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Sample records for plasma ion implantation

  1. Key issues in plasma source ion implantation

    SciTech Connect

    Rej, D.J.; Faehl, R.J.; Matossian, J.N.

    1996-09-01

    Plasma source ion implantation (PSII) is a scaleable, non-line-of-sight method for the surface modification of materials. In this paper, we consider three important issues that should be addressed before wide-scale commercialization of PSII: (1) implant conformality; (2) ion sources; and (3) secondary electron emission. To insure uniform implanted dose over complex shapes, the ion sheath thickness must be kept sufficiently small. This criterion places demands on ion sources and pulsed-power supplies. Another limitation to date is the availability of additional ion species beyond B, C, N, and 0. Possible solutions are the use of metal arc vaporization sources and plasma discharges in high-vapor-pressure organometallic precursors. Finally, secondary electron emission presents a potential efficiency and x-ray hazard issue since for many metallurgic applications, the emission coefficient can be as large as 20. Techniques to suppress secondary electron emission are discussed.

  2. A commercial plasma source ion implantation facility

    SciTech Connect

    Scheuer, J.T.; Adler, R.A.; Horne, W.G.

    1996-10-01

    Empire Hard Chrome has recently installed commercial plasma source ion implantation (PSU) equipment built by North Star Research Corporation. Los Alamos National Laboratory has assisted in this commercialization effort via two Cooperative Research and Development Agreements to develop the plasma source for the equipment and to identify low-risk commercial PSII applications. The PSII system consists of a 1 m x 1 m cylindrical vacuum chamber with a rf plasma source. The pulse modulator is capable of delivering pulses kV and peak currents of 300 A at maximum repetition rate of 400 Hz. thyratron tube to switch a pulse forming network which is tailored to match the dynamic PSII load. In this paper we discuss the PSII system, process facility, and early commercial applications to production tooling.

  3. Characterization of an RF plasma ion source for ion implantation

    SciTech Connect

    Kopalidis, Peter M.; Wan Zhimin

    2012-11-06

    A novel inductively coupled RF plasma ion source has been developed for use in a beamline ion implanter. Ion density data have been taken with an array of four Langmuir probes spaced equally at the source extraction arc slit. These provide ion density uniformity information as a function of source pressure, RF power and gas mixture composition. In addition, total extracted ion beam current data are presented for the same conditions. The comparative advantages of the RF source in terms of higher beam current, reduced maintenance and overall productivity improvement compared to a hot cathode source are discussed.

  4. Plasma immersion ion implantation for reducing metal ion release

    SciTech Connect

    Diaz, C.; Garcia, J. A.; Maendl, S.; Pereiro, R.; Fernandez, B.; Rodriguez, R. J.

    2012-11-06

    Plasma immersion ion implantation of Nitrogen and Oxygen on CoCrMo alloys was carried out to improve the tribological and corrosion behaviors of these biomedical alloys. In order to optimize the implantation results we were carried experiments at different temperatures. Tribocorrosion tests in bovine serum were used to measure Co, Cr and Mo releasing by using Inductively Coupled Plasma Mass Spectrometry analysis after tests. Also, X-ray Diffraction analysis were employed in order to explain any obtained difference in wear rate and corrosion tests. Wear tests reveals important decreases in rate of more than one order of magnitude for the best treatment. Moreover decreases in metal release were found for all the implanted samples, preserving the same corrosion resistance of the unimplanted samples. Finally this paper gathers an analysis, in terms of implantation parameters and achieved properties for industrial implementation of these treatments.

  5. Improved ion implant fluence uniformity in hydrogen enhanced glow discharge plasma immersion ion implantation into silicon

    SciTech Connect

    Luo, J.; Li, L. H. E-mail: paul.chu@cityu.edu.hk; Liu, H. T.; Xu, Y.; Zuo, X. J.; Zhu, P. Z.; Ma, Y. F.; Yu, K. M.; Fu, Ricky K. Y.; Chu, Paul K. E-mail: paul.chu@cityu.edu.hk

    2014-06-15

    Enhanced glow discharge plasma immersion ion implantation does not require an external plasma source but ion focusing affects the lateral ion fluence uniformity, thereby hampering its use in high-fluence hydrogen ion implantation for thin film transfer and fabrication of silicon-on-insulator. Insertion of a metal ring between the sample stage and glass chamber improves the ion uniformity and reduces the ion fluence non-uniformity as the cathode voltage is raised. Two-dimensional multiple-grid particle-in-cell simulation confirms that the variation of electric field inside the chamber leads to mitigation of the ion focusing phenomenon and the results are corroborated experimentally by hydrogen forward scattering.

  6. Method and apparatus for plasma source ion implantation

    DOEpatents

    Conrad, John R.

    1988-01-01

    Ion implantation into surfaces of three-dimensional targets is achieved by forming an ionized plasma about the target within an enclosing chamber and applying a pulse of high voltage between the target and the conductive walls of the chamber. Ions from the plasma are driven into the target object surfaces from all sides simultaneously without the need for manipulation of the target object. Repetitive pulses of high voltage, typically 20 kilovolts or higher, causes the ions to be driven deeply into the target. The plasma may be formed of a neutral gas introduced into the evacuated chamber and ionized therein with ionizing radiation so that a constant source of plasma is provided which surrounds the target object during the implantation process. Significant increases in the surface hardness and wear characteristics of various materials are obtained with ion implantation in this manner.

  7. Method and apparatus for plasma source ion implantation

    DOEpatents

    Conrad, J.R.

    1988-08-16

    Ion implantation into surfaces of three-dimensional targets is achieved by forming an ionized plasma about the target within an enclosing chamber and applying a pulse of high voltage between the target and the conductive walls of the chamber. Ions from the plasma are driven into the target object surfaces from all sides simultaneously without the need for manipulation of the target object. Repetitive pulses of high voltage, typically 20 kilovolts or higher, causes the ions to be driven deeply into the target. The plasma may be formed of a neutral gas introduced into the evacuated chamber and ionized therein with ionizing radiation so that a constant source of plasma is provided which surrounds the target object during the implantation process. Significant increases in the surface hardness and wear characteristics of various materials are obtained with ion implantation in this manner. 7 figs.

  8. High concentration of deuterium in palladium from plasma ion implantation

    SciTech Connect

    Uhm, H.S.; Lee, W.M. )

    1991-11-01

    Based on a theoretical calculation, a new scheme to increase deuterium density in palladium over its initial value is presented. This deuterium enrichment scheme makes use of plasma ion implantation. A cylindrical palladium rod (target) preloaded with deuterium atoms, coated with a diffusion-barrier material, is immersed in a deuterium plasma. The palladium rod is connected to a high-power modulator which provides a series of negative-voltage pulses. During these negative pulses, deuterium ions fall into the target, penetrate the diffusion barrier, and are implanted inside the palladium. For reasonable system parameters allowed by present technology, it is found from theoretical calculations that the saturation deuterium density after prolonged ion implantation can be several times the palladium atomic number density. Assuming an initial deuterium density, {ital n}{sub 0}=4{times}10{sup 22} cm{sup {minus}3}, it is also found that the deuterium density in palladium can triple its original value within a few days of the ion implantation for a reasonable target size. Because of the small diffusion coefficient in palladium, the incoming ions do not diffuse quickly inward, thereby accumulating near the target surface at the beginning of the implantation.

  9. Simulated plasma immersion ion implantation processing of thin wires

    SciTech Connect

    Lejars, A.; Duday, D.; Wirtz, T.; Manova, D.; Maendl, S.

    2010-09-15

    In plasma immersion ion implantation, the dependencies of sheath expansion and ion flux density on substrate geometry are well established. However, effects of extreme diameter variations have not been investigated explicitly. Using an analytical simulation code assuming an infinite mean free path, the sheath expansion, ion flux density, and resulting substrate temperature are explored down to wire diameters of 150 {mu}m. Comparing the results for planar substrates and cylindrical, thin wires, a reduction in the sheath width up to a factor of 10, a faster establishing of a new equilibrium sheath position, and an increase in the ion fluence by a factor of 100 is encountered. The smaller plasma sheath allows for a denser packing of wires during the treatment than for planar substrates. Additionally, the implantation time is reduced, allowing a fast wire transport through the chamber, further increasing the throughput.

  10. Biologic stability of plasma ion-implanted miniscrews

    PubMed Central

    Cho, Young-Chae; Cha, Jung-Yul; Hwang, Chung-Ju; Park, Young-Chel; Jung, Han-Sung

    2013-01-01

    Objective To gain basic information regarding the biologic stability of plasma ion-implanted miniscrews and their potential clinical applications. Methods Sixteen plasma ion-implanted and 16 sandblasted and acid-etched (SLA) miniscrews were bilaterally inserted in the mandibles of 4 beagles (2 miniscrews of each type per quadrant). Then, 250 - 300 gm of force from Ni-Ti coil springs was applied for 2 different periods: 12 weeks on one side and 3 weeks contralaterally. Thereafter, the animals were sacrificed and mandibular specimens including the miniscrews were collected. The insertion torque and mobility were compared between the groups. The bone-implant contact and bone volume ratio were calculated within 800 µm of the miniscrews and compared between the loading periods. The number of osteoblasts was also quantified. The measurements were expressed as percentages and analyzed by independent t-tests (p < 0.05). Results No significant differences in any of the analyzed parameters were noted between the groups. Conclusions The preliminary findings indicate that plasma ion-implanted miniscrews have similar biologic characteristics to SLA miniscrews in terms of insertion torque, mobility, bone-implant contact rate, and bone volume rate. PMID:23814706

  11. Chromium plating pollution source reduction by plasma source ion implantation

    SciTech Connect

    Chen, A.; Sridharan, K.; Dodd, R.A.; Conrad, J.R.; Qiu, X.; Hamdi, A.H.; Elmoursi, A.A.; Malaczynski, G.W.; Horne, W.G.

    1995-12-31

    There is growing concern over the environmental toxicity and workers` health issues due to the chemical baths and rinse water used in the hard chromium plating process. In this regard the significant hardening response of chromium to nitrogen ion implantation can be environmentally beneficial from the standpoint of decreasing the thickness and the frequency of application of chromium plating. In this paper the results of a study of nitrogen ion implantation of chrome plated test flats using the non-line-of-sight Plasma Source Ion Implantation (PSII) process, are discussed. Surface characterization was performed using Scanning Electron Microscopy (SEM), Auger Electron Spectroscopy (AES), and Electron Spectroscopy for Chemical Analysis (ESCA). The surface properties were evaluated using a microhardness tester, a pin-on-disk wear tester, and a corrosion measurement system. Industrial field testing of nitrogen PSII treated chromium plated parts showed an improvement by a factor of two compared to the unimplanted case.

  12. Deep Trench Doping by Plasma Immersion Ion Implantation in Silicon

    SciTech Connect

    Nizou, S.; Vervisch, V.; Etienne, H.; Torregrosa, F.; Roux, L.; Ziti, M.; Alquier, D.; Roy, M.

    2006-11-13

    The realization of three dimensional (3D) device structures remains a great challenge in microelectronics. One of the main technological breakthroughs for such devices is the ability to control dopant implantation along silicon trench sidewalls. Plasma Immersion Ion Implantation (PIII) has shown its wide efficiency for specific doping processing in semiconductor applications. In this work, we propose to study the capability of PIII method for large scale silicon trench doping. Ultra deep trenches with high aspect ratio were etched on 6'' N type Si wafers. Wafers were then implanted with a PIII Pulsion system using BF3 gas source at various pressures and energies. The obtained results evidence that PIII can be used and are of grateful help to define optimized processing conditions to uniformly dope silicon trench sidewalls through the wafers.

  13. Plasma source ion implantation technology for engineering surfaces of materials

    NASA Astrophysics Data System (ADS)

    Wilson, E. H.; Lawrence, D. F.; Sridharan, K.; Sandstrom, P. W.

    2001-07-01

    Plasma Source Ion Implantation* (PSII) is a non-line-of-sight technique for energetic ion surface modification of materials. At the University of Wisconsin there are presently three PSII systems two of which measure about 1 m3 and a third that measures 0.1 m3. Plasma generation is achieved in vacuum through filamentary, RF, DC-pulsed, or glow discharge. High voltage pulsing is achieved using a tetrode modulator that pulses at up to 60kV or by a solid-state pulser that can supply 20kV. Recently, a crossatron modulator capable of 40kV and 1kA peak anode current was built in-house. Surface properties of a wide range of materials have been beneficially modified using PSII in ion implantation, film deposition, energetic ion mixing, and sputtering modes. Industrial field testing of PSII-treated parts has yielded promising results but successful commercialization requires judicious selection of applications which effectively exploit the unique aspects of PSII as a surface modification tool.*J.R. Conrad U.S. Patent#4764394, 1988

  14. Plasma immersion ion implantation for SOI synthesis: SIMOX and ion-cut

    SciTech Connect

    Lu, X.; Iyer, S.S.K.; Hu, C.; Cheung, N.W.; Lee, J.; Doyle, B.; Fan, Z.; Chu, P.K.

    1998-09-01

    The authors have demonstrated feasibility to form silicon-on-insulator (SOI) substrates using plasma immersion ion implantation (PIII) for both separation by implantation of oxygen and ion-cut. This high throughput technique can substantially lower the high cost of SOI substrates due to the simpler implanter design as well as ease of maintenance. For separation by plasma implantation of oxygen wafers, secondary ion mass spectrometry analysis and cross-sectional transmission electron micrographs show continuous buried oxide formation under a single-crystal silicon overlayer with sharp Si/SiO{sub 2} interfaces after oxygen plasma implantation and high-temperature (1,300 C) annealing. Ion-cut SOI wafer fabrication technique is implemented for the first time using PIII. The hydrogen plasma can be optimized so that only one ion species is dominant in concentration and there are minimal effects by other residual ions on the ion-cut process. The physical mechanism of hydrogen induced silicon surface layer cleavage has been investigated. An ideal gas law model of the microcavity internal pressure combined with a two-dimensional finite element fracture mechanics model is used to approximate the fracture driving force which is sufficient to overcome the silicon fracture resistance.

  15. Magnetic insulation of secondary electrons in plasma source ion implantation

    SciTech Connect

    Rej, D.J.; Wood, B.P.; Faehl, R.J.; Fleischmann, H.H.

    1993-09-01

    The uncontrolled loss of accelerated secondary electrons in plasma source ion implantation (PSII) can significantly reduce system efficiency and poses a potential x-ray hazard. This loss might be reduced by a magnetic field applied near the workpiece. The concept of magnetically-insulated PSII is proposed, in which secondary electrons are trapped to form a virtual cathode layer near the workpiece surface where the local electric field is essentially eliminated. Subsequent electrons that are emitted can then be reabsorbed by the workpiece. Estimates of anomalous electron transport from microinstabilities are made. Insight into the process is gained with multi-dimensional particle-in-cell simulations.

  16. Metallic contamination in hydrogen plasma immersion ion implantation of silicon

    NASA Astrophysics Data System (ADS)

    Chu, Paul K.; Fu, Ricky K. Y.; Zeng, Xuchu; Kwok, Dixon T. K.

    2001-10-01

    In plasma immersion ion implantation (PIII), ions bombard all surfaces inside the PIII vacuum chamber, especially the negatively pulsed biased sample stage and to a lesser extent the interior of the vacuum chamber. As a result, contaminants sputtered from these exposed surfaces can be reimplanted into or adsorb on the silicon wafer. Using particle-in-cell theoretical simulation, we determine the relative ion doses incident on the top, side, and bottom surfaces of three typical sample chuck configurations: (i) a bare conducting stage with the entire sample platen and high-voltage feedthrough/supporting rod exposed and under a high voltage, (ii) a stage with only the sample platen exposed to the plasma but the high-voltage feedthrough protected by an insulating quartz shroud, and (iii) a bare stage with a silicon extension or guard ring to reduce the number of ions bombarding the side and bottom of the sample platen. Our simulation results reveal that the ratio of the incident dose impacting the top of the sample platen to that impacting the side and bottom of the sample stage can be improved to 49% using a guard ring. To corroborate our theoretical results, we experimentally determine the amounts of metallic contaminants on 100 mm silicon wafers implanted using a bare chuck and with a 150 mm silicon wafer inserted between the 100 mm wafer and sample stage to imitate the guard ring. We also discuss the effectiveness of a replaceable all-silicon liner inside the vacuum chamber to address the second source of contamination, that from the interior wall of the vacuum chamber. Our results indicate a significant improvement when an all-silicon liner and silicon guard ring are used simultaneously.

  17. Experimental investigation of plasma-immersion ion implantation treatment for biocompatible polyurethane implants production

    NASA Astrophysics Data System (ADS)

    Iziumov, R. I.; Beliaev, A. Y.; Kondyurina, I. V.; Shardakov, I. N.; Kondyurin, A. V.; Bilek, M. M.; McKenzie, D. R.

    2016-04-01

    Modification of the surface layer of polyurethane with plasma-immersion ion implantation (PIII) and studying its physical and chemical changes have been discussed in this paper. The goal of the research was to obtain carbonized layer allowing creating biocompatible polyurethane implants. The experiments of PIII treatment in various modes were performed. The investigation of the modified surface characteristics was carried out by observing the kinetics of free surface energy for two weeks after treatment. The regularities between treatment time and the level of free surface energy were detected. The explanation of high energy level was given through the appearance of free radicals in the surface layer of material. The confirmation of the chemical activation of the polyurethane surface after PIII treatment was obtained.

  18. Operations manual for the plasma source ion implantation economics program

    SciTech Connect

    Bibeault, M.L.; Thayer, G.R.

    1995-10-01

    Plasma Source Ion Implantation (PSII) is a surface modification technique for metal. PSIICOSTMODEL95 is an EXCEL-based program that estimates the cost for implementing a PSII system in a manufacturing setting where the number of parts to be processed is over 5,000 parts per day and the shape of each part does not change from day to day. Overall, the manufacturing process must be very well defined and should not change. This document is a self-contained manual for PSIICOSTMODEL95. It assumes the reader has some general knowledge of the technical requirements for PSII. Configuration of the PSII process versus design is used as the methodology in PSIICOSTMODEL95. The reason behind this is twofold. First, the design process cannot be programmed into a computer when the relationships between design variables are not understood. Second, the configuration methodology reduces the number of assumptions that must be programmed into our software. Misuse of results are less likely to occur if the user has fewer assumptions to understand.

  19. Effect of plasma immersion ion implantation in TiNi implants on its interaction with animal subcutaneous tissues

    NASA Astrophysics Data System (ADS)

    Lotkov, Aleksandr I.; Kashin, Oleg A.; Kudryavtseva, Yuliya A.; Shishkova, Darya K.; Krukovskii, Konstantin V.; Kudryashov, Andrey N.

    2016-08-01

    Here we investigated in vivo interaction of Si-modified titanium nickelide (TiNi) samples with adjacent tissues in a rat subcutaneous implant model to assess the impact of the modification on the biocompatibility of the implant. Modification was performed by plasma immersion ion processing, which allows doping of different elements into surface layers of complex-shaped articles. The aim of modification was to reduce the level of toxic Ni ions on the implant surface for increasing biocompatibility. We identified a thin connective tissue capsule, endothelial cells, and capillary-like structures around the Si-modified implants both 30 and 90 days postimplantation. No signs of inflammation were found. In conclusion, modification of TiNi samples with Si ions increases biocompatibility of the implant.

  20. Deuterium retention after deuterium plasma implantation in tungsten pre-damaged by fast C+ ions

    NASA Astrophysics Data System (ADS)

    Efimov, V. S.; Gasparyan, Yu M.; Pisarev, A. A.; Khripunov, B. I.; Koidan, V. S.; Ryazanov, A. I.; Semenov, E. V.

    2016-09-01

    Thermal desorption of deuterium from W was investigated. Virgin samples and samples damaged by 10 MeV C 3+ ions were implanted from plasma in the LENTA facility at 370 K and 773 K. In comparison with the undamaged sample, deuterium retention in the damaged sample slightly increased in the case of deuterium implantation at RT, but decreased in the case of deuterium implantation at 773 K. At 773 K, deuterium was concluded to diffuse far behind the D ion range in the virgin sample, while C implantation region was concluded to be a barrier for D diffusion in the damaged sample.

  1. Formation of Wear Resistant Steel Surfaces by Plasma Immersion Ion Implantation

    NASA Astrophysics Data System (ADS)

    Mändl, S.; Rauschenbach, B.

    2003-08-01

    Plasma immersion ion implantation (PIII) is a versatile and fast method for implanting energetic ions into large and complex shaped three-dimensional objects where the ions are accelerated by applying negative high voltage pulses to a substrate immersed in a plasma. As the line-of-sight restrictions of conventional implanters are circumvented, it results in a fast and cost-effective technology. Implantation of nitrogen at 30 - 40 keV at moderate temperatures of 200 - 400 °C into steel circumvents the diminishing thermal nitrogen activation encountered, e.g., in plasma nitriding in this temperature regime, thus enabling nitriding of additional steel grades. Nitride formation and improvement of the mechanical properties after PIII are presented for several steel grades, including AISI 316Ti (food industry), AISI D2 (used for bending tools) and AISI 1095 (with applications in the textile industry).

  2. Formation of Wear Resistant Steel Surfaces by Plasma Immersion Ion Implantation

    SciTech Connect

    Maendl, S.; Rauschenbach, B.

    2003-08-26

    Plasma immersion ion implantation (PIII) is a versatile and fast method for implanting energetic ions into large and complex shaped three-dimensional objects where the ions are accelerated by applying negative high voltage pulses to a substrate immersed in a plasma. As the line-of-sight restrictions of conventional implanters are circumvented, it results in a fast and cost-effective technology. Implantation of nitrogen at 30 - 40 keV at moderate temperatures of 200 - 400 deg. C into steel circumvents the diminishing thermal nitrogen activation encountered, e.g., in plasma nitriding in this temperature regime, thus enabling nitriding of additional steel grades. Nitride formation and improvement of the mechanical properties after PIII are presented for several steel grades, including AISI 316Ti (food industry), AISI D2 (used for bending tools) and AISI 1095 (with applications in the textile industry)

  3. Optical properties of surface modified polypropylene by plasma immersion ion implantation technique

    SciTech Connect

    Ahmed, Sk. Faruque; Moon, Myoung-Woon; Kim, Chansoo; Lee, Kwang-Ryeol; Jang, Yong-Jun; Han, Seonghee; Choi, Jin-Young; Park, Won-Woong

    2010-08-23

    The optical band gap and activation energy of polypropylene (PP) induced by an Ar plasma immersion ion implantation technique were studied in detail. It was revealed that the structural alternation with an increase in polymer chain cross-linking in the ion beam affected layer enhanced the optical properties of PP. The optical band gap, calculated from the transmittance spectra, decreased from 3.44 to 2.85 eV with the Ar plasma ion energy from 10 to 50 keV. The activation energy, determined from the band tail of the transmittance spectra, decreased while the electrical conductivity increased with the Ar plasma ion energy.

  4. Voltage dependence of cluster size in carbon films using plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    McKenzie, D. R.; Tarrant, R. N.; Bilek, M. M. M.; Pearce, G.; Marks, N. A.; McCulloch, D. G.; Lim, S. H. N.

    2003-05-01

    Carbon films were prepared using a cathodic arc with plasma immersion ion implantation (PIII). Using Raman spectroscopy to determine cluster size, a comparison is made between cluster sizes at high voltage and a low duty cycle of pulses with the cluster sizes produced at low voltage and a higher duty cycle. We find that for ion implantation in the range 2-20 kV, the cluster size depends more on implantation energy ( E) than implantation frequency ( f), unlike stress relief, which we have previously shown [M.M.M. Bilek, et al., IEEE Trans. in Plasma Sci., Proceedings 20th ISDEIV 1-5 July 2002, Tours, France, Cat. No. 02CH37331, IEEE, Piscataway, NJ, USA, p. 95] to be dependent on the product Ef. These differences are interpreted in terms of a model in which the ion impacts create thermal spikes.

  5. Method For Plasma Source Ion Implantation And Deposition For Cylindrical Surfaces

    DOEpatents

    Fetherston, Robert P. , Shamim, Muhammad M. , Conrad, John R.

    1997-12-02

    Uniform ion implantation and deposition onto cylindrical surfaces is achieved by placing a cylindrical electrode in coaxial and conformal relation to the target surface. For implantation and deposition of an inner bore surface the electrode is placed inside the target. For implantation and deposition on an outer cylindrical surface the electrode is placed around the outside of the target. A plasma is generated between the electrode and the target cylindrical surface. Applying a pulse of high voltage to the target causes ions from the plasma to be driven onto the cylindrical target surface. The plasma contained in the space between the target and the electrode is uniform, resulting in a uniform implantation or deposition of the target surface. Since the plasma is largely contained in the space between the target and the electrode, contamination of the vacuum chamber enclosing the target and electrodes by inadvertent ion deposition is reduced. The coaxial alignment of the target and the electrode may be employed for the ion assisted deposition of sputtered metals onto the target, resulting in a uniform coating of the cylindrical target surface by the sputtered material. The independently generated and contained plasmas associated with each cylindrical target/electrode pair allows for effective batch processing of multiple cylindrical targets within a single vacuum chamber, resulting in both uniform implantation or deposition, and reduced contamination of one target by adjacent target/electrode pairs.

  6. Plasma immersion ion implantation for the efficient surface modification of medical materials

    SciTech Connect

    Slabodchikov, Vladimir A. Borisov, Dmitry P. Kuznetsov, Vladimir M.

    2015-10-27

    The paper reports on a new method of plasma immersion ion implantation for the surface modification of medical materials using the example of nickel-titanium (NiTi) alloys much used for manufacturing medical implants. The chemical composition and surface properties of NiTi alloys doped with silicon by conventional ion implantation and by the proposed plasma immersion method are compared. It is shown that the new plasma immersion method is more efficient than conventional ion beam treatment and provides Si implantation into NiTi surface layers through a depth of a hundred nanometers at low bias voltages (400 V) and temperatures (≤150°C) of the substrate. The research results suggest that the chemical composition and surface properties of materials required for medicine, e.g., NiTi alloys, can be successfully attained through modification by the proposed method of plasma immersion ion implantation and by other methods based on the proposed vacuum equipment without using any conventional ion beam treatment.

  7. Basic Aspects of the Formation and Activation of Boron Junctions Using Plasma Immersion Ion Implantation

    SciTech Connect

    Zschaetzsch, G.; Vandervorst, W.; Hoffmann, T.; Goossens, J.; Everaert, J.-L.; Agua Borniquel, J. I. del; Poon, T.

    2008-11-03

    This study investigates the basic aspects of junction formation using Plasma Immersion Ion Implantation using BF{sub 3} and addresses the role of (pre)amorphization, C(F)-co-implantation, plasma parameters (bias, dose) and the thermal anneal cycle (spike versus msec laser anneal). The basic physics are studied using Secondary Ion Mass Spectrometry, sheet resistance and using four point probe and RsL. Profiles with junction depths ranging from 10-12 nm and sheet resistance values below 800 Ohm/sq are readily achievable.

  8. Influence of annular magnet on discharge characteristics in enhanced glow discharge plasma immersion ion implantation

    SciTech Connect

    Li Liuhe; Wang Zhuo; Lu Qiuyuan; Fu, Ricky K. Y.; Chu, Paul K.; Pang Enjing; Dun Dandan; He Fushun; Li Fen

    2011-01-10

    A permanent annular magnet positioned at the grounded anode alters the discharge characteristics in enhanced glow discharge plasma immersion ion implantation (EGD-PIII). The nonuniform magnetic field increases the electron path length and confines electron motion due to the magnetic mirror effect and electron-neutral collisions thus occur more frequently. The plasma potential and ion density measured by a Langmuir probe corroborate that ionization is improved near the grounded anode. This hybrid magnetic field EGD-PIII method is suitable for implantation of gases with low ionization rates.

  9. Initial operation of a large-scale Plasma Source Ion Implantation experiment

    SciTech Connect

    Wood, B.P.; Henins, I.; Gribble, R.J.; Reass, W.A.; Faehl, R.J.; Nastasi, M.A.; Rej, D.J.

    1993-10-01

    In Plasma Source Ion Implantation (PSII), a workpiece to be implanted is immersed in a weakly ionized plasma and pulsed to a high negative voltage. Plasma ions are accelerated toward the workpiece and implanted in its surface. Experimental PSII results reported in the literature have been for small workpieces. A large scale PSII experiment has recently been assembled at Los Alamos, in which stainless steel and aluminum workpieces with surface areas over 4 m{sup 2} have been implanted in a 1.5 m-diameter, 4.6 m-length cylindrical vacuum chamber. Initial implants have been performed at 50 kV with 20 {mu}s pulses of 53 A peak current, repeated at 500 Hz, although the pulse modulator will eventually supply 120 kV pulses of 60 A peak current at 2 kHz. A 1,000 W, 13.56 MHz capacitively-coupled source produces nitrogen plasma densities in the 10{sup 15} m{sup {minus}3} range at neutral pressures as low as 0.02 mtorr. A variety of antenna configurations have been tried, with and without axial magnetic fields of up to 60 gauss. Measurements of sheath expansion, modulator voltage and current, and plasma density fill-in following a pulse are presented. The authors consider secondary electron emission, x-ray production, workpiece arcing, implant conformality, and workpiece and chamber heating.

  10. Radial 32P ion implantation using a coaxial plasma reactor: Activity imaging and numerical integration

    NASA Astrophysics Data System (ADS)

    Fortin, M. A.; Dufresne, V.; Paynter, R.; Sarkissian, A.; Stansfield, B.

    2004-12-01

    Beta-emitting biomedical implants are currently employed in angioplasty, in the treatment of certain types of cancers, and in the embolization of aneurysms with platinum coils. Radioisotopes such as 32P can be implanted using plasma-based ion implantation (PBII). In this article, we describe a reactor that was developed to implant radioisotopes into cylindrical metallic objects. The plasma first ionizes radioisotopes sputtered from a target, and then acts as the source of particles to be implanted into the biased biomedical device. The plasma therefore plays a major role in the ionization/implantation process. Following a sequence of implantation tests, the liners protecting the interior walls of the reactor were changed and the radioactivity on them measured. This study demonstrates that the radioactive deposits on these protective liners, adequately imaged by radiography, can indicate the distribution of the radioisotopes that are not implanted. The resulting maps give unique information about the activity distribution, which is influenced by the sputtering of the 32P-containing fragments, their ionization in the plasma, and also by the subsequent ion transport mechanisms. Such information can be interpreted and used to significantly improve the efficiency of the implantation procedure. Using a surface barrier detector, a comparative study established a relationship between the gray scale of radiographs of the liners, and activity measurements. An integration process allows the quantification of the activities on the walls and components of the reactor. Finally, the resulting integral of the 32P activity is correlated to the sum of the radioactivity amounts that were sputtered from radioactive targets inside the implanter before the dismantling procedure. This balance addresses the issue of security regarding PBII technology and confirms the confinement of the radioactivity inside the chamber.

  11. Radial {sup 32}P ion implantation using a coaxial plasma reactor: Activity imaging and numerical integration

    SciTech Connect

    Fortin, M.A.; Dufresne, V.; Paynter, R.; Sarkissian, A.; Stansfield, B.

    2004-12-01

    Beta-emitting biomedical implants are currently employed in angioplasty, in the treatment of certain types of cancers, and in the embolization of aneurysms with platinum coils. Radioisotopes such as {sup 32}P can be implanted using plasma-based ion implantation (PBII). In this article, we describe a reactor that was developed to implant radioisotopes into cylindrical metallic objects. The plasma first ionizes radioisotopes sputtered from a target, and then acts as the source of particles to be implanted into the biased biomedical device. The plasma therefore plays a major role in the ionization/implantation process. Following a sequence of implantation tests, the liners protecting the interior walls of the reactor were changed and the radioactivity on them measured. This study demonstrates that the radioactive deposits on these protective liners, adequately imaged by radiography, can indicate the distribution of the radioisotopes that are not implanted. The resulting maps give unique information about the activity distribution, which is influenced by the sputtering of the {sup 32}P-containing fragments, their ionization in the plasma, and also by the subsequent ion transport mechanisms. Such information can be interpreted and used to significantly improve the efficiency of the implantation procedure. Using a surface barrier detector, a comparative study established a relationship between the gray scale of radiographs of the liners, and activity measurements. An integration process allows the quantification of the activities on the walls and components of the reactor. Finally, the resulting integral of the {sup 32}P activity is correlated to the sum of the radioactivity amounts that were sputtered from radioactive targets inside the implanter before the dismantling procedure. This balance addresses the issue of security regarding PBII technology and confirms the confinement of the radioactivity inside the chamber.

  12. High power impulse magnetron sputtering and related discharges: scalable plasma sources for plasma-based ion implantation and deposition

    SciTech Connect

    Anders, Andre

    2009-09-01

    High power impulse magnetron sputtering (HIPIMS) and related self-sputtering techniques are reviewed from a viewpoint of plasma-based ion implantation and deposition (PBII&D). HIPIMS combines the classical, scalable sputtering technology with pulsed power, which is an elegant way of ionizing the sputtered atoms. Related approaches, such as sustained self-sputtering, are also considered. The resulting intense flux of ions to the substrate consists of a mixture of metal and gas ions when using a process gas, or of metal ions only when using `gasless? or pure self-sputtering. In many respects, processing with HIPIMS plasmas is similar to processing with filtered cathodic arc plasmas, though the former is easier to scale to large areas. Both ion implantation and etching (high bias voltage, without deposition) and thin film deposition (low bias, or bias of low duty cycle) have been demonstrated.

  13. Influence of ion-neutral collision parameters on dynamic structure of magnetized sheath during plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    Khoram, Mansour; Ghomi, Hamid

    2016-03-01

    A cold magnetized plasma sheath is considered to examine the gas pressure effect on the sheath dynamics. A fluid model is used to describe the plasma sheath dynamic. The governing fluid equations in the plasma are solved from plasma center to the target using the finite difference method and some convenient initial and boundary conditions at the plasma center and target. It is found that, the ion-neutral collision has significant effect on the dynamic characteristics of the high-voltage sheath in the plasma immersion ion implantation (PIII). It means that, the temporal profile of the ion dose on the target and sheath width are decreased by increasing the gas pressure. Also, the gas pressure substantially diminishes the temporal psychograph of ion incident angle on the target.

  14. From plasma immersion ion implantation to deposition: A historical perspective on principles and trends

    SciTech Connect

    Anders, Andre

    2001-06-14

    Plasma immersion techniques of surface modification are known under a myriad of names. The family of techniques reaches from pure plasma ion implantation, to ion implantation and deposition hybrid modes, to modes that are essentially plasma film deposition with substrate bias. In the most general sense, all plasma immersion techniques have in common that the surface of a substrate (target) is exposed to plasma and that relatively high substrate bias is applied. The bias is usually pulsed. In this review, the roots of immersion techniques are explored, some going back to the 1800s, followed by a discussion of the groundbreaking works of Adler and Conrad in the 1980s. In the 1990s, plasma immersion techniques matured in theoretical understanding, scaling, and the range of applications. First commercial facilities are now operational. Various immersion concepts are compiled and explained in this review. While gas (often nitrogen) ion implantation dominated the early years, film-forming immersion techniques and semiconductor processing gained importance. In the 1980s and 1990s we have seen exponential growth of the field but signs of slowdown are clear since 1998. Nevertheless, plasma immersion techniques have found, and will continue to have, an important place among surface modification techniques.

  15. Plasma-based fluorine ion implantation into dental materials for inhibition of bacterial adhesion.

    PubMed

    Nurhaerani; Arita, Kenji; Shinonaga, Yukari; Nishino, Mizuho

    2006-12-01

    The aims of this study were to evaluate the fluorine depth profiles of pure titanium (Ti), stainless steel (SUS), and polymethyl methacrylate (PMMA) modified by plasma-based fluorine ion implantation and the effects of fluorine ion implantation on contact angle, fluoride ion release, and S. mutans adhesion. Fluorine-based gases used were Ar+F2 and CF4. By means of SIMS, it was found that the peak count of PMMA was the lowest while that of Ti was the highest. Then, up to one minute after Ar sputtering, the presence of fluorine and chromic fluoride could be detected by XPS in the surface and subsurface layer. As for the effects of using CF4 gas for fluorine ion implantation into SUS substrate, the results were: contact angle was significantly increased; no fluoride ion release was detected; antibacterial activity was significantly increased while initial adhesion was decreased. These findings thus indicated that plasma-based fluorine ion implantation into SUS with CF4 gas provided surface antibacterial activity which was useful in inhibiting bacterial adhesion.

  16. Nitrogen mass transfer models for plasma-based low-energy ion implantation

    SciTech Connect

    Zheng, Bocong; Wang, Kesheng; Zhang, Zhipeng; Che, Honglong; Lei, Mingkai

    2015-03-15

    The nitrogen mass transfer process in plasma-based low-energy ion implantation (PBLEII) is theoretically and experimentally studied in order to explore the process mechanism of PBLEII and therefore to optimize the apparatus design and the process conditions. An electron cyclotron resonance (ECR) microwave discharge generates the nitrogen plasma with a high density of 10{sup 11}–10{sup 12} ions/cm{sup 3}, which diffuses downstream to the process chamber along the divergent magnetic field. The nitrogen ions in the plasma implant into the surface and transport to the matrix of an austenitic stainless steel under the low negative pulsed bias of −2 kV at a process temperature of 400 °C. A global plasma model is used to simulate the ECR microwave plasma discharge for a range of working pressures and microwave powers. The fluid models are adopted to calculate the plasma downstream diffusion, the sheath expansion and the low-energy ion implantation on the surface. A nonlinear kinetic discrete model is established to describe the nitrogen transport in the austenitic stainless steel and the results are compared with the experimental measurements. Under an average implantation current density of 0.3–0.6 mA/cm{sup 2}, the surface nitrogen concentration in the range from 18.5 to 29 at. % is a critical factor for the nitrogen transport in the AISI 304 austenitic stainless steel by PBLEII, which accelerates the implanted nitrogen diffusion inward up to 6–12 μm during a nitriding time of 4 h.

  17. Plasma-based ion implantation and deposition: A review of physics,technology, and applications

    SciTech Connect

    Pelletier, Jacques; Anders, Andre

    2005-05-16

    After pioneering work in the 1980s, plasma-based ion implantation (PBII) and plasma-based ion implantation and deposition (PBIID) can now be considered mature technologies for surface modification and thin film deposition. This review starts by looking at the historical development and recalling the basic ideas of PBII. Advantages and disadvantages are compared to conventional ion beam implantation and physical vapor deposition for PBII and PBIID, respectively, followed by a summary of the physics of sheath dynamics, plasma and pulse specifications, plasma diagnostics, and process modeling. The review moves on to technology considerations for plasma sources and process reactors. PBII surface modification and PBIID coatings are applied in a wide range of situations. They include the by-now traditional tribological applications of reducing wear and corrosion through the formation of hard, tough, smooth, low-friction and chemically inert phases and coatings, e.g. for engine components. PBII has become viable for the formation of shallow junctions and other applications in microelectronics. More recently, the rapidly growing field of biomaterial synthesis makes used of PBII&D to produce surgical implants, bio- and blood-compatible surfaces and coatings, etc. With limitations, also non-conducting materials such as plastic sheets can be treated. The major interest in PBII processing originates from its flexibility in ion energy (from a few eV up to about 100 keV), and the capability to efficiently treat, or deposit on, large areas, and (within limits) to process non-flat, three-dimensional workpieces, including forming and modifying metastable phases and nanostructures. We use the acronym PBII&D when referring to both implantation and deposition, while PBIID implies that deposition is part of the process.

  18. Low flux and low energy helium ion implantation into tungsten using a dedicated plasma source

    NASA Astrophysics Data System (ADS)

    Pentecoste, Lucile; Thomann, Anne-Lise; Melhem, Amer; Caillard, Amael; Cuynet, Stéphane; Lecas, Thomas; Brault, Pascal; Desgardin, Pierre; Barthe, Marie-France

    2016-09-01

    The aim of this work is to investigate the first stages of defect formation in tungsten (W) due to the accumulation of helium (He) atoms inside the crystal lattice. To reach the required implantation conditions, i.e. low He ion fluxes (1011-1014 ions.cm2.s-1) and kinetic energies below the W atom displacement threshold (about 500 eV for He+), an ICP source has been designed and connected to a diffusion chamber. Implantation conditions have been characterized by means of complementary diagnostics modified for measurements in this very low density helium plasma. It was shown that lowest ion fluxes could only be reached for the discharge working in capacitive mode either in α or γ regime. Special attention was paid to control the energy gained by the ions by acceleration through the sheath at the direct current biased substrate. At very low helium pressure, in α regime, a broad ion energy distribution function was evidenced, whereas a peak centered on the potential difference between the plasma and the biased substrate was found at higher pressures in the γ mode. Polycrystalline tungsten samples were exposed to the helium plasma in both regimes of the discharge and characterized by positron annihilation spectroscopy in order to detect the formed vacancy defects. It was found that W vacancies are able to be formed just by helium accumulation and that the same final implanted state is reached, whatever the operating mode of the capacitive discharge.

  19. Plasma immersion ion implantation for sub-22 nm node devices: FD-SOI and Tri-Gate

    SciTech Connect

    Duchaine, J.; Milesi, F.; Coquand, R.; Barraud, S.; Reboh, S.; Gonzatti, F.; Mazen, F.; Torregrosa, Frank

    2012-11-06

    Here, we present and discuss the electrical characteristics of fully depleted MOSFET transistors of planar and tridimensional architecture, doped by Plasma Immersion Ion Implantation (PIII) or Beam Line Ion Implantation (BLII). Both techniques delivered similar and satisfactory results in considering the planar architecture. For tri-dimensional Tri-Gate transistors, the results obtained with PIII are superior.

  20. Bioactivity of titanium following sodium plasma immersion ion implantation and deposition.

    PubMed

    Maitz, M F; Poon, R W Y; Liu, X Y; Pham, M-T; Chu, Paul K

    2005-09-01

    Bio-activation of titanium surface by Na plasma immersion ion implantation and deposition (PIII and D) is illustrated by precipitation of calcium phosphate and cell culture. The bioactivity of the plasma-implanted titanium is compared to that of the untreated, Na beam-line implanted and NaOH-treated titanium samples. Our data show that the samples can be classified into two groups: non-bioactive (untreated titanium and beam-line Na implanted titanium) and bioactive (Na-PIII and D and NaOH-treated titanium). None of the four types of surfaces exhibited major cell toxicity as determined by lactate dehydrogenase (LDH) release. However, the LDH release was higher on the more bioactive PIII and NaOH-treated surfaces. From a morphological point of view, cell adherence on the NaOH-treated titanium is the best. On the other hand, the cell activity and protein production were higher on the non-bioactive surfaces. The high alkaline phosphatase activity per cell suggests that the active surfaces support an osteogenic differentiation of the bone marrow cells at the expense of lower proliferation. The use of Na-PIII and D provides an environmentally cleaner technology to improve the bioactivity of Ti compared to conventional wet chemical processes. The technique is also particularly useful for the uniform and conforming treatment of medical implants that typically possess an irregular shape and are difficult to treat by conventional ion beam techniques.

  1. Broad beam ion implanter

    DOEpatents

    Leung, K.N.

    1996-10-08

    An ion implantation device for creating a large diameter, homogeneous, ion beam is described, as well as a method for creating same, wherein the device is characterized by extraction of a diverging ion beam and its conversion by ion beam optics to an essentially parallel ion beam. The device comprises a plasma or ion source, an anode and exit aperture, an extraction electrode, a divergence-limiting electrode and an acceleration electrode, as well as the means for connecting a voltage supply to the electrodes. 6 figs.

  2. Broad beam ion implanter

    DOEpatents

    Leung, Ka-Ngo

    1996-01-01

    An ion implantation device for creating a large diameter, homogeneous, ion beam is described, as well as a method for creating same, wherein the device is characterized by extraction of a diverging ion beam and its conversion by ion beam optics to an essentially parallel ion beam. The device comprises a plasma or ion source, an anode and exit aperture, an extraction electrode, a divergence-limiting electrode and an acceleration electrode, as well as the means for connecting a voltage supply to the electrodes.

  3. Flexible system for multiple plasma immersion ion implantation-deposition processes

    NASA Astrophysics Data System (ADS)

    Tian, Xiubo; Fu, Ricky K. Y.; Chu, Paul K.; Anders, Andre; Gong, Chunzhi; Yang, Shiqin

    2003-12-01

    Multiple plasma immersion ion implantation-deposition offers better flexibility compared to other thin film deposition techniques with regard to process optimization. The plasmas may be based on either cathodic arc plasmas (metal ions) or gas plasmas (gas ions) or both of them. Processing parameters such as pulsing frequency, pulse duration, bias voltage amplitude, and so on, that critically affect the film structure, internal stress, surface morphology, and other surface properties can be adjusted relatively easily to optimize the process. The plasma density can be readily controlled via the input power to obtain the desirable gas-to-metal ion ratios in the films. The high-voltage pulses can be applied to the samples within (in-duration mode), before (before-duration mode), or after (after-duration mode) the firing of the cathodic arcs. Consequently, dynamic ion beam assisted deposition processes incorporating various mixes of gas and metal ions can be achieved to yield thin films with the desirable properties. The immersion configuration provides to a certain degree the ability to treat components that are large and possess irregular geometries without resorting to complex sample manipulation or beam scanning. In this article we describe the hardware functions of such a system, voltage-current behavior to satisfy the needs of different processes, as well as typical experimental results.

  4. Diamond-like carbon produced by plasma source ion implantation as a corrosion barrier

    SciTech Connect

    Lillard, R.S.; Butt, D.P.; Taylor, T.N.; Walter, K.C.; Nastasi, M.

    1998-03-01

    There currently exists a broad range of applications for which the ability to produce an adherent, hard, wear and, corrosion-resistant coating plays a vital role. These applications include engine components, orthopedic devices, textile manufacturing components, hard disk media, optical coatings, and cutting and machining tools (e.g., punches, taps, scoring dies, and extrusion dies). Ion beam processing can play an important role in all of these technologies. Plasma source ion implantation (PSII) is an emerging technology which has the potential to overcome the limitations of conventional ion implantation by: (1) reducing the time and expense for implanting onto complex shapes and large areas and (2) extending the thickness of the modification zone through ion beam enhanced plasma growth of surface coatings. In PSII, targets are placed directly in a plasma source and then pulse biased to produce a non-line-of-sight process for complex-shaped targets without complex fixturing. If the pulse bias is a relatively high negative potential (20 to 100 kV) ion implantation will result. If however, a low voltage (50--1,200 eV) high duty cycle pulse bias is applied, film deposition from the chamber gas will result, thereby increasing the extent of the surface modification into the 1--10 micron regime. To evaluate the potential for DLC to be used as a corrosion barrier, Electrochemical Impedance Spectroscopy (EIS) and traditional electrochemistry techniques were used to investigate the breakdown mechanism in chloride and nonchloride containing environments. The effect of surface preparation on coating breakdown was also evaluated.

