 = 1/20, with depositions times of 0.5-4.0 h. After a growth period of 2.0-4.0 h, this particular morphology revealed a rectangular structure stacked regularly on the diamond film. The orientation on {1 1 1}-textured diamond films grew a preferred orientation of {1 1 0} on the surface, as measured by XRD. The formation of the diamond epitaxial film formed textured octahedrons in ball shaped (or cauliflower-like) diamonds in the early stages (0.5 h), and the surface of the diamond film extended to pile the rectangular structure at 4.0 h. The width of the tier was approximately 200 nm at the 3.0 h point of deposition, according to TEM images. The results revealed that the textured diamond films showed two different morphological structures (typical ball shaped and rectangular diamonds), at different stages of the deposition period. The I- V characteristics of the oriented diamond films after 4.0 h of deposition time showed good conformity with the ohmic contact.

  9. Optical and electrical diagnostics of fluorocarbon plasma etching processes

    NASA Astrophysics Data System (ADS)

    Booth, Jean-Paul

    1999-05-01

    This article reviews recent work concerning the role of CF and CF2 radicals in etching and polymerization processes occurring in capacitively coupled radio-frequency plasmas in fluorocarbon gases used for the selective etching of SiO2 layers in microelectronic device fabrication. Laser-induced fluorescence (LIF) was used to determine time-resolved axial concentration profiles of these species in continuous and pulse-modulated CF4 and C2F6 plasmas. Calibration techniques, including broad-band UV absorption spectroscopy, were developed to put the LIF measurements on an absolute scale. A novel technique was used to determine the ion flux to the reactor walls in these polymerizing environments. The mass distribution of the ions arriving at the reactor walls was determined using a quadrupole mass spectrometer. It was found that CFx radicals are produced predominantly by the reflection of neutralized and dissociated CFx+ ions at the powered electrode surface. When the fluorine atom concentration is high, the CFx radicals are destroyed effectively by recombination catalysed by the reactor walls. When the fluorine atom concentration is lowered, the CF2 concentration rises markedly, and it participates in gas-phase oligomerization processes, forming large CxFy molecules and, after ionization, large CxFy+ ions. These species appear to be the true polymer precursors. This mechanism explains the well known correlation between high CF2 concentrations, polymer deposition and SiO2 over Si etch selectivity.

  10. Vaporization of a mixed precursors in chemical vapor deposition for YBCO films

    NASA Technical Reports Server (NTRS)

    Zhou, Gang; Meng, Guangyao; Schneider, Roger L.; Sarma, Bimal K.; Levy, Moises

    1995-01-01

    Single phase YBa2Cu3O7-delta thin films with T(c) values around 90 K are readily obtained by using a single source chemical vapor deposition technique with a normal precursor mass transport. The quality of the films is controlled by adjusting the carrier gas flow rate and the precursor feed rate.

  11. Surface treatment of polyimide film for metal magnetron deposition in vacuum

    NASA Astrophysics Data System (ADS)

    Petrov, V.; Vertyanov, D.; Timoshenkov, S.; Nikolaev, V.

    2014-12-01

    This paper brings forward a solution for acquisition of good quality metallization layers on the polyimide substrate by magnetron deposition in vacuum environment. Different film type structures have been analyzed after refining and activation surface treatment operations. Positive effect was shown after the application of polyimide lacquer for surface dielectric film planarization and for structural defects elimination.

  12. Deposition and characterization of La 2Ti 2O 7 thin films via spray pyrolysis process

    NASA Astrophysics Data System (ADS)

    Todorovsky, D. S.; Todorovska, R. V.; Milanova, M. M.; Kovacheva, D. G.

    2007-03-01

    Thin films of La 2Ti 2O 7 have been deposited on fused silica and Si substrates by a spray pyrolysis method using ethylene glycol solution of La(III)-Ti(IV)-citrate complexes as starting material and O 2 as a carrier gas. The composition, crystal structure and morphology of the films are studied.

  13. Effect of Post Deposition Annealing Treatments on Properties of AZO Thin Films for Schottky Diode Applications.

    PubMed

    Singh, Shaivalini; Park, Si-Hyun

    2016-01-01

    High-quality aluminum (Al) doped ZnO (AZO) thin films were deposited on silicon substrates by RF sputtering at room temperature. The deposited films were annealed from the temperatures 350 °C to 650 °C in pure nitrogen (N₂) ambient. The effects of annealing on the microstructural, optical and electrical properties of the AZO films were investigated. A detailed analysis by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Four Probe and Hall measurements was performed to study the properties of these AZO thin films. It was observed that all of the as-deposited and annealed AZO films have homogenous surfaces and hexagonal wurtzite structures with good crystalline quality. The study also suggested that there was an intermediate post annealing temperature (450 °C) at which the deposited ZnO film exhibit best surface characteristics. Pd/AZO Schottky devices were fabricated with 450 °C annealed AZO thin films and the parameters of Schottky devices were extracted from I-V characteristics. These results indicated that the Pd/AZO films were very much suitable for various optoelectronics applications particularly for metal semiconductor metal based UV detector application. PMID:27398537

  14. Fabricating functionally graded films with designed gradient profiles using pulsed laser deposition

    SciTech Connect

    Won, Yoo Jai; Ki, Hyungson

    2013-05-07

    A novel picosecond-laser pulsed laser deposition method has been developed for fabricating functionally graded films with pre-designed gradient profiles. Theoretically, the developed method is capable of precisely fabricating films with any thicknesses and any gradient profiles by controlling the laser beam powers for the two different targets based on the film composition profiles. As an implementation example, we have successfully constructed functionally graded diamond-like carbon films with six different gradient profiles: linear, quadratic, cubic, square root, cubic root, and sinusoidal. Energy dispersive X-ray spectroscopy is employed for investigating the chemical composition along the thickness of the film, and the deposition profile and thickness errors are found to be less than 3% and 1.04%, respectively. To the best of the authors' knowledge, this is the first method for fabricating films with designed gradient profiles and has huge potential in many areas of coatings and films, including multifunctional optical films. We believe that this method is not only limited to the example considered in this study, but also can be applied to all material combinations as long as they can be deposited using the pulsed laser deposition technique.

  15. Process Analysis Of Thin Film Deposition With An In Situ Ellipsometer

    NASA Astrophysics Data System (ADS)

    Savrda, Steven; Himel, Marc D.; Guenther, Karl H.; Urban, Frank K.

    1990-01-01

    Thin films deposited in high vacuum by thermal evaporation, electron beam evaporation, and ion assisted deposition are anything but smooth, homogeneous, stratified media with plane parallel boundaries as assumed in thin film design and theory. In particular, the porosity brought about by the columnar microstructure of these films has been a problem ever since their first use. The refractive index may change upon exposure to ambient atmosphere, as a result of H2O adsorption. In-situ rapid scanning spectrophotometers and ellipsometers have helped various researchers to determine the degree of index change and the packing density of the films. Low voltage reactive ion plating is a rather novel deposition technique which produces thin films with packing densities of unity and higher. The dense, vitreous or polycrystalline microstructure, which pre-vents the films from adsorbing water upon exposure to air, yields films with bulk-like optical properties that are constant in time. However, there are problems with increased absorption particularly with ion plated TiO2 and SiO2 multilayer thin-film stacks. Continuous measurements of n and k during deposition need to be studied in order to determine the location of the increased absorption. Engineering aspects of mounting a Rudolph Research ellipsometer on a Balzers BAP 800 vacuum system will also be discussed.

  16. Plasma enhanced chemical vapor deposition (PECVD) method of forming vanadium oxide films and vanadium oxide thin-films prepared thereby

    DOEpatents

    Zhang, Ji-Guang; Tracy, C. Edwin; Benson, David K.; Turner, John A.; Liu, Ping

    2000-01-01

    A method is disclosed of forming a vanadium oxide film on a substrate utilizing plasma enhanced chemical vapor deposition. The method includes positioning a substrate within a plasma reaction chamber and then forming a precursor gas comprised of a vanadium-containing chloride gas in an inert carrier gas. This precursor gas is then mixed with selected amounts of hydrogen and oxygen and directed into the reaction chamber. The amounts of precursor gas, oxygen and hydrogen are selected to optimize the final properties of the vanadium oxide film An rf plasma is generated within the reaction chamber to chemically react the precursor gas with the hydrogen and the oxygen to cause deposition of a vanadium oxide film on the substrate while the chamber deposition pressure is maintained at about one torr or less. Finally, the byproduct gases are removed from the plasma reaction chamber.

  17. Deposition of nanostructured photocatalytic zinc ferrite films using solution precursor plasma spraying

    SciTech Connect

    Dom, Rekha; Sivakumar, G.; Hebalkar, Neha Y.; Joshi, Shrikant V.; Borse, Pramod H.

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Highly economic solution precursor route capable of producing films/coating even for mass scale production. Black-Right-Pointing-Pointer Pure spinel phase ZnFe{sub 2}O{sub 4} porous, immobilized films deposited in single step. Black-Right-Pointing-Pointer Parameter optimization yields access to nanostructuring in SPPS method. Black-Right-Pointing-Pointer The ecofriendly immobilized ferrite films were active under solar radiation. Black-Right-Pointing-Pointer Such magnetic system display advantage w.r.t. recyclability after photocatalyst extraction. -- Abstract: Deposition of pure spinel phase, photocatalytic zinc ferrite films on SS-304 substrates by solution precursor plasma spraying (SPPS) has been demonstrated for the first time. Deposition parameters such as precursor solution pH, concentration, film thickness, plasma power and gun-substrate distance were found to control physico-chemical properties of the film, with respect to their crystallinity, phase purity, and morphology. Alkaline precursor conditions (7 < pH {<=} 10) were found to favor oxide film formation. The nanostructured films produced under optimized conditions, with 500 mM solution at pH {approx} 8.0, yielded pure cubic phase ZnFe{sub 2}O{sub 4} film. Very high/low precursor concentrations yielded mixed phase, less adherent, and highly inhomogeneous thin films. Desired spinel phase was achieved in as-deposited condition under appropriately controlled spray conditions and exhibited a band gap of {approx}1.9 eV. The highly porous nature of the films favored its photocatalytic performance as indicated by methylene blue de-coloration under solar radiation. These immobilized films display good potential for visible light photocatalytic applications.