  5. Performance Enhancement of PFET Planar Devices by Plasma Immersion Ion Implantation (P3I)

    SciTech Connect

    Ortolland, Claude; Horiguchi, Naoto; Kerner, Christoph; Chiarella, Thomas; Eyben, Pierre; Everaert, Jean-Luc; Hoffmann, Thomas; Del Agua Borniquel, Jose Ignacio; Poon, Tze; Santhanam, Kartik; Porshnev, Peter; Foad, Majeed; Schreutelkamp, Robert; Absil, Philippe; Vandervorst, Wilfried; Felch, Susan

    2008-11-03

    A study of doping the pMOS Lightly Doped Drain (LDD) by Plasma Immersion Ion Implantation (P3i) with BF3 is presented which demonstrates a better transistor performance compared to standard beam line Ion Implantation (I/I). The benefit of P3i comes from the broad angular distribution of the impinging ions thereby doping the poly-silicon gate sidewall as well. Gate capacitance of short channel devices has been measured and clearly shows this improvement. This model is clearly supported by high resolution 2D-carrier profiles using Scanning Spreading Resistance Microscopy (SSRM) which shows this gate sidewall doping. The broad angular distribution also implies a smaller directional sensitivity (to for instance the detailed gate edge shape) and leads to devices which are perfectly balanced, when Source and Drain electrode are switched.

  6. Investigation of dose uniformity on the inner races of bearings treated by plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    Zeng, Z. M.; Kwok, T. K.; Tian, X. B.; Tang, B. Y.; Chu, P. K.

    1999-07-01

    Plasma immersion ion implantation (PIII) is an effective technique for the surface modification of industrial components possessing an irregular shape. We have recently used PIII to treat a real industrial ball bearing to enhance the surface properties of the race surface on which the balls roll. The implantation dose uniformity along the groove is assessed using theoretical simulation and experiments. The two sets of results agree very well, showing larger doses near the center. However, the highest dose is not observed at the bottom or center of the groove, but rather offset toward the side close to the sample platen when the bearing is placed horizontally. The minimum dose is observed near the edge or corner of the groove and our model indicates that it is due to the more glancing ion incidence as a result of the evolution of the ion sheath near the corner. The dose nonuniformity along the groove surface is about 40% based on our experimental data.

  7. Ion temperature and gas pressure effects on the magnetized sheath dynamics during plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    Khoram, M.; Ghomi, H.; Navab Safa, N.

    2016-03-01

    Here, a collisional magnetized plasma with finite ion temperature is considered to examine the effects of the ion temperature and gas pressure on the plasma-sheath dynamics. We use the two-fluid model of plasma-sheath where the nonlinear equations of a dynamic sheath are solved using a full implicit scheme of finite difference method along with some convenient initial and boundary conditions at the plasma center and target. It is found that the ion temperature only has a significant effect on the characteristics of low voltage sheath, while the gas pressure (collision rate) seriously affects the dynamic characteristics of the low and high voltage plasma-sheath. One can see, increasing the ion temperature in low voltage plasma-sheath causes to increase the temporal curve of the ion dose and the ion impact energy on the target, reduces the temporal curve of the sheath width, and has no any effect on the temporal curve of the ion incident angle on the target. However, rising the gas pressure in low and high voltage plasma-sheath reduces all of these temporal curves.

  8. Radioactive sputter cathodes for 32P plasma-based ion implantation.

    PubMed

    Fortin, M A; Paynter, R W; Sarkissian, A; Stansfield, B L

    2006-05-01

    The development of clinical treatments involving the use of beta-emitting millimetric and sub-millimetric devices has been a continuing trend in nuclear medicine. Implanted a few nanometers below the surface of endovascular implants, seeds or beads, beta-emitting radioisotopes can be used in a variety of biomedical applications. Recently, new technologies have emerged to enable the rapid and efficient activation of such devices. A pulsed, coaxial electron cyclotron resonance plasma reactor was designed and tested to demonstrate the feasibility of plasma-based radioactive ion implantation (PBRII). It has been shown that such plasma reactors allow for the implantation of radioisotopes (32P) into biomedical devices with higher efficiencies than those obtained with conventional ion beams. Fragments containing radioactive atoms are produced in the implanter by means of a negatively biased solid sputter cathode that is inserted into an argon plasma. Dilute orthophosphoric acid solutions (H3(32)PO4) are used for the fabrication of flat sputter targets, since they offer a high radioisotope content. However, the aggregation of the radioactive solute into highly hygroscopic ring-like deposits rather than flat, thin radioactive films is observed on certain substrates. This article describes the effect of this nonuniform distribution of the radioisotopes on the efficiency of PBRII, and presents a technique which enables a better distribution of 32P by coating the substrates with iron. The iron coating is shown to enable optimal radioisotope sputtering rates, which are essential in 32P-PBRII for the efficient activation of millimetric biomedical devices such as stents or coils.

  9. Experiments on plasma immersion ion implantation inside conducting tubes embedded in an external magnetic field

    NASA Astrophysics Data System (ADS)

    Pillaca, E. J. D. M.; Ueda, M.; Reuther, H.; Pichon, L.; Lepienski, C. M.

    2015-12-01

    Tubes of stainless steel (SS) embedded in external magnetic field were used to study the effects of plasma immersion ion implantation (PIII) as a function of their diameter. The study was complemented with and without a grounded auxiliary electrode (AE) placed at the axis of the tube. During the discharge tests in tubes of larger diameter (D = 11 cm), with and without AE, nitrogen gas breakdown was established inside the tube at pressures near 2.0 × 10-2 mbar. Under the same operation conditions, stable plasmas with similar PIII current densities were obtained for both arrangements. Reducing the diameter of the tube (D = 1.5 cm) turned the plasma unstable and made it inappropriate for ion implantation. This situation was solved by supplying gas at higher pressure or using higher magnetic field, without the presence of an AE. Under these conditions, nitrogen PIII treatments of these small diameter tubes were performed but gave not the best implantation results yet. Our results have also shown higher ion implantation current density (16 mA/cm2) in tube of intermediate diameter (D = 4 cm) using AE, compared to largest diameter tube used. In this case, a thick nitrogen layer of about 9 μm was obtained in the SS sample placed inside the tube. As a consequence of this, its structural and mechanical properties were enhanced. These results are attributed to the thermal diffusion promoted by ions hitting the inner wall in a large number due to the presence of the AE and the magnetic field.

  10. Conversion electron Mössbauer spectroscopy of plasma immersion ion implanted H13 tool steel

    NASA Astrophysics Data System (ADS)

    Terwagne, G.; Collins, G. A.; Hutchings, R.

    1994-12-01

    Conversion electron Mössbauer spectroscopy (CEMS) has been used to investigate nitride formation in AISI-H13 tool steel after treatment by plasma immersion ion implantation (PI3) at 350 °C. With only slight variation in the plasma conditions, it is possible to influence the kinetics of nitride precipitation so as to obtain nitrogen concentrations that range from those associated with ɛ-Fe2N through ɛ-Fe3N to γ'-Fe4N. The CEMS results enable a more definite identification of the nitrides than that obtained by glancing-angle X-ray diffraction and nuclear reaction analysis alone.

  11. Surface modification of silicone medical materials by plasma-based ion implantation

    NASA Astrophysics Data System (ADS)

    Kobayashi, Tomohiro; Yokota, Toshihiko; Kato, Rui; Suzuki, Yoshiaki; Iwaki, Masaya; Terai, Takayuki; Takahashi, Noriyoshi; Miyasato, Tomonori; Ujiie, Hiroshi

    2007-04-01

    Silicone (polydimethylsiloxane) sheets and tubes for medical use were irradiated with inert gas ions using plasma-based ion implantation (PBII). The affinity of the surface with tissue examined by an animal test was improved by the irradiation at optimal conditions. The cell attachment percentage increased at an applied voltage of less than -7.5 kV; however, it decreased at higher voltage. The specimens irradiated at higher voltages were more hydrophobic than unirradiated specimens. The surface became rough with increasing voltage and textures, and small domains appeared. This effect was caused by different etching speeds in the amorphous and crystalline areas.

  12. Simultaneous Sterilization With Surface Modification Of Plastic Bottle By Plasma-Based Ion Implantation

    SciTech Connect

    Sakudo, N.; Ikenaga, N.; Ikeda, F.; Nakayama, Y.; Kishi, Y.; Yajima, Z.

    2011-01-07

    Dry sterilization of polymeric material is developed. The technique utilizes the plasma-based ion implantation which is same as for surface modification of polymers. Experimental data for sterilization are obtained by using spores of Bacillus subtilis as samples. On the other hand we previously showed that the surface modification enhanced the gas barrier characteristics of plastic bottles. Comparing the implantation conditions for the sterilization experiment with those for the surface modification, we find that both sterilization and surface modification are simultaneously performed in a certain range of implantation conditions. This implies that the present bottling system for plastic vessels will be simplified and streamlined by excluding the toxic peroxide water that has been used in the traditional sterilization processes.

  13. Simultaneous Sterilization With Surface Modification Of Plastic Bottle By Plasma-Based Ion Implantation

    NASA Astrophysics Data System (ADS)

    Sakudo, N.; Ikenaga, N.; Ikeda, F.; Nakayama, Y.; Kishi, Y.; Yajima, Z.

    2011-01-01

    Dry sterilization of polymeric material is developed. The technique utilizes the plasma-based ion implantation which is same as for surface modification of polymers. Experimental data for sterilization are obtained by using spores of Bacillus subtilis as samples. On the other hand we previously showed that the surface modification enhanced the gas barrier characteristics of plastic bottles. Comparing the implantation conditions for the sterilization experiment with those for the surface modification, we find that both sterilization and surface modification are simultaneously performed in a certain range of implantation conditions. This implies that the present bottling system for plastic vessels will be simplified and streamlined by excluding the toxic peroxide water that has been used in the traditional sterilization processes.

  14. Plasma immersion ion implantation of boron for ribbon silicon solar cells

    NASA Astrophysics Data System (ADS)

    Derbouz, K.; Michel, T.; De Moro, F.; Spiegel, Y.; Torregrosa, F.; Belouet, C.; Slaoui, A.

    2013-09-01

    In this work, we report for the first time on the solar cell fabrication on n-type silicon RST (for Ribbon on Sacrificial Template) using plasma immersion ion implantation. The experiments were also carried out on FZ silicon as a reference. Boron was implanted at energies from 10 to 15 kV and doses from 1015 to 1016 cm-2, then activated by a thermal annealing in a conventional furnace at 900 and 950 °C for 30 min. The n+ region acting as a back surface field was achieved by phosphorus spin-coating. The frontside boron emitter was passivated either by applying a 10 nm deposited SiOX plasma-enhanced chemical vapor deposition (PECVD) or with a 10 nm grown thermal oxide. The anti-reflection coating layer formed a 60 nm thick SiNX layer. We show that energies less than 15 kV and doses around 5 × 1015 cm-2 are appropriate to achieve open circuit voltage higher than 590 mV and efficiency around 16.7% on FZ-Si. The photovoltaic performances on ribbon silicon are so far limited by the bulk quality of the material and by the quality of the junction through the presence of silicon carbide precipitates at the surface. Nevertheless, we demonstrate that plasma immersion ion implantation is very promising for solar cell fabrication on ultrathin silicon wafers such as ribbons.

  15. Optimization of a plasma immersion ion implantation process for shallow junctions in silicon

    SciTech Connect

    Ray, Ashok; Nori, Rajashree; Bhatt, Piyush; Lodha, Saurabh; Pinto, Richard Rao, Valipe Ramgopal; Jomard, François; Neumann-Spallart, Michael

    2014-11-01

    A plasma immersion ion implantation (PIII) process has been developed for realizing shallow doping profiles of phosphorus and boron in silicon using an in-house built dual chamber cluster tool. High Si etch rates observed in a 5% PH{sub 3} in H{sub 2} plasma have been ascribed to high concentration of H(α) radicals. Therefore, subsequent work was carried out with 5% PH{sub 3} in He, leading to much smaller etch rates. By optical emission spectroscopy, the radical species H(α), PH*{sub 2}, and PH* have been identified. The concentration of all three species increased with pressure. Also, ion concentrations increased with pressure as evidenced by Langmuir data, with a maximum occurring at 0.12 mbar. The duty cycle of pulsed DC bias has a significant bearing on both the implantation and the etching process as it controls the leakage of positive charge collected at the surface of the silicon wafer during pulse on-time generated primarily due to secondary electron emission. The P implant process was optimized for a duty cycle of 10% or less at a pressure of 0.12 mbar with implant times as low as 30 s. Secondary ion mass spectroscopy showed a P dopant depth of 145 nm after rapid thermal annealing (RTA) at 950 °C for 5 s, resulting in a sheet resistance of 77 Ω/◻. Si n{sup +}/p diodes fabricated with phosphorus implantation using optimized PIII and RTA conditions exhibit J{sub on}/J{sub off} > 10{sup 6} with an ideality factor of nearly 1.2. Using similar conditions, shallow doping profiles of B in silicon have also been realized.

  16. Quenching of surface-exciton emission from ZnO nanocombs by plasma immersion ion implantation

    SciTech Connect

    Yang, Y.; Tay, B. K.; Sun, X. W.; Sze, J. Y.; Han, Z. J.; Wang, J. X.; Zhang, X. H.; Li, Y. B.; Zhang, S.

    2007-08-13

    Surface modification of ZnO nanocombs was performed through a Ti plasma immersion ion implantation (PIII) with low bias voltages ranging from 0 to 5 kV to quench surface-originated exciton emission. The ion energy dependent surface modification on ZnO was investigated using transmission electron microscopy and temperature-dependent photoluminescence (PL). The surface exciton (SX) was clearly identified for the as-grown sample at 4.5 K, and complete quenching was observed for sample treated with 5 kV PIII due to surface state passivation. The SX related surface states were located within 5 nm in depth from the surface corresponding to the implantation depth of 5 kV PIII. Room-temperature PL enhancement of these surface-modified ZnO nanocombs was observed and discussed. The results show that PIII can become a viable technique for nanostructure surface passivation.

  17. Low-energy plasma immersion ion implantation to induce DNA transfer into bacterial E. coli

    NASA Astrophysics Data System (ADS)

    Sangwijit, K.; Yu, L. D.; Sarapirom, S.; Pitakrattananukool, S.; Anuntalabhochai, S.

    2015-12-01

    Plasma immersion ion implantation (PIII) at low energy was for the first time applied as a novel biotechnology to induce DNA transfer into bacterial cells. Argon or nitrogen PIII at low bias voltages of 2.5, 5 and 10 kV and fluences ranging from 1 × 1012 to 1 × 1017 ions/cm2 treated cells of Escherichia coli (E. coli). Subsequently, DNA transfer was operated by mixing the PIII-treated cells with DNA. Successes in PIII-induced DNA transfer were demonstrated by marker gene expressions. The induction of DNA transfer was ion-energy, fluence and DNA-size dependent. The DNA transferred in the cells was confirmed functioning. Mechanisms of the PIII-induced DNA transfer were investigated and discussed in terms of the E. coli cell envelope anatomy. Compared with conventional ion-beam-induced DNA transfer, PIII-induced DNA transfer was simpler with lower cost but higher efficiency.

  18. Etching and structural changes in nitrogen plasma immersion ion implanted polystyrene films

    NASA Astrophysics Data System (ADS)

    Gan, B. K.; Bilek, M. M. M.; Kondyurin, A.; Mizuno, K.; McKenzie, D. R.

    2006-06-01

    Plasma immersion ion implantation (PIII), with nitrogen ions of energy 20 keV in the fluence range of 5 × 1014-2 × 1016 ions cm-2, is used to modify 100 nm thin films of polystyrene on silicon wafer substrates. Ellipsometry is used to study changes in thickness with etching and changes in optical constants. Two distinctly different etch rates are observed as the polymer structure is modified. FTIR spectroscopy data reveals the structural changes, including changes in aromatic and aliphatic groups and oxidation and carbonisation processes, occurring in the polystyrene film as a function of the ion fluence. The transformation to a dense amorphous carbon-like material was observed to progress through an intermediate structural form containing a high concentration of Cdbnd C and Cdbnd O bonds.

  19. Fourth-generation plasma immersion ion implantation and deposition facility for hybrid surface modification layer fabrication

    SciTech Connect

    Wang Langping; Huang Lei; Xie Zhiwen; Wang Xiaofeng; Tang Baoyin

    2008-02-15

    The fourth-generation plasma immersion ion implantation and deposition (PIIID) facility for hybrid and batch treatment was built in our laboratory recently. Comparing with our previous PIIID facilities, several novel designs are utilized. Two multicathode pulsed cathodic arc plasma sources are fixed on the chamber wall symmetrically, which can increase the steady working time from 6 h (the single cathode source in our previous facilities) to about 18 h. Meanwhile, the inner diameter of the pulsed cathodic arc plasma source is increased from the previous 80 to 209 mm, thus, large area metal plasma can be obtained by the source. Instead of the simple sample holder in our previous facility, a complex revolution-rotation sample holder composed of 24 shafts, which can rotate around its axis and adjust its position through revolving around the center axis of the vacuum chamber, is fixed in the center of the vacuum chamber. In addition, one magnetron sputtering source is set on the chamber wall instead of the top cover in the previous facility. Because of the above characteristic, the PIIID hybrid process involving ion implantation, vacuum arc, and magnetron sputtering deposition can be acquired without breaking vacuum. In addition, the PIIID batch treatment of cylinderlike components can be finished by installing these components on the rotating shafts on the sample holder.

  20. Plasma Immersion Ion Implantation with Solid Targets for Space and Aerospace Applications

    SciTech Connect

    Oliveira, R. M.; Goncalves, J. A. N.; Ueda, M.; Silva, G.; Baba, K.

    2009-01-05

    This paper describes successful results obtained by a new type of plasma source, named as Vaporization of Solid Targets (VAST), for treatment of materials for space and aerospace applications, by means of plasma immersion ion implantation and deposition (PIII and D). Here, the solid element is vaporized in a high pressure glow discharge, being further ionized and implanted/deposited in a low pressure cycle, with the aid of an extra electrode. First experiments in VAST were run using lithium as the solid target. Samples of silicon and aluminum alloy (2024) were immersed into highly ionized lithium plasma, whose density was measured by a double Langmuir probe. Measurements performed with scanning electron microscopy (SEM) showed clear modification of the cross-sectioned treated silicon samples. X-ray photoelectron spectroscopy (XPS) analysis revealed that lithium was implanted/deposited into/onto the surface of the silicon. Implantation depth profiles may vary according to the condition of operation of VAST. One direct application of this treatment concerns the protection against radiation damage for silicon solar cells. For the case of the aluminum alloy, X-ray diffraction analysis indicated the appearance of prominent new peaks. Surface modification of A12024 by lithium implantation/deposition can lower the coefficient of friction and improve the resistance to fatigue of this alloy. Recently, cadmium was vaporized and ionized in VAST. The main benefit of this element is associated with the improvement of corrosion resistance of metallic substrates. Besides lithium and cadmium, VAST allows to performing PIII and D with other species, leading to the modification of the near-surface of materials for distinct purposes, including applications in the space and aerospace areas.

  1. Surface, electrical and mechanical modifications of PMMA after implantation with laser produced iron plasma ions

    NASA Astrophysics Data System (ADS)

    Ahmed, Qazi Salman; Bashir, Shazia; Jalil, Sohail Abdul; Shabbir, Muhammad Kaif; Mahmood, Khaliq; Akram, Mahreen; Khalid, Ayesha; Yaseen, Nazish; Arshad, Atiqa

    2016-07-01

    Laser Produced Plasma (LPP) was employed as an ion source for the modifications in surface, electrical and mechanical properties of poly methyl (methacrylate) PMMA. For this purpose Nd:YAG laser (532 nm, 6 ns, 10 Hz) at a fluence of 12.7 J/cm2 was employed to generate Fe plasma. The fluence and energy measurements of laser produced Fe plasma ions were carried out by employing Thomson Parabola Technique in the presence of magnetic field strength of 0.5 T, using CR-39 as Solid State Nuclear Track Detector (SSNTD). It has been observed that ion fluence ejecting from ablated plasma was maximum at an angle of 5° with respect to the normal to the Fe target surface. PMMA substrates were irradiated with Fe ions of constant energy of 0.85 MeV at various ion fluences ranging from 3.8 × 106 ions/cm2 to 1.8 × 108 ions/cm2 controlled by varying laser pulses from 3000 to 7000. Optical microscope and Scanning Electron Microscope (SEM) were utilized for the analysis of surface features of irradiated PMMA. Results depicted the formation of chain scission, crosslinking, dendrites and star like structures. To explore the electrical behavior, four probe method was employed. The electrical conductivity of ion irradiated PMMA was increased with increasing ion fluence. The surface hardness was measured by shore D hardness tester and results showed the monotonous increment in surface hardness with increasing ion fluence. The increasing trend of surface hardness and electrical conductivity with increasing Fe ion fluence has been well correlated with the surface morphology of ion implanted PMMA. The temperature rise of PMMA surface due to Fe ion irradiation is evaluated analytically and comes out to be in the range of 1.72 × 104 to 1.82 × 104 K. The values of total Linear Energy Transfer (LET) or stopping power of 0.8 MeV Fe ions in PMMA is 61.8 eV/Å and their range is 1.34 μm evaluated by SRIM simulation.

  2. Improvement on corrosion resistance of NiTi orthopedic materials by carbon plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    Poon, Ray W. Y.; Ho, Joan P. Y.; Luk, Camille M. Y.; Liu, Xuanyong; Chung, Jonathan C. Y.; Chu, Paul K.; Yeung, Kelvin W. K.; Lu, William W.; Cheung, Kenneth M. C.

    2006-01-01

    Nickel-titanium shape memory alloys (NiTi) have potential applications as orthopedic implants because of their unique super-elastic properties and shape memory effects. However, the problem of out-diffusion of harmful Ni ions from the alloys during prolonged use inside a human body must be overcome before they can be widely used in orthopedic implants. In this work, we enhance the corrosion resistance of NiTi using carbon plasma immersion ion implantation and deposition (PIII&D). Our corrosion and simulated body fluid tests indicate that either an ion-mixed amorphous carbon coating fabricated by PIII&D or direct carbon PIII can drastically improve the corrosion resistance and block the out-diffusion of Ni from the materials. Results of atomic force microscopy (AFM) indicate that both C2H2-PIII&D and C2H2-PIII do not roughen the original flat surface to an extent that can lead to degradation in corrosion resistance.

  3. Two-dimensional particle-in-cell plasma source ion implantation of a prolate spheroid target

    NASA Astrophysics Data System (ADS)

    Liu, Cheng-Sen; Han, Hong-Ying; Peng, Xiao-Qing; Chang, Ye; Wang, De-Zhen

    2010-03-01

    A two-dimensional particle-in-cell simulation is used to study the time-dependent evolution of the sheath surrounding a prolate spheroid target during a high voltage pulse in plasma source ion implantation. Our study shows that the potential contour lines pack more closely in the plasma sheath near the vertex of the major axis, i.e. where a thinner sheath is formed, and a non-uniform total ion dose distribution is incident along the surface of the prolate spheroid target due to the focusing of ions by the potential structure. Ion focusing takes place not only at the vertex of the major axis, where dense potential contour lines exist, but also at the vertex of the minor axis, where sparse contour lines exist. This results in two peaks of the received ion dose, locating at the vertices of the major and minor axes of the prolate spheroid target, and an ion dose valley, staying always between the vertices, rather than at the vertex of the minor axis.

  4. Effect of charge imbalance parameter on LEKW in ion-implanted quantum semiconductor plasmas

    SciTech Connect

    Chaudhary, Sandhya; Yadav, Nishchhal; Ghosh, S.

    2015-07-31

    In this study we present an analytical investigation on the propagation characteristics of electro-kinetic wave modified through quantum correction term and charge imbalance parameter using quantum hydrodynamic model for an ion-implanted semiconductor plasma. The dispersion relation has been analyzed in two distinct velocity regimes. We found that as the number of negative charges resides on the colloids increases, their role become increasing effective. The present investigation is important for understanding of wave and instability phenomena and can be put to various interesting applications.

  5. Experimental and theoretical investigation of the effects of sample size on copper plasma immersion ion implantation into polyethylene

    SciTech Connect

    Zhang Wei; Wu Zhengwei; Liu Chenglong; Pu Shihao; Zhang Wenjun; Chu, Paul K.

    2007-06-01

    Polymers are frequently surface modified to achieve special surface characteristics such as antibacterial properties, wear resistance, antioxidation, and good appearance. The application of metal plasma immersion ion implantation (PIII) to polymers is of practical interest as PIII offers advantages such as low costs, small instrument footprint, large area, and conformal processing capability. However, the insulating nature of most polymers usually leads to nonuniform plasma implantation and the surface properties can be adversely impacted. Copper is an antibacterial element and our previous experiments have shown that proper introduction of Cu by plasma implantation can significantly enhance the long-term antibacterial properties of polymers. However, lateral variations in the implant fluence and implantation depth across the insulating substrate can lead to inconsistent and irreproducible antibacterial effects. In this work, the influence of the sample size on the chemical and physical properties of copper plasma-implanted polyethylene is studied experimentally and theoretically using Poisson's equation and plasma sheath theory. Our results indicate that the sample size affects the implant depth profiles. For a large sample, more deposition occurs in the center region, whereas the implantation to deposition ratio shows less variation across the smaller sample. However, the Cu elemental chemical state is not affected by this variation. Our theoretical study discloses that nonuniform metal implantation mainly results from the laterally different surface potential on the insulating materials due to surface charge buildup and more effective charge transfer near the edge of the sample.

  6. Modification of diamond-like carbon films by nitrogen incorporation via plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    Flege, S.; Hatada, R.; Hoefling, M.; Hanauer, A.; Abel, A.; Baba, K.; Ensinger, W.

    2015-12-01

    The addition of nitrogen to diamond-like carbon films affects properties such as the inner stress of the film, the conductivity, biocompatibility and wettability. The nitrogen content is limited, though, and the maximum concentration depends on the preparation method. Here, plasma immersion ion implantation was used for the deposition of the films, without the use of a separate plasma source, i.e. the plasma was generated by a high voltage applied to the samples. The plasma gas consisted of a mixture of C2H4 and N2, the substrates were silicon and glass. By changing the experimental parameters (high voltage, pulse length and repetition rate and gas flow ratio) layers with different N content were prepared. Additionally, some samples were prepared using a DC voltage. The nitrogen content and bonding was investigated with SIMS, AES, XPS, FTIR and Raman spectroscopy. Their influence on the electrical resistivity of the films was investigated. Depending on the preparation conditions different nitrogen contents were realized with maximum contents around 11 at.%. Those values were compared with the nitrogen concentration that can be achieved by implantation of nitrogen into a DLC film.

  7. Plasma analysis for the plasma immersion ion implantation processing by a PIC-MCC simulation

    NASA Astrophysics Data System (ADS)

    Miyagawa, Y.; Ikeyama, M.; Miyagawa, S.; Tanaka, M.; Nakadate, H.

    2007-07-01

    In order to analyze the plasma behavior during PIII processing, a computer simulation has been carried out using the simulation software "PEGASUS". The software uses a Particle-in-Cell (PIC) method for the movement of charged particles in the electromagnetic field and a Monte Carlo method for collisions of ions, electrons, and neutrals in the plasma and also a Monte Carlo method to analyze the background gas behavior for a low density gas system. This approach is based on the weighting collision simulation scheme allowing for disparate number densities of different species. The spatial distributions of potential and densities of ions, electrons and radicals in the coating system were calculated together with the flux of ions and electrons on the surface of the object. The gas pressure was 0.01 to 50 Pa and a negative and/or a positive pulse voltage ( V=0.1 to 20 kV) was applied to the object. The calculation is fully self-consistent. A two-dimensional Cartesian and a cylindrical coordinate system were used. The effects of gas pressure, applied voltage, and secondary electron emission coefficient by ion impact ( γ) on the sheath thickness, the spatial distribution of densities of electron, ion, and neutral atoms, the ion flux and its spatial distribution, etc. were studied for PIII processing of a trench shaped object, inner wall of a pipe and a PET bottle.

  8. Design of a Sputtering Cathode for Binary Alloys Deposition in Plasma Source Ion Implantation

    NASA Astrophysics Data System (ADS)

    Malik, Shamim; Breun, Robert; Fetherston, Paul; Sridharan, Kumar; Conrad, John

    1996-10-01

    In Plasma Source Ion Implantation (PSII)1,2 a target is immersed in a plasma and pulse biased to a high negative voltage ( 50kV). Ions are injected into the near surface of target material under the influence of the electric field. In order to produce Ion Assisted Deposition (IAD) films in PSII, materials of interest are sputtered using DC or RF bias and up to 20 kV negative bias pulses are applied while depositing films. We have performed deposition of titanium aluminum nitride (TiAlN) films using a perforated aluminum cathode stacked on a planar titanium cathode. Design characteristics of the sputtering cathodes as a function of the ratio of material area, plasma parameters, and stoichiometric deposition rates have been evaluated. Analysis of these results will be presented. * This work was supported by NSF. No DMI-9528746, US-Army No. DAALH 03-94-G-0283 1 J. R. Conrad, et al. J. Appl. Phys.62, 4951 (1987). 2 M.M. Shamim et al., J. Vac. Sci. Technol. 12, 843 (1994).

  9. Process Development for Deposition of Chromium Oxide Using Plasma Source Ion Implantation

    NASA Astrophysics Data System (ADS)

    Malik, Shamim

    1997-10-01

    In Plasma Source Ion Implantation (PSII)1,2 a substrate is immersed in a plasma and pulse biased to a high negative voltage ( 50kV). Ions are injected into the near surface of substrate material under the influence of the electric field. In order to produce Energetic Ion Assisted Mixing And Deposition (EIAMAD) of films in PSII, materials of interest are sputtered (using DC and RF power to the sputter target) onto a substrate and simultaneously negative bias pulses of upto 15 kV are applied to the substrate itself. We have performed deposition of chromium oxide inside hollow cylinder and on planar geometry. Chromium oxide forms various oxides with different colors and atomic composition. The process characteristics, plasma parameters, and deposition rates have been evaluated. Analysis of these results will be presented. * This work was supported by NSF. No DMI-9528746, US-Army No. DAALH 03-94-G-0283 1 J. R. Conrad, et al. J. Appl. Phys.62, 4951 (1987). 2 M.M. Shamim et al., J. Vac. Sci. Technol. 12, 843 (1994).

  10. Oxygen plasma immersion ion implantation treatment to enhance data retention of tungsten nanocrystal nonvolatile memory

    SciTech Connect

    Wang, Jer-Chyi Chang, Wei-Cheng; Lai, Chao-Sung; Chang, Li-Chun; Ai, Chi-Fong; Tsai, Wen-Fa

    2014-03-15

    Data retention characteristics of tungsten nanocrystal (W-NC) memory devices using an oxygen plasma immersion ion implantation (PIII) treatment are investigated. With an increase of oxygen PIII bias voltage and treatment time, the capacitance–voltage hysteresis memory window is increased but the data retention characteristics become degraded. High-resolution transmission electron microscopy images show that this poor data retention is a result of plasma damage on the tunneling oxide layer, which can be prevented by lowering the bias voltage to 7 kV. In addition, by using the elevated temperature retention measurement technique, the effective charge trapping level of the WO{sub 3} film surrounding the W-NCs can be extracted. This measurement reveals that a higher oxygen PIII bias voltage and treatment time induces more shallow traps within the WO{sub 3} film, degrading the retention behavior of the W-NC memory.

  11. DBR laser with nondynamic plasma grating formed by focused ion beam implanted dopants

    NASA Technical Reports Server (NTRS)

    Boenke, Myra M.; Wu, M. C.; Wang, Shyh; Clark, William M., Jr.; Stevens, Eugene H.

    1989-01-01

    A static plasma grating has been demonstrated experimentally (Wu et al., 1988) in a large-optical-cavity focused-ion-beam-distributed-Bragg-reflector (FIB-DBR) GaAlAs/GaAs laser diode. The grating is formed by implanting stripes of dopants with a focused ion beam. The dopants ionize to form periodic fluctuations in the carrier concentration which, through the Kramers-Kronig relations, form an index grating. A model of the grating strength for optimizaton of the laser design is developed and presented. The computed results show that the coupling coefficient k can be increased by more than an order of magnitude over the 15/cm experimentally. Therefore, FIB-DBR or FIB-distributed-feedback (DFB) lasers with performance comparable to that of conventional DBR (or DFB) lasers can be expected.

  12. Ti-PS nanocomposites by plasma immersion ion implantation and deposition

    NASA Astrophysics Data System (ADS)

    Han, Z. J.; Tay, B. K.

    2009-02-01

    We synthesize Ti-PS nanocomposites by plasma immersion ion implantation and deposition (PIII&D) technique. Ti nanoparticles at size of 5-15 nm are found in PS matrix. We propose the formation of Ti nanoparticles as a result of the combined effect of ion implantation and ion condensation in PIII&D process. X-ray photoelectron spectroscopy measurements reveal that Ti atoms have three different chemical states, metal, oxide and carbide. While surface Ti atoms are oxidized, embedded Ti atoms keep their metallic states by surrounding PS matrix. We characterize optical absorbance of Ti-PS nanocomposites by UV-VIS measurements. An adsorption peak due to the excitation of localized surface plasmon is found at wavelength 337.5 nm and the fractal nature of Ti-PS nanocomposites broaden absorption wavelength from UV to infrared. In addition, we use a protein assay to measure protein immobilization. It is found that the amount of protein immobilized on Ti-PS nanocomposites is almost twice than that on pristine PS. The enhancement mechanisms are attributed to the increased surface roughness as well as covalent linkages between protein molecules and functional groups on the surface of Ti-PS nanocomposites.

  13. Mechanical Properties of Plasma Immersion Ion Implanted PEEK for Bioactivation of Medical Devices.

    PubMed

    Wakelin, Edgar A; Fathi, Ali; Kracica, Masturina; Yeo, Giselle C; Wise, Steven G; Weiss, Anthony S; McCulloch, Dougal G; Dehghani, Fariba; Mckenzie, David R; Bilek, Marcela M M

    2015-10-21

    Plasma immersion ion implantation (PIII) is used to modify the surface properties of polyether ether ketone for biomedical applications. Modifications to the mechanical and chemical properties are characterized as a function of ion fluence (treatment time) to determine the suitability of the treated surfaces for biological applications. Young's modulus and elastic recovery were found to increase with respect to treatment time at the surface from 4.4 to 5.2 MPa and from 0.49 to 0.68, respectively. The mechanical properties varied continuously with depth, forming a graded layer where the mechanical properties returned to untreated values deep within the layer. The treated surface layer exhibited cracking under cyclical loads, associated with an increased modulus due to dehydrogenation and cross-linking; however, it did not show any sign of delamination, indicating that the modified layer is well integrated with the substrate, a critical factor for bioactive surface coatings. The oxygen concentration remained unchanged at the surface; however, in contrast to ion implanted polymers containing only carbon and hydrogen, the oxygen concentration within the treated layer was found to decrease. This effect is attributed to UV exposure and suggests that PIII treatments can modify the surface to far greater depths than previously reported. Protein immobilization on PIII treated surfaces was found to be independent of treatment time, indicating that the surface mechanical properties can be tuned for specific applications without affecting the protein coverage. Our findings on the mechanical properties demonstrate such treatments render PEEK well suited for use in orthopedic implantable devices. PMID:26366514

  14. Bio-functionalisation of polyether ether ketone using plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    Wakelin, Edgar; Yeo, Giselle; Kondyurin, Alexey; Davies, Michael; McKenzie, David; Weiss, Anthony; Bilek, Marcela

    2015-12-01

    Plasma immersion ion implantation (PIII) is used here to improve the surface bioactivity of polyether ether ketone (PEEK) by modifying the chemical and mechanical properties and by introducing radicals. Modifications to the chemical and mechanical properties are characterised as a function of ion fluence (proportional to treatment time) to determine the suitability of the treated surfaces for biological applications. Radical generation increases with treatment time, where treatments greater than 400 seconds result in a high concentration of long-lived radicals. Radical reactions are responsible for oxidation of the surface, resulting in a permanent increase in the polar surface energy. The nano-scale reduced modulus was found to increase with treatment time at the surface from 4.4 to 5.2 GPa. The macromolecular Young's modulus was also found to increase, but by an amount corresponding to the volume fraction of the ion implanted region. The treated surface layer exhibited cracking under cyclical loads, associated with an increased modulus due to dehydrogenation and crosslinking, however it did not show any sign of delamination, indicating that the modified layer is well integrated with the substrate - a critical factor for bioactive surface coatings to be used in-vivo. Protein immobilisation on the PIII treated surfaces was found to saturate after 240 seconds of treatment, indicating that there is room to tune surface mechanical properties for specific applications without affecting the protein coverage. Our findings indicate that the modification of the chemical and mechanical properties by PIII treatments as well as the introduction of radicals render PEEK well suited for use in orthopaedic implantable devices.

  15. Boron Ion Implantation into Silicon by Use of the Boron Vacuum-Arc Plasma Generator

    SciTech Connect

    Williams, J. M.; Klepper, C. C.; Chivers, D. J.; Hazelton, R. C.; Moschella, J. J.; Keitz, M. D.

    2006-11-13

    This paper continues with presentation of experimental work pertaining to use of the boron vacuum arc (a.k.a. cathodic arc) plasma generator for boron doping in semiconductor silicon, particularly with a view to the problems associated with shallow junction doping. Progress includes development of an excellent and novel macroparticle filter and subsequent ion implantations. An important perceived issue for vacuum arc generators is the production of copious macroparticles from cathode material. This issue is more important for cathodes of materials such as carbon or boron, for which the particles are not molten or plastic, but instead are elastic, and tend to recoil from baffles used in particle filters. The present design starts with two vanes of special orientation, so as to back reflect the particles, while steering the plasma between the vanes by use of high countercurrents in the vanes. Secondly, behind and surrounding the vanes is a complex system of baffles that has been designed by a computer-based strategy to ultimately trap the particles for multiple bounces. The statistical transmittance of particles is less than 5 per coulomb of boron ions transmitted at a position just a few centimeters outside the filter. This value appears adequate for the silicon wafer application, but improvement is easily visualized as wafers will be situated much further away when they are treated in systems. A total of 11 silicon samples, comprising an area of 250 cm2, have been implanted. Particles were not detected. Sample biases ranged from 60 to 500 V. Boron doses ranged from 5 x 1014 to 5 x 1015/cm2. Exposure times ranged from 20 to 200 ms for average transmitted boron current values of about 125 mA. SIMS concentration profiles from crystalline material are presented. The results appear broadly favorable in relation to competitive techniques and will be discussed. It is concluded that doubly charged boron ions are not present in the plume.

  16. The generation, detection and measurement of laser-induced carbon plasma ions and their implantation effects on brass substrate

    NASA Astrophysics Data System (ADS)

    Ahmad, Shahbaz; Bashir, Shazia; Shahid Rafique, M.; Yousaf, Daniel; Ahmad, Riaz

    2016-05-01

    The generation, detection and measurement of laser-induced carbon plasma ions and their implantation effects on brass substrate have been investigated. Thomson parabola technique was employed to measure the energy and flux of carbon ions. The magnetic field of strength 80 mT was applied on the graphite plasma plume to provide an appropriate trajectory to the generated ions. The energy of carbon ions is 678 KeV for laser fluence of 5.1 J/cm2 which was kept constant for all exposures. The flux of ions varies from 32 × 1011 to 72 × 1014 ions/cm2 for varying numbers of laser pulses from 3000 to 12,000. In order to explore the ion irradiation effects on brass, four brass substrates were irradiated by carbon ions of different flux. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) are used to analyze the surface morphology and crystallographic structure of ion-implanted brass, respectively. SEM analysis reveals the formation and growth of nano-/micro-sized cavities, pores and pits for the various ion flux for varying numbers of laser pulses from 3000 to 12,000. By increasing ion flux by increasing the number of pulses up to 9000 shots, the dendritic structures initiate to grow along with cavities and pores. At the maximum ion flux for 12,000 shots, the unequiaxed dendritic structures become distinct and the distance between the dendrites is decreased, whereas cavities, pores and pits are completely finished. The XRD analysis reveals that a new phase of ZnC (0012) is formed in the brass substrate after ion implantation. Universal tensile testing machine and Vickers microhardness tester are used to explore the yield stress, ultimate tensile strength and microhardness of ion-implanted brass substrate. The mechanical properties monotonically increase by increasing the ion flux. Variations in mechanical properties are correlated with surface and structural modifications of brass.

  17. One-Step, Non-Contact Pattern Transfer by Direct-Current Plasma Immersion Ion Implantation

    NASA Astrophysics Data System (ADS)

    Kwok, Dixon T. K.; Chu, Paul K.

    2009-10-01

    A one-step non-contact pattern transferring method is demonstrated. Clear non-identical images with well-defined boundaries are simultaneously transferred to a substrate by -15 kV plasma immersion ion implantation through a patterned metal mask. The metal mask is 6 cm away from the substrate and no lens system is necessary for the pattern transfer. To avoid diversification of compensating ions, the electric field must be smoothed out by the fine mesh overlapping on top of the metal mask. Complex patterns with micrometer size line-widths can be transferred onto a silicon wafer by placing the metal masks 4 mm away from the wafer. Scanning electron microscopy (SEM) discloses that by negatively biasing the metal mask, ions coming from a hole with a diameter of 200 micrometers in the mask can be confined to a smaller region of 100 micrometers. The ion focusing effect is confirmed by two-dimensional multiple grid particle-in-cell (PIC) simulation.

  18. Adherent diamond like carbon coatings on metals via plasma source ion implantation

    SciTech Connect

    Walter, K.C.; Nastasi, M.; Munson, C.P.

    1996-12-01

    Various techniques are currently used to produce diamond-like carbon (DLC) coatings on various materials. Many of these techniques use metallic interlayers, such as Ti or Si, to improve the adhesion of a DLC coating to a ferrous substrate. An alternative processing route would be to use plasma source ion implantation (PSII) to create a carbon composition gradient in the surface of the ferrous material to serve as the interface for a DLC coating. The need for interlayer deposition is eliminated by using a such a graded interfaces PSII approach has been used to form adherent DLC coatings on magnesium, aluminum, silicon, titanium, chromium, brass, nickel, and tungsten. A PSII process tailored to create a graded interface allows deposition of adherent DLC coatings even on metals that exhibit a positive heat of formation with carbon, such as magnesium, iron, brass and nickel.

  19. New method of plasma immersion ion implantation and also deposition of industrial components using tubular fixture and plasma generated inside the tube by high voltage pulses

    NASA Astrophysics Data System (ADS)

    Ueda, Mario; Silva, Ataide Ribeiro da; Pillaca, Elver J. D. M.; Mariano, Samantha F. M.; Oliveira, Rogério de Moraes; Rossi, José Osvaldo; Lepienski, Carlos Mauricio; Pichon, Luc

    2016-01-01

    A new method of Plasma Immersion Ion Implantation (PIII) and deposition (PIII and D) for treating industrial components in the batch mode has been developed. A metal tubular fixture is used to allocate the components inside, around, and along the tube, exposing only the parts of each component that are to be ion implanted to the plasma. Hollow cathode-like plasma is generated only inside the tube filled with the desired gas, by applying high negative voltage pulses to the hollow cylindrical fixture which is insulated from the vacuum chamber walls. This is a very convenient method of batch processing of industrial parts by ion implantation, in which a large number of small to medium sized components can be treated by PIII and PIII and D, very quickly, efficiently, and also at low cost.

  20. A hybrid model for simulation of secondary electron emission in plasma immersion ion implantation under different pulse rise time

    SciTech Connect

    Navab Safa, N. Ghomi, H.

    2015-02-15

    A hybrid fluid Particle in Cell–Monte Carlo Collision (PiC–MCC) model is presented to study the effect of secondary electron emission on the plasma immersion ion implantation process under different pulse rise time. The model describes the temporal evolution of various parameters of plasma such as ion density, ion velocity, secondary electron density, and secondary electron current for different rise times. A 3D–3 V PiC–MCC model is developed to simulate the secondary electrons which are emitted from the sample surface while the plasma ions and electrons are treated using a 1D fluid model. The simulation results indicate that the secondary electron density and secondary electron current increase as the rise time decreases. The main differences between the results for different rise times are found during the initial phase of the pulse. The results are explained through studying the fundamental parameters of plasma.

  1. Surface modification of biomaterials using plasma immersion ion implantation and deposition

    PubMed Central

    Lu, Tao; Qiao, Yuqin; Liu, Xuanyong

    2012-01-01

    Although remarkable progress has been made on biomaterial research, the ideal biomaterial that satisfies all the technical requirements and biological functions is not available up to now. Surface modification seems to be a more economic and efficient way to adjust existing conventional biomaterials to meet the current and ever-evolving clinical needs. From an industrial perspective, plasma immersion ion implantation and deposition (PIII&D) is an attractive method for biomaterials owing to its capability of treating objects with irregular shapes, as well as the control of coating composition. It is well acknowledged that the physico-chemical characteristics of biomaterials are the decisive factors greatly affecting the biological responses of biomaterials including bioactivity, haemocompatibility and antibacterial activity. Here, we mainly review the recent advances in surface modification of biomaterials via PIII&D technology, especially titanium alloys and polymers used for orthopaedic, dental and cardiovascular implants. Moreover, the variations of biological performances depending on the physico-chemical properties of modified biomaterials will be discussed. PMID:23741609

  2. Determination of Ni Release in NiTi SMA with Surface Modification by Nitrogen Plasma Immersion Ion Implantation

    NASA Astrophysics Data System (ADS)

    de Camargo, Eliene Nogueira; Oliveira Lobo, Anderson; Silva, Maria Margareth Da; Ueda, Mario; Garcia, Edivaldo Egea; Pichon, Luc; Reuther, Helfried; Otubo, Jorge

    2011-07-01

    NiTi SMA is a promising material in the biomedical area due to its mechanical properties and biocompatibility. However, the nickel in the alloy may cause allergic and toxic reactions and thus limiting its applications. It was evaluated the influence of surface modification in NiTi SMA by nitrogen plasma immersion ion implantation (varying temperatures, and exposure time as follows: <250 °C/2 h, 290 °C/2 h, and 560 °C/1 h) in the amount of nickel released using immersion test in simulated body fluid. The depth of the nitrogen implanted layer increased as the implantation temperature increased resulting in the decrease of nickel release. The sample implanted in high implantation temperature presented 35% of nickel release reduction compared to reference sample.

  3. Plasma-based ion implantation: a valuable technology for the elaboration of innovative materials and nanostructured thin films

    NASA Astrophysics Data System (ADS)

    Vempaire, D.; Pelletier, J.; Lacoste, A.; Béchu, S.; Sirou, J.; Miraglia, S.; Fruchart, D.

    2005-05-01

    Plasma-based ion implantation (PBII), invented in 1987, can now be considered as a mature technology for thin film modification. After a brief recapitulation of the principle and physics of PBII, its advantages and disadvantages, as compared to conventional ion beam implantation, are listed and discussed. The elaboration of thin films and the modification of their functional properties by PBII have already been achieved in many fields, such as microelectronics (plasma doping/PLAD), biomaterials (surgical implants, bio- and blood-compatible materials), plastics (grafting, surface adhesion) and metallurgy (hard coatings, tribology), to name a few. The major advantages of PBII processing lie, on the one hand, in its flexibility in terms of ion implantation energy (from 0 to 100 keV) and operating conditions (plasma density, collisional or non-collisional ion sheath), and, on the other hand, in the easy transferrability of processes from the laboratory to industry. The possibility of modifying the composition and physical nature of the films, or of drastically changing their physical properties over several orders of magnitude makes this technology very attractive for the elaboration of innovative materials, including metastable materials, and the realization of micro- or nanostructures. A review of the state of the art in these domains is presented and illustrated through a few selected examples. The perspectives opened up by PBII processing, as well as its limitations, are discussed.

  4. Performance improvement of gadolinium oxide resistive random access memory treated by hydrogen plasma immersion ion implantation

    SciTech Connect

    Wang, Jer-Chyi Hsu, Chih-Hsien; Ye, Yu-Ren; Ai, Chi-Fong; Tsai, Wen-Fa

    2014-03-15

    Characteristics improvement of gadolinium oxide (Gd{sub x}O{sub y}) resistive random access memories (RRAMs) treated by hydrogen plasma immersion ion implantation (PIII) was investigated. With the hydrogen PIII treatment, the Gd{sub x}O{sub y} RRAMs exhibited low set/reset voltages and a high resistance ratio, which were attributed to the enhanced movement of oxygen ions within the Gd{sub x}O{sub y} films and the increased Schottky barrier height at Pt/Gd{sub x}O{sub y} interface, respectively. The resistive switching mechanism of Gd{sub x}O{sub y} RRAMs was dominated by Schottky emission, as proved by the area dependence of the resistance in the low resistance state. After the hydrogen PIII treatment, a retention time of more than 10{sup 4} s was achieved at an elevated measurement temperature. In addition, a stable cycling endurance with the resistance ratio of more than three orders of magnitude of the Gd{sub x}O{sub y} RRAMs can be obtained.

  5. Structure and tribological performance by nitrogen and oxygen plasma based ion implantation on Ti6Al4V alloy

    NASA Astrophysics Data System (ADS)

    Feng, Xingguo; Sun, Mingren; Ma, Xinxin; Tang, Guangze

    2011-09-01

    Ti6Al4V alloy was implanted with nitrogen-oxygen mixture by using plasma based ion implantation (PBII) at pulsed voltage -10, -30 and -50 kV. The implantation was up to 6 × 1017 ions/cm2 fluence. The changes in chemical composition, structure and hardness of the modified surfaces were studied by XPS and nanoindentation measurements. According to XPS, it was found that the modified layer was predominantly TiO2, but contained small amounts of TiO, Ti2O3, TiN and Al2O3 between the outmost layer and metallic substrate. Surface hardness and wear resistance of the samples increased significantly after PBII treatment, the wear rate of the sample implanted N2-O2 mixture at -50 kV decreased eight times than the untreated one. The sample implanted N2-O2 mixture showed better wear resistance than that of the sample only implanted oxygen at - 50 kV. The wear mechanism of untreated sample was abrasive-dominated and adhesive, and the wear scar of the sample implanted at -50 kV was characterized by abrasive wear-type ploughing.

  6. Physics of Plasma-Based Ion Implantation&Deposition (PBIID)and High Power Impulse Magnetron Sputtering (HIPIMS): A Comparison

    SciTech Connect

    Anders, Andre

    2007-08-28

    The emerging technology of High Power Impulse MagnetronSputtering (HIPIMS) has much in common with the more establishedtechnology of Plasma Based Ion Implantation&Deposition (PBIID):both use pulsed plasmas, the pulsed sheath periodically evolves andcollapses, the plasma-sheath system interacts with the pulse-drivingpower supply, the plasma parameters are affected by the power dissipated,surface atoms are sputtered and secondary electrons are emitted, etc.Therefore, both fields of science and technology could learn from eachother, which has not been fully explored. On the other hand, there aresignificant differences, too. Most importantly, the operation of HIPIMSheavilyrelies on the presence of a strong magnetic field, confiningelectrons and causing their ExB drift, which is closed for typicalmagnetron configurations. Second, at the high peak power levels used forHIPIMS, 1 kW/cm2 or greater averaged over the target area, the sputteredmaterial greatly affects plasma generation. For PBIID, in contrast,plasma generation and ion processing of the surface (ion implantation,etching, and deposition) are considered rela-tively independentprocesses. Third, secondary electron emission is generally considered anuisance for PBIID, especially at high voltages, whereas it is a criticalingredient to the operation of HIPIMS. Fourth, the voltages in PBIID areoften higher than in HIPIMS. For the first three reasons listed above,modelling of PBIID seems to be easier and could give some guidance forfuture HIPIMS models, which, clearly, will be more involved.

  7. 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.

  8. Cluster of differentiation antibody microarrays on plasma immersion ion implanted polycarbonate.

    PubMed

    Kosobrodova, E; Mohamed, A; Su, Y; Kondyurin, A; dos Remedios, C G; McKenzie, D R; Bilek, M M M

    2014-02-01

    Plasma immersion ion implantation (PIII) modifies the surface properties of polymers, enabling them to covalently immobilize proteins without using linker chemistry. We describe the use of PIII treated polycarbonate (PC) slides as a novel platform for producing microarrays of cluster of differentiation (CD) antibodies. We compare their performance to identical antibody microarrays printed on nitrocellulose-coated glass slides that are currently the industry standard. Populations of leukocytes are applied to the CD microarrays and unbound cells are removed revealing patterns of differentially immobilized cells that are detected in a simple label-free approach by scanning the slides with visible light. Intra-slide and inter-slide reproducibility, densities of bound cells, and limits of detection were determined. Compared to the nitrocellulose-coated glass slides, PIII treated PC slides have a lower background noise, better sensitivity, and comparable or better reproducibility. They require three-fold lower antibody concentrations to yield equivalent signal strength, resulting in significant reductions in production cost. The improved transparency of PIII treated PC in the near-UV and visible wavelengths combined with superior immobilization of biomolecules makes them an attractive platform for a wide range of microarray applications.

  9. Enhanced retained dose uniformity in NiTi spinal correction rod treated by three-dimensional mesh-assisted nitrogen plasma immersion ion implantation

    SciTech Connect

    Lu, Q. Y.; Hu, T.; Kwok, Dixon T. K.; Chu, Paul K.

    2010-05-15

    Owing to the nonconformal plasma sheath in plasma immersion ion implantation of a rod sample, the retained dose can vary significantly. The authors propose to improve the implant uniformity by introducing a metal mesh. The depth profiles obtained with and without the mesh are compared and the implantation temperature at various locations is evaluated indirectly by differential scanning calorimeter. Our results reveal that by using the metal mesh, the retained dose uniformity along the length is greatly improved and the effects of the implantation temperature on the localized mechanical properties of the implanted NiTi shape memory alloy rod are nearly negligible.

  10. Pulsed source ion implantation apparatus and method

    DOEpatents

    Leung, K.N.

    1996-09-24

    A new pulsed plasma-immersion ion-implantation apparatus that implants ions in large irregularly shaped objects to controllable depth without overheating the target, minimizing voltage breakdown, and using a constant electrical bias applied to the target. Instead of pulsing the voltage applied to the target, the plasma source, for example a tungsten filament or a RF antenna, is pulsed. Both electrically conducting and insulating targets can be implanted. 16 figs.

  11. Pulsed source ion implantation apparatus and method

    DOEpatents

    Leung, Ka-Ngo

    1996-01-01

    A new pulsed plasma-immersion ion-implantation apparatus that implants ions in large irregularly shaped objects to controllable depth without overheating the target, minimizing voltage breakdown, and using a constant electrical bias applied to the target. Instead of pulsing the voltage applied to the target, the plasma source, for example a tungsten filament or a RF antenna, is pulsed. Both electrically conducting and insulating targets can be implanted.

  12. Evolution of local texture and grain morphology in metal plasma immersion ion implantation and deposition of TiN

    SciTech Connect

    Manova, D.; Attenberger, W.; Maendl, S.; Stritzker, B.; Rauschenbach, B.

    2004-11-01

    The local crystallographic texture and grain orientation was investigated for deposition of TiN by metal plasma immersion ion implantation and deposition (MePIIID) at different ion incident angles across one sample. A very good match between the tilt of (fiber) texture and the tilt of grains was observed, indicating the validity of models for ion beam assisted deposition (IBAD) also for MePIIID. A (100) orientation was obtained for 5 kV pulses at 9% duty cycle. The ion incident angle changed from near normal at the center towards 35 deg. tilt away from the surface normal at the sample edge for the substrate orientation at 45 deg. towards the cathode. However, due to the pulsed regime in MePIIID, there exist certain differences from IBAD.

  13. Controlled fabrication of Si nanocrystal delta-layers in thin SiO{sub 2} layers by plasma immersion ion implantation for nonvolatile memories

    SciTech Connect

    Bonafos, C.; Ben-Assayag, G.; Groenen, J.; Carrada, M.; Spiegel, Y.; Torregrosa, F.; Normand, P.; Dimitrakis, P.; Kapetanakis, E.; Sahu, B. S.; Slaoui, A.

    2013-12-16

    Plasma Immersion Ion Implantation (PIII) is a promising alternative to beam line implantation to produce a single layer of nanocrystals (NCs) in the gate insulator of metal-oxide semiconductor devices. We report herein the fabrication of two-dimensional Si-NCs arrays in thin SiO{sub 2} films using PIII and rapid thermal annealing. The effect of plasma and implantation conditions on the structural properties of the NC layers is examined by transmission electron microscopy. A fine tuning of the NCs characteristics is possible by optimizing the oxide thickness, implantation energy, and dose. Electrical characterization revealed that the PIII-produced-Si NC structures are appealing for nonvolatile memories.

  14. Dispersion and absorption of longitudinal electro-kinetic wave in ion-implanted GaN semiconductor plasmas

    SciTech Connect

    Soni, Dilip; Sharma, Giriraj; Saxena, Ajay; Jadhav, Akhilesh

    2015-07-31

    An analytical study on propagation characteristics of longitudinal electro-kinetic (LEK) waves is presented. Based on multi-fluid model of plasma, we have derived a dispersion relation for LEK waves in colloid laden GaN semiconductor plasmas. It is assumed that ions are implanted to form colloids in the GaN sample. The colloids are continuously bombarded by the plasma particles and stick on them, but they acquire a net negative charge due to relatively higher mobility of electrons. It is found from the dispersion relation that the presence of charged colloids not only modifies the existing modes but also supports new novel modes of LEKWs. It is hoped that the study would enhance understanding on dispersion and absorption of LEKWs and help in singling out the appropriate configurations in which GaN crystal would be better suited for fabrication of microwave devices.

  15. Wear of UHMWPE against nitrogen-ion-implanted and NbN-coated Co-Cr-Mo alloy formed by plasma immersion ion implantation and deposition for artificial joints

    NASA Astrophysics Data System (ADS)

    Park, Won-Woong; Kim, Eun-Kyeom; Jeon, Jun-Hong; Choi, Jin-Young; Moon, Sun-Woo; Lim, Sang-Ho; Han, Seung-Hee

    2012-08-01

    NbN thin film was deposited on the Co-Cr-Mo alloy by plasma immersion ion implantation and deposition (PIII&D) to reduce the volume wear rate of UHMWPE. In addition, nitrogen ions were implanted on the surface of the Co-Cr-Mo alloy prior to the NbN film deposition in order to increase the hardness of the substrate. XPS analysis revealed that nitrogen ions were implanted into the surface of the Co-Cr-Mo alloy, leading to the formation of CrN and Cr2N. The UHMWPE volume wear rate was measured using a pin-on-disk tribometer. The wear test result showed that the volume wear rate of UHMWPE against NbN-coated Co-Cr-Mo alloy declined by 20% as compared to that in the untreated Co-Cr-Mo alloy. In addition, the UHMWPE wear rate against the nitrogen-ion-implanted and NbN-coated Co-Cr-Mo alloy could be drastically reduced by up to 48%. It can be concluded that a combination of prior nitrogen ion implantation and NbN coating via PIII&D is a promising surface treatment tool for extending the lifetime of metal-on-polymer artificial joints.

  16. Optical properties and oxidation of carbonized and cross-linked structures formed in polycarbonate by plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    Kosobrodova, E.; Kondyurin, A.; Chrzanowski, W.; McCulloch, D. G.; McKenzie, D. R.; Bilek, M. M. M.

    2014-06-01

    At ion fluences higher than 5 · 1015 ions/cm2, plasma immersion ion implantation (PIII) of polycarbonate (PC) results in a formation of a carbonized surface layer. The thickness of this layer is close to the depth of ion penetration. A comparison of PIII treated, spin-coated PC films with pre-treatment thicknesses designed to match and exceed the carbonized layer thickness is employed to study the properties of the carbonised layer independently from the less modified underlying structure. At ion fluencies higher than 1016 ions/cm2, the thinner PC film is completely transformed into an amorphous carbon-like material with no traces of the initial PC structure. The thicker films, however, incorporated two layers: a top carbonised layer and a cross-linked layer below. Compared to the two-layered PC film, the completely carbonized layer was found to have a much higher concentration of Cdbnd O bonds and much lower concentration of O-H bonds after exposure to atmospheric oxygen. The refractive index of the thicker PC films PIII treated with high ion fluencies is close to the refractive index of diamond-like carbon. Anomalous dispersion of the refractive index of the thicker PC films is observed after formation of the carbonised layer. The refractive index of the thinner PC film has normal dispersion at all ion fluences. At ion fluences of 2 · 1016 ions/cm2, both PC films were found to have the same etching rate as polystyrene. Washing in dichloromethane had no effect on the carbonised layer but affected the underlying material in the case of the thicker PC films leading to a wrinkled structure up to ion fluences of 2 · 1016 ions/cm2. At this and higher fluence, areas of an ordered island-like structure were observed.

  17. Ion implantation in polymers

    NASA Astrophysics Data System (ADS)

    Wintersgill, M. C.

    1984-02-01

    An introductory overview will be given of the effects of ion implantation on polymers, and certain areas will be examined in more detail. Radiation effects in general and ion implantation in particular, in the field of polymers, present a number of contrasts with those in ionic crystals, the most obvious difference being that the chemical effects of both the implanted species and the energy transfer to the host may profoundly change the nature of the target material. Common effects include crosslinking and scission of polymer chains, gas evolution, double bond formation and the formation of additional free radicals. Research has spanned the chemical processes involved, including polymerization reactions achievable only with the use of radiation, to applied research dealing both with the effects of radiation on polymers already in commercial use and the tailoring of new materials to specific applications. Polymers are commonly divided into two groups, in describing their behavior under irradiation. Group I includes materials which form crosslinks between molecules, whereas Group II materials tend to degrade. In basic research, interest has centered on Group I materials and of these polyethylene has been studied most intensively. Applied materials research has investigated a variety of polymers, particularly those used in cable insulation, and those utilized in ion beam lithography of etch masks. Currently there is also great interest in enhancing the conducting properties of polymers, and these uses would tend to involve the doping capabilities of ion implantation, rather than the energy deposition.

  18. System design and operation of a 100 kilovolt, 2 kilohertz pulse modulator for plasma source ion implantation

    SciTech Connect

    Reass, W.A.

    1994-07-01

    This paper describes the electrical design and operation of a high power modulator system implemented for the Los Alamos Plasma Source Ion Implantation (PSII) facility. To test the viability of the PSII process for various automotive components, the modulator must accept wide variations of load impedance. Components have varying area and composition which must be processed with different plasmas. Additionally, the load impedance may change by large factors during the typical 20 uS pulse, due to plasma displacement currents and sheath growth. As a preliminary design to test the system viability for automotive component implantation, suitable for a manufacturing environment, circuit topology must be able to directly scale to high power versions, for increased component through-put. We have chosen an evolutionary design approach with component families of characterized performance, which should Ion result in a reliable modulator system with component lifetimes. The modulator utilizes a pair of Litton L-3408 hollow beam amplifier tubes as switching elements in a ``hot-deck`` configuration. Internal to the main of planar triode hot deck, an additional pair decks, configured in a totem pole circuit, provide input drive to the L-3408 mod-anodes. The modulator can output over 2 amps average current (at 100 kV) with 1 kW of modanode drive. Diagnostic electronics monitor the load and stops pulses for 100 mS when a load arcs occur. This paper, in addition to providing detailed engineering design information, will provide operational characteristics and reliability data that direct the design to the higher power, mass production line capable modulators.

  19. P-type ZnO films by phosphorus doping using plasma immersion ion-implantation technique

    NASA Astrophysics Data System (ADS)

    Nagar, S.; Chakrabarti, S.

    2013-03-01

    ZnO has been a subject of intense research in the optoelectronics community owing to its wide bandgap (3.3eV) and large exciton binding energy (60meV). However, difficulty in doping it p-type posts a hindrance in fabricating ZnO-based devices. In order to make p-type ZnO films, phosphorus implantation, using plasma immersion ion-implantation technique (2kV, 900W, 10μs pulse width) for 30 seconds, was performed on ZnO thin film deposited by RF Magnetron Sputtering (Sample A). The implanted samples were subsequently rapid thermal annealed at 700°C and 1000°C (Samples B and C) in oxygen environment for 30 seconds. Low temperature (8K) photoluminescence spectra reveal dominant donor-bound exciton (D°X) peak at 3.36eV for samples A and B. However, for Sample B the peaks around 3.31eV and 3.22eV corresponding to the free electron-acceptor (FA) and donor to acceptor pair peaks (DAP) are also observed. A dominant peak around 3.35eV, corresponding to acceptor bound exciton (A°X) peak, is detected for Sample C along with the presence of FA and DAP peaks around 3.31eV and 3.22eV. Moreover, the deep level peak around 2.5eV is higher for Sample B which may be due to implantation and acceptor related defects. However, for Sample C, the deep level peaks are very weak compared to the near band edge peaks confirming that these peaks are mainly due to intrinsic defects and not related to acceptors. These results clearly show us a promising way to achieve p-type ZnO films using phosphorus doping.

  20. Tunable transport properties of n-type ZnO nanowires by Ti plasma immersion ion implantation

    SciTech Connect

    Liao, L.; Zhang, Z.; Yan, B.; Li, G. P.; Wu, T.; Shen, Z. X.; Yu, T.; Yang, Y.; Cao, H. T.; Chen, L. L.; Tay, B. K.; Sun, X. W.

    2008-10-01

    Single-crystalline, transparent conducting ZnO nanowires were obtained simply by Ti plasma immersion ion implantation (PIII). Electrical transport characterizations demonstrate that the n-type conduction of ZnO nanowire could be tuned by appropriate Ti-PIII. When the energy of PIII is increased, the resistivity of ZnO decreases from 4x10{sup 2} to 3.3x10{sup -3} {omega} cm, indicating a semiconductor-metal transition. The failure-current densities of the metallic ZnO could be up to 2.75x10{sup 7} A/cm{sup 2}. Therefore, this facile method may provide an inexpensive alternative to tin doped indium oxide as transparent conducting oxide materials.

  1. Haemocompatibility of hydrogenated amorphous carbon (a-C:H) films synthesized by plasma immersion ion implantation-deposition

    NASA Astrophysics Data System (ADS)

    Yang, P.; Kwok, S. C. H.; Chu, P. K.; Leng, Y. X.; Chen, J. Y.; Wang, J.; Huang, N.

    2003-05-01

    Diamond-like-carbon has attracted much attention recently as a potential biomaterial in blood contacting biomedical devices. However, previous reports in this area have not adequately addressed the biocompatibility and acceptability of the materials in blood contacting applications. In this study, hydrogenated amorphous carbon (a-C:H) films were fabricated on silicon wafers (1 0 0) using plasma immersion ion implantation-deposition. A series of a-C:H films with different structures and chemical bonds were fabricated under different substrate voltages. The results indicate that film graphitization is promoted at higher substrate bias. The film deposited at a lower substrate bias of -75 V possesses better blood compatibility than the films at higher bias and stainless steel. Our results suggest two possible paths to improve the blood compatibility, suppression of the endogenic clotting system and reduction of platelet activation.

  2. Diffusion, trapping, and isotope exchange of plasma implanted deuterium in ion beam damaged tungsten

    NASA Astrophysics Data System (ADS)

    Barton, Joseph Lincoln

    Tritium accumulation in nuclear fusion reactor materials is a major concern for practical and safe fusion energy. This work examines hydrogen isotope exchange as a tritium removal technique, analyzes the effects of neutron damage using high energy copper ion beams, and introduces a diffusion coefficient that is a function of the concentration of trapped atoms. Tungsten samples were irradiated with high energy (0.5 - 5 MeV) copper ions for controlled levels of damage - 10-3 to 10-1 displacements per atom (dpa) - at room temperature. Samples were then exposed to deuterium plasma at constant temperature (˜ 380 K) to a high fluence of 1024 ions/m2, where retention is at is maximized (i.e. saturated). By then subsequently exposing these samples to fractions of this fluence with hydrogen plasma, isotope exchange rates were observed. The resulting deuterium still trapped in the tungsten is then measured post mortem. Nuclear reaction analysis (NRA) gives the depth resolved deuterium retention profile with the 3He(D,p) 4He reaction, and thermal desorption spectroscopy (TDS) gives the total amount of deuterium trapped in the tungsten by heating a sample in vacuum up to 1200 K and measuring the evaporated gas molecules with a residual gas analyzer. Isotope exchange data show that hydrogen atoms can displace trapped deuterium atoms efficiently only up to the first few microns, but does not affect the atoms trapped at greater depths. In ion damaged tungsten, measurements showed a significant increase in retention in the damage region proportional to dpa 0.66, which results in a significant spike in total retention, and isotope exchange in damaged samples is still ineffective at depths greater than a few microns. Thus, isotope exchange is not an affective tritium removal technique; however, these experiments have shown that trapping in material defects greatly affects diffusion. These experiments lead to a simplified diffusion model with defect densities as the only free

  3. System design and operation of a 100 kilovolt, 2 kilohertz pulse modulator for plasma source ion implantation

    NASA Astrophysics Data System (ADS)

    Reass, W. A.

    This paper describes the electrical design and operation of a high power modulator system implemented for the Los Alamos Plasma Source Ion Implantation (PSII) facility. To test the viability of the PSII process for various automotive components, the modulator must accept wide variations of load impedance. Components have varying area and composition which must be processed with different plasmas. Additionally, the load impedance may change by large factors during the typical 20 uS pulse, due to plasma displacement currents and sheath growth. As a preliminary design to test the system viability for automotive component implantation, suitable for a manufacturing environment, circuit topology must be able to directly scale to high power versions, for increased component through-put. We have chosen an evolutionary design approach with component families of characterized performance, which should result in a reliable modulator system with component lifetimes. The modulator utilizes a pair of Litton L-3408 hollow beam amplifier tubes as switching elements in a 'hot-deck' configuration. Internal to the main of planar triode hot deck, an additional pair decks, configured in a totem pole circuit, provide input drive to the L-3408 mod-anodes. The modulator can output over 2 amps average current (at 100 kV) with 1 kW of modanode drive. Diagnostic electronics monitor the load and stops pulses for 100 mS when a load arcs occur. This paper, in addition to providing detailed engineering design information, will provide operational characteristics and reliability data that direct the design to the higher power, mass production line capable modulators.

  4. Ion implantation in silicate glasses

    SciTech Connect

    Arnold, G.W.

    1993-12-01

    This review examines the effects of ion implantation on the physical properties of silicate glasses, the compositional modifications that can be brought about, and the use of metal implants to form colloidal nanosize particles for increasing the nonlinear refractive index.

  5. Semiconductor Ion Implanters

    NASA Astrophysics Data System (ADS)

    MacKinnon, Barry A.; Ruffell, John P.

    2011-06-01

    In 1953 the Raytheon CK722 transistor was priced at 7.60. Based upon this, an Intel Xeon Quad Core processor containing 820,000,000 transistors should list at 6.2 billion! Particle accelerator technology plays an important part in the remarkable story of why that Intel product can be purchased today for a few hundred dollars. Most people of the mid twentieth century would be astonished at the ubiquity of semiconductors in the products we now buy and use every day. Though relatively expensive in the nineteen fifties they now exist in a wide range of items from high-end multicore microprocessors like the Intel product to disposable items containing `only' hundreds or thousands like RFID chips and talking greeting cards. This historical development has been fueled by continuous advancement of the several individual technologies involved in the production of semiconductor devices including Ion Implantation and the charged particle beamlines at the heart of implant machines. In the course of its 40 year development, the worldwide implanter industry has reached annual sales levels around 2B, installed thousands of dedicated machines and directly employs thousands of workers. It represents in all these measures, as much and possibly more than any other industrial application of particle accelerator technology. This presentation discusses the history of implanter development. It touches on some of the people involved and on some of the developmental changes and challenges imposed as the requirements of the semiconductor industry evolved.

  6. Semiconductor Ion Implanters

    SciTech Connect

    MacKinnon, Barry A.; Ruffell, John P.

    2011-06-01

    In 1953 the Raytheon CK722 transistor was priced at $7.60. Based upon this, an Intel Xeon Quad Core processor containing 820,000,000 transistors should list at $6.2 billion. Particle accelerator technology plays an important part in the remarkable story of why that Intel product can be purchased today for a few hundred dollars. Most people of the mid twentieth century would be astonished at the ubiquity of semiconductors in the products we now buy and use every day. Though relatively expensive in the nineteen fifties they now exist in a wide range of items from high-end multicore microprocessors like the Intel product to disposable items containing 'only' hundreds or thousands like RFID chips and talking greeting cards. This historical development has been fueled by continuous advancement of the several individual technologies involved in the production of semiconductor devices including Ion Implantation and the charged particle beamlines at the heart of implant machines. In the course of its 40 year development, the worldwide implanter industry has reached annual sales levels around $2B, installed thousands of dedicated machines and directly employs thousands of workers. It represents in all these measures, as much and possibly more than any other industrial application of particle accelerator technology. This presentation discusses the history of implanter development. It touches on some of the people involved and on some of the developmental changes and challenges imposed as the requirements of the semiconductor industry evolved.

  7. Mechanical properties of nitrogen-rich surface layers on SS304 treated by plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    Fernandes, B. B.; Mändl, S.; Oliveira, R. M.; Ueda, M.

    2014-08-01

    The formation of hard and wear resistant surface regions for austenitic stainless steel through different nitriding and nitrogen implantation processes at intermediate temperatures is an established technology. As the inserted nitrogen remains in solid solution, an expanded austenite phase is formed, accounting for these surface improvements. However, experiments on long-term behavior and exact wear processes within the expanded austenite layer are still missing. Here, the modified layers were produced using plasma immersion ion implantation with nitrogen gas and had a thickness of up to 4 μm, depending on the processing temperature. Thicker layers or those with higher surface nitrogen contents presented better wear resistance, according to detailed microscopic investigation on abrasion, plastic deformation, cracking and redeposition of material inside the wear tracks. At the same time, cyclic fatigue testing employing a nanoindenter equipped with a diamond ball was carried out at different absolute loads and relative unloadings. As the stress distribution between the modified layer and the substrate changes with increasing load, additional simulations were performed for obtaining these complex stress distributions. While high nitrogen concentration and/or thicker layers improve the wear resistance and hardness, these modifications simultaneously reduce the surface fatigue resistance.

  8. Model development of plasma implanted hydrogenic diffusion and trapping in ion beam damaged tungsten

    NASA Astrophysics Data System (ADS)

    Barton, J. L.; Wang, Y. Q.; Doerner, R. P.; Tynan, G. R.

    2016-10-01

    A Cu ion beam is used to induce controlled levels of damage (10-3, 10-2, and 10-1 dpa) in room temperature W samples. A single 5 MeV beam energy yielding a peaked damage profile 0.8 μm into the material, or three beam energies (0.5, 2, and 5 MeV) producing a relatively uniform damage profile from the near surface up to 0.8 μm were used. The W samples were then exposed to a D plasma ion fluence of 1024 ions m-2 at 380 K, and the resulting D retention was measured using the D(3He,p)4He reaction analysis (NRA) and thermal desorption spectroscopy (TDS). We observe that within experimental error there is no significant difference in retention whether the damage profile is peaked or uniform. The increase in retention is observed to increase proportional to \\text{dp}{{\\text{a}}0.66} estimated from the dpa peak calculated from the SRIM program. A simplified retention model is proposed that provides concentration profiles that can be directly compared to NRA data and total retention measurements. Taking the trapping energies due to three defect types calculated from density functional theory (DFT), the only free-parameters are three defect densities of in-grain monovacancies, dislocations, and grain boundary vacancies, and we assume these defects to be the dominant trapping locations. The model can fit D retention data in a pristine W sample within the experimental error of the measurements, and in subsequent modeling these intrinsic defect densities are then fixed. We model the retention profile after ion damage by adding the SRIM predicted vacancy profile to the intrinsic monovacancy defect density. Since the increase in retention, and therefore the increase in vacancy production, does not increase linearly with dpa, a correction factor is multiplied to the predicted vacancy profile to fit the data. A new diffusion coefficient is calculated with the model that is a function of the concentration of trapped atoms. This calculation may resolve discrepancies of various

  9. Study rationale and protocol: prospective randomized comparison of metal ion concentrations in the patient's plasma after implantation of coated and uncoated total knee prostheses

    PubMed Central

    Lützner, Jörg; Dinnebier, Gerd; Hartmann, Albrecht; Günther, Klaus-Peter; Kirschner, Stephan

    2009-01-01

    Background Any metal placed in a biological environment undergoes corrosion. Thus, with their large metallic surfaces, TKA implants are particularly prone to corrosion with subsequent release of metal ions into the human body which may cause local and systemic toxic effects and hypersensitivity reactions, and increase cancer risk. To address this problem, a new 7-layer zirconium coating developed especially for cobalt-chrome orthopaedic implants was tested biomechanically and found to lower metal ion release. The purpose of the proposed clinical trial is to compare the metal ion concentration in patients' plasma before and after implantation of a coated or uncoated TKA implant. Methods/Design In this randomised controlled trial, 120 patients undergoing primary TKA will be recruited at the Department of Orthopaedic Surgery of the University Hospital in Dresden, Germany, and randomised to either the coated or uncoated prosthesis. Outcome assessments will be conducted preoperatively and at 3 months, 12 months and 5 years postoperatively. The primary clinical endpoint will be the chromium ion concentration in the patient's plasma after 1 and 5 years. Secondary outcomes include cobalt, molybdenum and nickel ion concentrations after 1 and 5 years, allergy testing for hypersensitivity against one of these metals, the Knee Society Score to assess clinical and physical function of the knee joint, the self-assessment Oxford Score and the Short Form 36 quality of live questionnaire. Discussion The metal ion concentration in the patient's plasma has been shown to increase after TKA, its eventual adverse effects being widely debated. In the light of this discussion, ways to reduce metal ion release from orthopaedic implants should be studied in detail. The results of this investigation may lead to a new method to achieve this goal. Trials register Clinicaltrials registry NCT00862511 PMID:19828019

  10. Ion implantation at elevated temperatures

    SciTech Connect

    Lam, N.Q.; Leaf, G.K.

    1985-11-01

    A kinetic model has been developed to investigate the synergistic effects of radiation-enhanced diffusion, radiation-induced segregation and preferential sputtering on the spatial redistribution of implanted solutes during implantation at elevated temperatures. Sample calculations were performed for Al and Si ions implanted into Ni. With the present model, the influence of various implantation parameters on the evolution of implant concentration profiles could be examined in detail.

  11. Two-wavelength Raman study of poly(ethylene terephthalate) surfaces modified by helium plasma-based ion implantation

    NASA Astrophysics Data System (ADS)

    Veres, M.; Tóth, A.; Mohai, M.; Bertóti, I.; Szépvölgyi, J.; Tóth, S.; Himics, L.; Koós, M.

    2012-12-01

    The surface of poly(ethylene terephthalate) (PET) was modified by helium plasma-based ion implantation (He PBII). The untreated and surface modified samples were characterised with optical absorption spectroscopy and two-wavelength micro-Raman spectroscopy excited with 488 nm and 785 nm light sources, allowing to examine the chemical bonding configuration of the surface layers on different depths and by selective enhancement of vibrations of different structural units. Upon treatment, simultaneously with the development of the broad D and G bands, a gradual decrease of the peaks corresponding to the Cdbnd C stretching and Cdbnd O stretching modes were observed with both excitations. Downshifting and broadening were detected for the Cdbnd C peak with both excitations and also for the Cdbnd O peak with the 488 nm excitation due to formation of condensed aromatic rings. Oppositely, upshifting was found with 785 nm excitation for the Cdbnd O peak and especially for its broad shoulder newly developed at the high wavenumber side. The latter feature was assigned to Cdbnd O groups attached to polymer chains without conjugation and the bands behaviour was interpreted by breaking of the Cdbnd C bonds of the polymer, leading to the formation of a crosslinked, disordered and stressed structure with still intact Cdbnd O groups, due to the increased nuclear damage at the end of the ion track.

  12. Beam-plasma concepts for wafer charging control during ion implantation

    SciTech Connect

    Current, M.I.; Vella, M.C.; Lukaszek, W.

    1996-12-31

    With the development of quantitative measures of current-voltage characteristics (CHARM{reg_sign}-2) and a beam-plasma model for charge flows to and from the wafer surface, a more comprehensive view of wafer charging has emerged. A beam-plasma model has been developed which describes both positive and negative current-voltage characteristics of the beam plasma. A quantitative description has been achieved for a variety of charge control systems; including dense and dilute plasma flows, electron showers as well as for photoresist outgassing effects.

  13. Ion sources for use in ion implantation

    NASA Astrophysics Data System (ADS)

    White, Nicholas R.

    1989-02-01

    This paper reviews high current ion sources suitable for commercial use. Although the production of high currents of a variety of ions is a vital consideration, this paper focuses on other aspects of ion source performance. The modern ion implanter is a major item of expensive capital equipment, with the ion source being its least reliable component. So, the most critical issues today are reliability and lifetime, as well as safety, flexibility, and ease of service. The Freeman ion source has clearly dominated the field, yet a number of alternative sources have found commercial acceptance, including microwave sources. Factors affecting the ultimate usefulness of various sources in different implantation applications are discussed.

  14. Influence of the residual oxygen in the plasma immersion ion implantation (PI3) processing of materials

    NASA Astrophysics Data System (ADS)

    Ueda, M.; Silva, A. R.; Mello, Carina B.; Silva, G.; Reuther, H.; Oliveira, V. S.

    2011-12-01

    In this work, we investigated the effects of the contaminants present in the vacuum chamber of the PI3 system, in particular, the residual oxygen, which results in the formation of the oxide compounds on the surface and hence is responsible for the high implantation energies required to achieve reasonably thick treated layers. We used a mass spectrometer (RGA) with a quadruple filter to verify the composition of the residual vacuum and pressure of the elements present in the chamber. Initially we found a high proportion of residual oxygen in a vacuum with a pressure of 1 × 10 -3 Pa. Minimizing the residual oxygen percentage in about 80%, by efficient cleaning of the chamber walls and by improving the gas feeding process, we mitigated the formation of oxides during the PI3 process. Therefore we achieved a highly efficient PI3 processing obtaining implanted layers reaching about 50 nm, even in cases such as an aluminum alloy, where is very difficult to nitrogen implant at low energies. We performed nitrogen PI3 treatment of SS304 and Al7075 using pulses of only 3 kV and 15 × 10 -6 s at 1 kHz with an operating pressure of 1 Pa.

  15. Bioactivity of plasma implanted biomaterials

    NASA Astrophysics Data System (ADS)

    Chu, Paul K.

    2006-01-01

    Plasma immersion ion implantation and deposition (PIII&D) is an effective technique to enhance the surface bioactivity of materials. In this paper, recent progress made in our laboratory on plasma surface modification of biomedical materials is described. NiTi alloys have unique super-elastic and shape memory properties and are suitable for orthopedic implants but the leaching of toxic Ni may pose health hazards in humans. We have recently investigated the use of acetylene, oxygen and nitrogen PIII&D to prevent out-diffusion of nickel and good results have been obtained. Silicon is the most important material in the microelectronics industry but its surface biocompatibility has not been investigated in details. We have recently performed hydrogen PIII into silicon to improve the surface bioactivity and observed biomimetic growth of apatite on the surface in simulated body fluids. Diamond-like carbon (DLC) is widely used in the industry due to its excellent mechanical properties and chemical inertness and by incorporation of elements such as nitrogen and phosphorus, the surface blood compatibility can be improved. The properties as well as in vitro biological test results are discussed in this article.

  16. Ion sources for ion implantation technology (invited)

    SciTech Connect

    Sakai, Shigeki Hamamoto, Nariaki; Inouchi, Yutaka; Umisedo, Sei; Miyamoto, Naoki

    2014-02-15

    Ion sources for ion implantation are introduced. The technique is applied not only to large scale integration (LSI) devices but also to flat panel display. For LSI fabrication, ion source scheduled maintenance cycle is most important. For CMOS image sensor devices, metal contamination at implanted wafer is most important. On the other hand, to fabricate miniaturized devices, cluster ion implantation has been proposed to make shallow PN junction. While for power devices such as silicon carbide, aluminum ion is required. For doping processes of LCD fabrication, a large ion source is required. The extraction area is about 150 cm × 10 cm, and the beam uniformity is important as well as the total target beam current.

  17. Highly Stripped Ion Sources for MeV Ion Implantation

    SciTech Connect

    Hershcovitch, Ady

    2009-06-30

    manufacturing industry by lowering power consumption by as much as 30 kW per ion implanter. Major problem was meeting commercialization goals did not succeed for the following reasons (which were discovered after R&D completion): record output of high charge state phosphorous would have thermally damage wafers; record high charge state of antimony requires tool (ion implanting machine in ion implantation jargon) modification, which did not make economic sense due to the small number of users. High fraction boron ion was delivered to PVI client Axcelis for retrofit and implantation testing; the source could have reduced beam preinjector power consumption by a factor of 3.5. But, since the source generated some lithium (though in miniscule amounts); last minute decision was made not to employ the source in implanters. An additional noteworthy reason for failure to commercialize is the fact that the ion implantation manufacturing industry had been in a very deep bust cycle. BNL, however, has benefited from advances in high-charge state ion generation, due to the need high charge state ions in some RHIC preinjectors. Since the invention of the transistor, the trend has been to miniaturize semiconductor devices. As semiconductors become smaller (and get miniaturized), ion energy needed for implantation decreases, since shallow implantation is desired. But, due to space charge (intra-ion repulsion) effects, forming and transporting ion beams becomes a rather difficult task. A few small manufacturers of low quality semiconductors use plasma immersion to circumvent the problem. However, in plasma immersion undesired plasma impurity ions are also implanted; hence, the quality of those semiconductors is poor. For high quality miniature semiconductor manufacturing, pure, low energy ion beams are utilized. But, low energy ion implanters are characterized by low current (much lower than desirable) and, therefore, low production rates. Consequently, increasing the current of pure low energy

  18. Characteristics of diamond-like carbon film synthesized on AISI 304 austenite stainless steel using plasma immersion ion implantation and deposition

    NASA Astrophysics Data System (ADS)

    Liang, J. H.; Chen, M. H.; Tsai, W. F.; Lee, S. C.; Ai, C. F.

    2007-04-01

    This study examines the characteristics of diamond-like carbon (DLC) film synthesized on AISI 304 austenite stainless steel by means of a hybrid process of plasma immersion ion implantation and deposition (PIII&D) maintained at 60 °C. The former and latter processes under investigation were carried out using methane (0-20 kV) and acetylene (1-2 kV, 0.13-0.40 Pa) plasmas, respectively. Glow discharge spectrometry (GDS), Raman scattering spectroscopy (RSS), atomic force microscopy (AFM), a nano-indentation probe (NIP) and a Rockwell-C hardness tester were employed to characterize, respectively, elemental depth profiles, sp3-to-sp2 ratio, surface morphology, hardness and adhesion strength of the DLC specimen. The results revealed that the mixing layer at the interface generated by plasma immersion ion implantation of methane at a higher voltage could enhance adhesive strength of the DLC film to the substrate. Furthermore, a higher sp3-to-sp2 ratio, a smoother surface, greater hardness, but weaker adhesion strength were obtained for the DLC film synthesized using plasma immersion ion deposition of acetylene at a lower bias voltage or higher gas pressure.

  19. Carbon, nitrogen, and oxygen ion implantation of stainless steel

    SciTech Connect

    Rej, D.J.; Gavrilov, N.V.; Emlin, D.

    1995-12-31

    Ion implantation experiments of C, N, and O into stainless steel have been performed, with beam-line and plasma source ion implantation methods. Acceleration voltages were varied between 27 and 50 kV, with pulsed ion current densities between 1 and 10 mA/cm{sup 2}. Implanted doses ranged from 0.5 to 3 {times} 10{sup 18}cm{sup -2}, while workpiece temperatures were maintained between 25 and 800 C. Implant concentration profiles, microstructure, and surface mechanical properties of the implanted materials are reported.

  20. Adhesion improvement of TiN film on tool steel by a hybrid process of unbalanced magnetron sputtering and plasma-based ion implantation

    NASA Astrophysics Data System (ADS)

    Ono, T.; Uemura, M.; Yatsuzuka, M.

    2007-04-01

    An interfacial mixing layer and a titanium (Ti) layer between the titanium-nitride (TiN) film and the substrate material was produced to improve the adhesion of TiN film on tool substrates by a hybrid process of unbalanced magnetron sputtering (UBM) and plasma-based ion implantation (PBII). Before TiN deposition by UBM, the negative high-voltage pulse and DC-bias were applied to the substrate immersed in the Ti plasma, resulting in implantation as well as deposition of Ti ions to the substrate. As a result, a Ti layer and a graded mixing layer of Ti and substrate materials was produced to work as a buffer interface between substrate and TiN film. The adhesion strength of TiN film with the interfacial treatment on tool steel substrates was evaluated by scratch and indentation tests, showing the considerable improvement of adhesion by the formation of the Ti and the interfacial mixing layers. The suitable ion implantation energy for the improvement of adhesion strength was found.

  1. Effects of phosphorus doping by plasma immersion ion implantation on the structural and optical characteristics of Zn0.85Mg0.15O thin films

    NASA Astrophysics Data System (ADS)

    Saha, S.; Nagar, S.; Chakrabarti, S.

    2014-08-01

    ZnMgO thin films deposited on <100> Si substrates by RF sputtering were annealed at 800, 900, and 1000 °C after phosphorus plasma immersion ion implantation. X-ray diffraction spectra confirmed the presence of <101¯0> and <101¯3> peaks for all the samples. However, in case of the annealed samples, the <0002> peak was also observed. Scanning electron microscopy images revealed the variation in surface morphology caused by phosphorus implantation. Implanted and non-implanted samples were compared to examine the effects of phosphorus implantation on the optical properties of ZnMgO. Optical characteristics were investigated by low-temperature (15 K) photoluminescence experiments. Inelastic exciton-exciton scattering and localized, and delocalized excitonic peaks appeared at 3.377, 3.42, and 3.45 eV, respectively, revealing the excitonic effect resulting from phosphorus implantation. This result is important because inelastic exciton-exciton scattering leads to nonlinear emission, which can improve the performance of many optoelectronic devices.

  2. Thermal stability of diamondlike carbon buried layer fabricated by plasma immersion ion implantation and deposition in silicon on insulator

    SciTech Connect

    Di Zengfeng; Huang Anping; Fu, Ricky K.Y.; Chu, Paul K.; Shao Lin; Hoechbauer, T.; Nastasi, M.; Zhang Miao; Liu Weili; Shen Qinwo; Luo Suhua; Song Zhitang; Lin Chenglu

    2005-09-01

    Diamondlike carbon (DLC) as a potential low-cost substitute for diamond has been extended to microelectronics and we have demonstrated the fabrication of silicon on diamond (SOD) as a silicon-on-insulator structure using plasma immersion ion implantation and deposition in conjunction with layer transfer and wafer bonding. The thermal stability of our SOD structure was found to be better than that expected for conventional DLC films. In the work reported here, we investigate the mechanism of the enhanced thermal stability. We compare the thermal stability of exposed and buried DLC films using Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). Our Raman analysis indicates that the obvious separation of the D and G peaks indicative of nanocrystalline graphite emerges at 500 deg. C in the exposed DLC film. In contrast, the separation appears in the buried DLC film only at annealing temperatures above 800 deg. C. Analysis of the XPS C{sub 1s} core-level spectra shows that the (sp{sup 3}+C-H) carbon content of the unprotected DLC film decreases rapidly between 300-700 deg. C indicating the rapid transformation of sp{sup 3}-bonded carbon to sp{sup 2}-bonded carbon combined with hydrogen evolution. In comparison, the decrease in the (sp{sup 3}+C-H) carbon content of the buried DLC film is slower below 800 deg. C. Elastic recoil detection results show that this superior thermal stability is due to the slower hydrogen out diffusion from the buried DLC film thereby impeding the graphitization process. We propose that the SiO{sub 2} overlayer retards the graphitization process during annealing by shifting the chemical equilibrium.

  3. Cell surface antigen profiling using a novel type of antibody array immobilised to plasma ion-implanted polycarbonate.

    PubMed

    Main, Heather; Radenkovic, Jelena; Kosobrodova, Elena; McKenzie, David; Bilek, Marcela; Lendahl, Urban

    2014-10-01

    To identify and sort out subpopulations of cells from more complex and heterogeneous assemblies of cells is important for many biomedical applications, and the development of cost- and labour-efficient techniques to accomplish this is warranted. In this report, we have developed a novel array-based platform to discriminate cellular populations based on differences in cell surface antigen expressions. These cell capture microarrays were produced through covalent immobilisation of CD antibodies to plasma ion immersion implantation-treated polycarbonate (PIII-PC), which offers the advantage of a transparent matrix, allowing direct light microscopy visualisation of captured cells. The functionality of the PIII-PC array was validated using several cell types, resulting in unique surface antigen expression profiles. PIII-PC results were compatible with flow cytometry, nitrocellulose cell capture arrays and immunofluorescent staining, indicating that the technique is robust. We report on the use of this PIII-PC cluster of differentiation (CD) antibody array to gain new insights into neural differentiation of mouse embryonic stem (ES) cells and into the consequences of genetic targeting of the Notch signalling pathway, a key signalling mechanism for most cellular differentiation processes. Specifically, we identify CD98 as a novel marker for neural precursors and polarised expression of CD9 in the apical domain of ES cell-derived neural rosettes. We further identify expression of CD9 in hitherto uncharacterised non-neural cells and enrichment of CD49e- and CD117-positive cells in Notch signalling-deficient ES cell differentiations. In conclusion, this work demonstrates that covalent immobilisation of antibody arrays to the PIII-PC surface provides faithful cell surface antigen data in a cost- and labour-efficient manner. This may be used to facilitate high throughput identification and standardisation of more precise marker profiles during stem cell differentiation and in

  4. Ion implanted dielectric elastomer circuits

    NASA Astrophysics Data System (ADS)

    O'Brien, Benjamin M.; Rosset, Samuel; Anderson, Iain A.; Shea, Herbert R.