  18. Electrochromic properties of molybdenum trioxide thin films prepared by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Maruyama, Toshiro; Kanagawa, Tetsuya

    1995-05-01

    Electrochromic molybdenum trioxide thin films were prepared by chemical vapor deposition. The source material was molybdenum carbonyl. Amorphous molybdenum trioxide thin films were produced at a substrate temperature 300 C. Reduction and oxidation of the films in a 0.3M LiClO4 propylene carbon ate solution caused desirable changes in optical absorption. Coulometry indicated that the coloration efficiency was 25.8 sq cm center-dot C(exp -1).

  19. Electron field emission characteristics of nano-catkin carbon films deposited by electron cyclotron resonance microwave plasma chemical vapour deposition

    NASA Astrophysics Data System (ADS)

    Gu, Guang-Rui; Wu, Bao-Jia; Jin, Zhe; Ito, Toshimichi

    2008-02-01

    This paper reported that the nano-catkin carbon films were prepared on Si substrates by means of electron cyclotron resonance microwave plasma chemical vapour deposition in a hydrogen and methane mixture. The surface morphology and the structure of the fabricated films were characterized by using scanning electron microscopes and Raman spectroscopy, respectively. The stable field emission properties with a low threshold field of 5V/μm corresponding to a current density of about 1μA/cm2 and a current density of 3.2mA/cm2 at an electric field of 10V/μm were obtained from the carbon film deposited at CH4 concentration of 8%. The mechanism that the threshold field decreased with the increase of the CH4 concentration and the high emission current appeared at the high CH4 concentration was explained by using the Fowler-Nordheim theory.

  20. Property transformation of graphene with Al{sub 2}O{sub 3} films deposited directly by atomic layer deposition

    SciTech Connect

    Zheng, Li; Cao, Duo; Wang, Zhongjian; Xia, Chao; Cheng, Xinhong Yu, Yuehui; Shen, Dashen

    2014-01-13

    Al{sub 2}O{sub 3} films are deposited directly onto graphene by H{sub 2}O-based atomic layer deposition (ALD), and the films are pinhole-free and continuously cover the graphene surface. The growth process of Al{sub 2}O{sub 3} films does not introduce any detective defects in graphene, suppresses the hysteresis effect and tunes the graphene doping to n-type. The self-cleaning of ALD growth process, together with the physically absorbed H{sub 2}O and oxygen-deficient ALD environment consumes OH{sup −} bonds, suppresses the p-doping of graphene, shifts Dirac point to negative gate bias and enhances the electron mobility.

  1. Large-Area Nanoparticle Films by Continuous Automated Langmuir-Blodgett Assembly and Deposition.

    PubMed

    Li, Xue; Gilchrist, James F

    2016-02-01

    The operating parameters and resulting surface morphology of automated Langmuir-Blodgett deposition of monosized micrometer-scale silica colloids from an aqueous suspension are investigated. This apparatus allows continuous roll-to-roll deposition of particles into well-ordered arrays. The reproducible deposition of particle monolayers at low to moderate deposition rates at web speeds of less than 10 mm/s is possible and accurately characterized by a simple mass balance of particles deposited from solution. At faster deposition rates, Landau-Levich flow increases the film thickness such that flow instabilities hinder uniform particle deposition. A simple phase diagram outlines transitions from dispersed to multilayer coatings and from uniform to erratic deposition patterns. While the threshold of maximum deposition rate is well-defined for these conditions, changing operating parameters, particle size, and fluid viscosity and evaporation rate, the maximum speed can be increased significantly.

  2. Thermodynamic properties of gaseous fluorocarbons and isentropic equilibrium expansions of two binary mixtures of fluorocarbons and argon

    NASA Technical Reports Server (NTRS)

    Talcott, N. A., Jr.

    1977-01-01

    Equations and computer code are given for the thermodynamic properties of gaseous fluorocarbons in chemical equilibrium. In addition, isentropic equilibrium expansions of two binary mixtures of fluorocarbons and argon are included. The computer code calculates the equilibrium thermodynamic properties and, in some cases, the transport properties for the following fluorocarbons: CCl2F, CCl2F2, CBrF3, CF4, CHCl2F, CHF3, CCL2F-CCl2F, CCLF2-CClF2, CF3-CF3, and C4F8. Equilibrium thermodynamic properties are tabulated for six of the fluorocarbons(CCl3F, CCL2F2, CBrF3, CF4, CF3-CF3, and C4F8) and pressure-enthalpy diagrams are presented for CBrF3.

  3. Ion implantation induced phase transformation and enhanced crystallinity of as deposited copper oxide thin films by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Bind, Umesh Chandra; Dutta, Raj Kumar; Sekhon, Gurpreet Kaur; Yadav, Kanhaiya Lal; Krishna, J. B. M.; Menon, Ranjini; Nabhiraj, P. Y.

    2015-08-01

    Copper oxide thin film of about 260-280 nm thickness was deposited using pulsed laser deposition (PLD) on glass substrate at 350 °C and post depositional sample treatment was performed by ion implantation with 50 keV N5+ ion beam with varying particle fluence. Amorphous copper oxide thin film deposited at 80 mTorr partial pressure of oxygen was transformed to cubic Cu2O phase (20.2 nm) when implanted at 1 × 1016 particles/cm2. While mixed Cu2O and CuO phases in the thin film deposited at 100 mTorr oxygen pressure was transformed to single phase of Cu2O (23.5 nm), with enhanced crystallinity when implanted with 2.5 × 1015 particles/cm2. The phase transformation and improved crystallinity is attributed to thermal effect owing to stopping of incident ion beam. Implantation with higher particle fluence led to transformation to CuO phase with reduced crystallite sized and the increased electrical conductivity.

  4. The impact of thickness and thermal annealing on refractive index for aluminum oxide thin films deposited by atomic layer deposition.

    PubMed

    Wang, Zi-Yi; Zhang, Rong-Jun; Lu, Hong-Liang; Chen, Xin; Sun, Yan; Zhang, Yun; Wei, Yan-Feng; Xu, Ji-Ping; Wang, Song-You; Zheng, Yu-Xiang; Chen, Liang-Yao

    2015-01-01

    The aluminum oxide (Al2O3) thin films with various thicknesses under 50 nm were deposited by atomic layer deposition (ALD) on silicon substrate. The surface topography investigated by atomic force microscopy (AFM) revealed that the samples were smooth and crack-free. The ellipsometric spectra of Al2O3 thin films were measured and analyzed before and after annealing in nitrogen condition in the wavelength range from 250 to 1,000 nm, respectively. The refractive index of Al2O3 thin films was described by Cauchy model and the ellipsometric spectra data were fitted to a five-medium model consisting of Si substrate/SiO2 layer/Al2O3 layer/surface roughness/air ambient structure. It is found that the refractive index of Al2O3 thin films decrease with increasing film thickness and the changing trend revised after annealing. The phenomenon is believed to arise from the mechanical stress in ALD-Al2O3 thin films. A thickness transition is also found by transmission electron microscopy (TEM) and SE after 900°C annealing. PMID:25852343

  5. Structure and properties of TiAlLaN films deposited at various bias voltages

    NASA Astrophysics Data System (ADS)

    Du, Hao; Xiong, Ji; Zhao, Haibo; Wu, Yuemei; Wan, Weicai; Wang, Linlin

    2014-02-01

    The TiAlLaN films were deposited on YG8 and silicon (1 1 1) substrates by a hybrid PVD coater which is combined with medium frequency reactive magnetron sputtering and ion-plating evaporation. The effects of lanthanum addition and bias voltages on the composition, crystal morphology, microstructure, mechanical properties, and oxidation resistance of the TiAlLaN films were investigated systematically. With lanthanum addition in the TiAlN film, the crystal morphology changed from columnar to equiaxial, and the grain refinement accompanied by the increase of hardness and elastic modulus was found. The indentation adhesion test showed that the adhesion strength was deteriorated by adding lanthanum in the deposited film; however, the scratch adhesion test expressed a better morphology of the scratch track line for the TiAlLaN film. With the substrate bias increasing, the elements concentration of films were alternated, and the equiaxial crystals were turned to columnar crystals. The oxidation resistance of the deposited films increased with the increase of bias voltage. The adhesion qualities, which are affected by the increasing hardness and elastic modulus, were worse for the TiAlLaN films under higher bias voltages. The TiAlLaN film under the bias of -10 V showed the highest H/E ratio.

  6. Engineering the Crystalline Morphology of Polymer Thin Films via Physical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Jeong, Hyuncheol; Arnold, Craig; Priestley, Rodney

    Thin-film growth via physical vapor deposition (PVD) has been successfully exploited for the delicate control of film structure for molecular and atomic systems. The application of such a high-energetic process to polymeric film growth has been challenged by chemical degradation. However, recent development of Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique opened up a way to deposit a variety of macromolecules in a PVD manner. Here, employing MAPLE technique to the growth of semicrystalline polymer thin films, we show the engineering of crystalline film morphology can be achieved via manipulation of substrate temperature. This is accomplished by exploiting temperature effect on crystallization kinetics of polymers. During the slow film growth crystallization can either be permitted or suppressed, and crystal thickness can be tuned via temperature modulation. In addition, we report that the crystallinity of polymer thin films may be significantly altered with deposition temperature in MAPLE processing. We expect that this ability to manipulate crystallization kinetics during polymeric film growth will open the possibility to engineer structure in thin film polymeric-based devices in ways that are difficult by other means.

  7. Friction and wear of plasma-deposited amorphous hydrogenated films on silicon nitride

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1991-01-01

    An investigation was conducted to examine the friction and wear behavior of amorphous hydrogenated carbon (a-C:H) films in sliding contact with silicon nitride pins in both dry nitrogen and humid air environments. Amorphous hydrogenated carbon films approximately 0.06 micron thick were deposited on silicon nitride flat substrates by using the 30 kHz ac glow discharge of a planar plasma reactor. The results indicate that an increase in plasma deposition power gives an increase in film density and hardness. The high-density a-C:H films deposited behaved tribologically much like bulk diamond. In the dry nitrogen environment, a tribochemical reaction produced a substance, probably a hydrocarbon-rich layer, that decreased the coefficient of friction. In the humid air environment, tribochemical interactions drastically reduced the wear life of a-C:H films and water vapor greatly increased the friction. Even in humid air, effective lubrication is possible with vacuum-annealed a-C:H films. The vacuum-annealed high-density a-C:H film formed an outermost superficial graphitic layer, which behaved like graphite, on the bulk a-C:H film. Like graphite, the annealed a-C:H film with the superficial graphitic layer showed low friction when adsorbed water vapor was present.

  8. Assessment of effects on vegetation of degradation products from alternative fluorocarbons

    NASA Technical Reports Server (NTRS)

    Mccune, D. C.; Weinstein, L. H.

    1990-01-01

    Concern with the effects of fluorides on plants has been devoted to that resulting from dry deposition (mainly with reference to gaseous HF and secondarily with particulate forms). The occurrence of precipitation as rain or mist and the presence of dew or free water on the foliage has mainly been considered with respect to their effects on the accumulation of air-borne fluoride and not with fluoride in wet deposition. That is, precipitation has been viewed primarily with respect to its facilitation of the solution and subsequent absorption of deposits by the foliar tissues or its elution of deposited fluoride from foliage. Accordingly, our evaluation of inorganic fluoride from fluorocarbon degradation rests upon a comparison with what is known about the effects of industrial emissions and what could be considered the natural condition.

  9. Reaction engineering and precursor film deposition for CIS synthesis

    NASA Astrophysics Data System (ADS)

    Stanbery, B. J.; Davydov, A.; Chang, C. H.; Anderson, T. J.

    1997-02-01

    We present an analysis of alternative reaction pathways for the synthesis of CuInSe2-based films for photovoltaic applications based on our recent and ongoing investigations of the thermochemistry in the Cu-In-Se ternary, Na-Cu-In-Se quaternary, and constituent unary and binary systems. We also describe our efforts to determine the relationship between film growth conditions in our novel rotating-disc system and resultant phase constitution of precursor reactant films intended for subsequent ex-situ rapid thermal processing. A model for the phase chemistry of sodium in CIS films is presented.

  10. Field emission from CNT films deposited on porous Si

    NASA Astrophysics Data System (ADS)

    Stepińska, Izabela; Wronka, Halina; Waszuk, Stanisław; Radomska, Joanna; Kozłowski, Mirosław; Czerwosz, ElŻbieta; Craciunoiu, Florea

    2015-09-01

    The carbon nanotubes films on various type of porous Si substrate were prepared. Three methods of porous Si preparation electrolysis, wet etching with silver nitrate and with potassium hydroxide were used. CNTs films were obtained by two step method containing PVD and CVD process. These yield of field emission depended on the type of film. I-U characteristics and F-N plots are discussed for these films. The short-term stability of emission measurements results are also presented. Depending on technological parameters of Si etching the topography of samples is different and it affects on the emission currents intensity and the electric threshold field.

  11. Structural and Critical Behaviors of Ag Rough Films Deposited on Liquid Substrates

    NASA Astrophysics Data System (ADS)

    Ye, Gao-xiang; Feng, Chun-mu; Zhang, Qi-rui; Ge, Hong-liang; Zhang, Xuan-jia

    1996-10-01

    A new Ag rough film system, deposited on silicone oil surfaces by rf-magnetron sputtering method, has been fabricated. The chrysanthemum-like surface morphology at micron length scale is observed. It is proposed that the anomalous critical behavior mainly results from the relative shift between the Ag atom clusters and the substrate. The discussion of the deposition mechanism is also presented.

  12. Development of a fluorescence based flux sensor for thin film growth and nanoparticle deposition

    NASA Astrophysics Data System (ADS)

    De Roo, Bert; Vervaele, Mattias; Rajala, Markku; Miller, Toni; Guillon, Herve; Seo, Jin Won; Locquet, Jean-Pierre

    2016-07-01

    An optical flux sensor, based on the fluorescence properties of materials and nanoparticles, has been developed to control the deposition rate in thin film deposition systems. Using a simple diode laser and a photomultiplier tube with a light filter, we report the detection of gallium atoms and CdSe-ZnS quantum dots. This setup has a high sensitivity and reproducibility.

  13. Development of a fluorescence based flux sensor for thin film growth and nanoparticle deposition.

    PubMed

    De Roo, Bert; Vervaele, Mattias; Rajala, Markku; Miller, Toni; Guillon, Herve; Seo, Jin Won; Locquet, Jean-Pierre

    2016-07-01

    An optical flux sensor, based on the fluorescence properties of materials and nanoparticles, has been developed to control the deposition rate in thin film deposition systems. Using a simple diode laser and a photomultiplier tube with a light filter, we report the detection of gallium atoms and CdSe-ZnS quantum dots. This setup has a high sensitivity and reproducibility. PMID:27475600

  14. Vacancies ordered in screw form (VOSF) and layered indium selenide thin film deposition by laser back ablation

    NASA Astrophysics Data System (ADS)

    Beck, Kenneth M.; Wiley, William R.; Venkatasubramanian, Eswaranand; Ohuchi, Fumio

    2009-09-01

    Indium selenide thin films are important due to their applications in non-volatile memory and solar cells. In this work, we present an initial study of a new application of deposition-site selective laser back ablation (LBA) for making thin films of In 2Se 3. Invacuo annealing and subsequent characterization of the films by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) indicate that control of substrate temperature during deposition and post-deposition annealing temperature is critical in determining the phase and composition of the films. The initial laser fluence and target film thickness determine the amount of material deposited onto the substrate.

  15. Vacancies Ordered in Screw Form (VOSF) and Layered Indium Selenide Thin Film Deposition by Laser Back Ablation

    SciTech Connect

    Beck, Kenneth M.; Wiley, William R.; Venkatasubramanian, Eswaranand; Ohuchi, Fumio S.

    2009-09-30

    Indium selenide thin films are important due to their applications in non-volatile memory and solar cells. In this work, we present an initial study of a new application of deposition-site selective laser back ablation (LBA) for making thin films of In2Se3. In-vacuo annealing and subsequent characterization of the films by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) indicate that control of substrate temperature during deposition and post-deposition annealing temperature is critical in determining the phase and composition of the films. The initial laser fluence and target film thickness determine the amount of material deposited onto the substrate.

  16. Properties of LiNbO3 Thin Film Deposited by Chemical Vapor Deposition and Frequency Characteristics of Film Bulk Acoustic Wave Resonator

    NASA Astrophysics Data System (ADS)

    Kadota, Michio; Suzuki, Yusuke; Ito, Yoshihiro

    2011-07-01

    We have realized the fabrication of a film bulk acoustic wave resonator (FBAR) using a thin LiNbO3 film deposited by chemical vapor deposition (CVD) for the first time. As a result, a 2.9 GHz FBAR with an impedance ratio of 40 dB at resonant ( fr) and antiresonant ( fa) frequencies was realized. The LiNbO3 film has a mixed polarity. As a result of scanning nonlinear dielectric microscopy (SNDM), -c domains and +c domains occupy 82 and 18% of the LiNbO3 film, respectively. A shear mode was not excited on the fabricated FABR. According to a calculation, it is found that the shear wave mode can be suppressed by selecting the thickness of electrodes without any changes in the main responses of the longitudinal mode wave. It is important to deposit another oriented LiNbO3 film with a larger coupling factor to realize a wider-band device.

  17. Metalcone Chemistry: In pursuit of improved mechanical properties in thin film deposition

    NASA Astrophysics Data System (ADS)

    Hall, Robert A.