    2013-06-01

    Starfish and octopuses control their infinite degree-of-freedom arms with panache—capabilities typical of nature where the distribution of reflex-like intelligence throughout soft muscular networks greatly outperforms anything hard, heavy, and man-made. Dielectric elastomer actuators show great promise for soft artificial muscle networks. One way to make them smart is with piezo-resistive Dielectric Elastomer Switches (DES) that can be combined with artificial muscles to create arbitrary digital logic circuits. Unfortunately there are currently no reliable materials or fabrication process. Thus devices typically fail within a few thousand cycles. As a first step in the search for better materials we present a preliminary exploration of piezo-resistors made with filtered cathodic vacuum arc metal ion implantation. DES were formed on polydimethylsiloxane silicone membranes out of ion implanted gold nano-clusters. We propose that there are four distinct regimes (high dose, above percolation, on percolation, low dose) in which gold ion implanted piezo-resistors can operate and present experimental results on implanted piezo-resistors switching high voltages as well as a simple artificial muscle inverter. While gold ion implanted DES are limited by high hysteresis and low sensitivity, they already show promise for a range of applications including hysteretic oscillators and soft generators. With improvements to implanter process control the promise of artificial muscle circuitry for soft smart actuator networks could become a reality.

  5. Improvements of anti-corrosion and mechanical properties of NiTi orthopedic materials by acetylene, nitrogen and oxygen plasma immersion ion implantation

    NASA Astrophysics Data System (ADS)

    Poon, Ray W. Y.; Ho, Joan P. Y.; Liu, Xuanyong; Chung, C. Y.; Chu, Paul K.; Yeung, Kelvin W. K.; Lu, William W.; Cheung, Kenneth M. C.

    2005-08-01

    Nickel-titanium shape memory alloys (NiTi) are useful materials in orthopedics and orthodontics due to their unique super-elasticity and shape memory effects. However, the problem associated with the release of harmful Ni ions to human tissues and fluids has been raising safety concern. Hence, it is necessary to produce a surface barrier to impede the out-diffusion of Ni ions from the materials. We have conducted acetylene, nitrogen and oxygen plasma immersion ion implantation (PIII) into NiTi alloys in an attempt to improve the surface properties. All the implanted and annealed samples surfaces exhibit outstanding corrosion and Ni out-diffusion resistance. Besides, the implanted layers are mechanically stronger than the substrate underneath. XPS analyses disclose that the layer formed by C2H2 PIII is composed of mainly TiCx with increasing Ti to C concentration ratios towards the bulk. The nitrogen PIII layer is observed to be TiN, whereas the oxygen PIII layer is composed of oxides of Ti4+, Ti3+ and Ti2+.

  6. Hardness of ion implanted ceramics

    SciTech Connect

    Oliver, W.C.; McHargue, C.J.; Farlow, G.C.; White, C.W.

    1985-01-01

    It has been established that the wear behavior of ceramic materials can be modified through ion implantation. Studies have been done to characterize the effect of implantation on the structure and composition of ceramic surfaces. To understand how these changes affect the wear properties of the ceramic, other mechanical properties must be measured. To accomplish this, a commercially available ultra low load hardness tester has been used to characterize Al/sub 2/O/sub 3/ with different implanted species and doses. The hardness of the base material is compared with the highly damaged crystalline state as well as the amorphous material.

  7. Oxygen depth profiling by resonant backscattering and glow discharge optical emission spectroscopy of Ti-6Al-4V alloy oxidized by ion implantation and plasma based treatment

    NASA Astrophysics Data System (ADS)

    Nsengiyumva, S.; Topic, M.; Pichon, L.; Comrie, C. M.; Mtshali, C.

    2016-10-01

    Oxygen depth profiling by means of 16O(α,α)16O backscattering and glow discharge optical emission spectroscopy (GDOES) was investigated in two different sets of Ti-6Al-4V samples. The first set was made of Ti-6Al-4V samples implanted at room temperature and 550 °C with 50 and 150 keV O+ ions at fluences ranging from 1.5 × 1017 to 6.0 × 1017 ions/cm2. The second set consisted of Ti-6Al-4V samples treated at 550 °C for 7 h and 24 h under low pressure (8 Pa) oxygen, eventually with RF plasma activation. These results are part of a wider investigation on Ti-6Al-4V motivated by recent publications which have shown that an oxide layer can enhance hydrogen absorption and can then promote Ti-6Al-4V alloys as efficient hydrogen storage materials. The results obtained by the two characterization techniques were compared and discussed, enabling to adjust the dependence to the oxygen concentration of the sputtering rates to be used in the time-to-depth transformation required in GDOES analysis. Considering the low thickness of oxidized alloy, usual procedures employed in GDOES depth calculation were indeed not adapted. Once calibrated thanks to the resonant RBS, GDOES can then be easily employed as fast characterization of oxidized and/or hydrogenated surface of Ti-6Al-4V. The obtained results show that the oxygen content into the surface oxidized layer slightly increases in samples implanted at higher fluence and higher temperature. However the overall oxidized layer thickness (<200 nm) remains within the projected ion depth range and is not significantly increased by thermal diffusion at 550 °C. Taken into account the initial oxide layer, the incorporated oxygen quantity mainly corresponds to the implanted fluence but it can be slightly higher with 550 °C implantation, indicating a slight additional oxidation by residual oxygen or surface contamination. The oxygen penetrations and contents in samples oxidized by thermally activated diffusion treatments were more

  8. Contamination Control in Ion Implantation

    SciTech Connect

    Eddy, R.; Doi, D.; Santos, I.; Wriggins, W.

    2011-01-07

    The investigation and elimination or control of metallic contamination in ion implanters has been a leading, continuous effort at implanter OEMs and in fabs/IDMs alike. Much of the efforts have been in the area of control of sputtering through material and geometry changes in apertures, beamline and target chamber components. In this paper, we will focus on an area that has not, heretofore, been fully investigated or controlled. This is the area of lubricants and internal and external support material such as selected cleaning media. Some of these materials are designated for internal use (beamline/vacuum) only while others are for internal and/or external use. Many applications for selected greases, for example, are designated for or are used for platens, implant disks/wheels and for wafer handling components. We will present data from popular lubricants (to be unnamed) used worldwide in ion implanters. This paper will review elements of concern in many lubricants that should be tracked and monitored by all fabs.Proper understanding of the characteristics, risks and the control of these potential contaminants can provide for rapid return to full process capability following major PMs or parts changes. Using VPD-ICPMS, Glow Discharge Mass Spectrometry and Ion Chromatography (IC) data, we will review the typical cleaning results and correlation to ''on wafer'' contamination by elements of concern--and by some elements that are otherwise barred from the fab.

  9. Synthesis of unattainable ion implantation profiles — 'Pseudo-implantation'

    NASA Astrophysics Data System (ADS)

    Brown, I. G.; Anders, A.; Anders, S.; Castro, R. A.; Dickinson, M. R.; MacGill, R. A.; Wang, Z.

    1995-12-01

    Metal implantation provides a powerful tool for the formation of non-equilibrium alloy layers for a wide variety of basic and applied materials applications, but the technique is fundamentally limited in two important ways: (i) the implanted species concentration is limited by sputtering of the modified layer by the incident ion beam itself, and the sputter-limited retained dose is often disappointingly low; (ii) the thickness of the modified layer is limited by the maximum ion energy available, and for practical reasons (implanter voltage) the layer thickness is often just a few hundred ångströms. We describe here a metal-plasma-immersion-based method for synthesizing non-equilibrium alloy layers of arbitrarily high dopant concentration and of arbitrary thickness. By repetitively pulse biasing the substrate to high negative voltage while it is immersed in the metal plasma from a vacuum arc plasma gun, a layer can be synthesized that is atomically mixed into the substrate with an interface width determined by the early-time bias voltage and with a thickness determined by the overall duration of the process. The species is that of the vacuum arc cathode material, which for this purpose can be a mixture of the substrate metal and the wanted dopant metal. We have used the method to form a high concentration Ta layer on the copper rails of an electromagnetic rail gun, with total surface area treated about 3000 cm 2; the Ta depth profile was flat at about 50 at.% Ta in Cu to a depth of about 1000 Å.

  10. Hemocompatibility of nitrogen-doped, hydrogen-free diamond-like carbon prepared by nitrogen plasma immersion ion implantation-deposition.

    PubMed

    Kwok, Sunny C H; Yang, Ping; Wang, Jin; Liu, Xuanyong; Chu, Paul K

    2004-07-01

    Amorphous hydrogenated carbon (a-C:H) has been shown to be a potential material in biomedical devices such as artificial heart valves, bone implants, and so on because of its chemical inertness, low coefficient of friction, high wear resistance, and good biocompatibility. However, the biomedical characteristics such as blood compatibility of doped hydrogen-free diamond-like carbon (DLC) have not been investigated in details. We recently began to investigate the potential use of nitrogen-doped, hydrogen-free DLC in artificial heart valves. In our experiments, a series of hydrogen-free DLC films doped with nitrogen were synthesized by plasma immersion ion implantation-deposition (PIII-D) utilizing a pulsed vacuum arc plasma source and different N to Ar (FN/FAr) gas mixtures in the plasma chamber. The structures and properties of the film were evaluated by Raman spectroscopy, Rutherford backscattering spectrometry (RBS), and X-ray photoelectron spectroscopy (XPS). To assess the blood compatibility of the films and the impact on the blood compatibility by the presence of nitrogen, platelet adhesion tests were conducted. Our results indicate that the blood compatibility of both hydrogen-free carbon films (a-C) and amorphous carbon nitride films are better than that of low-temperature isotropic pyrolytic carbon (LTIC). The experimental results are consistent with the relative theory of interfacial energy and surface tension including both dispersion and polar components. Our results also indicate that an optimal fraction of sp2 bonding is desirable, but an excessively high nitrogen concentration degrades the properties to an extent that the biocompatibility can be worse than that of LTIC.

  11. Controlled ion implant damage profile for etching

    DOEpatents

    Arnold, Jr., George W.; Ashby, Carol I. H.; Brannon, Paul J.

    1990-01-01

    A process for etching a material such as LiNbO.sub.3 by implanting ions having a plurality of different kinetic energies in an area to be etched, and then contacting the ion implanted area with an etchant. The various energies of the ions are selected to produce implant damage substantially uniformly throughout the entire depth of the zone to be etched, thus tailoring the vertical profile of the damaged zone.

  12. Quantitative photothermal characterization of ion-implanted layers in Si

    NASA Astrophysics Data System (ADS)

    Salnick, Alex; Opsal, Jon

    2002-03-01

    Quantitative analysis of ion-implanted layers in Si using the damage-based theoretical modeling and experimental results obtained with the photomodulated reflectance (PMR) technique are described. Our theoretical approach combines the conventional quantum mechanics based calculations of the ion-induced damage depth profiles in semiconductors with the corresponding scaling of the thermal and carrier plasma parameters followed by the calculation of the photothermal response from a multilayered sample. The theoretical limit of the photothermal signal sensitivity to the implantation dose in the absence of optical and carrier plasma-wave interference effects is estimated. Simulations of the photothermal amplitude and phase dose dependencies allow us to follow the dynamics of the thermal- and carrier plasma waves in an ion-implanted semiconductor. The validity of the proposed damage-based modeling approach to the problem of quantitative analysis of surface-modified semiconductors is analyzed. It is shown that the results of the photothermal damage-based modeling are in a very good agreement with experimentally observed PMR signal implantation dose behavior for B+-implanted Si across the entire range of practically important implantation doses: 109-1015 cm-2.

  13. Ion implantation and laser annealing

    NASA Astrophysics Data System (ADS)

    Three ion implantation and laser annealing projects have been performed by ORNL through the DOE sponsored Seed Money Program. The research has contributed toward improving the characteristics of wear, hardness, and corrosion resistance of some metals and ceramics, as well as the electrical properties of semiconductors. The work has helped to spawn related research, at ORNL and elsewhere, concerning the relationships between microstructure and materials properties. ORNL research has resulted in major advances in extended life and non-corrosive artificial joints (hip and knee), high performance semiconductors, failure resistant ceramics (with potential energy applications), and solar cells. The success of the seed money projects was instrumental in the formation of ORNL's Surface Modification and Characterization Facility (SMAC). More than 60 universities and companies have participated in SMAC programs.

  14. Optimised Charging Performance On Quantum X Ion Implanters

    NASA Astrophysics Data System (ADS)

    Kirkwood, David A.; Sakase, Takao; Miura, Ryuichi; Goldberg, Richard D.; Murrell, Adrian J.

    2006-11-01

    A key parameter in the optimisation of CMOS device yield is the minimisation of charging-induced damage and/or breakdown of the gate dielectric material during ion implantation. In typical ion beams used for transistor doping applications, beam potentials can charge up the wafer surface if not controlled, and hence this potential must be neutralised to avoid damage to devices. MOS capacitor TEG (Test Element Group) wafers are an industry standard metric for determining the charging performance of ion implanters. By optimising the performance of the High Density Plasma Flood System (HDPFS) of the Applied Materials Quantum X ion implanter, TEG device yields of >90% at antenna ratios of 1E5:1 for a gate dielectric thickness of 3.5 nm on 300 mm wafers have been demonstrated.

  15. Physical and Tribological Characteristics of Ion-Implanted Diamond Films

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Heidger, S.; Korenyi-Both, A. L.; Jayne, D. T.; Herrera-Fierro, P.; Shogrin, B.; Wilbur, P. J.; Wu, R. L. C.; Garscadden, A.; Barnes, P. N.

    1994-01-01

    Unidirectional sliding friction experiments were conducted with a natural, polished diamond pin in contact with both as-deposited and carbon-ion-implanted diamond films in ultrahigh vacuum. Diamond films were deposited on silicon, silicon carbide, and silicon nitride by microwave-plasma-assisted chemical vapor deposition. The as-deposited diamond films were impacted with carbon ions at an accelerating energy of 60 keV and a current density of 50 micron A/cm(exp 2) for approximately 6 min, resulting in a dose of 1.2 x 10(exp 17) carbon ions/cm(exp 2). The results indicate that the carbon ion implantation produced a thin surface layer of amorphous, nondiamond carbon. The nondiamond carbon greatly decreased both friction and wear of the diamond films. The coefficients of friction for the carbon-ion-implanted, fine-grain diamond films were less than 0.1, factors of 20 to 30 lower than those for the as-deposited, fine-grain diamond films. The coefficients of friction for the carbon-ion-implanted, coarse-grain diamond films were approximately 0.35, a factor of five lower than those for the as-deposited, coarse-grain diamond films. The wear rates for the carbon-ion-implanted, diamond films were on the order of 10(exp -6) mm(exp 3)/Nm, factors of 30 to 80 lower than that for the as-deposited diamond films, regardless of grain size. The friction of the carbon-ion-implanted diamond films was greatly reduced because the amorphous, nondiamond carbon, which had a low shear strength, was restricted to the surface layers (less than 0.1 micron thick) and because the underlying diamond materials retained their high hardness. In conclusion, the carbon-ion-implanted, fine-grain diamond films can be used effectively as wear resistant, self-lubricating coatings for ceramics, such as silicon nitride and silicon carbide, in ultrahigh vacuum.

  16. Ion Implantation with Scanning Probe Alignment

    SciTech Connect

    Persaud, A.; Liddle, J.A.; Schenkel, T.; Bokor, J.; Ivanov, Tzv.; Rangelow, I.W.

    2005-07-12

    We describe a scanning probe instrument which integrates ion beams with the imaging and alignment function of a piezo-resistive scanning probe in high vacuum. The beam passes through several apertures and is finally collimated by a hole in the cantilever of the scanning probe. The ion beam spot size is limited by the size of the last aperture. Highly charged ions are used to show hits of single ions in resist, and we discuss the issues for implantation of single ions.

  17. Optimization of the ion implantation process

    NASA Astrophysics Data System (ADS)

    Maczka, D.; Latuszynski, A.; Kuduk, R.; Partyka, J.

    This work is devoted to the optimization of the ion implantation process in the implanter Unimas of the Institute of Physics, Maria Curie-Sklodowska University, Lublin. The results obtained during several years of operation allow us to determine the optimal work parameters of the device [1-3].

  18. Application of ion implantation to electrochemical studies

    SciTech Connect

    Vallet, C.E.; White, C.W.

    1990-01-01

    The application of ion implantation to electrochemical studies is illustrated with a study of electrocatalysis of the chlorine evolution reaction at RuO{sub 2}, IrO{sub 2}, TiO{sub 2} mixed oxide anodes in chloride solutions. Electrode/solution interfaces of well defined catalyst composition are generated in a reproducible manner by implantation of Ru (or Ir) into Ti followed by in situ oxidation of the near surface titanium alloys. Ion implantation enables the tailoring on an atomic scale of an electrochemical interface. Analysis by Rutherford backscattering adds the ability of quantitative mechanistic study in terms of actual ion concentration at the interface. In addition, ion implantation, as a processing technique, creates new materials with improved properties which may have future practical use in catalytic materials.

  19. Surface Protection and Improved Performance of Satellite Components as well as Mitigation of Space Environmental Pollution by Plasma Ion Implantation

    SciTech Connect

    Ueda, M.; Takahashi, W. K.; Marcondes, A. R.; Tan, I. H.; Silva, G.

    2009-01-05

    Three plasma processing systems based on PII technique have been used in the improvement of surface properties of different materials important for aerospace and space applications. Metal plasma PII of Al and Mg was used for surface protection of polymers used in space such as Kapton, Mylar and polyethylene. Al alloys were treated with nitrogen PII for improved resistance to corrosion aiming at aerospace applications. A rigid polymer UHMWPE was also treated in a nitrogen PII to produce a protective layer with DLC. Although not very light, SS304 stainless steel components are being used in a imaging camera in space, and some components made of this material showed endurance to vibration tests after nitrogen PII, therefore being qualified for on-board application.

  20. Effects of phosphorus doping by plasma immersion ion implantation on the structural and optical characteristics of Zn{sub 0.85}Mg{sub 0.15}O thin films

    SciTech Connect

    Saha, S.; Nagar, S.; Chakrabarti, S.

    2014-08-11

    ZnMgO thin films deposited on 〈100〉 Si substrates by RF sputtering were annealed at 800, 900, and 1000 °C after phosphorus plasma immersion ion implantation. X-ray diffraction spectra confirmed the presence of 〈101{sup ¯}0〉 and 〈101{sup ¯}3〉 peaks for all the samples. However, in case of the annealed samples, the 〈0002〉 peak was also observed. Scanning electron microscopy images revealed the variation in surface morphology caused by phosphorus implantation. Implanted and non-implanted samples were compared to examine the effects of phosphorus implantation on the optical properties of ZnMgO. Optical characteristics were investigated by low-temperature (15 K) photoluminescence experiments. Inelastic exciton–exciton scattering and localized, and delocalized excitonic peaks appeared at 3.377, 3.42, and 3.45 eV, respectively, revealing the excitonic effect resulting from phosphorus implantation. This result is important because inelastic exciton–exciton scattering leads to nonlinear emission, which can improve the performance of many optoelectronic devices.

  1. Effects of electrical conductivity of substrate materials on microstructure of diamond-like carbon films prepared by bipolar-type plasma based ion implantation

    NASA Astrophysics Data System (ADS)

    Nakao, S.; Sonoda, T.

    2013-03-01

    Diamond-like carbon (DLC) films are prepared by a bipolar-type plasma based ion implantation, and the structural differences between DLC films deposited on different electrical conductive substrates, i.e., conductive Si wafers and insulating glass plates are examined by Raman spectroscopy and x-ray photo emission spectroscopy (XPS). In the Raman measurements, graphite (G) and disorder (D) peaks are observed for both samples. However, the additional photo luminescence is overlapped on the spectra in the case of on-glass sample. To elucidate the structural difference, the intensity ratio of D to G peak (I(D)/I(G)), G peak position and full width at half maximum (FWHM) are obtained by curve fitting using Gaussian function and linear baseline. It is found that the I(D)/I(G) is lower, G peak position is higher and FWHM of G peak is narrower for on-glass sample than for on-Si sample. According to Robertson [1], lower I(D)/I(G) seems more sp3 C-C bonding in amount for on-glass sample. In contrast, higher G peak position and narrower FWHM of G peak suggest less sp3 C-C bonding in amount for on-glass sample. The results of XPS analysis with C1s spectra reveal that sp3 ratio, i.e., the intensity ratio of sp3/(sp3+sp2) is smaller for on-glass sample than for on-Si sample. The inconsistency of the trend between I(D)/I(G) and other parameters (G peak position and FWHM of G peak) might be caused by the overlap of photo luminescence signal on Raman spectrum as to on-glass sample. From these results, it is considered that sp3 C-C bonding is reduced in amount when using insulating substrate in comparison with conductive substrate.

  2. Ion implantations of oxide dispersion strengthened steels

    NASA Astrophysics Data System (ADS)

    Sojak, S.; Simeg Veternikova, J.; Slugen, V.; Petriska, M.; Stacho, M.

    2015-12-01

    This paper is focused on a study of radiation damage and thermal stability of high chromium oxide dispersion strengthened steel MA 956 (20% Cr), which belongs to the most perspective structural materials for the newest generation of nuclear reactors - Generation IV. The radiation damage was simulated by the implantation of hydrogen ions up to the depth of about 5 μm, which was performed at a linear accelerator owned by Slovak University of Technology. The ODS steel MA 956 was available for study in as-received state after different thermal treatments as well as in ions implanted state. Energy of the hydrogen ions chosen for the implantation was 800 keV and the implantation fluence of 6.24 × 1017 ions/cm2. The investigated specimens were measured by non-destructive technique Positron Annihilation Lifetime Spectroscopy in order to study the defect behavior after different thermal treatments in the as-received state and after the hydrogen ions implantation. Although, different resistance to defect production was observed in individual specimens of MA 956 during the irradiation, all implanted specimens contain larger defects than the ones in as-received state.

  3. High-intensity laser for Ta and Ag implantation into different substrates for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Cutroneo, M.; Mackova, A.; Malinsky, P.; Matousek, J.; Torrisi, L.; Ullschmied, J.

    2015-07-01

    High-intensity lasers generating non-equilibrium plasma, can be employed to accelerate ions in the keV-MeV region, useful for many applications. In the present work, we performed study of ion implantation into different substrates by using a high-intensity laser at the PALS laboratory in Prague. Multi-energy ions generated by plasma from Ta and Ag targets were implanted into polyethylene and metallic substrates (Al, Ti) at energies of tens of keV per charge state. The ion emission was monitored online using time-of-flight detectors and electromagnetic deflection systems. Rutherford Backscattering Spectrometry (RBS) was used to characterise the elemental composition in the implanted substrates by ion plasma emission and to provide the implanted ion depth profiling. These last measurements enable offline plasma characterisation and provide information on the useful potentiality of multi-ion species and multi-energy ion implantation into different substrates. XPS analysis gives information on the chemical bonds and their modifications in the first superficial implanted layers. The depth distributions of implanted Ta and Ag ions were compared with the theoretical ones achieved by using the SRIM-2012 simulation code.

  4. Molecular ion sources for low energy semiconductor ion implantation (invited)

    NASA Astrophysics Data System (ADS)

    Hershcovitch, A.; Gushenets, V. I.; Seleznev, D. N.; Bugaev, A. S.; Dugin, S.; Oks, E. M.; Kulevoy, T. V.; Alexeyenko, O.; Kozlov, A.; Kropachev, G. N.; Kuibeda, R. P.; Minaev, S.; Vizir, A.; Yushkov, G. Yu.

    2016-02-01

    Smaller semiconductors require shallow, low energy ion implantation, resulting space charge effects, which reduced beam currents and production rates. To increase production rates, molecular ions are used. Boron and phosphorous (or arsenic) implantation is needed for P-type and N-type semiconductors, respectively. Carborane, which is the most stable molecular boron ion leaves unacceptable carbon residue on extraction grids. A self-cleaning carborane acid compound (C4H12B10O4) was synthesized and utilized in the ITEP Bernas ion source resulting in large carborane ion output, without carbon residue. Pure gaseous processes are desired to enable rapid switch among ion species. Molecular phosphorous was generated by introducing phosphine in dissociators via 4PH3 = P4 + 6H2; generated molecular phosphorous in a pure gaseous process was then injected into the HCEI Calutron-Bernas ion source, from which P4+ ion beams were extracted. Results from devices and some additional concepts are described.

  5. Molecular ion sources for low energy semiconductor ion implantation (invited).

    PubMed

    Hershcovitch, A; Gushenets, V I; Seleznev, D N; Bugaev, A S; Dugin, S; Oks, E M; Kulevoy, T V; Alexeyenko, O; Kozlov, A; Kropachev, G N; Kuibeda, R P; Minaev, S; Vizir, A; Yushkov, G Yu

    2016-02-01

    Smaller semiconductors require shallow, low energy ion implantation, resulting space charge effects, which reduced beam currents and production rates. To increase production rates, molecular ions are used. Boron and phosphorous (or arsenic) implantation is needed for P-type and N-type semiconductors, respectively. Carborane, which is the most stable molecular boron ion leaves unacceptable carbon residue on extraction grids. A self-cleaning carborane acid compound (C4H12B10O4) was synthesized and utilized in the ITEP Bernas ion source resulting in large carborane ion output, without carbon residue. Pure gaseous processes are desired to enable rapid switch among ion species. Molecular phosphorous was generated by introducing phosphine in dissociators via 4PH3 = P4 + 6H2; generated molecular phosphorous in a pure gaseous process was then injected into the HCEI Calutron-Bernas ion source, from which P4(+) ion beams were extracted. Results from devices and some additional concepts are described.

  6. Enhanced patterning by tilted ion implantation

    NASA Astrophysics Data System (ADS)

    Kim, Sang Wan; Zheng, Peng; Kato, Kimihiko; Rubin, Leonard; Liu, Tsu-Jae King

    2016-03-01

    Tilted ion implantation (TII) is proposed as a lower-cost alternative to self-aligned double patterning (SADP) for pitch halving. This new approach is based on an enhancement in etch rate of a hard-mask layer by implant-induced damage. Ar+ implantation into a thin layer of silicon dioxide (SiO2) is shown to enhance its etch rate in dilute hydrofluoric acid (HF) solution, by up to 9× for an implant dose of 3×1014 cm-2. The formation of sub-lithographic features defined by masked tilted Ar+ implantation into a SiO2 hard-mask layer is experimentally demonstrated. Features with sizes as small as ~21 nm, self-aligned to the lithographically patterned mask, are achieved. As compared with SADP, enhanced patterning by TII requires far fewer and lower-cost process steps and hence is expected to be much more cost-effective.

  7. Ion implantation of boron in germanium

    SciTech Connect

    Jones, K.S.

    1985-05-01

    Ion implantation of /sup 11/B/sup +/ into room temperature Ge samples leads to a p-type layer prior to any post implant annealing steps. Variable temperature Hall measurements and deep level transient spectroscopy experiments indicate that room temperature implantation of /sup 11/B/sup +/ into Ge results in 100% of the boron ions being electrically active as shallow acceptor, over the entire dose range (5 x 10/sup 11//cm/sup 2/ to 1 x 10/sup 14//cm/sup 2/) and energy range (25 keV to 100 keV) investigated, without any post implant annealing. The concentration of damage related acceptor centers is only 10% of the boron related, shallow acceptor center concentration for low energy implants (25 keV), but becomes dominant at high energies (100 keV) and low doses (<1 x 10/sup 12//cm/sup 2/). Three damage related hole traps are produced by ion implantation of /sup 11/B/sup +/. Two of these hole traps have also been observed in ..gamma..-irradiated Ge and may be oxygen-vacancy related defects, while the third trap may be divacancy related. All three traps anneal out at low temperatures (<300/sup 0/C). Boron, from room temperature implantation of BF/sub 2//sup +/ into Ge, is not substitutionally active prior to a post implant annealing step of 250/sup 0/C for 30 minutes. After annealing additional shallow acceptors are observed in BF/sub 2//sup +/ implanted samples which may be due to fluorine or flourine related complexes which are electrically active.

  8. More-reliable SOS ion implantations

    NASA Technical Reports Server (NTRS)

    Woo, D. S.

    1980-01-01

    Conducting layer prevents static charges from accumulating during implantation of silicon-on-sapphire MOS structures. Either thick conducting film or thinner film transparent to ions is deposited prior to implantation, and gaps are etched in regions to be doped. Grounding path eliminates charge flow that damages film or cracks sapphire wafer. Prevention of charge buildup by simultaneously exposing structure to opposite charges requires equipment modifications less practical and more expensive than deposition of conducting layer.

  9. Diffusion mechanism and the thermal stability of fluorine ions in GaN after ion implantation

    SciTech Connect

    Wang, M. J.; Yuan, L.; Chen, K. J.; Xu, F. J.; Shen, B.

    2009-04-15

    The diffusion mechanisms of fluorine ions in GaN are investigated by means of time-of-flight secondary ion mass spectrometry. Instead of incorporating fluorine ions close to the sample surface by fluorine plasma treatment, fluorine ion implantation with an energy of 180 keV is utilized to implant fluorine ions deep into the GaN bulk, preventing the surface effects from affecting the data analysis. It is found that the diffusion of fluorine ions in GaN is a dynamic process featuring an initial out-diffusion followed by in- diffusion and the final stabilization. A vacancy-assisted diffusion model is proposed to account for the experimental observations, which is also consistent with results on molecular dynamic simulation. Fluorine ions tend to occupy Ga vacancies induced by ion implantation and diffuse to vacancy rich regions. The number of continuous vacancy chains can be significantly reduced by a dynamic thermal annealing process. As a result, strong local confinement and stabilization of fluorine ions can be obtained in GaN crystal, suggesting excellent thermal stability of fluorine ions for device applications.

  10. Single Ion Implantation and Deterministic Doping

    SciTech Connect

    Schenkel, Thomas

    2010-06-11

    The presence of single atoms, e.g. dopant atoms, in sub-100 nm scale electronic devices can affect the device characteristics, such as the threshold voltage of transistors, or the sub-threshold currents. Fluctuations of the number of dopant atoms thus poses a complication for transistor scaling. In a complementary view, new opportunities emerge when novel functionality can be implemented in devices deterministically doped with single atoms. The grand price of the latter might be a large scale quantum computer, where quantum bits (qubits) are encoded e.g. in the spin states of electrons and nuclei of single dopant atoms in silicon, or in color centers in diamond. Both the possible detrimental effects of dopant fluctuations and single atom device ideas motivate the development of reliable single atom doping techniques which are the subject of this chapter. Single atom doping can be approached with top down and bottom up techniques. Top down refers to the placement of dopant atoms into a more or less structured matrix environment, like a transistor in silicon. Bottom up refers to approaches to introduce single dopant atoms during the growth of the host matrix e.g. by directed self-assembly and scanning probe assisted lithography. Bottom up approaches are discussed in Chapter XYZ. Since the late 1960's, ion implantation has been a widely used technique to introduce dopant atoms into silicon and other materials in order to modify their electronic properties. It works particularly well in silicon since the damage to the crystal lattice that is induced by ion implantation can be repaired by thermal annealing. In addition, the introduced dopant atoms can be incorporated with high efficiency into lattice position in the silicon host crystal which makes them electrically active. This is not the case for e.g. diamond, which makes ion implantation doping to engineer the electrical properties of diamond, especially for n-type doping much harder then for silicon. Ion

  11. Hybrid quantum circuit with implanted erbium ions

    SciTech Connect

    Probst, S.; Rotzinger, H.; Tkalčec, A.; Kukharchyk, N.; Wieck, A. D.; Wünsch, S.; Siegel, M.; Ustinov, A. V.; Bushev, P. A.

    2014-10-20

    We report on hybrid circuit quantum electrodynamics experiments with focused ion beam implanted Er{sup 3+} ions in Y{sub 2}SiO{sub 5} coupled to an array of superconducting lumped element microwave resonators. The Y{sub 2}SiO{sub 5} crystal is divided into several areas with distinct erbium doping concentrations, each coupled to a separate resonator. The coupling strength is varied from 5 MHz to 18.7 MHz, while the linewidth ranges between 50 MHz and 130 MHz. We confirm the paramagnetic properties of the implanted spin ensemble by evaluating the temperature dependence of the coupling. The efficiency of the implantation process is analyzed and the results are compared to a bulk doped Er:Y{sub 2}SiO{sub 5} sample. We demonstrate the integration of these engineered erbium spin ensembles with superconducting circuits.

  12. Implantation of sodium ions into germanium

    SciTech Connect

    Korol', V. M.; Kudriavtsev, Yu.

    2012-02-15

    The donor properties of Na atoms introduced by ion implantation into p-Ge with the resistivity 20-40 {Omega} cm are established for the first time. Na profiles implanted into Ge (the energies 70 and 77 keV and the doses (0.8, 3, 30) Multiplication-Sign 10{sup 14} cm{sup -2}) are studied. The doses and annealing temperatures at which the thermoprobe detects n-type conductivity on the sample surface are established. After implantation, the profiles exhibit an extended tail. The depth of the concentration maximum is in good agreement with the calculated mean projected range of Na ions R{sub p}. Annealing for 30 min at temperatures of 250-700 Degree-Sign C brings about a redistribution of Na atoms with the formation of segregation peaks at a depth, which is dependent on the ion dose, and is accompanied by the diffusion of Na atoms to the surface with subsequent evaporation. After annealing at 700 Degree-Sign C less than 7% of the implanted ions remain in the matrix. The shape of the profile tail portions measured after annealing at temperatures 300-400 Degree-Sign C is indicative of the diffusion of a small fraction of Na atoms into the depth of the sample.

  13. Metal ion implantation for large scale surface modification

    SciTech Connect

    Brown, I.G.

    1992-10-01

    Intense energetic beams of metal ions can be produced by using a metal vapor vacuum arc as the plasma discharge from which the ion beam is formed. We have developed a number of ion sources of this kind and have built a metal ion implantation facility which can produce repetitively pulsed ion beams with mean ion energy up to several hundred key, pulsed beam current of more than an ampere, and time averaged current of several tens of milliamperes delivered onto a downstream target. We've also done some preliminary work on scaling up this technology to very large size. For example, a 50-cm diameter (2000 cm[sup 2]) set of beam formation electrodes was used to produce a pulsed titanium beam with ion current over 7 amperes at a mean ion energy of 100 key. Separately, a dc embodiment has been used to produce a dc titanium ion beam with current over 600 mA, power supply limited in this work, and up to 6 amperes of dc plasma ion current was maintained for over an hour. In a related program we've developed a plasma immersion method for applying thin metallic and compound films in which the added species is atomically mixed to the substrate. By adding a gas flow to the process, well-bonded compound films can also be formed; metallic films and multilayers as well as oxides and nitrides with mixed transition zones some hundreds of angstroms thick have been synthesized. Here we outline these parallel metal-plasma-based research programs and describe the hardware that we've developed and some of the surface modification research that we've done with it.

  14. Activation Mechanisms in Ion-Implanted Gallium -

    NASA Astrophysics Data System (ADS)

    Morris, Neil

    Available from UMI in association with The British Library. Rapid Thermal Annealing has been used to study the electrical activation of a range of donor and acceptor species in ion-implanted GaAs. By varying the time and temperature of the post implant anneal, it was found that the activation processes for most implants can be characterised in terms of two distinct regions. The first of these occurs at short annealing times, where the electrical activity is seen to follow a time-dependent behaviour. At longer annealing times, however, a time-independent saturation value is reached, this value being dependent on the annealing temperature. By analysing the data from Be, Mg, S and Se implants in GaAs, a comprehensive model has been evolved for the time and temperature dependence of the sheet electrical properties. Application of this model to each of the ions studied suggests that the activation processes may be dominated by the extent to which ions form impurity-vacancy complexes. An analysis of the time-dependent regime also shows that, at short annealing times, the mobile species is more likely to be the substrate atoms (or vacancies) rather than the implanted impurities. In the time-dependent region, the values of diffusion energy were found to be between 2.3 to 3.0 eV for all ions, these values corresponding to a diffusion of Ga or As vacancies (or atoms). In the saturation region, activation energies of 0.3 to 0.4 eV and 1.0 to 1.2 eV were obtained for the activation processes of interstitial or complexed impurities respectively.

  15. Ion sources for energy extremes of ion implantation.

    PubMed

    Hershcovitch, A; Johnson, B M; Batalin, V A; Kropachev, G N; Kuibeda, R P; Kulevoy, T V; Kolomiets, A A; Pershin, V I; Petrenko, S V; Rudskoy, I; Seleznev, D N; Bugaev, A S; Gushenets, V I; Litovko, I V; Oks, E M; Yushkov, G Yu; Masunov, E S; Polozov, S M; Poole, H J; Storozhenko, P A; Svarovski, A Ya

    2008-02-01

    For the past four years a joint research and development effort designed to develop steady state, intense ion sources has been in progress with the ultimate goal to develop ion sources and techniques that meet the two energy extreme range needs of meV and hundreads of eV ion implanters. This endeavor has already resulted in record steady state output currents of high charge state of antimony and phosphorus ions: P(2+) [8.6 pmA (particle milliampere)], P(3+) (1.9 pmA), and P(4+) (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb(3+)Sb(4+), Sb(5+), and Sb(6+) respectively. For low energy ion implantation, our efforts involve molecular ions and a novel plasmaless/gasless deceleration method. To date, 1 emA (electrical milliampere) of positive decaborane ions was extracted at 10 keV and smaller currents of negative decaborane ions were also extracted. Additionally, boron current fraction of over 70% was extracted from a Bernas-Calutron ion source, which represents a factor of 3.5 improvement over currently employed ion sources.

  16. ION SOURCES FOR ENERGY EXTREMES OF ION IMPLANTATION.

    SciTech Connect

    HERSCHCOVITCH,A.; JOHNSON, B.M.; BATALIN, V.A.; KROPACHEV, G.N.; KUIBEDA, R.P.; KULEVOY, T.V.; KOLOMIETS, A.A.; PERSHIN, V.I.; PETRENKO, S.V.; RUDSKOY, I.; SELEZNEV, D.N.; BUGAEV, A.S.; GUSHENETS, V.I.; LITOVKO, I.V.; OKS, E.M.; YUSHKOV, G. YU.; MASEUNOV, E.S.; POLOZOV, S.M.; POOLE, H.J.; STOROZHENKO, P.A.; SVAROVSKI, YA.

    2007-08-26

    For the past four years a joint research and development effort designed to develop steady state, intense ion sources has been in progress with the ultimate goal to develop ion sources and techniques, which meet the two energy extreme range needs of mega-electron-volt and 100's of electron-volt ion implanters. This endeavor has already resulted in record steady state output currents of high charge state of Antimony and Phosphorous ions: P{sup 2+} (8.6 pmA), P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+} Sb{sup 4+}, Sb{sup 5+}, and Sb{sup 6+} respectively. For low energy ion implantation our efforts involve molecular ions and a novel plasmaless/gasless deceleration method. To date, 1 emA of positive Decaborane ions were extracted at 10 keV and smaller currents of negative Decaborane ions were also extracted. Additionally, Boron current fraction of over 70% was extracted from a Bemas-Calutron ion source, which represents a factor of 3.5 improvement over currently employed ion sources.

  17. Method for ion implantation induced embedded particle formation via reduction

    DOEpatents

    Hampikian, Janet M; Hunt, Eden M

    2001-01-01

    A method for ion implantation induced embedded particle formation via reduction with the steps of ion implantation with an ion/element that will chemically reduce the chosen substrate material, implantation of the ion/element to a sufficient concentration and at a sufficient energy for particle formation, and control of the temperature of the substrate during implantation. A preferred embodiment includes the formation of particles which are nano-dimensional (<100 m-n in size). The phase of the particles may be affected by control of the substrate temperature during and/or after the ion implantation process.

  18. Rhenium ion beam for implantation into semiconductors

    SciTech Connect

    Kulevoy, T. V.; Seleznev, D. N.; Alyoshin, M. E.; Kraevsky, S. V.; Yakushin, P. E.; Khoroshilov, V. V.; Gerasimenko, N. N.; Smirnov, D. I.; Fedorov, P. A.; Temirov, A. A.

    2012-02-15

    At the ion source test bench in Institute for Theoretical and Experimental Physics the program of ion source development for semiconductor industry is in progress. In framework of the program the Metal Vapor Vacuum Arc ion source for germanium and rhenium ion beam generation was developed and investigated. It was shown that at special conditions of ion beam implantation it is possible to fabricate not only homogenous layers of rhenium silicides solid solutions but also clusters of this compound with properties of quantum dots. At the present moment the compound is very interesting for semiconductor industry, especially for nanoelectronics and nanophotonics, but there is no very developed technology for production of nanostructures (for example quantum sized structures) with required parameters. The results of materials synthesis and exploration are presented.

  19. Production of Endohedral Fullerenes by Ion Implantation

    SciTech Connect

    Diener, M.D.; Alford, J. M.; Mirzadeh, S.

    2007-05-31

    The empty interior cavity of fullerenes has long been touted for containment of radionuclides during in vivo transport, during radioimmunotherapy (RIT) and radioimaging for example. As the chemistry required to open a hole in fullerene is complex and exceedingly unlikely to occur in vivo, and conformational stability of the fullerene cage is absolute, atoms trapped within fullerenes can only be released during extremely energetic events. Encapsulating radionuclides in fullerenes could therefore potentially eliminate undesired toxicity resulting from leakage and catabolism of radionuclides administered with other techniques. At the start of this project however, methods for production of transition metal and p-electron metal endohedral fullerenes were completely unknown, and only one method for production of endohedral radiofullerenes was known. They therefore investigated three different methods for the production of therapeutically useful endohedral metallofullerenes: (1) implantation of ions using the high intensity ion beam at the Oak Ridge National Laboratory (ORNL) Surface Modification and Characterization Research Center (SMAC) and fullerenes as the target; (2) implantation of ions using the recoil energy following alpha decay; and (3) implantation of ions using the recoil energy following neutron capture, using ORNL's High Flux Isotope Reactor (HFIR) as a thermal neutron source. While they were unable to obtain evidence of successful implantation using the ion beam at SMAC, recoil following alpha decay and neutron capture were both found to be economically viable methods for the production of therapeutically useful radiofullerenes. In this report, the procedures for preparing fullerenes containing the isotopes {sup 212}Pb, {sup 212}Bi, {sup 213}Bi, and {sup 177}Lu are described. None of these endohedral fullerenes had ever previously been prepared, and all of these radioisotopes are actively under investigation for RIT. Additionally, the chemistry for

  20. Enhanced life ion source for germanium and carbon ion implantation

    SciTech Connect

    Hsieh, Tseh-Jen; Colvin, Neil; Kondratenko, Serguei

    2012-11-06

    Germanium and carbon ions represent a significant portion of total ion implantation steps in the process flow. Very often ion source materials that used to produce ions are chemically aggressive, especially at higher temperatures, and result in fast ion source performance degradation and a very limited lifetime [B.S. Freer, et. al., 2002 14th Intl. Conf. on Ion Implantation Technology Proc, IEEE Conf. Proc., p. 420 (2003)]. GeF{sub 4} and CO{sub 2} are commonly used to generate germanium and carbon beams. In the case of GeF{sub 4} controlling the tungsten deposition due to the de-composition of WF{sub 6} (halogen cycle) is critical to ion source life. With CO{sub 2}, the materials oxidation and carbon deposition must be controlled as both will affect cathode thermionic emission and anti-cathode (repeller) efficiencies due to the formation of volatile metal oxides. The improved ion source design Extended Life Source 3 (Eterna ELS3) together with its proprietary co-gas material implementation has demonstrated >300 hours of stable continuous operation when using carbon and germanium ion beams. Optimizing cogas chemistries retard the cathode erosion rate for germanium and carbon minimizes the adverse effects of oxygen when reducing gas is introduced for carbon. The proprietary combination of hardware and co-gas has improved source stability and the results of the hardware and co-gas development are discussed.

  1. Accelerating degradation rate of pure iron by zinc ion implantation.

    PubMed

    Huang, Tao; Zheng, Yufeng; Han, Yong

    2016-12-01

    Pure iron has been considered as a promising candidate for biodegradable implant applications. However, a faster degradation rate of pure iron is needed to meet the clinical requirement. In this work, metal vapor vacuum arc technology was adopted to implant zinc ions into the surface of pure iron. Results showed that the implantation depth of zinc ions was about 60 nm. The degradation rate of pure iron was found to be accelerated after zinc ion implantation. The cytotoxicity tests revealed that the implanted zinc ions brought a slight increase on cytotoxicity of the tested cells. In terms of hemocompatibility, the hemolysis of zinc ion implanted pure iron was lower than 2%. However, zinc ions might induce more adhered and activated platelets on the surface of pure iron. Overall, zinc ion implantation can be a feasible way to accelerate the degradation rate of pure iron for biodegradable applications. PMID:27482462

  2. Accelerating degradation rate of pure iron by zinc ion implantation

    PubMed Central

    Huang, Tao; Zheng, Yufeng; Han, Yong

    2016-01-01

    Pure iron has been considered as a promising candidate for biodegradable implant applications. However, a faster degradation rate of pure iron is needed to meet the clinical requirement. In this work, metal vapor vacuum arc technology was adopted to implant zinc ions into the surface of pure iron. Results showed that the implantation depth of zinc ions was about 60 nm. The degradation rate of pure iron was found to be accelerated after zinc ion implantation. The cytotoxicity tests revealed that the implanted zinc ions brought a slight increase on cytotoxicity of the tested cells. In terms of hemocompatibility, the hemolysis of zinc ion implanted pure iron was lower than 2%. However, zinc ions might induce more adhered and activated platelets on the surface of pure iron. Overall, zinc ion implantation can be a feasible way to accelerate the degradation rate of pure iron for biodegradable applications. PMID:27482462

  3. Shallow nitrogen ion implantation: Evolution of chemical state and defect structure in titanium

    NASA Astrophysics Data System (ADS)

    Manojkumar, P. A.; Chirayath, V. A.; Balamurugan, A. K.; Krishna, Nanda Gopala; Ilango, S.; Kamruddin, M.; Amarendra, G.; Tyagi, A. K.; Raj, Baldev

    2016-09-01

    Evolution of chemical states and defect structure in titanium during low energy nitrogen ion implantation by Plasma Immersion Ion Implantation (PIII) process is studied. The underlying process of chemical state evolution is investigated using secondary ion mass spectrometry and X-ray photoelectron spectroscopy. The implantation induced defect structure evolution as a function of dose is elucidated using variable energy positron annihilation Doppler broadening spectroscopy (PAS) and the results were corroborated with chemical state. Formation of 3 layers of defect state was modeled to fit PAS results.

  4. Plasma polymerization for cell adhesive/anti-adhesive implant coating

    NASA Astrophysics Data System (ADS)

    Meichsner, Juergen; Testrich, Holger; Rebl, Henrike; Nebe, Barbara

    2015-09-01

    Plasma polymerization of ethylenediamine (C2H8N2, EDA) and perfluoropropane (C3F8, PFP) with admixture of argon and hydrogen, respectively, was studied using an asymmetric 13.56 MHz CCP. The analysis of the plasma chemical gas phase processes for stable molecules revealed consecutive reactions: C2H8N2 consumption, intermediate product NH3, and main final product HCN. In C3F8- H2 plasma the precursor molecule C3F8 and molecular hydrogen are consumed and HF as well as CF4 and C2F6 are found as main gaseous reaction products. The deposited plasma polymer films on the powered electrode are strongly cross-linked due to ion bombardment. The stable plasma polymerized films from EDA are characterized by high content of nitrogen with N/C ratio of about 0.35. The plasma polymerized fluorocarbon film exhibit a reduced F/C ratio of about 1.2. Adhesion tests with human osteoblast cell line MG-63 on coated Ti6Al4V samples (polished) compared with uncoated reference sample yielded both, the enhanced cell adhesion for plasma polymerized EDA and significantly reduced cell adhesion for fluorocarbon coating, respectively. Aging of the plasma polymerized EDA film, in particular due to the reactions with oxygen from air, showed no significant change in the cell adhesion. The fluorocarbon coating with low cell adhesion is of interest for temporary implants. Funded by the Campus PlasmaMed.