    Atomic Layer Deposition (ALD) and its subset, Molecular layer deposition (MLD), is a thin film deposition technique using alternating self-limiting precursors to grow thin films on a substrates. Recent research has expanded MLD to use reactive metal alkyls/halides and organic fragments containing alcohol groups such as ethylene glycol for use in protective barriers. Unfortunately using ethylene glycol as a precursor causes film stability issues and does not provide adequate mechanical properties for projected uses. The current research looks into the investigation of using different metal alkyls and metal halides with the trifunctional precursor glycerol. The three main films investigated were the AlGL using trimethylaluminum and glycerol, ZnGL using diethyl zinc and glycerol and TIGL using titanium (IV) chloride and glycerol. The films were investigated using quartz crystal microbalance, X-ray reflectivity, and spectroscopic ellipsometry for characterization of their film growth. All films exhibited linear growth at a range of temperatures above 130°C with AlGL, ZnGL and TiGL displaying a growth rate at 150°C of ˜2.34A/cycle, ˜1.29A/cycle, and ˜2.2A/cycle respectfully. Initially film growth was investigated in situ using quartz crystal microbalance and then the growth rates confirmed ex situ using X-ray reflectivity. Once the film growth and mechanism were investigated, the mechanical properties were investigated to determine if there was an improvement in cross-linking in the films. The mechanical properties of these MLD films were also investigated using a mechanical testing system and nanoindenter. The mechanical properties for AlGL and ZnGL showed a large improvement from 0.69% to 1.2% for their critical tensile strain compared to previous MLD films. The films also showed an increase in mechanical properties from their nanoindentation results consistent with an increase in cross-linking.

  18. Electron cyclotron resonance deposition and plasma diagnostics of a-Si:H and a-C:H films

    NASA Technical Reports Server (NTRS)

    Shing, Y. H.

    1989-01-01

    Amorphous silicon (a-Si:H) and amorphous carbon (a-C:H) films deposited by electron cyclotron resonance (ECR) microwave plasma-enhanced chemical vapor deposition are discussed. It is shown that the ECR microwave plasma deposition technique can produce a-Si:H films with material qualities similar to and with a deposition rate one order of magnitude higher than for films deposited by radio-frequency glow discharge. The ECR-deposited a-C:H films are characterized by fluorescence, IR, and Raman spectroscopy. In situ optical emission spectroscopy plasma diagnostics indicates that ECR plasmas have a strong emission at 434 nm, which indicates a higher chemical reactivity than radio-frequency glow discharge plasmas. The radio frequency bias to the substrate is found to play a critical role in determining the film structure and the carbon bonding configuration of ECR-deposited a-C:H films.

  19. Metal-organic chemical vapour deposition of polycrystalline tetragonal indium sulphide (InS) thin films

    NASA Technical Reports Server (NTRS)

    Macinnes, Andrew N.; Cleaver, William M.; Barron, Andrew R.; Power, Michael B.; Hepp, Aloysius F.

    1992-01-01

    The dimeric indium thiolate /(t Bu)2In(mu-S sup t Bu)/2 has been used as a single-source precursor for the MOCVD of InS thin films. The dimeric In2S2 core is proposed to account for the formation of the nonequilibrium high-pressure tetragonal phase in the deposited films. Analysis of the deposited films has been obtained by TEM, with associated energy-dispersive X-ray analysis and X-ray photoelectron spectroscopy.

  20. Ionization sensitization of doping in co-deposited organic semiconductor films

    SciTech Connect

    Shinmura, Yusuke Yamashina, Yohei; Kaji, Toshihiko; Hiramoto, Masahiro

    2014-11-03

    Sensitization of the dopant ionization in co-deposited films of organic semiconductors was found. The ionization rate of cesium carbonate (Cs{sub 2}CO{sub 3}), which acts as a donor dopant in single films of metal-free phthalocyanine (H{sub 2}Pc) and fullerene (C{sub 60}), was increased from 10% to 97% in a H{sub 2}Pc:C{sub 60} co-deposited film. A charge separation superlattice model that includes electron transfer from the conduction band of H{sub 2}Pc to that of C{sub 60}, which increases the rate of dopant ionization, is proposed.

  1. Laser Ablative Deposition of Polymer Films: A Promise for Sensor Fabrication

    NASA Astrophysics Data System (ADS)

    Blazevska-Gilev, Jadranka; Kupčík, Jaroslav; Šubrt, Jan; Pola, Josef

    There is a continuing interest in the use of polymer films as insulating components of sensors; a number of such films have been prepared by polymer sputtering or vacuum deposition processes involving gas phase pyrolysis/photolysis and by plasma decomposition of monomers. An attractive and rather new technique for the deposition of novel polymer films is IR laser ablation of polymers containing polar groups. We have recently studied this process with poly(vinyl chloride) (PVC), poly(vinyl acetate) (PVAc) and poly(vinyl chloride-co-vinyl acetate) P(VC/VAc) to establish its specific features and differences to conventional pyrolysis.

  2. The deposition of boron nitride and carbon films on silica glass fibers

    SciTech Connect

    Smith, W.L.; Michalske, T.A.; Rye, R.R.

    1993-11-01

    A chemical vapor deposition technique is used to produce amorphous boron nitride and carbon thin films on high strength silica glass fibers. In this method, the fiber is drawn under ultra high vacuum conditions and low pressure process gases, in the presence of a hot tungsten filament, are used to grow films at low substrate temperatures. Films deposited with this technique do not degrade the intrinsic pristine strength of the silica fibers under dry conditions and, when stressed in chemically aggressive environments, act as effective barrier coatings.

  3. Aligned carbon nanotube, graphene and graphite oxide thin films via substrate-directed rapid interfacial deposition.

    PubMed

    D'Arcy, Julio M; Tran, Henry D; Stieg, Adam Z; Gimzewski, James K; Kaner, Richard B

    2012-05-21

    A procedure for depositing thin films of carbon nanostructures is described that overcomes the limitations typically associated with solution based methods. Transparent and conductively continuous carbon coatings can be grown on virtually any type of substrate within seconds. Interfacial surface tension gradients result in directional fluid flow and film spreading at the water/oil interface. Transparent films of carbon nanostructures are produced including aligned ropes of single-walled carbon nanotubes and assemblies of single sheets of chemically converted graphene and graphite oxide. Process scale-up, layer-by-layer deposition, and a simple method for coating non-activated hydrophobic surfaces are demonstrated.

  4. Chemical vapor deposition and characterization of poly(p-phenylene vinylene) films

    NASA Astrophysics Data System (ADS)

    Gedelilan, Cynthia Ann

    2008-10-01

    As a conducting, electroluminescent, and photoluminescent polymer, poly(p-phenylene vinylene) (PPV) is a material of much interest for electronic and optical applications. Although this polymer has traditionally been deposited using spin-on methods and soluble precursor polymers, the technique has several drawbacks including an increase in contamination and defects from the solvent, the need to convert the precursor into PPV without adding further impurities or damaging the film, and the processing restrictions when dealing with liquid depositions. Chemical vapor deposition (CVD), on the other hand, deposits the precursor polymer in the gas phase and therefore eliminates the need for a solvent and creates the capability for conformal deposition on many types of nanostructured substrates. However, PPV films deposited by CVD remain understudied. This work aims to investigate properties of those films including the removal of bromine left from the CVD precursor, the behavior and structure of PPV after heat treatment at elevated temperatures (>450°C), the usefulness of encapsulation materials for preventing photodegradation, and characteristics of films deposited on top of nanosize porous materials. Bromine from the precursor polymer is removed during the first thirty minutes of heating. Films annealed at 300°C in nitrogen gas consisted of 0.36% bromine; however, photoluminescence spectra comparing films annealed at 150 and 300°C showed more defects in the 300°C film. Heat treatment of PPV beyond the initial anneal showed that the film degrades at 500°C by emitting monomer fragments without crosslinking. Photodegradation of PPV films due to incorporation of oxygen during light exposure can be reduced from 80% to 30% under UV light and nearly prevented under blue light when encapsulated with 10 nm aluminum oxide. Encapsulation with organic Parylene shows no significant improvement. Use of the Stern-Volmer equation to examine self-quenching in films shows larger

  5. Laser deposition of SmCo thin film and coating on different substrates

    NASA Astrophysics Data System (ADS)

    Allocca, L.; Bonavolontà, C.; Giardini, A.; Lopizzo, T.; Morone, A.; Valentino, M.; Verrastro, M. F.; Viggiano, V.

    2008-10-01

    Thin films and coatings of permanent magnetic materials are very important for different electronic and micromechanical applications. This paper deals with the fabrication, using pulsed laser deposition (PLD) technique, of good quality magnetic SmCo thin films on polycarbonate, steel, silicon and amorphous quartz substrates, for low cost electronic applications like radio frequency identification (RFID) antennas and electromechanical devices for fuel feeding control in the automotive. X-ray fluorescence and magnetic scanning measurements using giant magneto-resistive (GMR) sensors have been performed to study the functional magnetic properties of the deposited thin films.

  6. Contributions of gas-phase plasma chemistry to surface modifications and gas-surface interactions: investigations of fluorocarbon rf plasmas

    NASA Astrophysics Data System (ADS)

    Cuddy, Michael F., II

    The fundamental aspects of inductively coupled fluorocarbon (FC) plasma chemistry were examined, with special emphasis on the contributions of gas-phase species to surface modifications. Characterization of the gas-phase constituents of single-source CF4-, C2F6-, C3F 8-, and C3F6-based plasmas was performed using spectroscopic and mass spectrometric techniques. The effects of varying plasma parameters, including applied rf power (P) and system pressure (p) were examined. Optical emission spectroscopy (OES) and laser-induced fluorescence (LIF) spectroscopy were employed to monitor the behavior of excited and ground CFx (x = 1,2) radicals, respectively. Mass spectrometric techniques, including ion energy analyses, elucidated behaviors of nascent ions in the FC plasmas. These gas-phase data were correlated with the net effect of substrate processing for Si and ZrO2 surfaces. Surface-specific analyses were performed for post-processed substrates via x-ray photoelectron spectroscopy (XPS) and contact angle goniometry. Generally, precursors with lower F/C ratios tended to deposit robust FC films of high surface energy. Precursors of higher F/C ratio, such as CF4, were associated with etching or removal of material from surfaces. Nonetheless, a net balance between deposition of FC moieties and etching of material exists for each plasma system. The imaging of radicals interacting with surfaces (IRIS) technique provided insight into the phenomena occurring at the interface of the plasma gas-phase and substrate of interest. IRIS results demonstrate that CFx radicals scatter copiously, with surface scatter coefficients, S, generally greater than unity under most experimental conditions. Such considerable S values imply surface-mediated production of the CFx radicals at FC-passivated sites. It is inferred that the primary route to surface production of CFx arises from energetic ion bombardment and ablation of surface FC films. Other factors which may influence the observed CFx

  7. Barrier properties to surrogates of hydrogenated carbon nano-films deposited on PET by plasma-enhanced chemical vapour deposition.

    PubMed

    Oliveira, Éder C; Echegoyen, Yolanda; Nerin, Cristina; Cruz, Sandra A

    2014-01-01

    Poly(ethylene terephthalate) resin was contaminated with a series of surrogates using a US Food and Drug Administration protocol. The contaminated samples were coated with two different kinds of hydrogenated amorphous carbon thin films (a-C:H): one with diamond-like hydrogenated amorphous carbon and another with polymer-like hydrogenated carbon (PLCH) phases. To evaluate the barrier properties of the a-C:H films, migration assays were performed using food simulants. After the tests, analysis by gas chromatography with different detectors was carried out. The appearance of the films before and after the migration experiments was studied by field emission scanning electron microscopy. The results showed that a-C:H films have good barrier properties for most of the evaluated compounds, mainly when they are deposited as PLCH phase. PMID:25254307

  8. Low-temperature deposition of transparent diamond films with a microwave cavity plasma reactor

    NASA Astrophysics Data System (ADS)

    Ulczynski, Michael J.

    1998-10-01

    Low-temperature diamond deposition with Microwave Cavity Plasma Reactor (MCPR) technology was investigated for application to temperature sensitive substrates. The substrate temperature during most CVD diamond deposition processes is typically greater then 600 C; however, there are some applications where temperature sensitive materials are used and the deposition temperature must be maintained below 550 C. These applications include materials like boro-silicate glass, which has a relatively low strain-point temperature, and integrated circuits that contain low melting point components. Experiments were conducted in three areas. The first area was MCPR development, the second was benchmark deposition and characterization of diamond films on silicon substrates and the third was deposition and characterization of diamond films on boro-silicate glass substrates. MCPR development included an investigation of various MCPR configurations that were designed and adapted for uniform, low-temperature diamond deposition over areas as large as 80-cm2. Reactors were investigated with end-feed microwave excitation and side-feed microwave excitation for maximum deposition area and uniformity. Various substrate receptor configurations were also investigated including a substrate heater and cooler. From these investigations, deposition parameters such as substrate temperature, deposition rate, deposition area and deposition uniformity were characterized. The benchmark silicon diamond deposition experiments were conducted for comparison to previous high temperature, >550 C, MCPR research and growth models. Here deposition results such as deposition rate and film quality were compared with applications of diamond growth models by Harris-Goodwin and Bachmann. Additionally, characterization experiments were conducted to investigate film attributes that are critical to optical applications, such as film surface roughness and deposition uniformity. Included as variables in these

  9. Fabrication of Ce:YIG film with different composition by pulsed-laser deposition

    NASA Astrophysics Data System (ADS)

    Nakata, Yoshiki; Tashiro, Yuko; Okada, Tatsuo; Maeda, Mitsuo; Higuchi, Sadao; Ueda, Kiyotaka

    2002-02-01

    Ce-doped yttrium iron garnet (Ce:YIG) with different compositions of Y2CeFe5O12, Y2CeFe4.25Ga0.75O12, Y1.6Gd0.4CeFe5O12 were deposited by PLD on GGG(111) SUBSTRATE. The crystallinity, transmittance and surface morphology were observed for the films deposited at different depositions conditions of argon or oxygen gas pressures and substrate temperatures.

  10. Graphene Films: Synthesis of Graphene Films on Copper Foils by Chemical Vapor Deposition (Adv. Mater. 29/2016).

    PubMed

    Li, Xuesong; Colombo, Luigi; Ruoff, Rodney S

    2016-08-01

    Synthesis of graphene films on copper foils is discussed by X. Li, L. Colombo, and R. S. Ruoff on page 6247. Graphene can grow on metal substrates by chemical vapor deposition of hydrocarbons. Hydrocarbons crack on a metal surface, nucleate, grow, and finally merge to form a continuous graphene film. Copper is one of the best candidates for graphene growth due to the advantages of good control over the graphene thickness, the growth of high-quality graphene, and the ease for graphene transfer, and has been widely used for production of large-area graphene films in both academia and industry. PMID:27478085

  11. Pulsed laser deposition and refractive index measurement of fully substituted bismuth iron garnet films

    NASA Astrophysics Data System (ADS)

    Tepper, T.; Ross, C. A.

    2003-08-01

    A systematic study of the pulsed-laser deposition of fully substituted bismuth iron garnet (BIG, or Bi 3Fe 5O 12) has been carried out. Garnet-structure BIG films grow epitaxially onto gallium gadolinium garnet substrates under deposition conditions that lead to a stoichiometric film. The variation of stoichiometry with deposition conditions is discussed. The refractive index, n, of BIG decreases from 2.819 at 633 nm to 2.584 at 1550 nm, with an imaginary part, k, less than 0.05.

  12. Stabilizing laser energy density on a target during pulsed laser deposition of thin films

    DOEpatents

    Dowden, Paul C.; Jia, Quanxi

    2016-05-31

    A process for stabilizing laser energy density on a target surface during pulsed laser deposition of thin films controls the focused laser spot on the target. The process involves imaging an image-aperture positioned in the beamline. This eliminates changes in the beam dimensions of the laser. A continuously variable attenuator located in between the output of the laser and the imaged image-aperture adjusts the energy to a desired level by running the laser in a "constant voltage" mode. The process provides reproducibility and controllability for deposition of electronic thin films by pulsed laser deposition.

  13. Structural and transport properties of CdS films deposited on flexible substrates

    NASA Astrophysics Data System (ADS)

    Shur, M. S.; Rumyantsev, S.; Gaska, R.; Wei, B. Q.; Vajtai, R.; Ajayan, P. M.; Sinius, J.

    2002-09-01

    We report on structural and electrical properties of CdS films chemically deposited at temperatures 60-70 °C from solutions containing cadmium citrate complex-ions and thiourea. We demonstrated the material deposition on a variety of flexible substrates, including viewfoils, cloth, and threads and fabricated devices on the deposited films including solar cells, stress sensors, and photoconductive sensors. Scanning electron microscopy and high resolution transmission electron microscopy data show that the films consist of nanocrystalline grains. The X-ray diffraction data identify crystalline CdS with hexagonal structure with a very high degree of crystallinity. The relative intensity of the peaks in the X-ray spectrum shows that the crystallites are oriented. The nanostructure of the CdS films results in a giant reproducible sensitivity to stress (tension) under UV illumination.

  14. Rectifying properties of ZnO thin films deposited on FTO by electrodeposition technique

    NASA Astrophysics Data System (ADS)

    Lv, Jianguo; Sun, Yue; Zhao, Min; Cao, Li; Xu, Jiayuan; He, Gang; Zhang, Miao; Sun, Zhaoqi

    2016-03-01

    ZnO thin films were successfully grown on fluorine-doped tin oxide glass by electrodeposition technique. The crystal structure, surface morphology and optical properties of the thin films were investigated. The average crystallite size and intensity of A1(LO) mode increase with improving the absolute value of deposition potential. The best preferential orientation along c-axis and the richest oxygen interstitial defects have been observed in the sample deposited at -0.8 V. A heterojunction device consisting of ZnO thin film and n-type fluorine-doped tin oxide was fabricated. The current-voltage (I-V) characteristic of the p-n heterojunction device deposited at -0.8 V shows the best rectifying diode behavior. The p-type conductivity of the ZnO thin film could be attributed to complex defect of unintentional impurity and interstitial oxygen.

  15. Magnetic properties of pulsed laser deposition-fabricated isotropic Fe-Pt film magnets

    SciTech Connect

    Nakano, M.; Oniki, W.; Yanai, T.; Fukunaga, H.

    2011-04-01

    A high-speed pulsed laser deposition method with the deposition rate of several tens of microns per 1 h enabled us to obtain isotropic Fe-Pt thick film magnets. Increase in the laser power enabled us to obtain as-deposited films with L1{sub 0} ordered phase due to the heat radiation from a target, which means that a substrate heating system and a post-annealing process are not required to achieve hard magnetic properties in the process. Use of an Fe-rich target enhanced the magnetic properties, and as a result (BH){sub max} value exceeded 100 kJ/m{sup 3} in an isotropic Fe-Pt film fabricated at the power of 3 W, which was comparable to those of isotropic Fe-Pt thick film magnets prepared by a sputtering method.

  16. Silicon surface passivation using thin HfO2 films by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Gope, Jhuma; Vandana; Batra, Neha; Panigrahi, Jagannath; Singh, Rajbir; Maurya, K. K.; Srivastava, Ritu; Singh, P. K.

    2015-12-01

    Hafnium oxide (HfO2) is a potential material for equivalent oxide thickness (EOT) scaling in microelectronics; however, its surface passivation properties particularly on silicon are not well explored. This paper reports investigation on passivation properties of thermally deposited thin HfO2 films by atomic layer deposition system (ALD) on silicon surface. As-deposited pristine film (∼8 nm) shows better passivation with <100 cm/s surface recombination velocity (SRV) vis-à-vis thicker films. Further improvement in passivation quality is achieved with annealing at 400 °C for 10 min where the SRV reduces to ∼20 cm/s. Conductance measurements show that the interface defect density (Dit) increases with film thickness whereas its value decreases after annealing. XRR data corroborate with the observations made by FTIR and SRV data.