  5. An experiment on the dynamics of ion implantation and sputtering of surfaces

    SciTech Connect

    Wright, G. M.; Barnard, H. A.; Kesler, L. A.; Peterson, E. E.; Stahle, P. W.; Sullivan, R. M.; Whyte, D. G.; Woller, K. B.

    2014-02-15

    A major impediment towards a better understanding of the complex plasma-surface interaction is the limited diagnostic access to the material surface while it is undergoing plasma exposure. The Dynamics of ION Implantation and Sputtering Of Surfaces (DIONISOS) experiment overcomes this limitation by uniquely combining powerful, non-perturbing ion beam analysis techniques with a steady-state helicon plasma exposure chamber, allowing for real-time, depth-resolved in situ measurements of material compositions during plasma exposure. Design solutions are described that provide compatibility between the ion beam analysis requirements in the presence of a high-intensity helicon plasma. The three primary ion beam analysis techniques, Rutherford backscattering spectroscopy, elastic recoil detection, and nuclear reaction analysis, are successfully implemented on targets during plasma exposure in DIONISOS. These techniques measure parameters of interest for plasma-material interactions such as erosion/deposition rates of materials and the concentration of plasma fuel species in the material surface.

  6. The influence of DC biasing on the uniformity of a-C:H films for three-dimensional substrates by using a plasma-based ion implantation technique

    NASA Astrophysics Data System (ADS)

    Watanabe, Toshiya; Yamamoto, Kazuhiro; Tsuda, Osamu; Tanaka, Akihiro; Koga, Yoshinori; Takai, Osamu

    2003-05-01

    Amorphous hydrogenated carbon (a-C:H) films were synthesized by the use of a PBII technique using an electron cyclotron resonance plasma source with a mirror field, and the influence of the biasing conditions on the properties and the uniformity of the three-dimensional surfaces of a-C:H films was investigated. For convex faces, the film thickness was almost constant, independent of the deposition conditions, because a uniform plasma surrounded the substrates. For concave faces, the thickness of the films that formed without biasing and with only the application of a pulse bias decreased when the microwave-incident angle was decreased. On the other hand, when a DC bias was applied to the substrate in addition to a pulse bias, the uniformity of the thickness was much improved with a distribution within ±10%. The improvement in the uniformity was assumed to be the result of the continuous supply of ions in the plasma to the surfaces by the DC biasing.

  7. Simulation of ion beam transport through the 400 Kv ion implanter at Michigan Ion Beam Laboratory

    NASA Astrophysics Data System (ADS)

    Naab, F. U.; Toader, O. F.; Was, G. S.

    2013-04-01

    The Michigan Ion Beam Laboratory houses a 400 kV ion implanter. An application that simulates the ion beam trajectories through the implanter from the ion source to the target was developed using the SIMION® code. The goals were to have a tool to develop an intuitive understanding of abstract physics phenomena and diagnose ion trajectories. Using this application, new implanter users of different fields in science quickly understand how the machine works and quickly learn to operate it. In this article we describe the implanter simulation application and compare the parameters of the implanter components obtained from the simulations with the measured ones. The overall agreement between the simulated and measured values of magnetic fields and electric potentials is ˜10%.

  8. Biodegradable radioactive implants for glaucoma filtering surgery produced by ion implantation

    NASA Astrophysics Data System (ADS)

    Assmann, W.; Schubert, M.; Held, A.; Pichler, A.; Chill, A.; Kiermaier, S.; Schlösser, K.; Busch, H.; Schenk, K.; Streufert, D.; Lanzl, I.

    2007-04-01

    A biodegradable, β-emitting implant has been developed and successfully tested which prevents fresh intraocular pressure increase after glaucoma filtering surgery. Ion implantation has been used to load the polymeric implants with the β-emitter 32P. The influence of ion implantation and gamma sterilisation on degradation and 32P-fixation behavior has been studied by ion beam and chemical analysis. Irradiation effects due to the applied ion fluence (1015 ions/cm2) and gamma dose (25 kGy) are found to be tolerable.

  9. Energetic ions in ITER plasmas

    NASA Astrophysics Data System (ADS)

    Pinches, S. D.; Chapman, I. T.; Lauber, Ph. W.; Oliver, H. J. C.; Sharapov, S. E.; Shinohara, K.; Tani, K.

    2015-02-01

    This paper discusses the behaviour and consequences of the expected populations of energetic ions in ITER plasmas. It begins with a careful analytic and numerical consideration of the stability of Alfvén Eigenmodes in the ITER 15 MA baseline scenario. The stability threshold is determined by balancing the energetic ion drive against the dominant damping mechanisms and it is found that only in the outer half of the plasma ( r / a > 0.5 ) can the fast ions overcome the thermal ion Landau damping. This is in spite of the reduced numbers of alpha-particles and beam ions in this region but means that any Alfvén Eigenmode-induced redistribution is not expected to influence the fusion burn process. The influence of energetic ions upon the main global MHD phenomena expected in ITER's primary operating scenarios, including sawteeth, neoclassical tearing modes and Resistive Wall Modes, is also reviewed. Fast ion losses due to the non-axisymmetric fields arising from the finite number of toroidal field coils, the inclusion of ferromagnetic inserts, the presence of test blanket modules containing ferromagnetic material, and the fields created by the Edge Localised Mode (ELM) control coils in ITER are discussed. The greatest losses and associated heat loads onto the plasma facing components arise due to the use of the ELM control coils and come from neutral beam ions that are ionised in the plasma edge.

  10. Computational stochastic model of ions implantation

    SciTech Connect

    Zmievskaya, Galina I. Bondareva, Anna L.; Levchenko, Tatiana V.; Maino, Giuseppe

    2015-03-10

    Implantation flux ions into crystal leads to phase transition /PT/ 1-st kind. Damaging lattice is associated with processes clustering vacancies and gaseous bubbles as well their brownian motion. System of stochastic differential equations /SDEs/ Ito for evolution stochastic dynamical variables corresponds to the superposition Wiener processes. The kinetic equations in partial derivatives /KE/, Kolmogorov-Feller and Einstein-Smolukhovskii, were formulated for nucleation into lattice of weakly soluble gases. According theory, coefficients of stochastic and kinetic equations uniquely related. Radiation stimulated phase transition are characterized by kinetic distribution functions /DFs/ of implanted clusters versus their sizes and depth of gas penetration into lattice. Macroscopic parameters of kinetics such as the porosity and stress calculated in thin layers metal/dielectric due to Xe{sup ++} irradiation are attracted as example. Predictions of porosity, important for validation accumulation stresses in surfaces, can be applied at restoring of objects the cultural heritage.

  11. Aluminum ion implantation under backfilling oxygen

    NASA Astrophysics Data System (ADS)

    Hausner, R. M.; Baumann, H.; Bethge, K.

    1996-06-01

    High dose ion implantation ( F ≥ 2 × 10 18 ions/cm 2) of 40 keV Al ions into stainless steel (AISI 321) under increased partial pressure of oxygen and oxygen compounds ( P ≥ 1 × 10 -8 hPa O 2, CO 2, N 2O) leads to the formation of a homogenous Al film on the sample surface due to a reduced self-sputtering yield of Al. The depth distribution of the implanted aluminum and the thickness of the Al film grown up on the sample were measured using the resonant nuclear reaction 27Al(p, γ) 28Si at 992 keV and by the (α, α) elastic backscattering at 3.05 MeV. The concentrations of the low- Z impurity oxygen and carbon were determined with the extremely strong resonances of the (α, α) elastic scattering under backward angles at 7.6 MeV for 16O and at 5.75 MeV for 12C. Furthermore the properties of the formed Al film were investigated by SEM, surface profile and microhardness measurements. The self-sputtering yield of Al was measured under normal vacuum conditions and under increased O 2 partial pressure, and the results were compared with the data obtained from calculations using the computer code T-DYN.

  12. Effect of Implantation Machine Parameters on N+ ion Implantation for Upland Cotton(Gossypium hirsutum L.) Pollen

    NASA Astrophysics Data System (ADS)

    Yue, Jieyu; Yu, Lixiang; Wu, Yuejin; Tang, Canming

    2008-10-01

    Effect of parameters of ion implantation machine, including ion energy, total dose, dose rate, impulse energy and implantation interval on the pollen grains of upland cotton implanted with nitrogen ion beam were studied. The best parameters were screened out. The results also showed that the vacuum condition before the nitrogen ion implantation does not affect the pollen viability.

  13. Ion implanted GaAs microwave FET's

    NASA Astrophysics Data System (ADS)

    Gill, S. S.; Blockley, E. G.; Dawsey, J. R.; Foreman, B. J.; Woodward, J.; Ball, G.; Beard, S. J.; Gaskell, J. M.; Allenson, M. B.

    1988-06-01

    The combination of ion implantation and photolithographic patterning techniques was applied to the fabrication of GaAs microwave FETs to provide a large number of devices having consistently predictable dc and high frequency characteristics. To validate the accuracy and repeatability of the high frequency device parameters, an X-band microwave circuit was designed and realized. The performance of this circuit, a buffered amplifier, is very close to the design specification. The availability of a large number of reproducible, well-characterized transistors enabled work to commence on the development of a large signal model for FETs. Work in this area is also described.

  14. Ion implantation effects in 'cosmic' dust grains

    NASA Technical Reports Server (NTRS)

    Bibring, J. P.; Langevin, Y.; Maurette, M.; Meunier, R.; Jouffrey, B.; Jouret, C.

    1974-01-01

    Cosmic dust grains, whatever their origin may be, have probably suffered a complex sequence of events including exposure to high doses of low-energy nuclear particles and cycles of turbulent motions. High-voltage electron microscope observations of micron-sized grains either naturally exposed to space environmental parameters on the lunar surface or artificially subjected to space simulated conditions strongly suggest that such events could drastically modify the mineralogical composition of the grains and considerably ease their aggregation during collisions at low speeds. Furthermore, combined mass spectrometer and ionic analyzer studies show that small carbon compounds can be both synthesized during the implantation of a mixture of low-energy D, C, N ions in various solids and released in space by ion sputtering.

  15. Mg ion implantation on SLA-treated titanium surface and its effects on the behavior of mesenchymal stem cell.

    PubMed

    Kim, Beom-Su; Kim, Jin Seong; Park, Young Min; Choi, Bo-Young; Lee, Jun

    2013-04-01

    Magnesium (Mg) is one of the most important ions associated with bone osseointegration. The aim of this study was to evaluate the cellular effects of Mg implantation in titanium (Ti) surfaces treated with sand blast using large grit and acid etching (SLA). Mg ions were implanted into the surface via vacuum arc source ion implantation. The surface morphology, chemical properties, and the amount of Mg ion release were evaluated by scanning electron microscopy (SEM), Auger electron spectroscopy (AES), Rutherford backscattering spectroscopy (RBS), and inductively coupled plasma-optical emission spectrometer (ICP-OES). Human mesenchymal stem cells (hMSCs) were used to evaluate cellular parameters such as proliferation, cytotoxicity, and adhesion morphology by MTS assay, live/dead assay, and SEM. Furthermore, osteoblast differentiation was determined on the basis of alkaline phosphatase (ALP) activity and the degree of calcium accumulation. In the Mg ion-implanted disk, 2.3×10(16) ions/cm(2) was retained. However, after Mg ion implantation, the surface morphology did not change. Implanted Mg ions were rapidly released during the first 7 days in vitro. The MTS assay, live/dead assay, and SEM demonstrated increased cell attachment and growth on the Mg ion-implanted surface. In particular, Mg ion implantation increased the initial cell adhesion, and in an osteoblast differentiation assay, ALP activity and calcium accumulation. These findings suggest that Mg ion implantation using the plasma source ion implantation (PSII) technique may be useful for SLA-treated Ti dental implants to improve their osseointegration capacity.

  16. PLEPS study of ions implanted RAFM steels

    NASA Astrophysics Data System (ADS)

    Sojak, S.; Slugeň, V.; Egger, W.; Ravelli, L.; Petriska, M.; Veterníková, J.; Stacho, M.; Sabelová, V.

    2014-04-01

    Current nuclear power plants (NPP) require radiation, heat and mechanical resistance of their structural materials with the ability to stay operational during NPP planned lifetime. Radiation damage much higher, than in the current NPP, is expected in new generations of nuclear power plants, such as Generation IV and fusion reactors. Investigation of perspective structural materials for new generations of nuclear power plants is among others focused on study of reduced activation ferritic/martensitic (RAFM) steels. These steels have good characteristics as reduced activation, good resistance to volume swelling, good radiation, and heat resistance. Our experiments were focused on the study of microstructural changes of binary Fe-Cr alloys with different chromium content after irradiation, experimentally simulated by ion implantations. Fe-Cr alloys were examined, by Pulsed Low Energy Positron System (PLEPS) at FRM II reactor in Garching (Munich), after helium ion implantations at the dose of 0.1 C/cm2. The investigation was focused on the chromium effect and the radiation defects resistivity. In particular, the vacancy type defects (monovacancies, vacancy clusters) have been studied. Based on our previous results achieved by conventional lifetime technique, the decrease of the defects size with increasing content of chromium is expected also for PLEPS measurements.

  17. Mechanical stresses and amorphization of ion-implanted diamond

    NASA Astrophysics Data System (ADS)

    Khmelnitsky, R. A.; Dravin, V. A.; Tal, A. A.; Latushko, M. I.; Khomich, A. A.; Khomich, A. V.; Trushin, A. S.; Alekseev, A. A.; Terentiev, S. A.

    2013-06-01

    Scanning white light interferometry and Raman spectroscopy were used to investigate the mechanical stresses and structural changes in ion-implanted natural diamonds with different impurity content. The uniform distribution of radiation defects in implanted area was obtained by the regime of multiple-energy implantation of keV He+ ions. A modification of Bosia's et al. (Nucl. Instrum. Meth. B 268 (2010) 2991) method for determining the internal stresses and the density variation in an ion-implanted diamond layer was proposed that suggests measuring, in addition to the surface swelling of a diamond plate, the radius of curvature of the plate. It is shown that, under multiple-energy implantation of He+, mechanical stresses in the implanted layer may be as high as 12 GPa. It is shown that radiation damage reaches saturation for the implantation fluence characteristic of amorphization of diamond but is appreciably lower than the graphitization threshold.

  18. Subcutoff microwave driven plasma ion sources for multielemental focused ion beam systems.

    PubMed

    Mathew, Jose V; Chowdhury, Abhishek; Bhattacharjee, Sudeep

    2008-06-01

    A compact microwave driven plasma ion source for focused ion beam applications has been developed. Several gas species have been experimented including argon, krypton, and hydrogen. The plasma, confined by a minimum B multicusp magnetic field, has good radial and axial uniformity. The octupole multicusp configuration shows a superior performance in terms of plasma density (~1.3 x 10(11) cm(-3)) and electron temperature (7-15 eV) at a power density of 5-10 Wcm(2). Ion current densities ranging from a few hundreds to over 1000 mA/cm(2) have been obtained with different plasma electrode apertures. The ion source will be combined with electrostatic Einzel lenses and should be capable of producing multielemental focused ion beams for nanostructuring and implantations. The initial simulation results for the focused beams have been presented.

  19. Self-organized surface ripple pattern formation by ion implantation

    NASA Astrophysics Data System (ADS)

    Hofsäss, Hans; Zhang, Kun; Bobes, Omar

    2016-10-01

    Ion induced ripple pattern formation on solid surfaces has been extensively studied in the past and the theories describing curvature dependent ion erosion as well as redistribution of recoil atoms have been very successful in explaining many features of the pattern formation. Since most experimental studies use noble gas ion irradiation, the incorporation of the ions into the films is usually neglected. In this work we show that the incorporation or implantation of non-volatile ions also leads to a curvature dependent term in the equation of motion of a surface height profile. The implantation of ions can be interpreted as a negative sputter yield; and therefore, the effect of ion implantation is opposite to the one of ion erosion. For angles up to about 50°, implantation of ions stabilizes the surface, whereas above 50°, ion implantation contributes to the destabilization of the surface. We present simulations of the curvature coefficients using the crater function formalism and we compare the simulation results to the experimental data on the ion induced pattern formation using non-volatile ions. We present several model cases, where the incorporation of ions is a crucial requirement for the pattern formation.

  20. Nitrogen ion implantation into various materials using 28 GHz electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Shin, Chang Seouk; Lee, Byoung-Seob; Choi, Seyong; Yoon, Jang-Hee; Kim, Hyun Gyu; Ok, Jung-Woo; Park, Jin Yong; Kim, Seong Jun; Bahng, Jungbae; Hong, Jonggi; Lee, Seung Wook; Won, Mi-Sook

    2016-02-01

    The installation of the 28 GHz electron cyclotron resonance ion source (ECRIS) ion implantation beamline was recently completed at the Korea Basic Science Institute. The apparatus contains a beam monitoring system and a sample holder for the ion implantation process. The new implantation system can function as a multipurpose tool since it can implant a variety of ions, ranging hydrogen to uranium, into different materials with precise control and with implantation areas as large as 1-10 mm2. The implantation chamber was designed to measure the beam properties with a diagnostic system as well as to perform ion implantation with an in situ system including a mass spectrometer. This advanced implantation system can be employed in novel applications, including the production of a variety of new materials such as metals, polymers, and ceramics and the irradiation testing and fabrication of structural and functional materials to be used in future nuclear fusion reactors. In this investigation, the first nitrogen ion implantation experiments were conducted using the new system. The 28 GHz ECRIS implanted low-energy, multi-charged nitrogen ions into copper, zinc, and cobalt substrates, and the ion implantation depth profiles were obtained. SRIM 2013 code was used to calculate the profiles under identical conditions, and the experimental and simulation results are presented and compared in this report. The depths and ranges of the ion distributions in the experimental and simulation results agree closely and demonstrate that the new system will enable the treatment of various substrates for advanced materials research.

  1. Nitrogen ion implantation into various materials using 28 GHz electron cyclotron resonance ion source.

    PubMed

    Shin, Chang Seouk; Lee, Byoung-Seob; Choi, Seyong; Yoon, Jang-Hee; Kim, Hyun Gyu; Ok, Jung-Woo; Park, Jin Yong; Kim, Seong Jun; Bahng, Jungbae; Hong, Jonggi; Lee, Seung Wook; Won, Mi-Sook

    2016-02-01

    The installation of the 28 GHz electron cyclotron resonance ion source (ECRIS) ion implantation beamline was recently completed at the Korea Basic Science Institute. The apparatus contains a beam monitoring system and a sample holder for the ion implantation process. The new implantation system can function as a multipurpose tool since it can implant a variety of ions, ranging hydrogen to uranium, into different materials with precise control and with implantation areas as large as 1-10 mm(2). The implantation chamber was designed to measure the beam properties with a diagnostic system as well as to perform ion implantation with an in situ system including a mass spectrometer. This advanced implantation system can be employed in novel applications, including the production of a variety of new materials such as metals, polymers, and ceramics and the irradiation testing and fabrication of structural and functional materials to be used in future nuclear fusion reactors. In this investigation, the first nitrogen ion implantation experiments were conducted using the new system. The 28 GHz ECRIS implanted low-energy, multi-charged nitrogen ions into copper, zinc, and cobalt substrates, and the ion implantation depth profiles were obtained. SRIM 2013 code was used to calculate the profiles under identical conditions, and the experimental and simulation results are presented and compared in this report. The depths and ranges of the ion distributions in the experimental and simulation results agree closely and demonstrate that the new system will enable the treatment of various substrates for advanced materials research.

  2. Nitrogen ion implantation into various materials using 28 GHz electron cyclotron resonance ion source.

    PubMed

    Shin, Chang Seouk; Lee, Byoung-Seob; Choi, Seyong; Yoon, Jang-Hee; Kim, Hyun Gyu; Ok, Jung-Woo; Park, Jin Yong; Kim, Seong Jun; Bahng, Jungbae; Hong, Jonggi; Lee, Seung Wook; Won, Mi-Sook

    2016-02-01

    The installation of the 28 GHz electron cyclotron resonance ion source (ECRIS) ion implantation beamline was recently completed at the Korea Basic Science Institute. The apparatus contains a beam monitoring system and a sample holder for the ion implantation process. The new implantation system can function as a multipurpose tool since it can implant a variety of ions, ranging hydrogen to uranium, into different materials with precise control and with implantation areas as large as 1-10 mm(2). The implantation chamber was designed to measure the beam properties with a diagnostic system as well as to perform ion implantation with an in situ system including a mass spectrometer. This advanced implantation system can be employed in novel applications, including the production of a variety of new materials such as metals, polymers, and ceramics and the irradiation testing and fabrication of structural and functional materials to be used in future nuclear fusion reactors. In this investigation, the first nitrogen ion implantation experiments were conducted using the new system. The 28 GHz ECRIS implanted low-energy, multi-charged nitrogen ions into copper, zinc, and cobalt substrates, and the ion implantation depth profiles were obtained. SRIM 2013 code was used to calculate the profiles under identical conditions, and the experimental and simulation results are presented and compared in this report. The depths and ranges of the ion distributions in the experimental and simulation results agree closely and demonstrate that the new system will enable the treatment of various substrates for advanced materials research. PMID:26931931

  3. Dopant profile engineering of advanced Si MOSFET's using ion implantation

    NASA Astrophysics Data System (ADS)

    Stolk, P. A.; Ponomarev, Y. V.; Schmitz, J.; van Brandenburg, A. C. M. C.; Roes, R.; Montree, A. H.; Woerlee, P. H.

    1999-01-01

    Ion implantation has been used to realize non-uniform, steep retrograde (SR) dopant profiles in the active channel region of advanced Si MOSFET's. After defining the transistor configuration, SR profiles were formed by dopant implantation through the polycrystalline Si gate and the gate oxide (through-the-gate, TG, implantation). The steep nature of the as-implanted profile was retained by applying rapid thermal annealing for dopant activation and implantation damage removal. For NMOS transistors, TG implantation of B yields improved transistor performance through increased carrier mobility, reduced junction capacitances, and reduced susceptibility to short-channel effects. Electrical measurements show that the gate oxide quality is not deteriorated by the ion-induced damage, demonstrating that transistor reliability is preserved. For PMOS transistors, TG implantation of P or As leads to unacceptable source/drain junction broadening as a result of transient enhanced dopant diffusion during thermal activation.

  4. Single ion implantation for solid state quantum computer development

    SciTech Connect

    Schenkel, Thomas; Meijers, Jan; Persaud, Arun; McDonald, Joseph W.; Holder, Joseph P.; Schneider, Dieter H.

    2001-12-18

    Several solid state quantum computer schemes are based on the manipulation of electron and nuclear spins of single donor atoms in a solid matrix. The fabrication of qubit arrays requires the placement of individual atoms with nanometer precision and high efficiency. In this article we describe first results from low dose, low energy implantations and our development of a low energy (<10 keV), single ion implantation scheme for {sup 31}P{sup q+} ions. When {sup 31}P{sup q+} ions impinge on a wafer surface, their potential energy (9.3 keV for P{sup 15+}) is released, and about 20 secondary electrons are emitted. The emission of multiple secondary electrons allows detection of each ion impact with 100% efficiency. The beam spot on target is controlled by beam focusing and collimation. Exactly one ion is implanted into a selected area avoiding a Poissonian distribution of implanted ions.

  5. Sources and transport systems for low energy extreme of ion implantation

    SciTech Connect

    Hershcovitch, A.; Batalin, V.A.; Bugaev, A.S.; Gushenets, V.I.; Alexeyenko, O.; Gurkova, E.; Johnson, B.M.; Kolomiets, A.A.; Kropachev, G.N.; Kuibeda, R.P.; Kulevoy, T.V.; Masunov, E.S.; Oks, E.M.; Pershin, V.I.; Polozov, S.M.; Poole, H.J.; Seleznev, D.N.; Storozhenko, P.A.; Vizir, A.; Svarovski, A.Ya.; Yakushin, P.; Yushkov, G.Yu.

    2010-06-06

    For the past seven years a joint research and development effort focusing on the design of steady state, intense ion sources has been in progress with the ultimate goal being to meet the two, energy extreme range needs of mega-electron-volt and 100's of electron-volt ion implanters. However, since the last Fortier is low energy ion implantation, focus of the endeavor has shifted to low energy ion implantation. For boron cluster source development, we started with molecular ions of decaborane (B{sub 10}H{sub 14}), octadecaborane (B{sub 18}H{sub 22}), and presently our focus is on carborane (C{sub 2}B{sub 10}H{sub 12}) ions developing methods for mitigating graphite deposition. Simultaneously, we are developing a pure boron ion source (without a working gas) that can form the basis for a novel, more efficient, plasma immersion source. Our Calutron-Berna ion source was converted into a universal source capable of switching between generating molecular phosphorous P{sub 4}{sup +}, high charge state ions, as well as other types of ions. Additionally, we have developed transport systems capable of transporting a very large variety of ion species, and simulations of a novel gasless/plasmaless ion beam deceleration method were also performed.

  6. Effect of Platelet-Rich-Plasma (PRP) and Implant Surface Topography on Implant Stability and Bone

    PubMed Central

    Kundu, Renu

    2014-01-01

    Purpose: To evaluate the effect of Platelet-Rich-Plasma (PRP) and different implant surface topography on implant stability and bone levels around immediately loaded dental implants. Materials and Methods: Dental implants were placed in subjects divided into two groups and four subgroups on basis of implant treatment with PRP and implant surface topography used. A total of 30 implants were placed, 15 in each group. For PRP group, implants were placed after surface treatment with PRP. Temporization was done within two weeks and final prosthesis was given after three months. Implant stability was measured with Periotest at baseline, one month and three months. Bone height was measured on mesial & distal side on standardized IOPA x-rays. Results: A statistically significant difference was noticed in implant stability with PRP at baseline. The effect of PRP on bone height changes was not statistically significant. A synergistic effect of PRP and square thread-form was observed on improved implant stability and bone levels; however, no such effect is seen with PRP and reverse buttress thread-form. Conclusion: Within the limitation of this study, enhancement on implant stability and bone healing was observed with PRP treated implant surfaces, and with use of implant with square thread-form. PMID:25121060

  7. Temperature-dependant study of phosphorus ion implantation in germanium

    NASA Astrophysics Data System (ADS)

    Razali, M. A.; Smith, A. J.; Jeynes, C.; Gwilliam, R. M.

    2012-11-01

    We present experimental results on shallow junction formation in germanium by phosphorus ion implantation and standard rapid thermal processing. An attempt is made to improve phosphorus activation by implanting phosphorus at high and low temperature. The focus is on studying the germanium damage and phosphorus activation as a function of implant temperature. Rutherford backscattering spectrometry with channelling and Hall Effect measurements are employed for characterisation of germanium damage and phosphorus activation, respectively. High and low temperature implants were found to be better compared to room temperature implant.

  8. Microstructure evolution in carbon-ion implanted sapphire

    SciTech Connect

    Orwa, J. O.; McCallum, J. C.; Jamieson, D. N.; Prawer, S.; Peng, J. L.; Rubanov, S.

    2010-01-15

    Carbon ions of MeV energy were implanted into sapphire to fluences of 1x10{sup 17} or 2x10{sup 17} cm{sup -2} and thermally annealed in forming gas (4% H in Ar) for 1 h. Secondary ion mass spectroscopy results obtained from the lower dose implant showed retention of implanted carbon and accumulation of H near the end of range in the C implanted and annealed sample. Three distinct regions were identified by transmission electron microscopy of the implanted region in the higher dose implant. First, in the near surface region, was a low damage region (L{sub 1}) composed of crystalline sapphire and a high density of plateletlike defects. Underneath this was a thin, highly damaged and amorphized region (L{sub 2}) near the end of range in which a mixture of i-carbon and nanodiamond phases are present. Finally, there was a pristine, undamaged sapphire region (L{sub 3}) beyond the end of range. In the annealed sample some evidence of the presence of diamond nanoclusters was found deep within the implanted layer near the projected range of the C ions. These results are compared with our previous work on carbon implanted quartz in which nanodiamond phases were formed only a few tens of nanometers from the surface, a considerable distance from the projected range of the ions, suggesting that significant out diffusion of the implanted carbon had occurred.

  9. Ion-implanted planar-buried-heterostructure diode laser

    DOEpatents

    Brennan, Thomas M.; Hammons, Burrell E.; Myers, David R.; Vawter, Gregory A.

    1991-01-01

    A Planar-Buried-Heterostructure, Graded-Index, Separate-Confinement-Heterostructure semiconductor diode laser 10 includes a single quantum well or multi-quantum well active stripe 12 disposed between a p-type compositionally graded Group III-V cladding layer 14 and an n-type compositionally graded Group III-V cladding layer 16. The laser 10 includes an ion implanted n-type region 28 within the p-type cladding layer 14 and further includes an ion implanted p-type region 26 within the n-type cladding layer 16. The ion implanted regions are disposed for defining a lateral extent of the active stripe.

  10. Photosensitivity enhancement of PLZT ceramics by positive ion implantation

    DOEpatents

    Peercy, P.S.; Land, C.E.

    1980-06-13

    The photosensitivity of lead lanthanum zirconate titanate (PLZT) ceramic material used in high resolution, high contrast, and non-volatile photoferroelectric image storage and display devices is enhanced significantly by positive ion implantation of the PLZT near its surface. Ions that are implanted include H/sup +/, He/sup +/, Ar/sup +/, and a preferred co-implant of Ar/sup +/ and Ne/sup +/. The positive ion implantation advantageously serves to shift the band gap energy threshold of the PLZT material from near-uv light to visible blue light. As a result, photosensitivity enhancement is such that the positive ion implanted PLZT plate is sensitive even to sunlight and conventional room lighting, such as fluorescent and incandescent light sources. The method disclosed includes exposing the PLZT plate to these positive ions of sufficient density and with sufficient energy to provide an image. The PLZT material may have a lanthanum content ranging from 5 to 10%; a lead zirconate content ranging from 62 to 70 mole %; and a lead titanate content ranging from 38 to 30%. The region of ion implantation is in a range from 0.1 to 2 microns below the surface of the PLZT plate. Density of ions is in the range from 1 x 10/sup 12/ to 1 x 10/sup 17/ ions/cm/sup 2/ and having an energy in the range from 100 to 500 keV.

  11. Some plasma aspects and plasma diagnostics of ion sources (invited)

    SciTech Connect

    Wiesemann, Klaus

    2008-02-15

    We consider plasma properties in the most advanced type of plasma ion sources, electron cyclotron resonance ion sources for highly charged ions. Depending on the operation conditions the plasma in these sources may be highly ionized, which completely changes its transport properties. The most striking difference to weakly ionized plasma is that diffusion will become intrinsically ambipolar. We further discuss means of plasma diagnostics. As noninvasive diagnostic methods we will discuss analysis of the ion beam, optical spectroscopy, and measurement of the x-ray bremsstrahlung continuum. From beam analysis and optical spectroscopy one may deduce ion densities, and electron densities and distribution functions as a mean over the line of sight along the axis (optical spectroscopy) or at the plasma edge (ion beam). From x-ray spectra one obtains information about the population of highly energetic electrons and the energy transfer from the driving electromagnetic waves to the plasma--basic data for plasma modeling.

  12. Some plasma aspects and plasma diagnostics of ion sources.

    PubMed

    Wiesemann, Klaus

    2008-02-01

    We consider plasma properties in the most advanced type of plasma ion sources, electron cyclotron resonance ion sources for highly charged ions. Depending on the operation conditions the plasma in these sources may be highly ionized, which completely changes its transport properties. The most striking difference to weakly ionized plasma is that diffusion will become intrinsically ambipolar. We further discuss means of plasma diagnostics. As noninvasive diagnostic methods we will discuss analysis of the ion beam, optical spectroscopy, and measurement of the x-ray bremsstrahlung continuum. From beam analysis and optical spectroscopy one may deduce ion densities, and electron densities and distribution functions as a mean over the line of sight along the axis (optical spectroscopy) or at the plasma edge (ion beam). From x-ray spectra one obtains information about the population of highly energetic electrons and the energy transfer from the driving electromagnetic waves to the plasma -- basic data for plasma modeling.

  13. Plasma ion sources and ion beam technology inmicrofabrications

    SciTech Connect

    Ji, Lili

    2007-01-01

    For over decades, focused ion beam (FIB) has been playing a very important role in microscale technology and research, among which, semiconductor microfabrication is one of its biggest application area. As the dimensions of IC devices are scaled down, it has shown the need for new ion beam tools and new approaches to the fabrication of small-scale devices. In the meanwhile, nanotechnology has also deeply involved in material science research and bioresearch in recent years. The conventional FIB systems which utilize liquid gallium ion sources to achieve nanometer scale resolution can no longer meet the various requirements raised from such a wide application area such as low contamination, high throughput and so on. The drive towards controlling materials properties at nanometer length scales relies on the availability of efficient tools. In this thesis, three novel ion beam tools have been developed and investigated as the alternatives for the conventional FIB systems in some particular applications. An integrated focused ion beam (FIB) and scanning electron microscope (SEM) system has been developed for direct doping or surface modification. This new instrument employs a mini-RF driven plasma source to generate focused ion beam with various ion species, a FEI two-lens electron (2LE) column for SEM imaging, and a five-axis manipulator system for sample positioning. An all-electrostatic two-lens column has been designed to focus the ion beam extracted from the source. Based on the Munro ion optics simulation, beam spot sizes as small as 100 nm can be achieved at beam energies between 5 to 35 keV if a 5 μm-diameter extraction aperture is used. Smaller beam spot sizes can be obtained with smaller apertures at sacrifice of some beam current. The FEI 2LE column, which utilizes Schottky emission, electrostatic focusing optics, and stacked-disk column construction, can provide high-resolution (as small as 20 nm) imaging capability, with fairly long working distance (25

  14. Ion implantation induced nanotopography on titanium and bone cell adhesion

    NASA Astrophysics Data System (ADS)

    Braceras, Iñigo; Vera, Carolina; Ayerdi-Izquierdo, Ana; Muñoz, Roberto; Lorenzo, Jaione; Alvarez, Noelia; de Maeztu, Miguel Ángel

    2014-08-01

    Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40-80 keV), fluence (1-2 e17 ion/cm2) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted surfaces, without surface chemistry modification, are in the same range and that such modifications, in certain conditions, do have a statistically significant effect on bone tissue forming cell adhesion.

  15. Ion Beam Analysis applied to laser-generated plasmas

    NASA Astrophysics Data System (ADS)

    Cutroneo, M.; Macková, A.; Havranek, V.; Malinsky, P.; Torrisi, L.; Kormunda, M.; Barchuk, M.; Ullschmied, J.; Dudzak, R.

    2016-04-01

    This paper presents the research activity on Ion Beam Analysis methods performed at Tandetron Laboratory (LT) of the Institute of Nuclear Physics AS CR, Rez, Czech Republic. Recently, many groups are paying attention to implantation by laser generated plasma. This process allows to insert a controllable amount of energetic ions into the surface layers of different materials modifying the physical and chemical properties of the surface material. Different substrates are implanted by accelerated ions from plasma through terawatt iodine laser, at nominal intensity of 1015 W/cm2, at the PALS Research Infrastructure AS CR, in the Czech Republic. This regime of the laser matter interaction generates, multi-MeV proton beams, and multi-charged ions that are tightly confined in time (hundreds ps) and space (source radius of a few microns). These ion beams have a much lower transverse temperature, a much shorter duration and a much higher current than those obtainable from conventional accelerators. The implementation of protons and ions acceleration driven by ultra-short high intensity lasers is exhibited by adopting suitable irradiation conditions as well as tailored targets. An overview of implanted targets and their morphological and structural characterizations is presented and discussed.

  16. Development of vertical compact ion implanter for gemstones applications

    NASA Astrophysics Data System (ADS)

    Intarasiri, S.; Wijaikhum, A.; Bootkul, D.; Suwannakachorn, D.; Tippawan, U.; Yu, L. D.; Singkarat, S.

    2014-08-01

    Ion implantation technique was applied as an effective non-toxic treatment of the local Thai natural corundum including sapphires and rubies for the enhancement of essential qualities of the gemstones. Energetic oxygen and nitrogen ions in keV range of various fluences were implanted into the precious stones. It has been thoroughly proved that ion implantation can definitely modify the gems to desirable colors together with changing their color distribution, transparency and luster properties. These modifications lead to the improvement in quality of the natural corundum and thus its market value. Possible mechanisms of these modifications have been proposed. The main causes could be the changes in oxidation states of impurities of transition metals, induction of charge transfer from one metal cation to another and the production of color centers. For these purposes, an ion implanter of the kind that is traditionally used in semiconductor wafer fabrication had already been successfully applied for the ion beam bombardment of natural corundum. However, it is not practical for implanting the irregular shape and size of gem samples, and too costly to be economically accepted by the gem and jewelry industry. Accordingly, a specialized ion implanter has been requested by the gem traders. We have succeeded in developing a prototype high-current vertical compact ion implanter only 1.36 m long, from ion source to irradiation chamber, for these purposes. It has been proved to be very effective for corundum, for example, color improvement of blue sapphire, induction of violet sapphire from low value pink sapphire, and amelioration of lead-glass-filled rubies. Details of the implanter and recent implantation results are presented.

  17. Bacterial adhesion on ion-implanted stainless steel surfaces

    NASA Astrophysics Data System (ADS)

    Zhao, Q.; Liu, Y.; Wang, C.; Wang, S.; Peng, N.; Jeynes, C.

    2007-08-01

    Stainless steel disks were implanted with N +, O + and SiF 3+, respectively at the Surrey Ion Beam Centre. The surface properties of the implanted surfaces were analyzed, including surface chemical composition, surface topography, surface roughness and surface free energy. Bacterial adhesion of Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus aureus, which frequently cause medical device-associated infections was evaluated under static condition and laminar flow condition. The effect of contact time, growth media and surface properties of the ion-implanted steels on bacterial adhesion was investigated. The experimental results showed that SiF 3+-implanted stainless steel performed much better than N +-implanted steel, O +-implanted steel and untreated stainless steel control on reducing bacterial attachment under identical experimental conditions.

  18. Software for goniometer control in the Triple Ion Implantation Facility

    SciTech Connect

    Allen, W.R.

    1994-02-01

    A computer program is described tat controls the goniometer employed in the ion scattering chamber of the Triple Ion Implantation Facility (TIF) in the Metals and Ceramics Division at Oak Ridge National Laboratory. Details of goniometer operation and its incorporation into the ion scattering setup specific to the TIF are also discussed.

  19. Method of fabricating optical waveguides by ion implantation doping

    DOEpatents

    Appleton, Bill R.; Ashley, Paul R.; Buchal, Christopher J.

    1989-01-01

    A method for fabricating high-quality optical waveguides in optical quality oxide crystals by ion implantation doping and controlled epitaxial recrystallization is provided. Masked LiNbO.sub.3 crystals are implanted with high concentrations of Ti dopant at ion energies of about 350 keV while maintaining the crystal near liquid nitrogen temperature. Ion implantation doping produces an amorphous, Ti-rich nonequilibrium phase in the implanted region. Subsequent thermal annealing in a water-saturated oxygen atmosphere at up to 1000.degree. C. produces solid-phase epitaxial regrowth onto the crystalline substrate. A high-quality single crystalline layer results which incorporates the Ti into the crystal structure at much higher concentrations than is possible by standard diffusion techniques, and this implanted region has excellent optical waveguides properties.

  20. Method of fabricating optical waveguides by ion implantation doping

    DOEpatents

    Appleton, B.R.; Ashley, P.R.; Buchal, C.J.

    1987-03-24

    A method for fabricating high-quality optical waveguides in optical quality oxide crystals by ion implantation doping and controlled epitaxial recrystallization is provided. Masked LiNbO/sub 3/ crystals are implanted with high concentrations of Ti dopant at ion energies of about 360 keV while maintaining the crystal near liquid nitrogen temperature. Ion implantation doping produces an amorphous, Ti-rich nonequilibrium phase in the implanted region. Subsequent thermal annealing in a water-saturated oxygen atmosphere at up to 1000/degree/C produces solid-phase epitaxial regrowth onto the crystalline substrate. A high-quality crystalline layer results which incorporates the Ti into the crystal structure at much higher concentrations than is possible by standard diffusion techniques, and this implanted region has excellent optical waveguiding properties.

  1. Bone tissue response to plasma-nitrided titanium implant surfaces

    PubMed Central

    FERRAZ, Emanuela Prado; SVERZUT, Alexander Tadeu; FREITAS, Gileade Pereira; SÁ, Juliana Carvalho; ALVES, Clodomiro; BELOTI, Marcio Mateus; ROSA, Adalberto Luiz

    2015-01-01

    A current goal of dental implant research is the development of titanium (Ti) surfaces to improve osseointegration. Plasma nitriding treatments generate surfaces that favor osteoblast differentiation, a key event to the process of osteogenesis. Based on this, it is possible to hypothesize that plasma-nitrided Ti implants may positively impact osseointegration. Objective The aim of this study was to evaluate the in vivo bone response to Ti surfaces modified by plasma-nitriding treatments. Material and Methods Surface treatments consisted of 20% N2 and 80% H2, 450°C and 1.5 mbar during 1 h for planar and 3 h for hollow cathode. Untreated surface was used as control. Ten implants of each surface were placed into rabbit tibiae and 6 weeks post-implantation they were harvested for histological and histomorphometric analyses. Results Bone formation was observed in contact with all implants without statistically significant differences among the evaluated surfaces in terms of bone-to-implant contact, bone area between threads, and bone area within the mirror area. Conclusion Our results indicate that plasma nitriding treatments generate Ti implants that induce similar bone response to the untreated ones. Thus, as these treatments improve the physico-chemical properties of Ti without affecting its biocompatibility, they could be combined with modifications that favor bone formation in order to develop new implant surfaces. PMID:25760262

  2. Shallow drain extension by angled ion implantation

    SciTech Connect

    Alvis, R.; Luning, S.; Griffin, P.

    1996-12-31

    In this work, we describe the construction and microstructural characterization of a simple spacerless metal-oxide semiconductor (MOS) transistor with a self-aligned shallow drain extension. Transistor structures were fabricated at Stanford University`s Center for Integrated Systems using a single masking step to pattern the gate mask for the self-aligned structures. A 200{angstrom} gate oxide was grown and a 3000{angstrom} polysilicon blanket film was subsequently deposited on the wafer. The polysilicon was patterned into an array of 2.0{mu}m lines and 3.0{mu}m spaces. Arsenic was implanted at 120keV with a nominal dose of 1e15 ions/cm{sup 2} at 20{degrees} from normal incidence and rapid thermal annealed at 1000{degrees}C for 30 seconds. Cross-sectional transmission electron microscopy and atomic force microscopy (TEM, XAFM) samples were prepared using standard metallographic procedures with the doped regions delineated by chemical etching. A one-dimensionally calibrated process simulation was performed using Athena v2.0.13, a commercial derivative of SUPREM IV.

  3. Improving Sustainability of Ion Implant Modules

    NASA Astrophysics Data System (ADS)

    Mayer, Jim

    2011-01-01

    Semiconductor fabs have long been pressured to manage capital costs, reduce energy consumption and increasingly improve efforts to recycle and recover resources. Ion implant tools have been high-profile offenders on all three fronts. They draw such large volumes of air for heat dissipation and risk reduction that historically, they are the largest consumer of cleanroom air of any process tool—and develop energy usage and resource profiles to match. This paper presents a documented approach to reduce their energy consumption and dramatically downsize on-site facilities support for cleanroom air manufacture and abatement. The combination produces significant capital expenditure savings. The case entails applying SAGS Type 1 (sub-atmospheric gas systems) toxic gas packaging to enable engineering adaptations that deliver the energy savings and cost benefits without any reduction in environmental health and safety. The paper also summarizes benefits as they relate to reducing a fabs carbon emission footprint (and longer range advantages relative to potential cap and trade programs) with existing technology.

  4. Emission Characteristics of Ion-Implanted Silicon Emitter Tips

    NASA Astrophysics Data System (ADS)

    Hirano, Takayuki; Kanemaru, Seigo; Tanoue, Hisao; Itoh, Junji

    1995-12-01

    An ion implantation technique has been applied to control the energy band structure of Si field-emitter tip surface. B+ or P+ ions were implanted after fabrication of a gated emitter structure. No changes in emitter structure were observed after ion implantation and successive annealing at 800° C. Current-voltage ( I-V ) characteristics of n, p, p/n and n/p emitter tips were measured: p/n indicates an n-type tip with B+ ions implanted into the tip surface. It was found from the experimental results that n and p/n tips had I-V characteristics in agreement with the Fowler-Nordheim theory. The p and n/p tips, on the other hand, exhibited a current saturation property in high electric field. The present saturation mechanism is explained by considering the energy band structure of the tip surface.

  5. Industrial applications of ion implantation into metal surfaces

    SciTech Connect

    Williams, J.M.

    1987-07-01

    The modern materials processing technique, ion implantation, has intriguing and attractive features that stimulate the imaginations of scientists and technologists. Success of the technique for introducing dopants into semiconductors has resulted in a stable and growing infrastructure of capital equipment and skills for use of the technique in the economy. Attention has turned to possible use of ion implantation for modification of nearly all surface related properties of materials - optical, chemical and corrosive, tribological, and several others. This presentation provides an introduction to fundamental aspects of equipment, technique, and materials science of ion implantation. Practical and economic factors pertaining to the technology are discussed. Applications and potential applications are surveyed. There are already available a number of ion-implanted products, including ball-and-roller bearings and races, punches-and-dies, injection screws for plastics molding, etc., of potential interest to the machine tool industry.

  6. SEM analysis of ion implanted SiC

    NASA Astrophysics Data System (ADS)

    Malherbe, Johan B.; van der Berg, N. G.; Botha, A. J.; Friedland, E.; Hlatshwayo, T. T.; Kuhudzai, R. J.; Wendler, E.; Wesch, W.; Chakraborty, P.; da Silveira, E. F.