  17. Perpendicular coercivity enhancement of CoPt/TiN films by nitrogen incorporation during deposition

    NASA Astrophysics Data System (ADS)

    An, Hongyu; Wang, Jian; Szivos, Janos; Harumoto, Takashi; Sannomiya, Takumi; Muraishi, Shinji; Safran, Gyorgy; Nakamura, Yoshio; Shi, Ji

    2015-11-01

    The effect of N incorporation on the structure and magnetic properties of CoPt thin films deposited on glass substrates with TiN seed layers has been investigated. During the deposition of CoPt, introducing 20% N2 into Ar atmosphere promotes the (001) texture and enhances the perpendicular coercivity of CoPt film compared with the film deposited in pure Ar and post-annealed under the same conditions. From the in situ x-ray diffraction results, it is confirmed that N incorporation expands the lattice parameter of CoPt, which favors the epitaxial growth of CoPt on TiN. During the post-annealing process, N releases from CoPt film and promotes the L10 ordering transformation of CoPt.

  18. Enzymatically controlled material design with casein--from defined films to localized deposition of particles.

    PubMed

    Strube, Oliver I; Rüdiger, Arne A; Bremser, Wolfgang

    2015-05-10

    A new concept for deposition and material design of coatings from biological compounds is presented. An enzymatic reaction triggers the specific coagulation of particles on a support surface. The first examined model system is casein and is based on the natural rennet reaction as applied in the process of cheese-making. The aspartic protease chymosin is immobilized on a support surface and cleaves the hydrophilic parts of the casein micelles, inducing deposition. The concept allows for a high level of control over film characteristics and enables the formation of site-specific film structures. The variability rages from formation of casein films with several micrometers film thickness to the targeted deposition of casein micelles. PMID:25456052

  19. Interaction of platelets, fibrinogen and endothelial cells with plasma deposited PEO-like films

    NASA Astrophysics Data System (ADS)

    Yang, Zhilu; Wang, Jin; Li, Xin; Tu, Qiufen; Sun, Hong; Huang, Nan

    2012-02-01

    For blood-contacting biomedical implants like retrievable vena cava filters, surface-based diagnostic devices or in vivo sensors, limiting thrombosis and cell adhesion is paramount, due to a decrease even failure in performance. Plasma deposited PEO-like films were investigated as surface modifications. In this work, mixed gas composed of tetraethylene glycol dimethyl ether (tetraglyme) vapor and oxygen was used as precursor. It was revealed that plasma polymerization under high ratio of oxygen/tetraglyme led to deposition of the films that had high content of ether groups. This kind of PEO-like films had good stability in phosphate buffer solution. In vitro hemocompatibility and endothelial cell (EC) adhesion revealed low platelet adhesion, platelet activation, fibrinogen adhesion, EC adhesion and proliferation on such plasma deposited PEO-like films. This made it a potential candidate for the applications in anti-fouling surfaces of blood-contacting biomedical devices.

  20. Perpendicular coercivity enhancement of CoPt/TiN films by nitrogen incorporation during deposition

    SciTech Connect

    An, Hongyu; Harumoto, Takashi; Sannomiya, Takumi; Muraishi, Shinji; Nakamura, Yoshio; Shi, Ji; Wang, Jian; Szivos, Janos; Safran, Gyorgy

    2015-11-28

    The effect of N incorporation on the structure and magnetic properties of CoPt thin films deposited on glass substrates with TiN seed layers has been investigated. During the deposition of CoPt, introducing 20% N{sub 2} into Ar atmosphere promotes the (001) texture and enhances the perpendicular coercivity of CoPt film compared with the film deposited in pure Ar and post-annealed under the same conditions. From the in situ x-ray diffraction results, it is confirmed that N incorporation expands the lattice parameter of CoPt, which favors the epitaxial growth of CoPt on TiN. During the post-annealing process, N releases from CoPt film and promotes the L1{sub 0} ordering transformation of CoPt.

  1. Crystallization kinetics of GeTe phase-change thin films grown by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Sun, Xinxing; Thelander, Erik; Gerlach, Jürgen W.; Decker, Ulrich; Rauschenbach, Bernd

    2015-07-01

    Pulsed laser deposition was employed to the growth of GeTe thin films on Silicon substrates. X-ray diffraction measurements reveal that the critical crystallization temperature lies between 220 and 240 °C. Differential scanning calorimetry was used to investigate the crystallization kinetics of the as-deposited films, determining the activation energy to be 3.14 eV. Optical reflectivity and in situ resistance measurements exhibited a high reflectivity contrast of ~21% and 3-4 orders of magnitude drop in resistivity of the films upon crystallization. The results show that pulsed laser deposited GeTe films can be a promising candidate for phase-change applications.

  2. Versatility of metalorganic chemical vapor deposition process for fabrication of high quality YBCO superconducting thin films

    NASA Astrophysics Data System (ADS)

    Chern, C. S.; Kear, B. H.; Zhao, J.; Norris, P. E.; Li, Y. Q.

    1991-03-01

    YBCO films, having critical current densities in excess of 10 to the 6th A/sq cm at 77 K and transition temperatures of about 89 K, successfully deposited on close lattice matched substrate materials at substrate temperature in the range from 720 to 740 C, are presented. The critical current densities are 10,000 A/sq cm at 70 K and the critical temperatures are 82 K for the films deposited on sapphire substrates. Successful deposition of c-axis oriented YBCO films with a transition temperature of 85 K was also achieved on silver substrates. Detailed analyses of the films were carried out by X-ray diffraction, EDS, SEM, resistivity measurements, critical current density measurements, and magnetization susceptibility measurements.

  3. Oxygen reduction activity of N-doped carbon-based films prepared by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Hakoda, Teruyuki; Yamamoto, Shunya; Kawaguchi, Kazuhiro; Yamaki, Tetsuya; Kobayashi, Tomohiro; Yoshikawa, Masahito

    2010-12-01

    Carbon-based films with nitrogen species on their surface were prepared on a glassy carbon (GC) substrate for application as a non-platinum cathode catalyst for polymer electrolyte fuel cells. Cobalt and carbon were deposited in the presence of N 2 gas using a pulsed laser deposition method and then the metal Co was removed by HCl-washing treatment. Oxygen reduction reaction (ORR) activity was electrochemically determined using a rotating disk electrode system in which the film samples on the GC substrate were replaceable. The ORR activity increased with the temperature of the GC substrate during deposition. A carbon-based film prepared at 600 °C in the presence of N 2 at 66.7 Pa showed the highest ORR activity among the tested samples (0.66 V vs. NHE). This film was composed of amorphous carbons doped with pyridine type nitrogen atoms on its surface.

  4. Pulsed laser deposition of YBCO thin films on IBAD-YSZ substrates

    NASA Astrophysics Data System (ADS)

    Li, M.; Ma, B.; Koritala, R. E.; Fisher, B. L.; Venkataraman, K.; Balachandran, U.

    2003-01-01

    High-quality YBa2Cu3O7-x (YBCO) films were fabricated on yttria-stabilized zirconia (YSZ)-buffered Hastelloy C276 substrates by pulsed laser deposition. YSZ was grown by ion-beam-assisted deposition. A thin (approx10 nm) CeO2 layer was deposited before the deposition of YBCO. The crystalline structure and biaxial texture of the YBCO film and the buffer layer were examined by x-ray diffraction 2theta-scan, phi-scan and pole-figure analysis. Epitaxial growth of the YBCO film on the buffer layer was observed. Full width at half maximum (FWHM) value of 7.4° was measured from the phi-scan of YBCO(103). Raman spectroscopy showed compositional uniformity and phase integrity in the YBCO films. Surface morphologies of the YBCO films were examined by scanning electron microscopy. Comparative studies indicated that the CeO2 buffer layer significantly improves the structural alignment and superconducting properties of YBCO films. Tc = 90 K, with sharp transition, and transport Jc = 2.2 × 106 A cm-2 at 77 K in zero-external field were obtained on the 0.5 mum thick YBCO films. The dependence of Jc on the FWHM of the YBCO(103) phi-scan indicated that high Jc is associated with low FWHM.

  5. Filtered pulsed cathodic arc deposition of fullerene-like carbon and carbon nitride films

    SciTech Connect

    Tucker, Mark D. Broitman, Esteban; Näslund, Lars-Åke; Hultman, Lars; Rosen, Johanna; Czigány, Zsolt

    2014-04-14

    Carbon and carbon nitride films (CN{sub x}, 0 ≤ x ≤ 0.26) were deposited by filtered pulsed cathodic arc and were investigated using transmission electron microscopy and X-ray photoelectron spectroscopy. A “fullerene-like” (FL) structure of ordered graphitic planes, similar to that of magnetron sputtered FL-CN{sub x} films, was observed in films deposited at 175 °C and above, with N{sub 2} pressures of 0 and 0.5 mTorr. Higher substrate temperatures and significant nitrogen incorporation are required to produce similar FL structure by sputtering, which may, at least in part, be explained by the high ion charge states and ion energies characteristic of arc deposition. A gradual transition from majority sp{sup 3}-hybridized films to sp{sup 2} films was observed with increasing substrate temperature. High elastic recovery, an attractive characteristic mechanical property of FL-CN{sub x} films, is evident in arc-deposited films both with and without nitrogen content, and both with and without FL structure.