    2013-11-01

    SiC is a material used in two future energy production technologies, firstly as a photovoltaic layer to harness the UV spectrum in high efficient power solar cells, and secondly as a diffusion barrier material for radioactive fission products in the fuel elements of the next generation of nuclear power plants. For both applications, there is an interest in the implantation of reactive and non-reactive ions into SiC and their effects on the properties of the SiC. In this study 360 keV Ag+, I+ and Xe+ ions were separately implanted into 6H-SiC and in polycrystalline SiC at various substrate temperatures. The implanted samples were also annealed in vacuum at temperatures ranging from 900 °C to 1600 °C for various times. In recent years, there had been significant advances in scanning electron microscopy (SEM) with the introduction of an in-lens detector combined with field emission electron guns. This allows defects in solids, such as radiation damage created by the implanted ions, to be detected with SEM. Cross-sectional SEM images of 6H-SiC wafers implanted with 360 keV Ag+ ions at room temperature and at 600 °C and then vacuum annealed at different temperatures revealed the implanted layers and their thicknesses. A similar result is shown of 360 keV I+ ions implanted at 600 °C into 6H-SiC and annealed at 1600 °C. The 6H-SiC is not amorphized but remained crystalline when implanting at 600 °C. There are differences in the microstructure of 6H-SiC implanted with silver at the two temperatures as well as with reactive iodine ions. Voids (bubbles) are created in the implanted layers into which the precipitation of silver and iodine can occur after annealing of the samples. The crystallinity of the substrate via implantation temperature caused differences in the distribution and size of the voids. Implantation of xenon ions in polycrystalline SiC at 350 °C does not amorphize the substrate as is the case with room temperature heavy ion bombardment. Subsequent

  7. Improved wear properties of high energy ion-implanted polycarbonate

    SciTech Connect

    Rao, G.R.; Lee, E.H. ); Bhattacharya, R.; McCormick, A.W. )

    1995-01-01

    Polycarbonate (Lexan[sup TM]) (PC) was implanted with 2 MeV B[sup +] and O[sup +] ions separately to fluences of 5[times]10[sup 17], 1[times]10[sup 18], and 5[times]10[sup 18] ions/m[sup 2], and characterized for changes in surface hardness and tribological properties. Results of tests showed that hardness values of all implanted specimens increased over those of the unirradiated material, and the O[sup +] implantation was more effective in improving hardness for a given fluence than the B[sup +] implantation. Reciprocating sliding wear tests using a nylon ball counterface yielded significant improvements for all implanted specimens except for the 5[times]10[sup 17] ions/m[sup 2] B[sup +]-implanted PC. Wear tests conducted with a 52100 steel ball yielded significant improvements for the highest fluence of 5[times]10[sup 18] ions/m[sup 2] for both ions, but not for the two lower fluences. The improvements in properties were related to Linear Energy Transfer (LET) mechanisms, where it was shown that the O[sup +] implantation caused greater ionization, thereby greater cross-linking at the surface corresponding to much better improvements in properties. The results were also compared with a previous study on PC using 200 keV B[sup +] ions. The present study indicates that high energy ion irradiation produces thicker, more cross-linked, harder, and more wear-resistant surfaces on polymers and thereby improves properties to a greater extent and more efficiently than lower energy ion implantation.

  8. Ion-beam Plasma Neutralization Interaction Images

    SciTech Connect

    Igor D. Kaganovich; Edward Startsev; S. Klasky; Ronald C. Davidson

    2002-04-09

    Neutralization of the ion beam charge and current is an important scientific issue for many practical applications. The process of ion beam charge and current neutralization is complex because the excitation of nonlinear plasma waves may occur. Computer simulation images of plasma neutralization of the ion beam pulse are presented.

  9. Study of ion-irradiated tungsten in deuterium plasma

    NASA Astrophysics Data System (ADS)

    Khripunov, B. I.; Gureev, V. M.; Koidan, V. S.; Kornienko, S. N.; Latushkin, S. T.; Petrov, V. B.; Ryazanov, A. I.; Semenov, E. V.; Stolyarova, V. G.; Danelyan, L. S.; Kulikauskas, V. S.; Zatekin, V. V.; Unezhev, V. N.

    2013-07-01

    Experimental study aimed at investigation of neutron induced damage influence on fusion reactor plasma facing materials is reported. Displacement damage was produced in tungsten by high-energy helium and carbon ions at 3-10 MeV. The reached level of displacement damage ranged from several dpa to 600 dpa. The properties of the irradiated tungsten were studied in steady-state deuterium plasma on the LENTA linear divertor simulator. Plasma exposures were made at 250 eV of ion energy to fluence 1021-1022 ion/сm2. Erosion dynamics of the damaged layer and deuterium retention were observed. Surface microstructure modifications and important damage of the 5 μm layer shown. Deuterium retention in helium-damaged tungsten (ERD) showed its complex behavior (increase or decrease) depending on implanted helium quantity and the structure of the surface layer.

  10. Low erosion behavior of polystyrene films under erbium ion implantation

    SciTech Connect

    Bhattacharya, M.; Sanyal, M.K.; Chini, T.K.; Chakraborty, P.

    2006-02-13

    Erbium ion implantation in polystyrene (PS) thin films has been performed with 40 and 60 keV ions to a dose range between 1x10{sup 14} and 1x10{sup 16} ions/cm{sup 2}. The x-ray reflectivity technique was applied to determine the ion-induced eroded layer thickness and interestingly, the erosion rate is found to decrease with increasing ion doses exhibiting simple power law behavior of the form {approx}(dose){sup -b}. We propose the formation of a carbonaceous network at the top surface, which seems to prevent further erosion of the polymer with increasing the duration of implantation time. These findings may open up a possibility of loading a large amount of erbium in a polymer matrix by the implantation technique to make it suitable for various optoelectronic applications.

  11. Photosensitivity enhancement of PLZT ceramics by positive ion implantation

    DOEpatents

    Land, Cecil E.; Peercy, Paul S.

    1983-01-01

    The photosensitivity of lead lanthanum zirconate titanate (PLZT) ceramic material used in high resolution, high contrast, and non-volatile photoferroelectric image storage and display devices is enhanced significantly by positive ion implantation of the PLZT near its surface. Implanted ions include H.sup.+, He.sup.+, Ne.sup.+, Ar.sup.+, as well as chemically reactive ions from Fe, Cr, and Al. The positive ion implantation advantageously serves to shift the absorption characteristics of the PLZT material from near-UV light to visible light. As a result, photosensitivity enhancement is such that the positive ion implanted PLZT plate is sensitive even to sunlight and conventional room lighting, such as fluorescent and incandescent light sources. The method disclosed includes exposing the PLZT plate to the positive ions at sufficient density, from 1.times.10.sup.12 to 1.times.10.sup.17, and with sufficient energy, from 100 to 500 KeV, to provide photosensitivity enhancement. The PLZT material may have a lanthanum content ranging from 5 to 10%, a lead zirconate content of 62 to 70 mole %, and a lead titanate content of 38 to 30%. The ions are implanted at a depth of 0.1 to 2 microns below the surface of the PLZT plate.

  12. Vibrational spectroscopy of Ga+ ion implanted ta-C films

    NASA Astrophysics Data System (ADS)

    Berova, M.; Sandulov, M.; Tsvetkova, T.; Bischoff, L.; Boettger, R.; Abrashev, M.

    2016-02-01

    In the present work, low energy Ga+ ion beam implantation was used for the structural and optical properties modification of tetrahedral amorphous carbon (ta-C) thin films, using gallium (Ga+) as the ion species. Thin film samples (d∼40nm) of ta-C, deposited by filtered cathodic vacuum arc (FCVA), have been implanted with Ga+ at ion energy E = 20 keV and ion doses D=3.1014÷3.1015 cm-2. The Ga+ ion beam induced structural modification of the implanted material results in a considerable change of its optical properties, displayed in a significant shift of the optical absorption edge to lower photon energies as obtained from optical transmission measurements. This shift is accompanied by a considerable increase of the absorption coefficient (photo-darkening effect) in the measured photon energy range (0.5÷3.0 eV). These effects could be attributed both to additional defect introduction and increased graphitisation, as well as to accompanying formation of bonds between the implanted ions and the host atoms of the target, as confirmed by infra-red (IR) and Raman measurements. The optical contrast thus obtained (between implanted and unimplanted film material) could be made use of for information archiving, in the area of high-density optical data storage, while using focused Ga+ ion beams.

  13. Surface Engineering of Nanostructured Titanium Implants with Bioactive Ions.

    PubMed

    Kim, H-S; Kim, Y-J; Jang, J-H; Park, J-W

    2016-05-01

    Surface nanofeatures and bioactive ion chemical modification are centrally important in current titanium (Ti) oral implants for enhancing osseointegration. However, it is unclear whether the addition of bioactive ions definitively enhances the osteogenic capacity of a nanostructured Ti implant. We systematically investigated the osteogenesis process of human multipotent adipose stem cells triggered by bioactive ions in the nanostructured Ti implant surface. Here, we report that bioactive ion surface modification (calcium [Ca] or strontium [Sr]) and resultant ion release significantly increase osteogenic activity of the nanofeatured Ti surface. We for the first time demonstrate that ion modification actively induces focal adhesion development and expression of critical adhesion–related genes (vinculin, talin, and RHOA) of human multipotent adipose stem cells, resulting in enhanced osteogenic differentiation on the nanofeatured Ti surface. It is also suggested that fibronectin adsorption may have only a weak effect on early cellular events of mesenchymal stem cells (MSCs) at least in the case of the nanostructured Ti implant surface incorporating Sr. Moreover, results indicate that Sr overrides the effect of Ca and other important surface factors (i.e., surface area and wettability) in the osteogenesis function of various MSCs (derived from human adipose, bone marrow, and murine bone marrow). In addition, surface engineering of nanostructured Ti implants using Sr ions is expected to exert additional beneficial effects on implant bone healing through the proper balancing of the allocation of MSCs between adipogenesis and osteogenesis. This work provides insight into the future surface design of Ti dental implants using surface bioactive ion chemistry and nanotopography. PMID:26961491

  14. The Behavior of Ion-Implanted Hydrogen in Gallium Nitride

    SciTech Connect

    Myers, S.M.; Headley, T.J.; Hills, C.R.; Han, J.; Petersen, G.A.; Seager, C.H.; Wampler, W.R.

    1999-01-07

    Hydrogen was ion-implanted into wurtzite-phase GaN, and its transport, bound states, and microstructural effects during annealing up to 980 C were investigated by nuclear-reaction profiling, ion-channeling analysis, transmission electron microscopy, and infrared (IR) vibrational spectroscopy. At implanted concentrations 1 at.%, faceted H{sub 2} bubbles formed, enabling identification of energetically preferred surfaces, examination of passivating N-H states on these surfaces, and determination of the diffusivity-solubility product of the H. Additionally, the formation and evolution of point and extended defects arising from implantation and bubble formation were characterized. At implanted H concentrations 0.1 at.%, bubble formation was not observed, and ion-channeling analysis indicated a defect-related H site located within the [0001] channel.

  15. Effect of plasma-sprayed hydroxyapatite coating on the osteoconductivity of commercially pure titanium implants.

    PubMed

    Strnad, Z; Strnad, J; Povýsil, C; Urban, K

    2000-01-01

    Formation of a calcium phosphate layer was studied on the surfaces of plasma-sprayed hydroxyapatite (PSHA) and sandblasted commercially pure (cp) titanium in simulated body fluid with ion concentrations similar to those of human blood plasma. The PSHA surface induced the formation of calcium phosphate surface layers, while the precipitation of calcium phosphate on sandblasted cp titanium was not detected. Histologic evaluation of in vivo tests demonstrated that implants with a PSHA coating enabled the growth of bone tissue into gaps with a depth of up to 1 mm without significant formation of intermediate fibrous tissue. In comparison to sandblasted cp titanium, implants with PSHA coating exhibited greater tolerance to unfavorable conditions during healing, such as gaps at the interface or primary instability of the implant. In the case of good primary stability of the implant, filling of the gap with fibrous tissue was observed for sandblasted cp titanium implants over the greater part of the surface of gaps with a depth of 0.3 mm. Direct contact of cp titanium implants with bone was achieved only when the press-fit implantation model was used. PMID:10960980

  16. Blistering of implanted crystalline silicon by plasma hydrogenation investigated by Raman scattering spectroscopy

    SciTech Connect

    Duengen, W.; Job, R.; Mueller, T.; Ma, Y.; Fahrner, W. R.; Keller, L. O.; Horstmann, J. T.; Fiedler, H.

    2006-12-15

    Czochralski silicon wafers were implanted with H{sup +} ions at a dose of 1x10{sup 16} cm{sup -2} followed by hydrogen plasma treatments at different temperatures. The minimum hydrogen implantation dose required for silicon surface exfoliation of 3x10{sup 16} H{sup +}/cm{sup 2} without further hydrogen incorporation was reduced to one-third by subsequent plasma hydrogenation. The corresponding local vibrational modes of hydrogen molecules, vacancy-hydrogen complexes, and Si-H bonds on surfaces have been analyzed by micro-Raman scattering spectroscopy to investigate blistering and platelet formation. The surface profile has been studied by atomic force microscopy and scanning electron microscopy. The plasma treated samples were annealed to investigate the mechanism and applicability of the induced exfoliation. <111>-platelet formation occurred below plasma hydrogenation temperatures of 350 deg. C. At temperatures above 450 deg. C, <100>-platelet nucleation induced blistering.

  17. Charging and discharging in ion implanted dielectric films used for capacitive radio frequency microelectromechanical systems switch

    SciTech Connect

    Li Gang; Chen Xuyuan; San Haisheng

    2009-06-15

    In this work, metal-insulator-semiconductor (MIS) capacitor structure was used to investigate the dielectric charging and discharging in the capacitive radio frequency microelectromechanical switches. The insulator in MIS structure is silicon nitride films (SiN), which were deposited by either low pressure chemical vapor deposition (LPCVD) or plasma enhanced chemical vapor deposition (PECVD) processes. Phosphorus or boron ions were implanted into dielectric layer in order to introduce impurity energy levels into the band gap of SiN. The relaxation processes of the injected charges in SiN were changed due to the ion implantation, which led to the change in relaxation time of the trapped charges. In our experiments, the space charges were introduced by stressing the sample electrically with dc biasing. The effects of implantation process on charge accumulation and dissipation in the dielectric are studied by capacitance-voltage (C-V) measurement qualitatively and quantitatively. The experimental results show that the charging and discharging behavior of the ion implanted silicon nitride films deposited by LPCVD is quite different from the one deposited by PECVD. The charge accumulation in the dielectric film can be reduced by ion implantation with proper dielectric deposition method.

  18. Ion implantation in semiconductors studied by Mössbauer spectroscopy

    NASA Astrophysics Data System (ADS)

    Langouche, G.

    1989-03-01

    The application of Mössbauer spectroscopy as an extremely sensitive characterization technique for ion-implanted semiconductors, is illustrated. Factors influencing the final landing site of implanted ions are first reviewed, as well as ion beam induced material modifications. Recent applications of Mössbauer spectroscopy in this field are then discussed including the study of supersaturated solutions of Sb and Sn in Si, the formation of epitaxial and buried silicides and the search for the DX-center in GaAs.

  19. Photoreflectance Study of Boron Ion-Implanted (100) Cadmium Telluride

    NASA Technical Reports Server (NTRS)

    Amirtharaj, P. M.; Odell, M. S.; Bowman, R. C., Jr.; Alt, R. L.

    1988-01-01

    Ion implanted (100) cadmium telluride was studied using the contactless technique of photoreflectance. The implantations were performed using 50- to 400-keV boron ions to a maximum dosage of 1.5 x 10(16)/sq cm, and the annealing was accomplished at 500 C under vacuum. The spectral measurements were made at 77 K near the E(0) and E(1) critical points; all the spectra were computer-fitted to Aspnes' theory. The spectral line shapes from the ion damaged, partially recovered and undamaged, or fully recovered regions could be identified, and the respective volume fraction of each phase was estimated.

  20. Method For Silicon Surface Texturing Using Ion Implantation

    SciTech Connect

    Kadakia, Nirag; Naczas, Sebastian; Bakhru, Hassaram; Huang Mengbing

    2011-06-01

    As the semiconductor industry continues to show more interest in the photovoltaic market, cheaper and readily integrable methods of silicon solar cell production are desired. One of these methods - ion implantation - is well-developed and optimized in all commercial semiconductor fabrication facilities. Here we have developed a silicon surface texturing technique predicated upon the phenomenon of surface blistering of H-implanted silicon, using only ion implantation and thermal annealing. We find that following the H implant with a second, heavier implant markedly enhances the surface blistering, causing large trenches that act as a surface texturing of c-Si. We have found that this method reduces total broadband Si reflectance from 35% to below 5percent;. In addition, we have used Rutherford backscattering/channeling measurements investigate the effect of ion implantation on the crystallinity of the sample. The data suggests that implantation-induced lattice damage is recovered upon annealing, reproducing the original monocrystalline structure in the previously amorphized region, while at the same time retaining the textured surface.

  1. Some properties of ion and cluster plasma

    SciTech Connect

    Gudzenko, L.I.; Derzhiev, V.I.; Yakovlenko, S.I.

    1982-11-01

    The aggregate of problems connected with the physics of ion and cluster plasma is qualitatively considered. Such a plasma can exist when a dense gas is ionized by a hard ionizer. The conditions for the formation of an ion plasma and the difference between its characteristics and those of an ordinary electron plasma are discussed; a solvated-ion model and the distribution of the clusters with respect to the number of solvated molecules are considered. The recombination rate of the positively and negatively charged clusters is roughly estimated. The parameters of a ball-lightning plasma are estimated on the basis of the cluster model.

  2. Magnesium ion implantation on a micro/nanostructured titanium surface promotes its bioactivity and osteogenic differentiation function

    PubMed Central

    Wang, Guifang; Li, Jinhua; Zhang, Wenjie; Xu, Lianyi; Pan, Hongya; Wen, Jin; Wu, Qianju; She, Wenjun; Jiao, Ting; Liu, Xuanyong; Jiang, Xinquan

    2014-01-01

    As one of the important ions associated with bone osseointegration, magnesium was incorporated into a micro/nanostructured titanium surface using a magnesium plasma immersion ion-implantation method. Hierarchical hybrid micro/nanostructured titanium surfaces followed by magnesium ion implantation for 30 minutes (Mg30) and hierarchical hybrid micro/nanostructured titanium surfaces followed by magnesium ion implantation for 60 minutes (Mg60) were used as test groups. The surface morphology, chemical properties, and amount of magnesium ions released were evaluated by field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, field-emission transmission electron microscopy, and inductively coupled plasma-optical emission spectrometry. Rat bone marrow mesenchymal stem cells (rBMMSCs) were used to evaluate cell responses, including proliferation, spreading, and osteogenic differentiation on the surface of the material or in their medium extraction. Greater increases in the spreading and proliferation ability of rBMMSCs were observed on the surfaces of magnesium-implanted micro/nanostructures compared with the control plates. Furthermore, the osteocalcin (OCN), osteopontin (OPN), and alkaline phosphatase (ALP) genes were upregulated on both surfaces and in their medium extractions. The enhanced cell responses were correlated with increasing concentrations of magnesium ions, indicating that the osteoblastic differentiation of rBMMSCs was stimulated through the magnesium ion function. The magnesium ion-implanted micro/nanostructured titanium surfaces could enhance the proliferation, spreading, and osteogenic differentiation activity of rBMMSCs, suggesting they have potential application in improving bone-titanium integration. PMID:24940056

  3. Influence of Oxygen Ion Implantation on the Damage and Annealing Kinetics of Iron-Implanted Sapphire

    SciTech Connect

    Hunn, J.D.; McHargue, C.J.

    1999-11-14

    The effects of implanted oxygen on the damage accumulation in sapphire which was previously implanted with iron was studied for (0001) sapphire implanted with iron and then with oxygen. The energies were chosen to give similar projected ranges. One series was implanted with a 1:l ratio (4x10{sup 16} ions/cm{sup 2} each) and another with a ratio of 2:3 (4x10{sup 16} fe{sup +}/cm{sup 2}; 6x10{sup 16} O{sup +}/cm{sup 2}). Retained damage, X, in the Al-sublattice, was compared to that produced by implantation of iron alone. The observed disorder was less for the dual implantations suggesting that implantation of oxygen enhanced dynamic recovery during implantation. Samples were annealed for one hour at 800 and 1200 C in an oxidizing and in a reducing atmosphere. No difference was found in the kinetics of recovery in the Al-sublattice between the two dual implant conditions. However, the rate of recovery was different for each from samples implanted with iron alone.

  4. [Improve wear resistance of UHMWPE by O+ ion implanted].

    PubMed

    Xiong, Dangsheng

    2003-12-01

    Ultra high molecular weight polyethylene (UHMWPE) was implanted with 450 keV and 100 keV O+ ions at dosage of 1 x 10(15)/cm2, 5 x 10(15)/cm2, 3 x 10(14)/cm2, respectively. Its wear behaviors were studied under dry friction condition and lubrication by means of distilled water using a pin-on-disk tribometer with a Si3N4 ceramic ball as a counterface. The wear surfaces were examined with SEM. The experimental results showed that the wear rate of implanted UHMWPE is lower than that of un-implanted UHMWPE under both dry and distilled friction conditions, especially for 450 keV energy and 5 x 10(15)/cm2 dose implantation. The friction coefficient of O+ ions implanted UHMWPE is higher than that of un-implanted UHMWPE under both dry and distilled friction conditions. The adhesive, plow and plastic deformation are the wearing mechanism for un-implanted UHMWPE; the fatigue and abrasive wear are that for implanted UHMWPE.

  5. Thin hydroxyapatite surface layers on titanium produced by ion implantation

    NASA Astrophysics Data System (ADS)

    Baumann, H.; Bethge, K.; Bilger, G.; Jones, D.; Symietz, I.

    2002-11-01

    In medicine metallic implants are widely used as hip replacement protheses or artificial teeth. The biocompatibility is in all cases the most important requirement. Hydroxyapatite (HAp) is frequently used as coating on metallic implants because of its high acceptance by the human body. In this paper a process is described by which a HAp surface layer is produced by ion implantation with a continuous transition to the bulk material. Calcium and phosphorus ions are successively implanted into titanium under different vacuum conditions by backfilling oxygen into the implantation chamber. Afterwards the implanted samples are thermally treated. The elemental composition inside the implanted region was determined by nuclear analysis methods as (α,α) backscattering and the resonant nuclear reaction 1H( 15N,αγ) 12C. The results of X-ray photoelectron spectroscopy indicate the formation of HAp. In addition a first biocompatibility test was performed to compare the growing of marrow bone cells on the implanted sample surface with that of titanium.

  6. Nitrogen and boron ion implantation into electrodeposited hard chrome

    SciTech Connect

    Walter, K.C.; Tesmer, J.R.; Scarborough, W.K.; Woodring, J.S.; Nastasi, M.; Kern, K.T.

    1996-10-01

    Electrodeposited hard chrome was ion implanted with N alone, B alone, and a combination. Separate N and B implantation was done at 75 keV and incident doses of 2, 4, and 8x10{sup 17} at/cm{sup 2}. Samples with both N/B implants used 75 keV and incident dose levels of 4x10{sup 17} N- and B-at/cm{sup 2}. Beam-line system was used. Retained dose was measured using ion beam analysis, which indicated most of the incident dose was retained. Surface hardness, wear coefficient, and friction coefficient were determined by nanohardness indentation and pin-on-disk wear. At a depth of 50 nm, surface hardness increased from 18{+-}1 GPa (unimplanted) to a max of 23{+-}4 GPa for B implant and 26{+-}1 GPa for N implant. the wear coefficient was reduced by 1.3x to 7.4x, depending on implantation. N implant results in lower wear coefficients than B implant.

  7. Biofunctionalization of surfaces by energetic ion implantation: Review of progress on applications in implantable biomedical devices and antibody microarrays

    NASA Astrophysics Data System (ADS)

    Bilek, Marcela M. M.

    2014-08-01

    Despite major research efforts in the field of biomaterials, rejection, severe immune responses, scar tissue and poor integration continue to seriously limit the performance of today's implantable biomedical devices. Implantable biomaterials that interact with their host via an interfacial layer of active biomolecules to direct a desired cellular response to the implant would represent a major and much sought after improvement. Another, perhaps equally revolutionary, development that is on the biomedical horizon is the introduction of cost-effective microarrays for fast, highly multiplexed screening for biomarkers on cell membranes and in a variety of analyte solutions. Both of these advances will rely on effective methods of functionalizing surfaces with bioactive molecules. After a brief introduction to other methods currently available, this review will describe recently developed approaches that use energetic ions extracted from plasma to facilitate simple, one-step covalent surface immobilization of bioactive molecules. A kinetic theory model of the immobilization process by reactions with long-lived, mobile, surface-embedded radicals will be presented. The roles of surface chemistry and microstructure of the ion treated layer will be discussed. Early progress on applications of this technology to create diagnostic microarrays and to engineer bioactive surfaces for implantable biomedical devices will be reviewed.

  8. Mechanism of apatite formation on hydrogen plasma-implanted single-crystal silicon

    NASA Astrophysics Data System (ADS)

    Liu, Xuanyong; Fu, Ricky K. Y.; Chu, Paul K.; Ding, Chuanxian

    2004-10-01

    Hydrogen is implanted into single-crystal silicon wafers using plasma ion immersion implantation to improve the surface bioactivity and the mechanism of apatite formation is investigated. Our micro-Raman and transmission electron microscopy results reveal the presence of a disordered silicon surface containing Si-H bonds after hydrogen implantation. When the sample is immersed in a simulated body fluid, the Si-H bonds on the silicon wafer initially react with water to produce a negatively charged surface containing the functional group (Si-O-) that subsequently induces the formation of apatite. A good understanding of the formation mechanism of apatite on hydrogen implanted silicon is not only important from the viewpoint of biophysics but also vital to the actual use of silicon-based microchips and MEMS inside a human body.

  9. Material synthesis for silicon integrated-circuit applications using ion implantation

    NASA Astrophysics Data System (ADS)

    Lu, Xiang

    As devices scale down into deep sub-microns, the investment cost and complexity to develop more sophisticated device technologies have increased substantially. There are some alternative potential technologies, such as silicon-on-insulator (SOI) and SiGe alloys, that can help sustain this staggering IC technology growth at a lower cost. Surface SiGe and SiGeC alloys with germanium peak composition up to 16 atomic percent are formed using high-dose ion implantation and subsequent solid phase epitaxial growth. RBS channeling spectra and cross-sectional TEM studies show that high quality SiGe and SiGeC crystals with 8 atomic percent germanium concentration are formed at the silicon surface. Extended defects are formed in SiGe and SiGeC with 16 atomic percent germanium concentration. X-ray diffraction experiments confirm that carbon reduces the lattice strain in SiGe alloys but without significant crystal quality improvement as detected by RBS channeling spectra and XTEM observations. Separation by plasma implantation of oxygen (SPIMOX) is an economical method for SOI wafer fabrication. This process employs plasma immersion ion implantation (PIII) for the implantation of oxygen ions. The implantation rate for Pm is considerably higher than that of conventional implantation. The feasibility of SPIMOX has been demonstrated with successful fabrication of SOI structures implementing this process. Secondary ion mass spectrometry (SIMS) analysis and cross-sectional transmission electron microscopy (XTEM) micrographs of the SPIMOX sample show continuous buried oxide under single crystal overlayer with sharp silicon/oxide interfaces. The operational phase space of implantation condition, oxygen dose and annealing requirement has been identified. Physical mechanisms of hydrogen induced silicon surface layer cleavage have been investigated using a combination of microscopy and hydrogen profiling techniques. The evolution of the silicon cleavage phenomenon is recorded by a series

  10. The effect of plasma surface treatment on the bioactivity of titanium implant materials (in vitro)

    PubMed Central

    Abdelrahim, Ramy A.; Badr, Nadia A.; Baroudi, Kusai

    2016-01-01

    Background: The surface of an implantable biomaterial plays a very important role in determining the biocompatibility, osteoinduction, and osteointegration of implants because it is in intimate contact with the host bone and soft tissues. Objective: This study was aimed to assess the effect of plasma surface treatment on the bioactivity of titanium alloy (Ti–6Al–4V). Materials and Methods: Fifteen titanium alloy samples were used in this study. The samples were divided into three groups (with five samples in each group). Five samples were kept untreated and served as control (group A). Another five plasma samples were sprayed for nitrogen ion implantation on their surfaces (group B) and the last five samples were pre-etched with acid before plasma treatment (group C). All the investigated samples were immersed for 7 days in Hank's balanced salt solution (HBSS) which was used as a simulating body fluid (SBF) at pH 7.4 and 37°C. HBSS was renewed every 3 days. The different surfaces were characterized by X-ray diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDXA), and Fourier Transformation Infrared Spectroscopy (FTIR). Results: Nitriding of Ti-alloy samples via plasma nitrogen ion implantation increased the bioactivity of titanium. Moreover, the surface topography affected the chemical structure of the formed apatite. Increasing the surface roughness enhanced the bioactivity of the implant material. Conclusions: Nitridation can be exploited as an effective way to promote the formation of bone-like material on the implant surface. PMID:27011927

  11. High temperature annealing studies of strontium ion implanted glassy carbon

    NASA Astrophysics Data System (ADS)

    Odutemowo, O. S.; Malherbe, J. B.; Prinsloo, L.; Langa, D. F.; Wendler, E.

    2016-03-01

    Glassy carbon samples were implanted with 200 keV strontium ions to a fluence of 2 × 1016 ions/cm2 at room temperature. Analysis with Raman spectroscopy showed that ion bombardment amorphises the glassy carbon structure. Partial recovery of the glassy carbon structure was achieved after the implanted sample was vacuum annealed at 900 °C for 1 h. Annealing the strontium ion bombarded sample at 2000 °C for 5 h resulted in recovery of the glassy carbon substrate with the intensity of the D peak becoming lower than that of the pristine glassy carbon. Rutherford backscattering spectroscopy (RBS) showed that the implanted strontium diffused towards the surface of the glassy carbon after annealing the sample at 900 °C. This diffusion was also accompanied by loss of the implanted strontium. Comparison between the as-implanted and 900 °C depth profiles showed that less than 30% of the strontium was retained in the glassy carbon after heat treatment at 900 °C. The RBS profile after annealing at 2000 °C indicated that no strontium ions were retained after heat treatment at this temperature.

  12. Ion/water channels for embryo implantation barrier.

    PubMed

    Liu, Xin-Mei; Zhang, Dan; Wang, Ting-Ting; Sheng, Jian-Zhong; Huang, He-Feng

    2014-05-01

    Successful implantation involves three distinct processes, namely the embryo apposition, attachment, and penetration through the luminal epithelium of the endometrium to establish a vascular link to the mother. After penetration, stromal cells underlying the epithelium differentiate and surround the embryo to form the embryo implantation barrier, which blocks the passage of harmful substances to the embryo. Many ion/water channel proteins were found to be involved in the process of embryo implantation. First, ion/water channel proteins play their classical role in establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ions across the cell membrane. Second, most of ion/water channel proteins are regulated by steroid hormone (estrogen or progesterone), which may have important implications to the embryo implantation. Last but not least, these proteins do not limit themselves as pure channels but also function as an initiator of a series of consequences once activated by their ligand/stimulator. Herein, we discuss these new insights in recent years about the contribution of ion/water channels to the embryo implantation barrier construction during early pregnancy. PMID:24789983

  13. Osteoconductivity of hydrophilic microstructured titanium implants with phosphate ion chemistry.

    PubMed

    Park, Jin-Woo; Jang, Je-Hee; Lee, Chong Soo; Hanawa, Takao

    2009-07-01

    This study investigated the surface characteristics and bone response of titanium implants produced by hydrothermal treatment using H(3)PO(4), and compared them with those of implants produced by commercial surface treatment methods - machining, acid etching, grit blasting, grit blasting/acid etching or spark anodization. The surface characteristics were evaluated by scanning electron microscopy, thin-film X-ray diffractometry, X-ray photoelectron spectroscopy, contact angle measurement and stylus profilometry. The osteoconductivity of experimental implants was evaluated by removal torque testing and histomorphometric analysis after 6 weeks of implantation in rabbit tibiae. Hydrothermal treatment with H(3)PO(4) and subsequent heat treatment produced a crystalline phosphate ion-incorporated oxide (titanium oxide phosphate hydrate, Ti(2)O(PO(4))(2)(H(2)O)(2); TiP) surface approximately 5microm in thickness, which had needle-like surface microstructures and superior wettability compared with the control surfaces. Significant increases in removal torque forces and bone-to-implant contact values were observed for TiP implants compared with those of the control implants (p<0.001). After thorough cleaning of the implants removed during the removal torque testing, a considerable quantity of attached bone was observed on the surfaces of the TiP implants. PMID:19332400

  14. Surface modification of Natural Rubber by ion implantation: Evidence for implant doping

    NASA Astrophysics Data System (ADS)

    Predeep, P.; Najidha, S.; Sreeja, R.; Saxena, N. S.

    2005-12-01

    Ion implantation is one of the most powerful and well-known technique for surface modification in polymers. Thin films of Natural Rubber were modified by the implantation of 60 keV N + ions to the fluences of 10 11-10 15 cm -2. The electrical conductivity measurements of irradiated sample show 10 orders of magnitude compared to pristine state. Along with conductivity change there was a noticeable change in color to a dense shiny black for the most highly conducting films. The analysis of temperature dependence of dc electrical conductivity data reveals a three-dimensional variable range hopping mechanism. The microstructural evolution of the virgin and ion-beam modified samples was investigated by spectroscopic analysis such as UV/Vis & FTIR. These spectral studies gave evidence for the production of conjugate double bonds, which is a clear cut indication of implant doping. This is an important result since ion implantation usually does not produce doping in polymeric materials and only a few reports about the possibility of implant doping in polymers are available. The significant aspect of this study is that this confirms, the Natural Rubber's potential to be used as a microelectronic device material. Also an attempt has been made to compare the conductivity enhancement in Natural Rubber by chemical and implant doping.

  15. On carbon nitride synthesis at high-dose ion implantation

    NASA Astrophysics Data System (ADS)

    Romanovsky, E. A.; Bespalova, O. V.; Borisov, A. M.; Goryaga, N. G.; Kulikauskas, V. S.; Sukharev, V. G.; Zatekin, V. V.

    1998-04-01

    Rutherford backscattering spectrometry was used for the study of high dose 35 keV nitrogen ions implantation into graphites and glassy carbon. Quantitative data on depth profiles and its dependencies on irradiation fluence and ion beam density were obtained. The stationary dome-shaped depth profile with maximum nitrogen concentration 22-27 at.% and half-width more than twice exceeding projected range of ions is reached at fluence Φ ˜10 18 cm -2. The dependence of the maximum concentration in the profile on ion current density was studied. The largest concentration was obtained at reduced ion current density.

  16. GaAs Hall devices produced by local ion implantation

    NASA Astrophysics Data System (ADS)

    Pettenpaul, E.; Huber, J.; Weidlich, H.; Flossmann, W.; von Borcke, U.

    1981-08-01

    GaAs Hall devices were produced by complete planar technology using two selective silicon ion implantation steps. The fundamental characteristics of these devices with respect to reproducible implantation dose and geometry of cross-shaped elements are obtained both by experiment and calculation. The prominent properties of the GaAs Hall elements presented are high sensitivity and linearity, small temperature dependence of sensitivity and resistance, and low residual voltage.

  17. Dislocation mechanism of deuterium retention in tungsten under plasma implantation.

    PubMed

    Dubinko, V I; Grigorev, P; Bakaev, A; Terentyev, D; van Oost, G; Gao, F; Van Neck, D; Zhurkin, E E

    2014-10-01

    We have developed a new theoretical model for deuterium (D) retention in tungsten-based alloys on the basis of its being trapped at dislocations and transported to the surface via the dislocation network with parameters determined by ab initio calculations. The model is used to explain experimentally observed trends of D retention under sub-threshold implantation, which does not produce stable lattice defects to act as traps for D in conventional models. Saturation of D retention with implantation dose and effects due to alloying of tungsten with, e.g. tantalum, are evaluated, and comparison of the model predictions with experimental observations under high-flux plasma implantation conditions is presented.

  18. Surface modification of SKD-61 steel by ion implantation technique

    SciTech Connect

    Wen, F. L.; Lo, Y.-L.; Yu, Y.-C.

    2007-07-15

    The purpose of this study is to investigate how ion implantation affects the surface characteristics and nitrogenizing depth of the thin film by the use of a NEC 9SDH-2 3 MV Pelletron accelerator that implants nitrogen ions into SKD-61 tool steels for surface modification. Nitrogen ions were implanted into the surface layer of materials so that the hardness of modified films could be improved. Also, the nitride film stripping problems of the traditional nitrogenizing treatment could be overcome by a new approach in surface process engineering. As nitrogen ions with high velocity impacted on the surface of the substrate, the ions were absorbed and accumulated on the surface of the substrate. The experiments were performed with two energies (i.e., 1 and 2 MeV) and different doses (i.e., 2.5x10{sup 15}, 7.5x10{sup 15}, and 1.5x10{sup 16} ions/cm{sup 2}). Nitrogen ions were incorporated into the interface and then diffused through the metal to form a nitride layer. Analysis tools included the calculation of stopping and range of ions in matter (SRIM), the detection of a secondary ion mass spectrometry (SIMS), and nanoindentation testing. Through the depth analysis of SIMS, the effects of the ion-implanted SKD-61 steels after heating at 550 deg. C in a vacuum furnace were examined. The nanoindenting results indicate the variation of hardness of SKD-61 steels with the various ion doses. It reaches two to three times the original hardness of SKD-61 steels.

  19. Method For Silicon Surface Texturing Using Ion Implantation

    NASA Astrophysics Data System (ADS)

    Kadakia, Nirag; Naczas, Sebastian; Bakhru, Hassaram; Huang, Mengbing

    2011-06-01

    As the semiconductor industry continues to show more interest in the photovoltaic market, cheaper and readily integrable methods of silicon solar cell production are desired. One of these methods—ion implantation—is well-developed and optimized in all commercial semiconductor fabrication facilities. Here we have developed a silicon surface texturing technique predicated upon the phenomenon of surface blistering of H-implanted silicon, using only ion implantation and thermal annealing. We find that following the H implant with a second, heavier implant markedly enhances the surface blistering, causing large trenches that act as a surface texturing of c-Si. We have found that this method reduces total broadband Si reflectance from 35% to below 5percent;. In addition, we have used Rutherford backscattering/channeling measurements investigate the effect of ion implantation on the crystallinity of the sample. The data suggests that implantation-induced lattice damage is recovered upon annealing, reproducing the original monocrystalline structure in the previously amorphized region, while at the same time retaining the textured surface.

  20. Influence of ion implantation on titanium surfaces for medical applications

    NASA Astrophysics Data System (ADS)

    Krischok, Stefan; Blank, Claudia; Engel, Michael; Gutt, Richard; Ecke, Gernot; Schawohl, Jens; Spieß, Lothar; Schrempel, Frank; Hildebrand, Gerhard; Liefeith, Klaus

    2007-09-01

    The implantation of ions into the near surface layer is a new approach to improve the osseointegration of metallic biomaterials like titanium. Meanwhile it is well known that surface topography and surface physico-chemistry as well as visco-elastic properties influence the cell response after implantation of implants into the human body. To optimize the cell response of titanium, ion implantation techniques have been used to integrate calcium and phosphorus, both elements present in the inorganic bone phase. In this context, the concentration profile of the detected elements and their chemical state have been investigated using X-ray photoelectron spectroscopy and Auger electron spectroscopy depth profiling. Ion implantation leads to strong changes of the chemical composition of the near surface region, which are expected to modify the biofunctionality as observed in previous experiments on the cell response. The co-implantation of calcium and phosphorus samples, which showed best results in the performed tests (biological and physical), leads to a strong modification of the chemical surface composition.

  1. Observations of Ag diffusion in ion implanted SiC

    NASA Astrophysics Data System (ADS)

    Gerczak, Tyler J.; Leng, Bin; Sridharan, Kumar; Hunter, Jerry L.; Giordani, Andrew J.; Allen, Todd R.

    2015-06-01

    The nature and magnitude of Ag diffusion in SiC has been a topic of interest in connection with the performance of tristructural isotropic (TRISO) coated particle fuel for high temperature gas-cooled nuclear reactors. Ion implantation diffusion couples have been revisited to continue developing a more complete understanding of Ag fission product diffusion in SiC. Ion implantation diffusion couples fabricated from single crystal 4H-SiC and polycrystalline 3C-SiC substrates and exposed to 1500-1625 °C, were investigated by transmission electron microscopy and secondary ion mass spectrometry (SIMS). The high dynamic range of SIMS allowed for multiple diffusion régimes to be investigated, including enhanced diffusion by implantation-induced defects and grain boundary (GB) diffusion in undamaged SiC. Estimated diffusion coefficients suggest GB diffusion in bulk SiC does not properly describe the release observed from TRISO fuel.

  2. Observations of Ag diffusion in ion implanted SiC

    SciTech Connect

    Gerczak, Tyler J.; Leng, Bin; Sridharan, Kumar; Jerry L. Hunter, Jr.; Giordani, Andrew J.; Allen, Todd R.

    2015-03-17

    The nature and magnitude of Ag diffusion in SiC has been a topic of interest in connection with the performance of tristructural isotropic (TRISO) coated particle fuel for high temperature gas-cooled nuclear reactors. Ion implantation diffusion couples have been revisited to continue developing a more complete understanding of Ag fission product diffusion in SiC. Ion implantation diffusion couples fabricated from single crystal 4H-SiC and polycrystalline 3C-SiC substrates and exposed to 1500–1625°C, were investigated in this study by transmission electron microscopy and secondary ion mass spectrometry (SIMS). The high dynamic range of SIMS allowed for multiple diffusion régimes to be investigated, including enhanced diffusion by implantation-induced defects and grain boundary (GB) diffusion in undamaged SiC. Lastly, estimated diffusion coefficients suggest GB diffusion in bulk SiC does not properly describe the release observed from TRISO fuel.

  3. Ion implantation for manufacturing bent and periodically bent crystals

    SciTech Connect

    Bellucci, Valerio; Camattari, Riccardo; Guidi, Vincenzo Mazzolari, Andrea; Paternò, Gianfranco; Lanzoni, Luca

    2015-08-10

    Ion implantation is proposed to produce self-standing bent monocrystals. A Si sample 0.2 mm thick was bent to a radius of curvature of 10.5 m. The sample curvature was characterized by interferometric measurements; the crystalline quality of the bulk was tested by X-ray diffraction in transmission geometry through synchrotron light at ESRF (Grenoble, France). Dislocations induced by ion implantation affect only a very superficial layer of the sample, namely, the damaged region is confined in a layer 1 μm thick. Finally, an elective application of a deformed crystal through ion implantation is here proposed, i.e., the realization of a crystalline undulator to produce X-ray beams.

  4. Concepts and designs of ion implantation equipment for semiconductor processing

    NASA Astrophysics Data System (ADS)

    Rose, Peter H.; Ryding, Geoffrey

    2006-11-01

    Manufacturing ion implantation equipment for doping semiconductors has grown into a two billion dollar business. The accelerators developed for nuclear physics research and isotope separation provided the technology from which ion implanters have been developed but the unique requirements of the semiconductor industry defined the evolution of the architecture of these small accelerators. Key elements will be described including ion generation and beam transport systems as well as the techniques used to achieve uniform doping over large wafers. The wafers are processed one at a time or in batches and are moved in and out of the vacuum by automated handling systems. The productivity of an implanter is of economic importance and there is continuing need to increase the usable beam current especially at low energies.

  5. The history of uniformity mapping in ion implantation

    NASA Astrophysics Data System (ADS)

    Yarling, C. B.; Keenan, W. A.; Larson, L. A.

    1991-04-01

    In the early days of semiconductor manufacturing, the four-point probe became established as the tool-of-choice for monitoring diffusion processes. The application of the four-point probe to ion implantation in the early 1960s was basically limited to the single-point measurement of dose, since the equipment did not have the necessary precision or repeatability to provide useful uniformity results. As a result, implanter uniformity was determined by either a visual observation of a heavily doped wafer or by a mylar bum. Unfortunately, these techniques were either subject to interpretation by the user or could not provide a parameter that could be statistically tracked or characterized. During the last 30 years, the commercial ion implanter as well as the dose and uniformity characterization equipment used to characterize this production tool have progressed significantly. Indeed, several generations of electrical and optical equipment have been developed to measure both the dose and uniformity of the increasingly advanced and complex ion implanter. This paper will review all of the techniques and equipment used to measure the uniformity of ion implantation. In addition, various graphical techniques developed to present early measurement results will be discussed.

  6. Ion Implanted Passivated Contacts for Interdigitated Back Contacted Solar Cells

    SciTech Connect

    Young, David L.; Nemeth, William; LaSalvia, Vincenzo; Reedy, Robert; Bateman, Nicholas; Stradins, Pauls

    2015-06-14

    We describe work towards an interdigitated back contacted (IBC) solar cell utilizing ion implanted, passivated contacts. Formation of electron and hole passivated contacts to n-type CZ wafers using tunneling SiO2 and ion implanted amorphous silicon (a-Si) are described. P and B were ion implanted into intrinsic amorphous Si films at several doses and energies. A series of post-implant anneals showed that the passivation quality improved with increasing annealing temperatures up to 900 degrees C. The recombination parameter, Jo, as measured by a Sinton lifetime tester, was Jo ~ 14 fA/cm2 for Si:P, and Jo ~ 56 fA/cm2 for Si:B contacts. The contact resistivity for the passivated contacts, as measured by TLM patterns, was 14 milliohm-cm2 for the n-type contact and 0.6 milliohm-cm2 for the p-type contact. These Jo and pcontact values are encouraging for forming IBC cells using ion implantation to spatially define dopants.

  7. Plasma formed ion beam projection lithography system

    DOEpatents

    Leung, Ka-Ngo; Lee, Yung-Hee Yvette; Ngo, Vinh; Zahir, Nastaran

    2002-01-01

    A plasma-formed ion-beam projection lithography (IPL) system eliminates the acceleration stage between the ion source and stencil mask of a conventional IPL system. Instead a much thicker mask is used as a beam forming or extraction electrode, positioned next to the plasma in the ion source. Thus the entire beam forming electrode or mask is illuminated uniformly with the source plasma. The extracted beam passes through an acceleration and reduction stage onto the resist coated wafer. Low energy ions, about 30 eV, pass through the mask, minimizing heating, scattering, and sputtering.

  8. Ion implantation induced modification of a-SiC : H

    NASA Astrophysics Data System (ADS)

    Tzenov, N.; Tzolov, M.; Dimova-Malinovska, D.; Tsvetkova, T.; Angelov, C.; Adriaenssens, G.; Pattyn, H.

    1994-02-01

    Optical transmission measurements have been carried out on thin a-SiC:H alloy films, implanted with ions of group IV elements. High doses of the order of 10 17 cm -2 have been used leading to a considerable shift of the absorption edge to lower photon energies. This shift may be attributed both to additional defect introduction and to accompanying formation of bonds between implanted ions and the atoms of the alloy, as confirmed by IR and Raman measurements. The observed chemical modification results from the high concentration of introduced atoms which is of the order of those for the host elements.

  9. Temperature Activated Diffusion of Radicals through Ion Implanted Polymers.

    PubMed

    Wakelin, Edgar A; Davies, Michael J; Bilek, Marcela M M; McKenzie, David R

    2015-12-01

    Plasma immersion ion implantation (PIII) is a promising technique for immobilizing biomolecules on the surface of polymers. Radicals generated in a subsurface layer by PIII treatment diffuse throughout the substrate, forming covalent bonds to molecules when they reach the surface. Understanding and controlling the diffusion of radicals through this layer will enable efficient optimization of this technique. We develop a model based on site to site diffusion according to Fick's second law with temperature activation according to the Arrhenius relation. Using our model, the Arrhenius exponential prefactor (for barrierless diffusion), D0, and activation energy, EA, for a radical to diffuse from one position to another are found to be 3.11 × 10(-17) m(2) s(-1) and 0.31 eV, respectively. The model fits experimental data with a high degree of accuracy and allows for accurate prediction of radical diffusion to the surface. The model makes useful predictions for the lifetime over which the surface is sufficiently active to covalently immobilize biomolecules and it can be used to determine radical fluence during biomolecule incubation for a range of storage and incubation temperatures so facilitating selection of the most appropriate parameters.