  6. Biomimetic formation of titania thin films: effect of amino acids on the deposition process.

    PubMed

    Durupthy, Olivier; Jeurgens, Lars P H; Bill, Joachim

    2011-05-01

    Different types of amino acids have been used as additives to control the aqueous deposition of titanium dioxide thin films on single-crystal Si wafers. Thin titania films can be obtained through a chemical bath deposition (CBD) process using TiCl₄ as a precursor in an aqueous solution at temperatures below 100 °C. The addition of amino acids to the deposition solution was shown to reduce the thickness and roughness of the films and to increase their density. These protein building blocks were employed to modify the deposition rate as well as the size of aggregates that form the film. The thickness, crystallinity, morphology and composition of the grown films were characterized by a variety of techniques, including XRD, XPS, AFM and SEM. The consequences of the type of the amino acid additive (and its concentration in the solution) on the microstructural evolutions of the deposed films are thus revealed and discussed on the basis of the organic-inorganic interactions in solution and at the film surface. PMID:21480641

  7. Properties of NiO thin films deposited by intermittent spray pyrolysis process

    NASA Astrophysics Data System (ADS)

    Reguig, B. A.; Khelil, A.; Cattin, L.; Morsli, M.; Bernède, J. C.

    2007-02-01

    NiO thin films have been grown on glass substrates by intermittent spray pyrolysis deposition of NiCl 2·6H 2O diluted in distilled water, using a simple "perfume atomizer". The effect of the solution molarity on their properties was studied and compared to those of NiO thin films deposited with a classical spray system. It is shown that NiO thin films crystallized in the NiO structure are achieved after deposition. Whatever the precursor molarity, the grain size is around 25-30 nm. The crystallites are preferentially oriented along the (1 1 1) direction. All the films are p-type. However, the thickness and the conductivity of the NiO films depend on the precursor contraction. By comparison with the properties of films deposited by classical spray technique, it is shown that the critical precursor concentration, which induces strong thin films properties perturbations, is higher when a perfume atomizer is used. This broader stability domain can be attributed to better chlorides decomposition during the rest time used in the perfume atomizer technique.

  8. Protecting BOPP film from UV degradation with an atomic layer deposited titanium oxide surface coating

    NASA Astrophysics Data System (ADS)

    Lahtinen, Kimmo; Maydannik, Philipp; Seppänen, Tarja; Cameron, David C.; Johansson, Petri; Kotkamo, Sami; Kuusipalo, Jurkka

    2013-10-01

    Titanium oxide layers were deposited onto a BOPP film by atomic layer deposition in order to prevent UV degradation of the film. The coatings were deposited in a low-temperature process at 80 °C by using tetrakis(dimethylamido)titanium and ozone as titanium and oxygen precursors, respectively. UV block characteristics of the coatings and their effect on the polymer were measured by using UV-vis and IR spectrometry, and differential scanning calorimetry. According to the results, the coatings provided a considerable decrease in the photodegradation of the BOPP film during UV exposure. IR spectra showed that during a 6-week UV exposure, a 67 nm titanium oxide coating was able to almost completely prevent the formation of photodegradation products in the film. The mechanical properties of the film were also protected by the coating, but as opposed to what the IR study suggested they were still somewhat compromised by the UV light. After a 6-week exposure, the tensile strength and elongation at break of the 67 nm titanium oxide coated film decreased to half of the values measured before the treatment. This should be compared to the complete degradation suffered by the uncoated base sheet already after only 4 weeks of treatment. The results show that nanometre scale inorganic films deposited by ALD show a promising performance as effective UV protection for BOPP substrates.

  9. Dysprosium oxide and dysprosium-oxide-doped titanium oxide thin films grown by atomic layer deposition

    SciTech Connect

    Tamm, Aile Kozlova, Jekaterina; Aarik, Lauri; Aarik, Jaan; Kukli, Kaupo; Link, Joosep; Stern, Raivo

    2015-01-15

    Dysprosium oxide and dysprosium-oxide-doped titanium oxide thin films were grown by atomic layer deposition on silicon substrates. For depositing dysprosium and titanium oxides Dy(thd){sub 3}-O{sub 3} and TiCl{sub 4}-O{sub 3} were used as precursors combinations. Appropriate parameters for Dy(thd){sub 3}-O{sub 3} growth process were obtained by using a quartz crystal microbalance system. The Dy{sub 2}O{sub 3} films were deposited on planar substrates and on three-dimensional substrates with aspect ratio 1:20. The Dy/Ti ratio of Dy{sub 2}O{sub 3}-doped TiO{sub 2} films deposited on a planar silicon substrate ranged from 0.04 to 0.06. Magnetometry studies revealed that saturation of magnetization could not be observed in planar Dy{sub 2}O{sub 3} films, but it was observable in Dy{sub 2}O{sub 3} films on 3D substrates and in doped TiO{sub 2} films with a Dy/Ti atomic ratio of 0.06. The latter films exhibited saturation magnetization 10{sup −6} A cm{sup 2} and coercivity 11 kA/m at room temperature.

  10. Study of Flux Ratio of C60 to Ar Cluster Ion for Hard DLC Film deposition

    SciTech Connect

    Miyauchi, K.; Toyoda, N.; Kanda, K.; Matsui, S.; Kitagawa, T.; Yamada, I.

    2003-08-26

    To study the influence of the flux ratio of C60 molecule to Ar cluster ion on (diamond like carbon) DLC film characteristics, DLC films deposited under various flux ratios were characterized with Raman spectrometry and Near Edge X-ray Absorption Fine Structure (NEXAFS). From results of these measurements, hard DLC films were deposited when the flux ratio of C60 to Ar cluster ion was between 0.7 and 4. Furthermore the DLC film with constant sp2 content was obtained in the range of the ratio from 0.7 to 4, which contents are lower values than that of conventional films such as RF plasma. DLC films deposited under the ratio from 1 to 4 had hardness from 40 to 45GPa. It was shown that DLC films with stable properties of low sp2 content and high hardness were formed even when the fluxes were varied from 1 to 4 during deposition. It was indicated that this process was useful in the view of industrial application.

  11. Aerosol-Assisted Chemical Vapor Deposited Thin Films for Space Photovoltaics

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; McNatt, Jeremiah; Dickman, John E.; Jin, Michael H.-C.; Banger, Kulbinder K.; Kelly, Christopher V.; AquinoGonzalez, Angel R.; Rockett, Angus A.

    2006-01-01

    Copper indium disulfide thin films were deposited via aerosol-assisted chemical vapor deposition using single source precursors. Processing and post-processing parameters were varied in order to modify morphology, stoichiometry, crystallography, electrical properties, and optical properties in order to optimize device-quality material. Growth at atmospheric pressure in a horizontal hot-wall reactor at 395 C yielded best device films. Placing the susceptor closer to the evaporation zone and flowing a more precursor-rich carrier gas through the reactor yielded shinier, smoother, denser-looking films. Growth of (112)-oriented films yielded more Cu-rich films with fewer secondary phases than growth of (204)/(220)-oriented films. Post-deposition sulfur-vapor annealing enhanced stoichiometry and crystallinity of the films. Photoluminescence studies revealed four major emission bands (1.45, 1.43, 1.37, and 1.32 eV) and a broad band associated with deep defects. The highest device efficiency for an aerosol-assisted chemical vapor deposited cell was 1.03 percent.

  12. Atomic layer deposition of amorphous niobium carbide-based thin film superconductors.

    SciTech Connect

    Klug, J. A.; Prolier, T.; Elam, J. W.; Becker, N. G.; Pellin, M. J.

    2011-01-01

    Niobium carbide thin films were synthesized by atomic layer deposition (ALD) using trimethylaluminum (TMA), NbF{sub 5}, and NbCl{sub 5} precursors. In situ quartz crystal microbalance (QCM) measurements performed at 200 and 290 C revealed controlled, linear deposition with a high growth rate of 5.7 and 4.5 {angstrom}/cycle, respectively. The chemical composition, growth rate, structure, and electronic properties of the films were studied over the deposition temperature range 125-350 C. Varying amounts of impurities, including amorphous carbon (a-C), AlF{sub 3}, NbF{sub x}, and NbCl{sub x}, were found in all samples. A strong growth temperature dependence of film composition, growth rate, and room temperature DC resistivity was observed. Increasing film density, decreasing total impurity concentration, and decreasing resistivity were observed as a function of increasing deposition temperature for films grown with either NbF{sub 5} or NbCl{sub 5}. Superconducting quantum interference device (SQUID) magnetometry measurements down to 1.2 K revealed a superconducting transition at T{sub c} = 1.8 K in a 75 nm thick film grown at 350 C with TMA and NbF{sub 5}. The superconducting critical temperature could be increased up to 3.8 K with additional use of NH{sub 3} during ALD film growth.

  13. atomic layer deposition of amorphous niobium carbide-based thin film superconductors.

    SciTech Connect

    Prolier, T.; Klug, J. A.; Elam, J. W.; Claus, H.; Becker, N. G.; Pellin, M. J.

    2011-01-01

    Niobium carbide thin films were synthesized by atomic layer deposition (ALD) using trimethylaluminum (TMA), NbF{sub 5}, and NbCl{sub 5} precursors. In situ quartz crystal microbalance (QCM) measurements performed at 200 and 290 C revealed controlled, linear deposition with a high growth rate of 5.7 and 4.5 {angstrom}/cycle, respectively. The chemical composition, growth rate, structure, and electronic properties of the films were studied over the deposition temperature range 125-350 C. Varying amounts of impurities, including amorphous carbon (a-C), AlF{sub 3}, NbF{sub x}, and NbCl{sub x}, were found in all samples. A strong growth temperature dependence of film composition, growth rate, and room temperature DC resistivity was observed. Increasing film density, decreasing total impurity concentration, and decreasing resistivity were observed as a function of increasing deposition temperature for films grown with either NbF{sub 5} or NbCl{sub 5}. Superconducting quantum interference device (SQUID) magnetometry measurements down to 1.2 K revealed a superconducting transition at T{sub c} = 1.8 K in a 75 nm thick film grown at 350 C with TMA and NbF{sub 5}. The superconducting critical temperature could be increased up to 3.8 K with additional use of NH{sub 3} during ALD film growth.

  14. Evaluation of thermal stress in hydroxyapatite film fabricated by powder jet deposition.

    PubMed

    Akatsuka, Ryo; Matsumura, Ken; Noji, Miyoko; Kuriyagawa, Tsunemoto; Sasaki, Keiichi

    2013-10-01

    This study aimed to create a thick hydroxyapatite (HA) film on the surface of a human tooth via a powder jet deposition (PJD) device for dental handpieces, and to examine the microstructural and mechanical properties of the HA film. In particular, the effects of thermal stress on this film were evaluated. The HA film was created by blasting 3.18-μm HA particles, calcinated at 1,200°C, onto the enamel substrate at room temperature and atmospheric pressure. An HA film with an area of 3 mm × 3 mm was prepared and polished. The following HA film parameters were evaluated from the three-dimensional surface profile: surface roughness, Vickers hardness, and bonding strength before and after artificial aging induced by 500 cycles of thermal cycling (5-55°C). The HA particles in the deposited film were densely packed, and the surface of the HA film was unchanged after thermal cycling. There were also no significant differences in the hardness and the bonding strength of the HA film before and after thermal cycling. The HA film created in this study demonstrated excellent microstructural and mechanical properties, even after the application of thermal stress.

  15. Characteristic properties of the Casimir free energy for metal films deposited on metallic plates

    NASA Astrophysics Data System (ADS)

    Klimchitskaya, G. L.; Mostepanenko, V. M.

    2016-04-01

    The Casimir free energy and pressure of thin metal films deposited on metallic plates are considered using the Lifshitz theory and the Drude and plasma model approaches to the role of conduction electrons. The bound electrons are taken into account by using the complete optical data of film and plate metals. It is shown that for films of several tens of nanometers thickness the Casimir free energy and pressure calculated using these approaches differ by hundreds and thousands percent and can be easily discriminated experimentally. According to our results, the free energy of a metal film does not vanish in the limiting case of ideal metal if the Drude model approach is used in contradiction with the fact that the fluctuating field cannot penetrate in its interior. Numerical computations of the Casimir free energy and pressure of Ag and Au films deposited on Cu and Al plates have been performed using both theoretical approaches. It is shown that the free energy of a film can be both negative and positive depending on the metals used. For a Au film on a Ag plate and vice versa the Casimir energy of a film changes its sign with increasing film thickness. Applications of the obtained results for resolving the Casimir puzzle and the problem of stability of thin films are discussed.

  16. Self-limiting atomic layer deposition of conformal nanostructured silver films

    NASA Astrophysics Data System (ADS)

    Golrokhi, Zahra; Chalker, Sophia; Sutcliffe, Christopher J.; Potter, Richard J.

    2016-02-01

    The controlled deposition of ultra-thin conformal silver nanoparticle films is of interest for applications including anti-microbial surfaces, plasmonics, catalysts and sensors. While numerous techniques can produce silver nanoparticles, few are able to produce highly conformal coatings on high aspect ratio surfaces, together with sub-nanometre control and scalability. Here we develop a self-limiting atomic layer deposition (ALD) process for the deposition of conformal metallic silver nanoparticle films. The films have been deposited using direct liquid injection ALD with ((hexafluoroacetylacetonato)silver(I)(1,5-cyclooctadiene)) and propan-1-ol. An ALD temperature window between 123 and 128 °C is identified and within this range self-limiting growth is confirmed with a mass deposition rate of ∼17.5 ng/cm2/cycle. The effects of temperature, precursor dose, co-reactant dose and cycle number on the deposition rate and on the properties of the films have been systematically investigated. Under self-limiting conditions, films are metallic silver with a nano-textured surface topography and nanoparticle size is dependent on the number of ALD cycles. The ALD reaction mechanisms have been elucidated using in-situ quartz crystal microbalance (QCM) measurements, showing chemisorption of the silver precursor, followed by heterogeneous catalytic dehydrogenation of the alcohol to form metallic silver and an aldehyde.

  17. Antibiofouling Properties of Plasma-Deposited Oxazoline-Based Thin Films.

    PubMed

    Cavallaro, Alex A; Macgregor-Ramiasa, Melanie N; Vasilev, Krasimir

    2016-03-01

    Infections caused by the bacterial colonization of medical devices are a substantial problem to patients and healthcare. Biopassive polyoxazoline coatings are attracting attention in the biomedical field as one of the potential solutions to this problem. Here, we present an original and swift way to produce plasma-deposited oxazoline-based films for antifouling applications. The films developed via the plasma deposition of 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline have tunable thickness and surface properties. Diverse film chemistries were achieved by tuning and optimizing the deposition conditions. Human-derived fibroblasts were used to confirm the biocompatibility of oxazoline derived coatings. The capacity of the coatings to resist biofilm attachment was studied as a function of deposition power and mode (i.e., continuous wave or pulsed) and precursor flow rates for both 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline. After careful tuning of the deposition parameters films having the capacity to resist biofilm formation by more than 90% were achieved. The substrate-independent and customizable properties of the new generation of plasma deposited oxazoline thin films developed in this work make them attractive candidates for the coating of medical devices and other applications where bacteria surface colonization and biofilm formation is an issue. PMID:26901823

  18. Ag Nanodots Emitters Embedded in a Nanocrystalline Thin Film Deposited on Crystalline Si Solar Cells.

    PubMed

    Park, Seungil; Ryu, Sel Gi; Ji, HyungYong; Kim, Myeong Jun; Peck, Jong Hyeon; Kim, Keunjoo

    2016-06-01

    We fabricated crystalline Si solar cells with the inclusion of various Ag nanodots into the additional emitters of nanocrystallite Si thin films. The fabricated process was carried out on the emitter surface of p-n junction for the textured p-type wafer. The Ag thin films were deposited on emitter surfaces and annealed at various temperatures. The amorphous Si layers were also deposited on the Ag annealed surfaces by hot-wire chemical vapor deposition and then the deposited layers were doped by the second n-type doping process to form an additional emitter. From the characterization, both the Ag nanodots and the deposited amorphous Si thin films strongly reduce photo-reflectances in a spectral region between 200-400 nm. After embedding Ag nanodots in nanocrystallite Si thin films, a conversion efficiency of the sample with added emitter was achieved to 15.1%, which is higher than the 14.1% of the reference sample and the 14.7% of the de-posited sample with a-Si:H thin film after the Ag annealing process. The additional nanocrystallite emitter on crystalline Si with Ag nanodots enhances cell properties. PMID:27427665

  19. Deposition of SiNx Thin Film Using μ-SLAN Surface Wave Plasma Source

    NASA Astrophysics Data System (ADS)

    Ying-Yu, Xu; Takuya, Ogishima; Dariusz, Korzec; Yoichiro, Nakanishi; Yoshinori, Hatanaka

    1998-10-01

    Remote plasma CVD method has been used in fabrication of high quality thin films. It is a useful method in decreasing damage from ion bombardment and in analysis of film formation mechanism. In our research, as the film deposition rate depends on neutral radical density, hence high-density plasma is needed for high-speed deposition. In this research, a μ-SLAN (Slot ANtenna) microwave surface wave plasma source was adapted for thin film deposition. The μ-SLAN is an efficient plasma generator in which microwave power is coupled from a ring cavity with several slots around quartz discharge tube. We measured parameters of argon plasma along the discharge tube by a double Langmuir probe. The electron density was measured as about 10^11 cm-3 at an axial position of 43 cm from ring cavity, a microwave power of 500 W and a pressure of 0.5 torr. Using μ-SLAN, SiNx thin film was deposited and high deposition rate was obtained. The highest deposition rate of 280 nm/min was obtained for plasma gas containing 15% of hydrogen in nitrogen with the pressure and power of 1.5 torr and 500 W respectively.

  20. Some aspects over the quality of thin films deposited on special steels used in hydraulic blades

    NASA Astrophysics Data System (ADS)

    Tugui, C. A.; Vizureanu, P.; Iftimie, N.; Steigmann, R.

    2016-08-01

    The experimental research involved in this paper consists in the obtaining of superior physical, chemical and mechanical properties of stainless steels used in the construction of hydraulic turbine blades. These properties are obtained by deposition of hard thin films in order to improve the wear resistance, increasing the hardness but maintaining the tenacious core of the material. The chosen methods for deposition are electrospark deposition because it has relatively low costs, are easy to obtain, the layers have a good adherence to support and the thickness can be variable in function of the established conditions and the pulsed laser deposition because high quality films can be obtained at nanometric precision. The samples will be prepared for the analysis of the structure using optical method as well as for the obtaining of the optimal roughness for the deposition. The physical, chemical and mechanical properties will be determined after deposition using SEM and EDX, in order to emphasize the structure film-substrate and repartition of the deposition elements on the surface and in transversal section. The non-destructive testing has emphasized the good adherence between deposited layer and the metallic support, due to double deposition, spallation regions doesn't appear.