  10. Inductively generated streaming plasma ion source

    DOEpatents

    Glidden, Steven C.; Sanders, Howard D.; Greenly, John B.

    2006-07-25

    A novel pulsed, neutralized ion beam source is provided. The source uses pulsed inductive breakdown of neutral gas, and magnetic acceleration and control of the resulting plasma, to form a beam. The beam supplies ions for applications requiring excellent control of ion species, low remittance, high current density, and spatial uniformity.

  11. The Influence of Ion Implantation on cell Attachment to Glassy Polymeric Carbon

    SciTech Connect

    Zimmerman, R.; Ila, D.; Gurhan, I.; Ozdal-Kurt, F.; Sen, B. H.; Rodrigues, M.

    2006-11-13

    In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that near surface implantation of silver in Glassy Polymeric Carbon (GPC) can completely inhibit cell attachment on implanted areas while leaving adjacent areas unaffected. Patterned ion implantation permits precise control of tissue growth on medical applications of GPC. We have shown that silver ion implantation or argon ion assisted surface deposition of silver inhibits cell growth on GPC, a desirable improvement of current cardiac implants.

  12. A review on ion-ion plasmas created in weakly magnetized electronegative plasmas

    NASA Astrophysics Data System (ADS)

    Aanesland, A.; Bredin, J.; Chabert, P.

    2014-08-01

    Ion-Ion plasmas are electronegative plasmas where the electron density is several orders of magnitude lower than the negative ion density. These plasmas have been scarcely observed and investigated since the 1960s and are formed as a transient state of pulsed plasmas or in separate regions in magnetized plasmas. In this review we focus on the latter case of continuous formation of ion-ion plasmas created at the periphery of magnetized plasma columns or downstream localized magnetic barriers. We bring together and review experimental results already published elsewhere and complement them with new results to illustrate the physics important in ion-ion plasma formation and highlight in particular unanswered questions. We show that with a good design the density in the ion-ion region is dropping only by a factor of 2-3 from the initial plasma density. These plasmas can therefore be well suited for various ion source applications when both fluxes or beams of positive and negative ions are desired, and when electrons can cause harmful effects.

  13. Some consequences to ion source behavior of high plasma drift velocity

    SciTech Connect

    Brown, I. G.; Monteiro, O. R.; Bilek, M. M. M.; Keidar, M.; Oks, E. M.; Vizir, A.

    2000-02-01

    We consider the case of energetic ion beam formation when the ion streaming velocity within the source plasma is substantial, i.e., when the ions have a drift speed (in the positive downstream direction) that is on the order of or greater than the ion acoustic speed in the plasma. Some interesting consequences can follow, including the capability of a negatively biased substrate located in the plasma stream to maintain high bias voltage, and of an ion source with no extractor or ''conventionally poor'' extractor providing a kind of plasma immersion ion implantation mode of operation. Here we summarize the kind of plasma geometry in which this situation can occur, and describe some experimental observations we've made of these effects, with reference to a simple theoretical basis for the mechanism. (c) 2000 American Institute of Physics.

  14. Ion implantation induced swelling in 6H-SiC

    SciTech Connect

    Nipoti, R.; Albertazzi, E.; Bianconi, M.; Lotti, R.; Lulli, G.; Cervera, M.; Carnera, A.

    1997-06-01

    Ion implantation induced surface expansion (swelling) of 6H-SiC was investigated through the measurement of the step height between implanted and unimplanted areas. The samples were irradiated at room temperature with 500 keV Al{sup +} ions in the dose range 1.25{times}10{sup 14}{endash}3{times}10{sup 15}ionscm{sup {minus}2}. Swelling was related to dose and the area density of ion-induced damage measured by Rutherford backscattering channeling technique. The observed trend is consistent with the hypothesis that the volume expansion of the ion damaged crystal is proportional to the area density of displaced atoms, plus an additional relaxation occurring at the onset of the crystalline to amorphous transition. {copyright} {ital 1997 American Institute of Physics.}

  15. Ion implantation and annealing studies in III-V nitrides

    SciTech Connect

    Zolper, J.C.; Pearton, S.J.; Williams, J.S.; Tan, H.H.; Karlicek, R.J. Jr.; Stall, R.A.

    1996-12-31

    Ion implantation doping and isolation is expected to play an enabling role for the realization of advanced III-Nitride based devices. In fact, implantation has already been used to demonstrate n- and p-type doping of GaN with Si and Mg or Ca, respectively, as well as to fabricate the first GaN junction field effect transistor. Although these initial implantation studies demonstrated the feasibility of this technique for the III-Nitride materials, further work is needed to realize its full potential. After reviewing some of the initial studies in this field, the authors present new results for improved annealing sequences and defect studies in GaN. First, sputtered AlN is shown by electrical characterization of Schottky and Ohmic contacts to be an effect encapsulant of GaN during the 1,100 C implant activation anneal. The AlN suppresses N-loss from the GaN surface and the formation of a degenerate n{sup +}-surface region that would prohibit Schottky barrier formation after the implant activation anneal. Second, they examine the nature of the defect generation and annealing sequence following implantation using both Rutherford Backscattering (RBS) and Hall characterization. They show that for a Si-dose of 1 x 10{sup 16} cm{sup {minus}2} 50% electrical donor activation is achieved despite a significant amount of residual implantation-induced damage in the material.

  16. Nanocomposite formed by titanium ion implantation into alumina

    SciTech Connect

    Spirin, R. E.; Salvadori, M. C. Teixeira, F. S.; Sgubin, L. G.; Cattani, M.; Brown, I. G.

    2014-11-14

    Composites of titanium nanoparticles in alumina were formed by ion implantation of titanium into alumina, and the surface electrical conductivity measured in situ as the implantation proceeded, thus generating curves of sheet conductivity as a function of dose. The implanted titanium self-conglomerates into nanoparticles, and the spatial dimensions of the buried nanocomposite layer can thus be estimated from the implantation depth profile. Rutherford backscattering spectrometry was performed to measure the implantation depth profile, and was in good agreement with the calculated profile. Transmission electron microscopy of the titanium-implanted alumina was used for direct visualization of the nanoparticles formed. The measured conductivity of the buried layer is explained by percolation theory. We determine that the saturation dose, φ{sub 0}, the maximum implantation dose for which the nanocomposite material still remains a composite, is φ{sub 0} = 2.2 × 10{sup 16 }cm{sup −2}, and the corresponding saturation conductivity is σ{sub 0} = 480 S/m. The percolation dose φ{sub c}, below which the nanocomposite still has basically the conductivity of the alumina matrix, was found to be φ{sub c} = 0.84 × 10{sup 16 }cm{sup −2}. The experimental results are discussed and compared with a percolation theory model.

  17. Surface induced reactivity for titanium by ion implantation.

    PubMed

    Pham, M T; Reuther, H; Matz, W; Mueller, R; Steiner, G; Oswald, S; Zyganov, I

    2000-06-01

    Calcium and phosphorus storage in a thin layer of titanium surface was achieved by ion implantation. We study the reactivity of this surface in response to a hydrothermal treatment. The incipient implanted species are observed to convert to Ca(2+) and PO(4)(3-), the precursors for generating calcium phosphate polymorphs. Hydroxyapatite is formed from these precursors by an interface-liquid mediated mineralization preceded by the hydrolysis of oxygen compounds of Ca and P from the solid phase. The morphology and organization of apatite mineral is controlled by the fluid dynamics reflecting the surface remodeling to adapt to the available local environment. Exposed to calcium and phosphate ion containing solution, the hydrothermally treated surface templates hydroxyapatite deposition. Ca and P implanted Ti surface was shown to be chemically and morphologically actively involved in the interfacial reactions.

  18. Zinc ion implantation-deposition technique improves the osteoblast biocompatibility of titanium surfaces

    PubMed Central

    LIANG, YONGQIANG; XU, JUAN; CHEN, JING; QI, MENGCHUN; XIE, XUEHONG; HU, MIN

    2015-01-01

    The plasma immersion ion implantation and deposition (PIIID) technique was used to implant zinc (Zn) ions into smooth surfaces of pure titanium (Ti) disks for investigation of tooth implant surface modification. The aim of the present study was to evaluate the surface structure and chemical composition of a modified Ti surface following Zn ion implantation and deposition and to examine the effect of such modification on osteoblast biocompatibility. Using the PIIID technique, Zn ions were deposited onto the smooth surface of pure Ti disks. The physical structure and chemical composition of the modified surface layers were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. In vitro culture assays using the MG-63 bone cell line were performed to determine the effects of Zn-modified Ti surfaces following PIIID on cellular function. Acridine orange staining was used to detect cell attachment to the surfaces and cell cycle analysis was performed using flow cytometry. SEM revealed a rough ‘honeycomb’ structure on the Zn-modified Ti surfaces following PIIID processing and XPS data indicated that Zn and oxygen concentrations in the modified Ti surfaces increased with PIIID processing time. SEM also revealed significantly greater MG-63 cell growth on Zn-modified Ti surfaces than on pure Ti surfaces (P<0.05). Flow cytometric analysis revealed increasing percentages of MG-63 cells in S phase with increasing Zn implantation and deposition, suggesting that MG-63 apoptosis was inhibited and MG-63 proliferation was promoted on Zn-PIIID-Ti surfaces. The present results suggest that modification with Zn-PIIID may be used to improve the osteoblast biocompatibility of Ti implant surfaces. PMID:25673139

  19. Surface damage on diamond membranes fabricated by ion implantation and lift-off

    SciTech Connect

    Drumm, V. S.; Alves, A. D. C.; Fairchild, B. A.; Ganesan, K.; McCallum, J. C.; Jamieson, D. N.; Prawer, S.; Rubanov, S.; Kalish, R.; Feldman, L. C.

    2011-06-06

    Thin membranes with excellent optical properties are essential elements in diamond based photonic systems. Due to the chemical inertness of diamond, ion beam processing must be employed to carve photonic structures. One method to realize such membranes is ion-implantation graphitization followed by chemical removal of the sacrificial graphite. The interface revealed when the sacrificial layer is removed has interesting properties. To investigate this interface, we employed the surface sensitive technique of grazing angle channeled Rutherford backscattering spectroscopy. Even after high temperature annealing and chemical etching a thin layer of damaged diamond remains, however, it is removed by hydrogen plasma exposure.

  20. PARMELA simulations of RF linear accelerators for ion implantation

    SciTech Connect

    Swenson, D. R.; Wan Zhimin; Di Vergilio, W. F.; Saadatmand, K.

    1999-06-10

    RF linear accelerators (LINACs) offer the highest beam energies and currents available to the high-energy segment of the ion-implantation industry. We are using the computer code PARMELA to simulate a variety of beam parameters. The simulations are used to generate beam tunes, optimize LINAC performance, and to design new LINACs.

  1. Magnetic and Transport Properties of Mn-ion implanted Si

    NASA Astrophysics Data System (ADS)

    Preisler, V.; Ogawa, M.; Han, X.; Wang, K. L.

    2010-01-01

    We investigate the magnetic and transport properties of Mn-ion implanted Si. Both temperature dependent and field dependent measurements of the samples using a SQUID magnometer reveal ferromagnetic properties at room temperature. Magnetotransport measurements show a large positive magnetoresistance up to 4.5 T with no signs of saturation.

  2. Chaotic ion motion in magnetosonic plasma waves

    NASA Technical Reports Server (NTRS)

    Varvoglis, H.

    1984-01-01

    The motion of test ions in a magnetosonic plasma wave is considered, and the 'stochasticity threshold' of the wave's amplitude for the onset of chaotic motion is estimated. It is shown that for wave amplitudes above the stochasticity threshold, the evolution of an ion distribution can be described by a diffusion equation with a diffusion coefficient D approximately equal to 1/v. Possible applications of this process to ion acceleration in flares and ion beam thermalization are discussed.

  3. Electrostatic ion cyclotron and ion plasma waves in a symmetric pair-ion plasma cylinder.

    PubMed

    Kono, M; Vranjes, J; Batool, N

    2014-03-14

    Complicated wave behavior observed in the cylindrical pair-ion (fullerene) experiments by Oohara and co-workers are now identified to be low harmonic ion cyclotron waves combined with ion plasma oscillations inherent to kinetic theory. The electrostatic dispersion equation derived is based on an approximation for the current from the exact solutions of the characteristic cylindrical geometry form of the Vlasov plasma equation in a uniform magnetized plasma cylinder surrounded by a larger metal boundary outside a vacuum gap, which thus differs from that in unbounded plasmas. Positive and negative ions, differing only in the sign of their charge, respond to a potential in the same time scale and cooperate to reflect the enhanced kinetic orbital behaviors to the macroscopic propagation characteristics. In addition, the experimental value of the Larmor radius (comparable to the discharge radius but small enough to make the analytic approximation useful) makes higher harmonic ion cyclotron effects both observable and calculable with the appropriate approximation for the kinetic theory. PMID:24679299

  4. Ultrahigh-current-density metal-ion implantation and diamondlike-hydrocarbon films for tribological applications; Final report

    SciTech Connect

    Wilbur, P.J.

    1993-09-01

    The metal-ion-implantation system used to implant metals into substrates are described. The metal vapor required for operation is supplied by drawing sufficient electron current from the plasma discharge to an anode-potential crucible so a solid, pure metal placed in the crucible will be heated to the point of vaporization. The ion-producing, plasma discharge is initiated within a graphite-ion-source body, which operates at high temperature, by using an argon flow that is turned off once the metal vapor is present. Extraction of ion beams several cm in diameter at current densities ranging to several hundred {mu}A/cm{sup 2} on a target 50 cm downstream of the ion source have been demonstrated using Mg, Ag, Cr, Cu, Si, Ti, V, B and Zr. These metals were implanted into over 100 substrates (discs, pins, flats, wires). A model describing thermal stresses induced in materials (e.g. ceramic plates) during high-current-density implantation is presented. Tribological and microstructural characteristics of iron and 304-stainless-steel samples implanted with Ti or B are examined. Diamondlike-hydrocarbon coatings were applied to steel surfaces and found to exhibit good tribological performance.

  5. Ion thruster charge-exchange plasma flow

    NASA Technical Reports Server (NTRS)

    Carruth, M. R., Jr.; Gabriel, S. B.; Kitamura, S.

    1982-01-01

    The electron bombardment ion thruster has been under development for a number of years and during this time, studies of the plasmas produced by the thrusters and their interactions with spacecraft have been evaluated, based on available data. Due to diagnostic techniques used and facility effects, there is uncertainty as to the reliability of data from these early studies. This paper presents data on the flow of the charge-exchange plasma produced just downstream of the thruster's ion optics. The 'end-effect' of a cylindrical Langmuir probe is used to determine ion density and directed ion velocity. Results are compared with data obtained from a retarding potential analyzer-Faraday cup.

  6. Zinc-ion implanted and deposited titanium surfaces reduce adhesion of Streptococccus mutans

    NASA Astrophysics Data System (ADS)

    Xu, Juan; Ding, Gang; Li, Jinlu; Yang, Shenhui; Fang, Bisong; Sun, Hongchen; Zhou, Yanmin

    2010-10-01

    While titanium (Ti) is a commonly used dental implant material with advantageous biocompatible and mechanical properties, native Ti surfaces do not have the ability to prevent bacterial colonization. The objective of this study was to evaluate the chemical composition and bacterial adhesive properties of zinc (Zn) ion implanted and deposited Ti surfaces (Zn-PIIID-Ti) as potential dental implant materials. Surfaces of pure Ti (cp-Ti) were modified with increasing concentrations of Zn using plasma immersion ion implantation and deposition (PIIID), and elemental surface compositions were characterized by X-ray photoelectron spectrometry (XPS). To evaluate bacterial responses, Streptococcus mutans were seeded onto the modifiedTi surfaces for 48 h and subsequently observed by scanning electron microscopy. Relative numbers of bacteria on each surface were assessed by collecting the adhered bacteria, reculturing and counting colony forming units after 48 h on bacterial grade plates. Ti, oxygen and carbon elements were detected on all surfaces by XPS. Increased Zn signals were detected on Zn-PIIID-Ti surfaces, correlating with an increase of Zn-deposition time. Substantial numbers of S. mutans adhered to cp-Ti samples, whereas bacterial adhesion on Zn-PIIID-Ti surfaces signficantly decreased as the Zn concentration increased ( p < 0.01). In conclusion, PIIID can successfully introduce Zn onto a Ti surface, forming a modified surface layer bearing Zn ions that consequently deter adhesion of S. mutans, a common bacterium in the oral environment.

  7. Ion plasma wave and its instability in interpenetrating plasmas

    SciTech Connect

    Vranjes, J.; Kono, M.

    2014-04-15

    Some essential features of the ion plasma wave in both kinetic and fluid descriptions are presented. The wave develops at wavelengths shorter than the electron Debye radius. Thermal motion of electrons at this scale is such that they overshoot the electrostatic potential perturbation caused by ion bunching, which consequently propagates as an unshielded wave, completely unaffected by electron dynamics. So in the simplest fluid description, the electrons can be taken as a fixed background. However, in the presence of magnetic field and for the electron gyro-radius shorter than the Debye radius, electrons can participate in the wave and can increase its damping rate. This is determined by the ratio of the electron gyro-radius and the Debye radius. In interpenetrating plasmas (when one plasma drifts through another), the ion plasma wave can easily become growing and this growth rate is quantitatively presented for the case of an argon plasma.

  8. Versatile, high-sensitivity faraday cup array for ion implanters

    DOEpatents

    Musket, Ronald G.; Patterson, Robert G.

    2003-01-01

    An improved Faraday cup array for determining the dose of ions delivered to a substrate during ion implantation and for monitoring the uniformity of the dose delivered to the substrate. The improved Faraday cup array incorporates a variable size ion beam aperture by changing only an insertable plate that defines the aperture without changing the position of the Faraday cups which are positioned for the operation of the largest ion beam aperture. The design enables the dose sensitivity range, typically 10.sup.11 -10.sup.18 ions/cm.sup.2 to be extended to below 10.sup.6 ions/cm.sup.2. The insertable plate/aperture arrangement is structurally simple and enables scaling to aperture areas between <1 cm.sup.2 and >750 cm.sup.2, and enables ultra-high vacuum (UHV) applications by incorporation of UHV-compatible materials.

  9. Broad-beam, high current, metal ion implantation facility

    SciTech Connect

    Brown, I.G.; Dickinson, M.R.; Galvin, J.E.; Godechot, X.; MacGill, R.A.

    1990-07-01

    We have developed a high current metal ion implantation facility with which high current beams of virtually all the solid metals of the Periodic Table can be produced. The facility makes use of a metal vapor vacuum arc ion source which is operated in a pulsed mode, with pulse width 0.25 ms and repetition rate up to 100 pps. Beam extraction voltage is up to 100 kV, corresponding to an ion energy of up to several hundred keV because of the ion charge state multiplicity; beam current is up to several Amperes peak and around 10 mA time averaged delivered onto target. Implantation is done in a broad-beam mode, with a direct line-of-sight from ion source to target. Here we describe the facility and some of the implants that have been carried out using it, including the seeding' of silicon wafers prior to CVD with titanium, palladium or tungsten, the formation of buried iridium silicide layers, and actinide (uranium and thorium) doping of III-V compounds. 16 refs., 6 figs.

  10. Resonance ionization of holmium for ion implantation in microcalorimeters

    NASA Astrophysics Data System (ADS)

    Schneider, F.; Chrysalidis, K.; Dorrer, H.; Düllmann, Ch. E.; Eberhardt, K.; Haas, R.; Kieck, T.; Mokry, C.; Naubereit, P.; Schmidt, S.; Wendt, K.

    2016-06-01

    The determination of the electron neutrino mass by calorimetric measurement of the 163 Ho electron capture spectrum requires ultra-pure samples. Several collaborations, like ECHo or HOLMES, intend to employ microcalorimeters into which 163 Ho is implanted as an ion beam. This makes a selective and additionally very efficient ion source for holmium mandatory. For this purpose, laser resonance ionization of stable holmium 165 Ho was studied, using a three step excitation scheme driven by pulsed Ti:sapphire lasers. Five measurements with sample sizes of 1014 and 1015 atoms were performed for the efficiency investigation. In average, an excellent ionization efficiency of 32(5) % could be shown, demonstrating the suitability for ion beam implantation.

  11. Study of the amorphization of surface silicon layers implanted by low-energy helium ions

    NASA Astrophysics Data System (ADS)

    Lomov, A. A.; Myakon'kikh, A. V.; Oreshko, A. P.; Shemukhin, A. A.

    2016-03-01

    The structural changes in surface layers of Si(001) substrates subjected to plasma-immersion implantation by (2-5)-keV helium ions to a dose of D = 6 × 1015-5 × 1017 cm-2 have been studied by highresolution X-ray diffraction, Rutherford backscattering, and spectral ellipsometry. It is found that the joint application of these methods makes it possible to determine the density depth distribution ρ( z) in an implanted layer, its phase state, and elemental composition. Treatment of silicon substrates in helium plasma to doses of 6 × 1016 cm-2 leads to the formation of a 20- to 30-nm-thick amorphized surface layer with a density close to the silicon density. An increase in the helium dose causes the formation of an internal porous layer.

  12. Characterization of carbon ion implantation induced graded microstructure and phase transformation in stainless steel

    SciTech Connect

    Feng, Kai; Wang, Yibo; Li, Zhuguo; Chu, Paul K.

    2015-08-15

    Austenitic stainless steel 316L is ion implanted by carbon with implantation fluences of 1.2 × 10{sup 17} ions-cm{sup −} {sup 2}, 2.4 × 10{sup 17} ions-cm{sup −} {sup 2}, and 4.8 × 10{sup 17} ions-cm{sup −} {sup 2}. The ion implantation induced graded microstructure and phase transformation in stainless steel is investigated by X-ray diffraction, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy. The corrosion resistance is evaluated by potentiodynamic test. It is found that the initial phase is austenite with a small amount of ferrite. After low fluence carbon ion implantation, an amorphous layer and ferrite phase enriched region underneath are formed. Nanophase particles precipitate from the amorphous layer due to energy minimization and irradiation at larger ion implantation fluence. The morphology of the precipitated nanophase particles changes from circular to dumbbell-like with increasing implantation fluence. The corrosion resistance of stainless steel is enhanced by the formation of amorphous layer and graphitic solid state carbon after carbon ion implantation. - Highlights: • Carbon implantation leads to phase transformation from austenite to ferrite. • The passive film on SS316L becomes thinner after carbon ion implantation. • An amorphous layer is formed by carbon ion implantation. • Nanophase precipitate from amorphous layer at higher ion implantation fluence. • Corrosion resistance of SS316L is improved by carbon implantation.

  13. Miniaturized EAPs with compliant electrodes fabricated by ion implantation

    NASA Astrophysics Data System (ADS)

    Shea, H.

    2011-04-01

    Miniaturizing dielectric electroactive polymer (EAP) actuators will lead to highly-integrated mechanical systems on a chip, combining dozens to thousands of actuators and sensors on a few cm2. We present here µm to mm scale electroactive polymer (EAP) devices, batch fabricated on the chip or wafer scale, based on ion-implanted electrodes. Low-energy (2-10 keV) implantation of gold ions into a silicone elastomer leads to compliant stretchable electrodes consisting of a buried 20 nm thick layer of gold nanoparticles in a silicone matrix. These electrodes: 1) conduct at strains up to 175%, 2) are patternable on the µm scale, 3) have stiffness similar to silicone, 4) have good conductivity, and 5) excellent adhesion since implanted in the silicone. The EAP devices consist of 20 to 30 µm thick silicone membranes with µm to mm-scale ion-implanted electrodes on both sides, bonded to a holder. Depending on electrode shape and membrane size, several actuation modes are possible. Characterization of 3mm diameter bi-directional buckling mode actuators, mm-scale tunable lens arrays, 2-axis beam steering mirrors, as well as arrays of 72 cell-size (100x200 µm2) actuators to apply mechanical strain to single cells are reported. Speeds of up to several kHz are observed.

  14. Oxygen and sodium plasma-implanted nickel titanium shape memory alloy: A novel method to promote hydroxyapatite formation and suppress nickel leaching

    NASA Astrophysics Data System (ADS)

    Chan, Y. L.; Yeung, K. W. K.; Lu, W. W.; Ngan, A. H. W.; Luk, K. D. K.; Chan, D.; Wu, S. L.; Liu, X. M.; Chu, Paul K.; Cheung, K. M. C.

    2007-04-01

    This study aims at modifying the surface bioactivity of NiTi by sodium and oxygen plasma immersion ion implantation (PIII). Sodium ions were implanted into oxygen plasma-implanted NiTi and untreated NiTi. X-ray photoelectron spectroscopy (XPS) revealed that more sodium was implanted into the oxygen pre-implanted sample in comparison with the untreated surface. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX) detected calcium and phosphorus rich deposits on both samples after immersion in simulated body fluids for 7 and 21 days. Inductively-coupled plasma mass spectrometry (ICPMS) conducted on the deposits dissolved in diluted hydrochloric acid showed more calcium on the oxygen PIII samples. The improved corrosion resistance of the oxygen PIII NiTi was retained after sodium PIII as evaluated by potentiodynamic polarization tests. Better spreading and proliferation of osteoblasts were also observed on the treated samples.

  15. Engineering single photon emitters by ion implantation in diamond

    PubMed Central

    Naydenov, B.; Kolesov, R.; Batalov, A.; Meijer, J.; Pezzagna, S.; Rogalla, D.; Jelezko, F.; Wrachtrup, J.

    2009-01-01

    Diamond provides unique technological platform for quantum technologies including quantum computing and communication. Controlled fabrication of optically active defects is a key element for such quantum toolkit. Here we report the production of single color centers emitting in the blue spectral region by high energy implantation of carbon ions. We demonstrate that single implanted defects show sub-poissonian statistics of the emitted photons and can be explored as single photon source in quantum cryptography. Strong zero phonon line at 470.5 nm allows unambiguous identification of this defect as interstitial-related TR12 color center. PMID:19956415

  16. Engineering single photon emitters by ion implantation in diamond.

    PubMed

    Naydenov, B; Kolesov, R; Batalov, A; Meijer, J; Pezzagna, S; Rogalla, D; Jelezko, F; Wrachtrup, J

    2009-11-01

    Diamond provides unique technological platform for quantum technologies including quantum computing and communication. Controlled fabrication of optically active defects is a key element for such quantum toolkit. Here we report the production of single color centers emitting in the blue spectral region by high energy implantation of carbon ions. We demonstrate that single implanted defects show sub-poissonian statistics of the emitted photons and can be explored as single photon source in quantum cryptography. Strong zero phonon line at 470.5 nm allows unambiguous identification of this defect as interstitial-related TR12 color center. PMID:19956415

  17. Microwave annealing of ion implanted 6H-SiC

    SciTech Connect

    Gardner, J.A.; Rao, M.V.; Tian, Y.L.; Holland, O.W.; Kelner, G.; Freitas, J.A. Jr.; Ahmad, I.

    1996-05-01

    Microwave rapid thermal annealing has been utilized to remove the lattice damage caused by nitrogen (N) ion-implantation as well as to activate the dopant in 6H-SiC. Samples were annealed at temperatures as high as 1,400 C, for 10 min. Van der Pauw Hall measurements indicate an implant activation of 36%, which is similar to the value obtained for the conventional furnace annealing at 1,600 C. Good lattice quality restoration was observed in the Rutherford backscattering and photoluminescence spectra.

  18. Engineering single photon emitters by ion implantation in diamond

    NASA Astrophysics Data System (ADS)

    Naydenov, B.; Kolesov, R.; Batalov, A.; Meijer, J.; Pezzagna, S.; Rogalla, D.; Jelezko, F.; Wrachtrup, J.

    2009-11-01

    Diamond provides unique technological platform for quantum technologies including quantum computing and communication. Controlled fabrication of optically active defects is a key element for such quantum toolkit. Here we report the production of single color centers emitting in the blue spectral region by high energy implantation of carbon ions. We demonstrate that single implanted defects show sub-poissonian statistics of the emitted photons and can be explored as single photon source in quantum cryptography. Strong zero phonon line at 470.5 nm allows unambiguous identification of this defect as interstitial-related TR12 color center.

  19. Engineering single photon emitters by ion implantation in diamond.

    PubMed

    Naydenov, B; Kolesov, R; Batalov, A; Meijer, J; Pezzagna, S; Rogalla, D; Jelezko, F; Wrachtrup, J

    2009-11-01

    Diamond provides unique technological platform for quantum technologies including quantum computing and communication. Controlled fabrication of optically active defects is a key element for such quantum toolkit. Here we report the production of single color centers emitting in the blue spectral region by high energy implantation of carbon ions. We demonstrate that single implanted defects show sub-poissonian statistics of the emitted photons and can be explored as single photon source in quantum cryptography. Strong zero phonon line at 470.5 nm allows unambiguous identification of this defect as interstitial-related TR12 color center.

  20. Ion acoustic waves in a multi-ion plasma.

    NASA Technical Reports Server (NTRS)

    Fried, B. D.; White, R. B.; Samec, T. K.

    1971-01-01

    An exact treatment of the multispecies ion acoustic dispersion relation is given for an argon/helium plasma. Phase velocity and damping are obtained as a function of ion-electron temperature ratio and relative densities of the two species. There are two important modes in the plasma, with quite different phase velocities, which are referred to as principal heavy ion mode and principal light ion mode. Which of these is dominant depends on the relative densities of the two components, but, in general, the light ion mode becomes important for surprisingly small light ion contamination. Approximate analytic expressions are derived from damping rates and phase velocities and their domains of validity are investigated. Relevance of the results for the investigation of collisionless shocks is discussed.

  1. Application of Coaxial Ion Gun for Film Generation and Ion Implantation

    NASA Astrophysics Data System (ADS)

    Takatsu, Mikio; Asai, Tomohiko; Kurumi, Satoshi; Suzuki, Kaoru; Hirose, Hideharu; Masutani, Shigeyuki

    A magnetized coaxial plasma gun (MCPG) is here utilized for deposition on high-melting-point metals. MCPGs have hitherto been studied mostly in the context of nuclear fusion research, for particle and magnetic helicity injection and spheromak formation. During spheromak formation, the electrode materials are ionized and mixed into the plasmoid. In this study, this ablation process by gun-current sputtering is enhanced for metallic thin-film generation. In the proposed system geometry, only ionized materials are electromagnetically accelerated by the self-Lorentz force, with ionized operating gas as a magnetized thermal plasmoid, contributing to the thin-film deposition. This reduces the impurity and non-uniformity of the deposited thin-film. Furthermore, as the ions are accelerated in a parallel direction to the injection axis, vertical implantation of the ions into the substrate surface is achieved. To test a potential application of the developed system, experiments were conducted involving the formation of a buffer layer on hard ceramics, for use in dental materials.

  2. Experiments on Ion-Ion Plasmas From Discharges

    NASA Astrophysics Data System (ADS)

    Leonhardt, Darrin; Walton, Scott; Blackwell, David; Murphy, Donald; Fernsler, Richard; Meger, Robert

    2001-10-01

    Use of both positive and negative ions in plasma processing of materials has been shown to be advantageous[1] in terms of better feature evolution and control. In this presentation, experimental results are given to complement recent theoretical work[2] at NRL on the formation and decay of pulsed ion-ion plasmas in electron beam generated discharges. Temporally resolved Langmuir probe and mass spectrometry are used to investigate electron beam generated discharges during the beam on (active) and off (afterglow) phases in a variety of gas mixtures. Because electron-beam generated discharges inherently[3] have low electron temperatures (<0.5eV in molecular gases), negative ion characteristics are seen in the active as well as afterglow phases since electron detachment increases with low electron temperatures. Analysis of temporally resolved plasma characteristics deduced from these measurements will be presented for pure O_2, N2 and Ar and their mixtures with SF_6. Oxygen discharges show no noticeable negative ion contribution during the active or afterglow phase, presumably due to the higher energy electron attachment threshold, which is well above any electron temperature. In contrast, SF6 discharges demonstrate ion-ion plasma characteristics in the active glow and are completely ion-ion in the afterglow. Comparison between these discharges with published cross sections and production mechanisms will also be presented. [1] T.H. Ahn, K. Nakamura & H. Sugai, Plasma Sources Sci. Technol., 5, 139 (1996); T. Shibyama, H. Shindo & Y. Horiike, Plasma Sources Sci. Technol., 5, 254 (1996). [2] See presentation by R. F. Fernsler, at this conference. [3] D. Leonhardt, et al., 53rd Annual GEC, Houston, TX.

  3. Pulse height defect of energetic heavy ions in ion-implanted Si detectors

    NASA Astrophysics Data System (ADS)

    Pasquali, G.; Casini, G.; Bini, M.; Calamai, S.; Olmi, A.; Poggi, G.; Stefanini, A. A.; Saint-Laurent, F.; Steckmeyer, J. C.

    1998-02-01

    The pulse height defect in ion-implanted silicon detectors for elastically scattered 93Nb, 100Mo, 116Sn, 120Sn and 129Xe ions, at energies ranging from about 4 to 25 A MeV has been measured. The results are compared with two widely used parametrizations taken from the literature.

  4. Ion beam parameters of a plasma accelerator

    SciTech Connect

    Nazarov, V.G.; Vinogradov, A.M.; Veselovzorov, A.N.; Efremov, V.K.

    1987-08-01

    The aim of this investigation was to determine the dependences of the current density, the energy, and the divergence of the ion beams of an UZDP-type source (a plasma accelerator with closed electron drift in the accelerator channel and an extended zone of ion acceleration) on the parameters which determine its performance, and to establish qualitative relationships between these values.

  5. Charge neutralization apparatus for ion implantation system

    DOEpatents

    Leung, Ka-Ngo; Kunkel, Wulf B.; Williams, Malcom D.; McKenna, Charles M.

    1992-01-01

    Methods and apparatus for neutralization of a workpiece such as a semiconductor wafer in a system wherein a beam of positive ions is applied to the workpiece. The apparatus includes an electron source for generating an electron beam and a magnetic assembly for generating a magnetic field for guiding the electron beam to the workpiece. The electron beam path preferably includes a first section between the electron source and the ion beam and a second section which is coincident with the ion beam. The magnetic assembly generates an axial component of magnetic field along the electron beam path. The magnetic assembly also generates a transverse component of the magnetic field in an elbow region between the first and second sections of the electron beam path. The electron source preferably includes a large area lanthanum hexaboride cathode and an extraction grid positioned in close proximity to the cathode. The apparatus provides a high current, low energy electron beam for neutralizing charge buildup on the workpiece.

  6. Upgraded vacuum arc ion source for metal ion implantation

    SciTech Connect

    Nikolaev, A. G.; Oks, E. M.; Savkin, K. P.; Yushkov, G. Yu.; Brown, I. G.

    2012-02-15

    Vacuum arc ion sources have been made and used by a large number of research groups around the world over the past twenty years. The first generation of vacuum arc ion sources (dubbed ''Mevva,'' for metal vapor vacuum arc) was developed at Lawrence Berkeley National Laboratory in the 1980s. This paper considers the design, performance parameters, and some applications of a new modified version of this kind of source which we have called Mevva-V.Ru. The source produces broad beams of metal ions at an extraction voltage of up to 60 kV and a time-averaged ion beam current in the milliampere range. Here, we describe the Mevva-V.Ru vacuum arc ion source that we have developed at Tomsk and summarize its beam characteristics along with some of the applications to which we have put it. We also describe the source performance using compound cathodes.

  7. Develop techniques for ion implantation of PLZT for adaptive optics

    NASA Astrophysics Data System (ADS)

    Craig, R. A.; Batishko, C. R.; Brimhall, J. L.; Pawlewicz, W. T.; Stahl, K. A.

    1989-11-01

    Battelle Pacific Northwest Laboratory (PNL) conducted research into the preparation and characterization of ion-implanted adaptive optic elements based on lead-lanthanum-zirconate-titanate (PLZT). Over the 4-yr effort beginning FY 1985, the ability to increase the photosensitivity of PLZT and extend it to longer wavelengths was developed. The emphasis during the last two years was to develop a model to provide a basis for choosing implantation species and parameters. Experiments which probe the electronic structure were performed on virgin and implanted PLZT samples. Also performed were experiments designed to connect the developing conceptual model with the experimental results. The emphasis in FY 1988 was to extend the photosensitivity out to diode laser wavelengths. The experiments and modelling effort indicate that manganese will form appropriate intermediate energy states to achieve the longer wavelength photosensitivity. Preliminary experiments were also conducted to deposit thin film PLZT.

  8. Ion-implantation studies of nuclear-waste forms

    NASA Astrophysics Data System (ADS)

    Northrup, C. J. M., Jr.; Arnold, G. W.; Headley, T. J.

    1981-11-01

    The first observations of physical and chemical changes induced by lead implantation damage and leaching are reported for two proposed US nuclear waste forms for commercial wastes. To simulate the effects of recoil nuclei due to alpha decay, the materials were implanted with lead ions at equivalent doses. In the titanate waste form, the zirconolite, perovskite, hollandite, and rutile phases all exhibited a mottled appearance in the transmission electron microscopy (TEM) typical of defect clusters in radiation damaged, crystalline solids. One titanate phase containing uranium was found by TEM to be amorphous after implantation at the highest dose. No enhanced leaching (deionized water, room temperature, 24 hours) of the irradiated titanate waste form, including the amorphous phase, was detected by TEM, but Rutherford backscattering (RBS) suggested a loss of cesium and calcium after 21 hours of leaching.

  9. High yield antibiotic producing mutants of Streptomyces erythreus induced by low energy ion implantation

    NASA Astrophysics Data System (ADS)

    Yu, Chen; Zhixin, Lin; Zuyao, Zou; Feng, Zhang; Duo, Liu; Xianghuai, Liu; Jianzhong, Tang; Weimin, Zhu; Bo, Huang

    1998-05-01

    Conidia of Streptomyces erythreus, an industrial microbe, were implanted by nitrogen ions with energy of 40-60 keV and fluence from 1 × 10 11 to 5 × 10 14 ions/cm 2. The logarithm value of survival fraction had good linear relationship with the logarithm value of fluence. Some mutants with a high yield of erythromycin were induced by ion implantation. The yield increment was correlated with the implantation fluence. Compared with the mutation results induced by ultraviolet rays, mutation effects of ion implantation were obvious having higher increasing erythromycin potency and wider mutation spectrum. The spores of Bacillus subtilis were implanted by arsenic ions with energy of 100 keV. The distribution of implanted ions was measured by Rutherford Backscattering Spectrometry (RBS) and calculated in theory. The mechanism of mutation induced by ion implantation was discussed.

  10. Synergistic effects of dual Zn/Ag ion implantation in osteogenic activity and antibacterial ability of titanium.

    PubMed

    Jin, Guodong; Qin, Hui; Cao, Huiliang; Qian, Shi; Zhao, Yaochao; Peng, Xiaochun; Zhang, Xianlong; Liu, Xuanyong; Chu, Paul K

    2014-09-01

    Zinc (Zn) and silver (Ag) are co-implanted into titanium by plasma immersion ion implantation. A Zn containing film with Ag nanoparticles (Ag NPs) possessing a wide size distribution is formed on the surface and the corrosion resistance is improved due to the micro-galvanic couples formed by the implanted Zn and Ag. Not only are the initial adhesion, spreading, proliferation and osteogenic differentiation of rBMSCs observed from the Zn/Ag implanted Ti in vitro, but also bacteria killing is achieved both in vitro and in vivo. Electrochemical polarization and ion release measurements suggest that the excellent osteogenic activity and antibacterial ability of the Zn/Ag co-implanted titanium are related to the synergistic effect resulting from the long-range interactions of the released Zn ions and short-range interactions of the embedded Ag NPs. The Zn/Ag co-implanted titanium offers both excellent osteogenic activity and antibacterial ability and has large potential in orthopedic and dental implants. PMID:24947228

  11. Synergistic effects of dual Zn/Ag ion implantation in osteogenic activity and antibacterial ability of titanium.

    PubMed

    Jin, Guodong; Qin, Hui; Cao, Huiliang; Qian, Shi; Zhao, Yaochao; Peng, Xiaochun; Zhang, Xianlong; Liu, Xuanyong; Chu, Paul K

    2014-09-01

    Zinc (Zn) and silver (Ag) are co-implanted into titanium by plasma immersion ion implantation. A Zn containing film with Ag nanoparticles (Ag NPs) possessing a wide size distribution is formed on the surface and the corrosion resistance is improved due to the micro-galvanic couples formed by the implanted Zn and Ag. Not only are the initial adhesion, spreading, proliferation and osteogenic differentiation of rBMSCs observed from the Zn/Ag implanted Ti in vitro, but also bacteria killing is achieved both in vitro and in vivo. Electrochemical polarization and ion release measurements suggest that the excellent osteogenic activity and antibacterial ability of the Zn/Ag co-implanted titanium are related to the synergistic effect resulting from the long-range interactions of the released Zn ions and short-range interactions of the embedded Ag NPs. The Zn/Ag co-implanted titanium offers both excellent osteogenic activity and antibacterial ability and has large potential in orthopedic and dental implants.

  12. Pitting behavior of aluminum ion implanted with nitrogen

    SciTech Connect

    McCafferty, E.; Natishan, P.M.; Hubler, G.K.

    1997-07-01

    Ion implantation of {approx} 2 at% N into aluminum increased the pitting potential in 0.1 M sodium chloride by an average of 0.35 V. Surface analysis by x-ray photoelectron spectroscopy showed implanted nitrogen was present as several species: NH{sub 4}{sup +}, NO or NH{sub 3} (as a ligand), AIN, and weakly bound or interstitial nitrogen. With anodic polarization, there was an increase in the total amount of nitrogen in the near-surface region, a decrease in the relative amount of nitride, and an increase in the relative amount of NO or NH{sub 3}. These changes resulted from migration of implanted nitrogen from the substrate into the near-surface region with partial conversion of the AIN species to NO or NH{sub 3}. It was suggested that the effect of implanted nitrogen on pitting behavior of aluminum is similar to that in nitrogen-containing stainless steels, where nitrogen at the metal surface inhibits the dissolution kinetics or aids the repassivation process in the pit by forming NH{sub 4}{sup +} ions that buffer the pit electrolyte.

  13. Surface microanalytical studies of nitrogen ion-implanted steel

    NASA Astrophysics Data System (ADS)

    Dodd, Charles G.; Meeker, G. P.; Baumann, Scott M.; Norberg, James C.; Legg, Keith O.

    1985-03-01

    Five types of industrial steels, 1018, 52100, M-2, 440C, and 304 were ion implanted with nitrogen and subjected to surface microanalysis by three independent surface techniques: AES, RBS, and SIMS. The results provided understanding for earlier observations of the properties of various types of steel after nitrogen implantation. The steels that retained the most nitrogen and that have been reported to benefit the most in improved tribological properties from ion implantation were ferritic carbon and austenitic stainless steels, such as soft 1018 and 304, respectively. Heat-treated martensitic carbon steels such as 52100 and M-2 tool steel were found to retain the least nitrogen, and they have been reported to benefit less from nitrogen implantation; however, the interaction of transition metal carbides in M-2 with nitrogen has not been clarified. The data showed that 440C steel retained as much nitrogen as 1018 and 304, but treatment benefits may be limited to improvements in properties related to toughness and impact resistance.

  14. The enhanced anticoagulation for graphene induced by COOH(+) ion implantation.

    PubMed

    Liu, Xiaoqi; Cao, Ye; Zhao, Mengli; Deng, Jianhua; Li, Xifei; Li, Dejun

    2015-01-01

    Graphene may have attractive properties for some biomedical applications, but its potential adverse biological effects, in particular, possible modulation when it comes in contact with blood, require further investigation. Little is known about the influence of exposure to COOH(+)-implanted graphene (COOH(+)/graphene) interacting with red blood cells and platelets. In this paper, COOH(+)/graphene was prepared by modified Hummers' method and implanted by COOH(+) ions. The structure and surface chemical and physical properties of COOH(+)/graphene were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle measurement. Systematic evaluation of anticoagulation, including in vitro platelet adhesion assays and hemolytic assays, proved that COOH(+)/graphene has significant anticoagulation. In addition, at the dose of 5 × 10(17) ions/cm(2), COOH(+)/graphene responded best on platelet adhesion, aggregation, and platelet activation.

  15. Ion implantation, a method for fabricating light guides in polymers

    NASA Astrophysics Data System (ADS)

    Kulish, J. R.; Franke, H.; Singh, Amarjit; Lessard, Roger A.; Knystautas, Emile J.

    1988-04-01

    Li+ and N+ ions were implanted into aliphatic polymethylmethacrylate (PMMA), polyvinylalcohol (PVA), and aromatic polyimide (PI) polycarbonate (PC) polymers in the energy range of 100-130 keV. Planar optical waveguides guiding between one and three modes were formed. For low implantation doses (≤ 1014 ions/cm2), total waveguide loss values at λ=633 nm were found to be less than 2 dB/cm. The changes in the refractive index were found to be very large (Δn≥0.05) in the case of PMMA and PVA. We interpret this change in refractive index as being due to the formation of aromatic compounds in the regions of electronic scattering.

  16. FIM/IAP/TEM studies of ion implanted nickel emitters

    SciTech Connect

    Walck, S.D.; Hren, J.J.

    1985-01-01

    Accurate depth profiling of implanted hydrogen and its isotopes in metals is extremely important. Field ion microscopy and atom-probe techniques provide the most accurate depth profiling analytical method of any available. In addition, they are extremely sensitive to hydrogen. This paper reports our early work on hydrogen trapping at defects in metals using the Field Ion Microscope/Imaging Atom Probe (FIM/IAP). Our results deal primarily with the control experiments required to overcome instrumental difficulties associated with in situ implantation and the influence of a high electric field. Transmission Electron Microscopy (TEM) has been used extensively to independently examine the influence of high electric fields on emitters. 11 references, 7 figures.

  17. Ion response in a weakly ionized plasma with ion flow

    SciTech Connect

    Kompaneets, Roman; Tyshetskiy, Yuriy O.; Vladimirov, Sergey V.

    2013-04-15

    We study the ion response to an initial perturbation in a weakly ionized plasma with ion flow driven by a dc electric field. The analysis is made by extending the classical Landau work [J. Phys. (USSR) 10, 25 (1946)] to the ion kinetic equation including ion-neutral collisions and a dc electric field. We show, in particular, that the complex frequencies of ion waves can be directly found from a known expression for the ion susceptibility [A. V. Ivlev et al., Phys. Rev. E 71, 016405 (2005); V. A. Schweigert, Phys. Rep. 27, 997 (2001)]; this is not obvious from its original derivation, because it only aims to describe the ion response for real frequencies.

  18. Plasma Surface Functionalized Polyetheretherketone for Enhanced Osseo-Integration at Bone-Implant Interface.

    PubMed

    Zhao, Ying; Wong, Hoi Man; Lui, So Ching; Chong, Eva Y W; Wu, Guosong; Zhao, Xiaoli; Wang, Chong; Pan, Haobo; Cheung, Kenneth M C; Wu, Shuilin; Chu, Paul K; Yeung, Kelvin W K

    2016-02-17

    This study aims at improving osseo-integration at the bone-implant interface of polyetheretherketone (PEEK) by water (H2O) and ammonia (NH3) plasma immersion ion implantation (PIII). The pertinent surface characteristics including surface energy, roughness, morphology, and chemical composition are investigated systematically and the in vitro biological performance is evaluated by cell adhesion and proliferation, alkaline phosphatase (ALP) activity, real-time RT-PCR evaluation, and mineralization tests. In vivo osseo-integration is examined via implanting samples into the distal femur of the rats. The hydrophilicity, surface roughness, cell adhesion, and proliferation, ALP activity, and osteogenic differentiation after H2O PIII or NH3 PIII are improved significantly. Furthermore, substantially enhanced osseo-integration is achieved in vivo. Nonline-of-sight plasma surface functionalization, which is particularly suitable for biomedical implants with an irregular geometry, does not alter the bulk compressive yield strength and elastic modulus of the materials. Consequently, the favorable bulk attributes of PEEK are preserved while the surface biological properties are enhanced thus boding well for wider orthopedic application of the biopolymer. PMID:26796319

  19. Control of microelectromechanical systems membrane curvature by silicon ion implantation

    NASA Astrophysics Data System (ADS)

    Jin, S.; Mavoori, H.; Kim, J.; Aksyuk, V. A.

    2003-09-01

    Thin silicon membranes in microelectromechanical systems (MEMS) optical devices such as beam-steering, movable mirrors may exhibit undesirable curvature when their surface is metallized with light-reflecting metals to enhance optical performance. We have applied Si+ ion implantations at dose levels of 0.4-5×1016/cm2 into the gold metallization layer to successfully reduce the mirror curvature as well as the degree of its temperature-dependent changes. The curvature change as well as the temperature dependence is found to be dependent on the implantation dose. The mechanism of the observed curvature flattening effect is attributed mostly to the induced compressive stress in gold metallization caused by the insertion of foreign implanted atoms of silicon. Such a Si implantation approach can be useful as a means for post-fabrication correction of unwanted curvature in MEMS membranes, as well as a technique to intentionally introduce a desired degree of curvature if needed. A convenient blanket implantation process can be utilized with minimal contamination problems as Si is a common element already present in the MEMS.

  20. Temperature behavior of damage in sapphire implanted with light ions

    NASA Astrophysics Data System (ADS)

    Alves, E.; Marques, C.; Sáfrán, G.; McHargue, Carl J.

    2009-05-01

    In this study, we compare and discuss the defect behavior of sapphire single crystals implanted with different fluences (1 × 1016-1 × 1017 cm-2) of carbon and nitrogen with 150 keV. The implantation temperatures were RT, 500 °C and 1000 °C to study the influence of temperature on the defect structures. For all the ions the Rutherford backscattering-channeling (RBS-C) results indicate a surface region with low residual disorder in the Al-sublattice. Near the end of range the channeled spectrum almost reaches the random indicating a high damage level for fluences of 1 × 1017 cm-2. The transmission electron microscopy (TEM) photographs show a layered contrast feature for the C implanted sample where a buried amorphous region is present. For the N implanted sample the Electron Energy Loss Spectroscopy (EELS) elemental mapping give evidence for the presence of a buried damage layer decorated with bubbles. Samples implanted at high temperatures (500 °C and 1000 °C) show a strong contrast fluctuation indicating a defective crystalline structure of sapphire.

  1. Energy loss of ions implanted in MOS dielectric films

    NASA Astrophysics Data System (ADS)

    Shyam, Radhey

    Energy loss measurements of ions in the low kinetic energy regime have been made on as-grown SiO2(170-190nm) targets. Singly charged Na + ions with kinetic energies of 2-5 keV and highly charged ions Ar +Q (Q=4, 8 and 11) with a kinetic energy of 1 keV were used. Excitations produced by the ion energy loss in the oxides were captured by encapsulating the irradiated oxide under a top metallic contact. The resulting Metal-Oxide-Semiconductor (MOS) devices were probed with Capacitance-Voltage (C V) measurements and extracted the flatband voltages from the C-V curves. The C-V results for singly charged ion experiments reveal that the changes in the flatband voltage and slope for implanted devices relative to the pristine devices can be used to delineate effects due to implanted ions only and ion induced damage. The data shows that the flatband voltage shifts and C-V slope changes are energy dependent. The observed changes in flatband voltage which are greater than those predicted by calculations scaled for the ion dose and implantation range (SRIM). These results, however, are consistent with a columnar recombination model, where electron-hole pairs are created due to the energy deposited by the implanted ions within the oxide. The remaining holes left after recombination losses are diffused through the oxide at the room temperature and remain present as trapped charges. Comparison of the data with the total number of the holes generated gives a fractional yield of 0.0124 which is of the same order as prior published high energy irradiation experiments. Additionally, the interface trap density, extracted from high and low frequency C-V measurements is observed to increase by one order of magnitude over our incident beam energy. These results confirm that dose- and kinetic energy -dependent effects can be recorded for singly charged ion irradiation on oxides using this method. Highly charged ion results also confirm that dose as well as and charge-dependent effects can

  2. Calcium Plasma Implanted Titanium Surface with Hierarchical Microstructure for Improving the Bone Formation.

    PubMed

    Cheng, Mengqi; Qiao, Yuqin; Wang, Qi; Jin, Guodong; Qin, Hui; Zhao, Yaochao; Peng, Xiaochun; Zhang, Xianlong; Liu, Xuanyong

    2015-06-17

    Introducing hierarchical microstructure and bioactive trace elements simultaneously onto the surface of titanium implant is a very effective way to improve the osseointegration between bone and implant. In this work, hierarchical topography was prepared on Ti surface via acid etching and sandblasting (SLA) to form micropits and microcavities then underwent Ca plasma immersion ion implantation (Ca-PIII) process. The surface wettability and roughness did not change obviously before and after Ca-PIII process. The in vitro evaluations including cell adhesion, activity, alkaline phosphatase (ALP), osteogenic genes (Runx2, OSX, ALP, BSP, Col1a1, OPN, and OC), and protein (BSP, Col1a1, OPN, and OC) expressions revealed that the introduction of Ca ions onto the surface of SLA-treated Ti can promote greater osteoblasts adhesion, spread and proliferation, which in return further accelerated the maturation and mineralization of osteoblasts. More importantly, in vivo evaluations including Micro-CT evaluation, histological observations, push-out test, sequential fluorescent labeling and histological observations verified that Ca-SLA-treated Ti implants could efficiently promote new bone formation in early times. These promising results suggest that Ca-SLA-treated Ti has the potential for future application in orthopedic field.

  3. Elastic properties of sub-stoichiometric nitrogen ion implanted silicon

    NASA Astrophysics Data System (ADS)

    Sarmanova, M. F.; Karl, H.; Mändl, S.; Hirsch, D.; Mayr, S. G.; Rauschenbach, B.

    2015-04-01

    Elastic properties of sub-stoichiometric nitrogen implanted silicon were measured with nanometer-resolution using contact resonance atomic force microscopy (CR-AFM) as function of ion fluence and post-annealing conditions. The determined range of indentation moduli was between 100 and 180 GPa depending on the annealing duration and nitrogen content. The high indentation moduli can be explained by formation of Si-N bonds, as verified by X-ray photoelectron spectroscopy.

  4. Urinary catheter with polyurethane coating modified by ion implantation

    NASA Astrophysics Data System (ADS)

    Kondyurina, I.; Nechitailo, G. S.; Svistkov, A. L.; Kondyurin, A.; Bilek, M.

    2015-01-01

    A low friction urinary catheter that could be used without a lubricant is proposed in this work. A polyurethane coating was synthesised on the surface of a metal guide wire catheter. Ion implantation was applied to surface modify the polyurethane coating. FTIR ATR, wetting angle, AFM and friction tests were used for analysis. Low friction was found to be provided by the formation of a hard carbonised layer on the polyurethane surface.

  5. Magnetized relativistic electron-ion plasma expansion

    NASA Astrophysics Data System (ADS)

    Benkhelifa, El-Amine; Djebli, Mourad

    2016-03-01

    The dynamics of relativistic laser-produced plasma expansion across a transverse magnetic field is investigated. Based on a one dimensional two-fluid model that includes pressure, enthalpy, and rest mass energy, the expansion is studied in the limit of λD (Debye length) ≤RL (Larmor radius) for magnetized electrons and ions. Numerical investigation conducted for a quasi-neutral plasma showed that the σ parameter describing the initial plasma magnetization, and the plasma β parameter, which is the ratio of kinetic to magnetic pressure are the key parameters governing the expansion dynamics. For σ ≪ 1, ion's front shows oscillations associated to the break-down of quasi-neutrality. This is due to the strong constraining effect and confinement of the magnetic field, which acts as a retarding medium slowing the plasma expansion.

  6. The Development of In-Situ Ion Implant Cleaning Processes

    NASA Astrophysics Data System (ADS)

    Bishop, Steve; Kaim, Robert; Yedave, Sharad; Arnó, Josep; DiMeo, Frank; Wodjenski, Mike

    2006-11-01

    Considerable gains in implanter utilization efficiency can be attained with in-situ cleaning of deposited material, particularly in and around the ion source. Different methods of in-situ cleaning are described, and we discuss the relative merits of several chemical reagents. We introduce XeF2, a new and promising reagent for in-situ cleaning and present some preliminary experiments showing its ability to etch dopant materials. We also show that in some cases etching by XeF2 can be selective with respect to ion source construction materials such as tungsten.

  7. The effect of ion implantation on cellular adhesion.

    PubMed

    Howlett, C R; Evans, M D; Wildish, K L; Kelly, J C; Fisher, L R; Francis, G W; Best, D J

    1993-01-01

    As there are only a finite number of materials suitable for orthopaedic reconstruction, considerable effort has been devoted recently to investigating ways of altering the surface chemistry of prosthetic materials without altering their bulk properties. Ion beam implantation is one such technique which is appropriate for orthopaedic reconstructive materials. This paper investigates the early effect of ion beam modification on cellular attachment of bone derived cells using a prototype device which measures the strength of attachment of individual cells to a silicon substratum. The results point to several conclusions. (1) There is no evidence that ion beam implantation with nitrogen, phosphorus, manganese or magnesium produces increased adhesion of human bone derived cells. (2) Surface etching with hydrofluoric acid, electron bombardment and thermal oxidation increases the strength of attachment between cells and substrata. (3) There is a correlation between wettability and rate of cellular attachment to oxygen implanted substrata during the first 2 h after cellular seeding. However, the increase in cellular attachment cannot be entirely explained by the change in critical surface tension or via increased fibronectin attachment to the substrata.

  8. Defect engineering in the MOSLED structure by ion implantation

    NASA Astrophysics Data System (ADS)

    Prucnal, S.; Wójtowicz, A.; Pyszniak, K.; Drozdziel, A.; Zuk, J.; Turek, M.; Rebohle, L.; Skorupa, W.

    2009-05-01

    When amorphous SiO2 films are bombarded with energetic ions, various types of defects are created as a consequence of ion-solid interaction (peroxy radicals POR, oxygen deficient centres (ODC), non-bridging oxygen hole centres (NBOHC), E‧ centres, etc.). The intensity of the electroluminescence (EL) from oxygen deficiency centres at 2.7 eV, non-bridging oxygen hole centres at 1.9 eV and defect centres with emission at 2.07 eV can be easily modified by the ion implantation of the different elements (H, N, O) into the completely processed MOSLED structure. Nitrogen implanted into the SiO2:Gd layer reduces the concentration of the ODC and NBOHC while the doping of the oxygen increases the EL intensity observed from POR defect and NBOHC. Moreover, after oxygen or hydrogen implantation into the SiO2:Ge structure fourfold or fifth fold increase of the germanium related EL intensity was observed.

  9. Observations of Ag diffusion in ion implanted SiC

    DOE PAGESBeta

    Gerczak, Tyler J.; Leng, Bin; Sridharan, Kumar; Jerry L. Hunter, Jr.; Giordani, Andrew J.; Allen, Todd R.

    2015-03-17

    The nature and magnitude of Ag diffusion in SiC has been a topic of interest in connection with the performance of tristructural isotropic (TRISO) coated particle fuel for high temperature gas-cooled nuclear reactors. Ion implantation diffusion couples have been revisited to continue developing a more complete understanding of Ag fission product diffusion in SiC. Ion implantation diffusion couples fabricated from single crystal 4H-SiC and polycrystalline 3C-SiC substrates and exposed to 1500–1625°C, were investigated in this study by transmission electron microscopy and secondary ion mass spectrometry (SIMS). The high dynamic range of SIMS allowed for multiple diffusion régimes to be investigated,more » including enhanced diffusion by implantation-induced defects and grain boundary (GB) diffusion in undamaged SiC. Lastly, estimated diffusion coefficients suggest GB diffusion in bulk SiC does not properly describe the release observed from TRISO fuel.« less

  10. Ion implantation for corrosion inhibition of aluminum alloys in saline media

    NASA Astrophysics Data System (ADS)

    Williams, J. M.; Gonzales, A.; Quintana, J.; Lee, I.-S.; Buchanan, R. A.; Burns, F. C.; Culbertson, R. J.; Levy, M.; Treglio, J. R.

    1991-07-01

    The effects of ion implantation treatments on corrosion of 2014 and 1100 aluminum in saline media were investigated. Implanted constituents were N, Si, Ti, and Cr. Techniques included salt spray testing, electrochemical studies, Rutherford backscattering spectrometry, and profilometry. The principal conclusion was that ion implantation of Cr is of potential practical benefit for corrosion inhibition of 2014 Al in salt environments.

  11. Effects of nitrogen ion implantation time on tungsten films deposited by DC magnetron sputtering on AISI 410 martensitic stainless steel

    NASA Astrophysics Data System (ADS)

    Malau, Viktor; Ilman, Mochammad Noer; Iswanto, Priyo Tri; Jatisukamto, Gaguk

    2016-03-01

    Nitrogen ion implantation time on tungsten thin film deposited on surface of AISI 410 steel has been performed. Tungsten thin film produced by dc magnetron sputtering method was deposited on AISI 410 martensitic stainless steel substrates, and then the nitrogen ions were implanted on tungsten thin film. The objective of this research is to investigate the effects of implantation deposition time on surface roughness, microhardness, specific wear and corrosion rate of nitrogen implanted on tungsten film. Magnetron sputtering process was performed by using plasma gas of argon (Ar) to bombardier tungsten target (W) in a vacuum chamber with a pressure of 7.6 x 10-2 torr, a voltage of 300 V, a sputter current of 80 mA for sputtered time of 10 minutes. Nitrogen implantation on tungsten film was done with an initial pressure of 3x10-6 mbar, a fluence of 2 x 1017 ions/cm2, an energy of 100 keV and implantation deposition times of 0, 20, 30 and 40 minutes. The surface roughness, microhardness, specific wear and corrosion rate of the films were evaluated by surfcorder test, Vickers microhardness test, wear test and potentiostat (galvanostat) test respectively. The results show that the nitrogen ions implanted deposition time on tungsten film can modify the surface roughness, microhardness, specific wear and corrosion rate. The minimum surface roughness, specific wear and corrosion rate can be obtained for implantation time of 20 minutes and the maximum microhardness of the film is 329 VHN (Vickers Hardness Number) for implantation time of 30 minutes. The specific wear and corrosion rate of the film depend directly on the surface roughness.

  12. Mechanical properties of ion-beam-textured surgical implant alloys

    NASA Technical Reports Server (NTRS)

    Weigand, A. J.

    1977-01-01

    An electron-bombardment Hg ion thruster was used as an ion source to texture surfaces of materials used to make orthopedic and/or dental prostheses or implants. The materials textured include 316 stainless steel, titanium-6% aluminum, 4% vanadium, and cobalt-20% chromium, 15% tungsten. To determine the effect of ion texturing on the ultimate strength and yield strength, stainless steel and Co-Cr-W alloy samples were tensile tested to failure. Three types of samples of both materials were tested. One type was ion-textured (the process also heats each sample to 300 C), another type was simply heated to 300 C in an oven, and the third type was untreated. Stress-strain diagrams, 0.2% offset yield strength data, total elongation data, and area reduction data are presented. Fatigue specimens of ion textured and untextured 316 stainless steel and Ti-6% Al-4% V were tested. Included as an ion textured sample is a Ti-6% Al-4% V sample which was ion machined by means of Ni screen mask so as to produce an array of 140 mu m x 140 mu m x 60 mu m deep pits. Scanning electron microscopy was used to characterize the ion textured surfaces.

  13. Electrostatic ion waves in non-Maxwellian pair-ion plasmas

    SciTech Connect

    Arshad, Kashif; Mahmood, S.

    2010-12-15

    The electrostatic ion waves are studied for non-Maxwellian or Lorentzian distributed unmagnetized pair-ion plasmas. The Vlasov equation is solved and damping rates are calculated for electrostatic waves in Lorentzian pair-ion plasmas. The damping rates of the electrostatic ion waves are studied for the equal and different ion temperatures of pair-ion species. It is found that the Landau damping rate of the ion plasma wave is increased in Lorentzian plasmas in comparison with Maxwellian pair-ion plasmas. The numerical results are also presented for illustration by taking into account the parameters reported in fullerene pair-ion plasma experiments.

  14. Experimental results of a dual-beam ion source for 200 keV ion implanter

    SciTech Connect

    Chen, L. H. Cui, B. Q.; Ma, R. G.; Ma, Y. J.; Tang, B.; Huang, Q. H.; Jiang, W. S.; Zheng, Y. N.

    2014-02-15

    A dual beam ion source for 200 keV ion implanter aimed to produce 200 keV H{sub 2}{sup +} and He{sup +} beams simultaneously has been developed. Not suitable to use the analyzing magnet, the purity of beam extracted from the source becomes important to the performance of implanter. The performance of ion source was measured. The results of experiments show that the materials of inlet tube of ion source, the time of arc ionization in ion source, and the amount of gas flow have significant influence on the purity of beam. The measures by using copper as inlet tube material, long time of arc ionization, and increasing the inlet of gas flow could effectively reduce the impurity of beam. And the method using the gas mass flow controller to adjust the proportion of H{sub 2}{sup +} and He{sup +} is feasible.

  15. Titanium and zirconium based alloys modified by intensive plastic deformation and nitrogen ion implantation for biocompatible implants.

    PubMed

    Byeli, A V; Kukareko, V A; Kononov, A G

    2012-02-01

    Titanium and zirconium alloys are considered to be promising materials for orthopaedics because of their biocompatibility with tissues. Their main drawbacks for application as implants have generally been considered to be insufficient levels of mechanical and tribological properties. In this research the influence of equal channel angular pressing and nitrogen ion implantation on the structure and properties of Ti and Zr alloys has been investigated to ensure the optimum combination of the bulk material and surface layer properties. The data obtained showed that equal channel angular pressing and nitrogen ion implantation can be efficiently used to improve bulk and surface properties of Ti and Zr based implants.

  16. Susceptor Assisted Microwave Annealing Of Ion Implanted Silicon

    NASA Astrophysics Data System (ADS)

    Vemuri, Rajitha

    This thesis discusses the use of low temperature microwave anneal as an alternative technique to recrystallize materials damaged or amorphized due to implantation techniques. The work focuses on the annealing of high- Z doped Si wafers that are incapable of attaining high temperatures required for recrystallizing the damaged implanted layers by microwave absorption The increasing necessity for quicker and more efficient processing techniques motivates study of the use of a single frequency applicator microwave cavity along with a Fe2O3 infused SiC-alumina susceptor/applicator as an alternative post implantation process. Arsenic implanted Si samples of different dopant concentrations and implantation energies were studied pre and post microwave annealing. A set of as-implanted Si samples were also used to assess the effect of inactive dopants against presence of electrically active dopants on the recrystallization mechanisms. The extent of damage repair and Si recrystallization of the damage caused by arsenic and Si implantation of Si is determined by cross-section transmission electron microscopy and Raman spectroscopy. Dopant activation is evaluated for the As implanted Si by sheet resistance measurements. For the same, secondary ion mass spectroscopy analysis is used to compare the extent of diffusion that results from such microwave annealing with that experienced when using conventional rapid thermal annealing (RTA). Results show that compared to susceptor assisted microwave annealing, RTA caused undesired dopant diffusion. The SiC-alumina susceptor plays a predominant role in supplying heat to the Si substrate, and acts as an assistor that helps a high-Z dopant like arsenic to absorb the microwave energy using a microwave loss mechanism which is a combination of ionic and dipole losses. Comparisons of annealing of the samples were done with and without the use of the susceptor, and confirm the role played by the susceptor, since the samples donot recrystallize

  17. Ag-plasma modification enhances bone apposition around titanium dental implants: an animal study in Labrador dogs.

    PubMed

    Qiao, Shichong; Cao, Huiliang; Zhao, Xu; Lo, Hueiwen; Zhuang, Longfei; Gu, Yingxin; Shi, Junyu; Liu, Xuanyong; Lai, Hongchang

    2015-01-01

    Dental implants with proper antibacterial ability as well as ideal osseointegration are being actively pursued. The antimicrobial ability of titanium implants can be significantly enhanced via modification with silver nanoparticles (Ag NPs). However, the high mobility of Ag NPs results in their potential cytotoxicity. The silver plasma immersion ion-implantation (Ag-PIII) technique may remedy the defect. Accordingly, Ag-PIII technique was employed in this study in an attempt to reduce the mobility of Ag NPs and enhance osseointegration of sandblasted and acid-etched (SLA) dental implants. Briefly, 48 dental implants, divided equally into one control and three test groups (further treated by Ag-PIII technique with three different implantation parameters), were inserted in the mandibles of six Labrador dogs. Scanning electron microscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma optical emission spectrometry were used to investigate the surface topography, chemical states, and silver release of SLA- and Ag-PIII-treated titanium dental implants. The implant stability quotient examination, Microcomputed tomography evaluation, histological observations, and histomorphometric analysis were performed to assess the osseointegration effect in vivo. The results demonstrated that normal soft tissue healing around dental implants was observed in all the groups, whereas the implant stability quotient values in Ag-PIII groups were higher than that in the SLA group. In addition, all the Ag-PIII groups, compared to the SLA-group, exhibited enhanced new bone formation, bone mineral density, and trabecular pattern. With regard to osteogenic indicators, the implants treated with Ag-PIII for 30 minutes and 60 minutes, with the diameter of the Ag NPs ranging from 5-25 nm, were better than those treated with Ag-PIII for 90 minutes, with the Ag NPs diameter out of that range. These results suggest that Ag-PIII technique can reduce the mobility of Ag NPs and enhance

  18. Observations of strong ion-ion correlations in dense plasmas

    SciTech Connect

    Ma, T. Pak, A.; Landen, O. L.; Le Pape, S.; Turnbull, D.; Döppner, T.; Fletcher, L.; Galtier, E.; Hastings, J.; Lee, H. J.; Nagler, B.; Glenzer, S. H.; Chapman, D. A.; Falcone, R. W.; Fortmann, C.; Gericke, D. O.; Gregori, G.; White, T. G.; Neumayer, P.; Vorberger, J.; and others

    2014-05-15

    Using simultaneous spectrally, angularly, and temporally resolved x-ray scattering, we measure the pronounced ion-ion correlation peak in a strongly coupled plasma. Laser-driven shock-compressed aluminum at ∼3× solid density is probed with high-energy photons at 17.9 keV created by molybdenum He-α emission in a laser-driven plasma source. The measured elastic scattering feature shows a well-pronounced correlation peak at a wave vector of k=4Å{sup −1}. The magnitude of this correlation peak cannot be described by standard plasma theories employing a linear screened Coulomb potential. Advanced models, including a strong short-range repulsion due to the inner structure of the aluminum ions are however in good agreement with the scattering data. These studies have demonstrated a new highly accurate diagnostic technique to directly measure the state of compression and the ion-ion correlations. We have since applied this new method in single-shot wave-number resolved S(k) measurements to characterize the physical properties of dense plasmas.

  19. Friction and Wear Properties of As-Deposited and Carbon Ion-Implanted Diamond Films

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1996-01-01

    Recent work on the friction and wear properties of as-deposited and carbon ion-implanted diamond films was reviewed. Diamond films were produced by the microwave plasma chemical vapor deposition (CVD) technique. Diamond films with various grain sizes and surface roughnesses were implanted with carbon ions at 60 keV ion energy, resulting in a dose of 1.2 x 10(exp 17) carbon ions per cm(exp 2). Various analytical techniques, including Raman spectroscopy, proton recoil analysis, Rutherford backscattering, transmission and scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, were utilized to characterize the diamond films. Sliding friction experiments were conducted with a polished natural diamond pin in contact with diamond films in the three environments: humid air (40% relative humidity), dry nitrogen (less than 1 percent relative humidity), and ultrahigh vacuum (10(exp -7) Pa). The CVD diamond films indeed have friction and wear properties similar to those of natural diamond in the three environments. The as-deposited, fine-grain diamond films can be effectively used as self-lubricating, wear-resistant coatings that have low coefficients of friction (0.02 to 0.04) and low wear rates (10(exp -7) to lO(exp -8) mm(exp 3) N(exp -1) m(exp -1)) in both humid air and dry nitrogen. However, they have high coefficients of friction (1.5 to 1.7) and a high wear rate (10(exp -4) mm(exp 7) N(exp -1) m(exp -1)) in ultrahigh vacuum. The carbon ion implantation produced a thin surficial layer (less than 0.1 micron thick) of amorphous, non-diamond carbon on the diamond films. In humid air and dry nitrogen, the ion-implanted, fine and coarse-grain diamond films have a low coefficient of friction (around 0.1) and a low wear rate (10(exp -7) mm(exp 3) N(exp -1) m(exp-1)). Even in ultrahigh vacuum, the presence of the non-diamond carbon layer reduced the coefficient of friction of fine-grain diamond films to 0.1 or lower and the wear rate to 10(exp -6

  20. Ion Beam Plasma Interactions in the ASTRAL Helicon Plasma Source.

    NASA Astrophysics Data System (ADS)

    Boivin, R. F.; Kesterson, A.; Kamar, O.; Lin, Y.; Munoz, J.; Wang, X.

    2008-11-01

    A 100 KeV NEC duoplasmatron is used to produce an energetic ion beam (10 KeV < E < 100 KeV). The beam is sent through plasmas produced by the ASTRAL helicon plasma source. The beam current and beam size are measured by a device combining Retarding Field Analyzer (RFA) and Faraday Cup (FC) features. ASTRAL produces bright intense He/Ne/Ar plasmas with the following parameters: ne = 1E11 -- 1E13 cm-3 and Te = 2 - 10 eV, B-field < 1.3 kGauss, rf power <= 2 kWatt. RF compensated Langmuir probes are used to measure Te and ne. Depending on the ion beam energy and the ratio of beam density over plasma density different wave instabilities will be generated within the plasmas. A real-time spectrum analyzer will be used to identify the wave instabilities and their evolution in the plasma. We will present early experimental results together with some preliminary theoretical simulation using 2D and 3D hybrid simulation codes. In these codes, ions are treated as fully kinetic particles while electrons are treated as a fluid. Both species are moving in a self-consistent electromagnetic field.

  1. FeN foils by nitrogen ion-implantation

    SciTech Connect

    Jiang, Yanfeng; Wang, Jian-Ping; Al Mehedi, Md; Fu, Engang; Wang, Yongqiang

    2014-05-07

    Iron nitride samples in foil shape (free standing, 500 nm in thickness) were prepared by a nitrogen ion-implantation method. To facilitate phase transformation, the samples were bonded on the substrate followed by a post-annealing step. By using two different substrates, single crystal Si and GaAs, structural and magnetic properties of iron nitride foil samples prepared with different nitrogen ion fluences were characterized. α″-Fe{sub 16}N{sub 2} phase in iron nitride foil samples was obtained and confirmed by the proposed approach. A hard magnetic property with coercivity up to 780 Oe was achieved for the FeN foil samples bonded on Si substrate. The feasibility of using nitrogen ion implantation techniques to prepare FeN foil samples up to 500 nm thickness with a stable martensitic phase under high ion fluences has been demonstrated. A possible mechanism was proposed to explain this result. This proposed method could potentially be an alternative route to prepare rare-earth-free FeN bulk magnets by stacking and pressing multiple free-standing thick α″-Fe{sub 16}N{sub 2} foils together.

  2. Hydrophilic property by contact angle change of ion implanted polycarbonate

    SciTech Connect

    Lee, Chan Young; Kil, Jae Keun

    2008-02-15

    In this study, ion implantation was performed onto a polymer, polycarbonate (PC), in order to investigate surface hydrophilic property through contact angle measurement. PC was irradiated with N, Ar, and Xe ions at the irradiation energy of 20-50 keV and the dose range of 5x10{sup 15}, 1x10{sup 16}, 7x10{sup 16} ions/cm{sup 2}. The contact angle of water was estimated by means of the sessile drop method and was reduced with increasing fluence and ion mass but increased with increasing implanted energy. The changes of chemical and structural properties are discussed in view of Furier transform infrared and x-ray photoelectron spectroscopy, which shows increasing C-O bonding and C-C bonding. The surface roughness examined by atomic force microscopy measurement changed smoothly from 3.59 to 2.22 A as the fluence increased. It is concluded that the change in wettability may be caused by surface carbonization and oxidation as well as surface roughness.

  3. Evaluation of the ion implantation process for production of solar cells from silicon sheet materials

    NASA Technical Reports Server (NTRS)

    Spitzer, M. B.

    1983-01-01

    For the ion implantation tooling was fabricated with which to hold dendritic web samples. This tooling permits the expeditious boron implantation of the back to form the back surface field (BSF). Baseline BSF web cells were fabricated.

  4. Ion acoustic solitons in a plasma with finite temperature drifting ions: Limit on ion drift velocity

    SciTech Connect

    Malik, H.K.; Singh, S.; Dahiya, R.P. )

    1994-05-01

    Propagation of ion acoustic solitons in a plasma consisting of finite temperature drifting ions and nondrifting electrons has been studied. It is shown that in addition to the electron inertia and weak relativistic effects, the ion temperature also modifies the soliton behavior. By including the finite ion temperature, limit for the ion drift velocity [ital u][sub 0] for which the ion acoustic solitons are possible, is obtained. The solitons can exist for [ital v][sub [ital Te

  5. Assessment of Atmospheric Pressure Plasma Treatment for Implant Osseointegration

    PubMed Central

    Danna, Natalie R.; Beutel, Bryan G.; Tovar, Nick; Witek, Lukasz; Marin, Charles; Granato, Rodrigo; Suzuki, Marcelo; Coelho, Paulo G.

    2015-01-01

    This study assessed the osseointegrative effects of atmospheric pressure plasma (APP) surface treatment for implants in a canine model. Control surfaces were untreated textured titanium (Ti) and calcium phosphate (CaP). Experimental surfaces were their 80-second air-based APP-treated counterparts. Physicochemical characterization was performed to assess topography, surface energy, and chemical composition. One implant from each control and experimental group (four in total) was placed in one radius of each of the seven male beagles for three weeks, and one implant from each group was placed in the contralateral radius for six weeks. After sacrifice, bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were assessed. X-ray photoelectron spectroscopy showed decreased surface levels of carbon and increased Ti and oxygen, and calcium and oxygen, posttreatment for Ti and CaP surfaces, respectively. There was a significant (P < 0.001) increase in BIC for APP-treated textured Ti surfaces at six weeks but not at three weeks or for CaP surfaces. There were no significant (P = 0.57) differences for BAFO between treated and untreated surfaces for either material at either time point. This suggests that air-based APP surface treatment may improve osseointegration of textured Ti surfaces but not CaP surfaces. Studies optimizing APP parameters and applications are warranted. PMID:26090443

  6. Integration of Ion Implantation with Scanning ProbeAlignment

    SciTech Connect

    Persaud, A.; Rangelow, I.W.; Schenkel, T.

    2005-03-01

    We describe a scanning probe instrument which integrates ion beams with imaging and alignment functions of a piezo resistive scanning probe in high vacuum. Energetic ions (1 to a few hundred keV) are transported through holes in scanning probe tips [1]. Holes and imaging tips are formed by Focused Ion Beam (FIB) drilling and ion beam assisted thin film deposition. Transport of single ions can be monitored through detection of secondary electrons from highly charged dopant ions (e. g., Bi{sup 45+}) enabling single atom device formation. Fig. 1 shows SEM images of a scanning probe tip formed by ion beam assisted Pt deposition in a dual beam FIB. Ion beam collimating apertures are drilled through the silicon cantilever with a thickness of 5 {micro}m. Aspect ratio limitations preclude the direct drilling of holes with diameters well below 1 {micro}m, and smaller hole diameters are achieved through local thin film deposition [2]. The hole in Fig. 1 was reduced from 2 {micro}m to a residual opening of about 300 nm. Fig. 2 shows an in situ scanning probe image of an alignment dot pattern taken with the tip from Fig. 1. Transport of energetic ions through the aperture in the scanning probe tip allows formation of arbitrary implant patterns. In the example shown in Fig. 2 (right), a 30 nm thick PMMA resist layer on silicon was exposed to 7 keV Ar{sup 2+} ions with an equivalent dose of 10{sup 14} ions/cm{sup 2} to form the LBL logo. An exciting goal of this approach is the placement of single dopant ions into precise locations for integration of single atom devices, such as donor spin based quantum computers [3, 4]. In Fig. 3, we show a section of a micron size dot area exposed to a low dose (10{sup 11}/cm{sup 2}) of high charge state dopant ions. The Bi{sup 45+} ions (200 keV) were extracted from a low emittance highly charged ions source [5]. The potential energy of B{sup 45+}, i. e., the sum of the binding energies required to remove the electrons, amounts to 36 ke

  7. High- Tc superconductor characteristics control by ion implantation

    NASA Astrophysics Data System (ADS)

    Matsui, S.; Matsutera, H.; Yoshitake, T.; Fujita, J.; Satoh, T.

    1989-03-01

    Transition temperature ( Tc) control and annealing effects of YBa 2Cu 3O x and Bi 2Sr 1.4 Ca 1.8Cu 2.2O y superconductor thin films implanted by 200 keV Ne + have been investigated. YBa 2Cu 3 O xTc end points for 0, 1 × 10 14, 1 × 10 15 and 1 × 10 16 ions/cm 2 doses are 75, 71, 62 and 16 K, respectively. On the other hand, Bi 2Sr 1.4Ca 1.8Cu 2.2O y, Tc end points for 0, 1 × 10 12 and 1 × 10 13 ions/cm 2 doses are 78, 76 and 54 K, respectively, c lattice constant increases were observed for the implanted films. It is confirmed that the superconducting characteristics for films, are recovered by anneaing in O 2 atomosphere. Moreover, microcrystal growth caused by annealing the implanted YBa 2Cu 3O x film was observed on the surface.

  8. Effects of cesium ion-implantation on mechanical and electrical properties of organosilicate low-k films

    NASA Astrophysics Data System (ADS)

    Li, W.; Pei, D.; Guo, X.; Cheng, M. K.; Lee, S.; Lin, Q.; King, S. W.; Shohet, J. L.

    2016-05-01

    The effects of cesium (Cs) ion-implantation on uncured plasma-enhanced chemical-vapor-deposited organosilicate low dielectric constant (low-k) (SiCOH) films have been investigated and compared with an ultraviolet (UV) cured film. The mechanical properties, including the elastic modulus and hardness, of the SiCOH low-k films are improved by up to 30% with Cs implantation, and further up to 52% after annealing at 400 °C in a N2 ambient for 1 h. These improvements are either comparable to or better than the effects of UV-curing. They are attributed to an enhancement of the Si-O-Si network structure. The k-value of the SiCOH films increased slightly after Cs implantation, and increased further after annealing. These increases are attributed to two carbon-loss mechanisms, i.e., the carbon loss due to Si-CH3 bond breakage from implanted Cs ions, and the carbon loss due to oxidation during the annealing. The time-zero dielectric breakdown strength was improved after the Cs implantation and the annealing, and was better than the UV-cured sample. These results indicate that Cs ion implantation could be a supplement to or a substitution for the currently used UV curing method for processing SiCOH low-k films.

  9. High Frequency Plasma Generators for Ion Thrusters

    NASA Technical Reports Server (NTRS)

    Divergilio, W. F.; Goede, H.; Fosnight, V. V.

    1981-01-01

    The results of a one year program to experimentally adapt two new types of high frequency plasma generators to Argon ion thrusters and to analytically study a third high frequency source concept are presented. Conventional 30 cm two grid ion extraction was utilized or proposed for all three sources. The two plasma generating methods selected for experimental study were a radio frequency induction (RFI) source, operating at about 1 MHz, and an electron cyclotron heated (ECH) plasma source operating at about 5 GHz. Both sources utilize multi-linecusp permanent magnet configurations for plasma confinement. The plasma characteristics, plasma loading of the rf antenna, and the rf frequency dependence of source efficiency and antenna circuit efficiency are described for the RFI Multi-cusp source. In a series of tests of this source at Lewis Research Center, minimum discharge losses of 220+/-10 eV/ion were obtained with propellant utilization of .45 at a beam current of 3 amperes. Possible improvement modifications are discussed.

  10. Biodegradable poly(butylene succinate) modified by gas plasmas and their in vitro functions as bone implants.

    PubMed

    Wang, Huaiyu; Xu, Ming; Wu, Zhengwei; Zhang, Wei; Ji, Junhui; Chu, Paul K

    2012-08-01

    Artificial implants are alternatives to autologous grafts in repairing severe bone damage and in many clinical applications, the artificial implant materials should be biodegradable in order to avoid chronic problems associated with biostable implants. In this study, a biodegradable biopolymer, poly(butylene succinate) (PBSu), is treated by N(2), NH(3) and H(2)O plasmas and investigated as bone replacement materials in vitro to obtain a better understanding of the behavior of osteoblasts on the different plasma-treated materials. N(2), NH(3), and H(2)O plasma immersion ion implantation (PIII) produces dominant C-N, C═N, and C-O surface functional groups, respectively rendering the materials with hydrophilic characteristics which favor osteoblast adhesion and early proliferation. In particular, N-containing groups, especially C═N, are more positive to osteogenic differentiation of the seeded osteoblasts than C-O. Among the 3 plasma treatments, NH(3) PIII is the most effective, yielding surface properties that are suitable for artificial bone implants.

  11. Investigation of the ion beam emission from a pulsed power plasma device

    NASA Astrophysics Data System (ADS)

    Henríquez, A.; Bhuyan, H.; Favre, M.; Retamal, M. J.; Volkmann, U.; Wyndham, E.; Chuaqui, H.

    2014-05-01

    Plasma Focus (PF) devices are well known as ion beam sources with characteristic energy among the hundreds of keV to tens of MeV. The information on ion beam energy, ion distribution and composition is essential from the viewpoint of understanding fundamental physics behind their production and acceleration and also their applications in various fields, such as surface properties modification, ion implantation, thin film deposition, semiconductor doping and ion assisted coating. An investigation from a low energy, 1.8 kJ 160 kA, Mather type plasma focus device operating with nitrogen using CR-39 detectors was conducted to study the emission of ions at different angular positions. Tracks on CR-39 detectors at different angular positions reveal the existence of angular ion anisotropy. The results obtained are comparable with the time integrated measurements using FC. Preliminary results of this work are presented.

  12. Acid Etching and Plasma Sterilization Fail to Improve Osseointegration of Grit Blasted Titanium Implants

    PubMed Central

    Saksø, Mikkel; Jakobsen, Stig S; Saksø, Henrik; Baas, Jørgen; Jakobsen, Thomas; Søballe, Kjeld

    2012-01-01

    Interaction between implant surface and surrounding bone influences implant fixation. We attempted to improve the bone-implant interaction by 1) adding surface micro scale topography by acid etching, and 2) removing surface-adherent pro-inflammatory agents by plasma cleaning. Implant fixation was evaluated by implant osseointegration and biomechanical fixation. The study consisted of two paired animal sub-studies where 10 skeletally mature Labrador dogs were used. Grit blasted titanium alloy implants were inserted press fit in each proximal tibia. In the first study grit blasted implants were compared with acid etched grit blasted implants. In the second study grit blasted implants were compared with acid etched grit blasted implants that were further treated with plasma sterilization. Implant performance was evaluated by histomorphometrical investigation (tissue-to-implant contact, peri-implant tissue density) and mechanical push-out testing after four weeks observation time. Neither acid etching nor plasma sterilization of the grit blasted implants enhanced osseointegration or mechanical fixation in this press-fit canine implant model in a statistically significant manner. PMID:22962567

  13. Stoichiometric disturbances in compound semiconductors due to ion implantation

    NASA Technical Reports Server (NTRS)

    Avila, R. E.; Fung, C. D.

    1986-01-01

    A method is developed to calculate the depth distribution of the local stoichiometric disturbance (SD) resulting from ion implantation in binary-compound substrates. The calculation includes first-order recoils considering projected range straggle of projectiles and recoils and lateral straggle of recoils. The method uses tabulated final-range statistics to infer the projectile range distributions at intermediate energies. This approach greatly simplifies the calculation with little compromise on accuracy as compared to existing procedures. As an illustration, the SD profile is calculated for implantation of boron, silicon, and aluminum in silicon carbide. The results for the latter case suggest that the SD may be responsible for otherwise unexplained distortions in the annealed aluminum profile. A comparison with calculations by other investigators using the Boltzmann transport equation shows good agreement.

  14. Xenon doping of glow discharge polymer by ion implantation

    NASA Astrophysics Data System (ADS)

    Shin, Swanee J.; Kucheyev, Sergei O.; Orme, Christine A.; Youngblood, Kelly P.; Nikroo, Abbas; Moreno, Kari A.; Chen, Bryan; Hamza, Alex V.

    2012-05-01

    We demonstrate controlled doping of a glow discharge polymer by implantation with 500 keV Xe ions at room temperature. The Xe retention exhibits a threshold behavior, with a threshold dose of ˜2 × 1014 cm-2. Doping is accompanied by irradiation-induced changes in the polymer composition, including gradual H loss and a more complex non-monotonic behavior of the O concentration. The matrix composition saturates at C0.77H0.22O0.01 for Xe doses above ˜5 × 1014 cm-2 and up to the maximum dose studied (5 × 1015 cm-2). The retention mechanism is attributed to the modification of the polymer from a chain-like to clustered ring structure. The dopant profile and the elemental composition of the implanted polymer exhibit good stability upon thermal annealing up to 305 °C.

  15. Ion heating in a plasma focus

    NASA Technical Reports Server (NTRS)

    Hohl, F.; Gary, S. P.

    1974-01-01

    Ion acceleration and heating in a plasma focus were investigated by the numerical integration of the three-dimensional equations of motion. The electric and magnetic fields given were derived from experimental data. The results obtained show that during the collapse phase of focus formation, ions are efficiently heated to temperatures of several keV. During the phase of rapid current reduction, ions are accelerated to large velocities in the axial direction. The results obtained with the model are in general agreement with experimental results.

  16. Defect trapping of ion-implanted deuterium in nickel

    SciTech Connect

    Besenbacher, F.; Bottiger, J.; Myers, S.M.

    1982-05-01

    Trapping of ion-implanted deuterium by lattice defects in nickel has been studied by ion-beam-analysis techniques in the temperature range between 30 and 380 K. The deuterium-depth profiles were determined by measuring either the ..cap alpha.. particles or the protons from the /sup 3/He-excited nuclear reaction D(/sup 3/He,..cap alpha..)p, and the deuterium lattice location was obtained by means of ion channeling. Linear-ramp annealing (1 K/min) following a 10-keV D/sup +/ implantation in nickel produced two annealing stages at 275 and 320 K, respectively. The release-vs-temperature data were analyzed by solving the diffusion equation with appropriate trapping terms, yielding 0.24 and 0.43 eV for the trap-binding enthalpies associated with the two stages, referred to as an untrapped solution site. The 0.24-eV trap corresponds to deuterium close to the octahedral interstitial site where it is believed to be trapped at a vacancy, whereas it is suggested that the defect correlated with the 0.43-eV trap is a multiple-vacancy defect. The previously air-exposed and electropolished nickel surface was essentially permeable; the surface-recombination coefficient was determined to be K> or approx. =10/sup -19/ cm/sup 4//s at 350 K.

  17. Modifications in surface, structural and mechanical properties of brass using laser induced Ni plasma as an ion source

    NASA Astrophysics Data System (ADS)

    Ahmad, Shahbaz; Bashir, Shazia; Rafique, M. Shahid; Yousaf, Daniel

    2016-03-01

    Laser induced Ni plasma has been employed as source of ion implantation for surface, structural and mechanical properties of brass. Excimer laser (248 nm, 20 ns, 120mJ and 30 Hz) was used for the generation of Ni plasma. Thomson parabola technique was employed to estimate the energy of generated ions using CR39 as a detector. In response to stepwise increase in number of laser pulses from 3000 to 12000, the ion dose varies from 60 × 1013 to 84 × 1016 ions/cm2 with constant energy of 138 KeV. SEM analysis reveals the growth of nano/micro sized cavities, pores, pits, voids and cracks for the ion dose ranging from 60 × 1013 to 70 × 1015 ions/cm2. However, at maximum ion dose of 84 × 1016 ions/cm2 the granular morphology is observed. XRD analysis reveals that new phase of CuZnNi (200) is formed in the brass substrate after ion implantation. However, an anomalous trend in peak intensity, crystallite size, dislocation line density and induced stresses is observed in response to the implantation with various doses. The increase in ion dose causes to decrease the Yield Stress (YS), Ultimate Tensile Strength (UTS) and hardness. However, for the maximum ion dose the highest values of these mechanical properties are achieved. The variations in the mechanical properties are correlated with surface and crystallographical changes of ion implanted brass.

  18. Ion implantation: surface treatment for improving the bone integration of titanium and Ti6Al4V dental implants.

    PubMed

    De Maeztu, Miguel A; Alava, J Iñaki; Gay-Escoda, Cosme

    2003-02-01

    Dental implants subjected to surface treatment have shown better bone integration than implants which have only been turned (machined). Three main types of treatment are presently available: the addition of material or coating, the removal of material, and surface modification. Ion implantation corresponds to the third approach. A histomorphometric study is made following the rabbit tibial bone placement of 88 commercial dental implants of pure titanium and Ti6AI4V subjected to surface treatment in the form of different ion implants (C+, CO+, N+, Ne+). Light microscopic, scanning electron microscopic (SEM), electron microsonde (EDS) and X-ray photoelectron spectroscopy (XPS) studies were made. The results indicate improved bone integration (expressed as percentage bone-implant contact) in those specimens subjected to ion implantation versus the non-treated controls, the difference being statistically significant for the groups treated with C+ and CO+. In these groups, XPS showed a Ti-O-C junction (bone-implant interface) involving covalent type bonds, these being stronger and more stable than the ion-type bonds usually established between the titanium oxide and bone.

  19. P-type Gate Electrode Formation Using B18H22 Ion Implantation

    NASA Astrophysics Data System (ADS)

    Henke, Dietmar; Jakubowski, Frank; Deichler, Josef; Venezia, Vincent C.; Ameen, M. S.; Harris, M. A.

    2006-11-01

    We have investigated the use of octadecaborane (B18H22) cluster ion implantation to form highly active p-type gate electrodes in a 90 nm CMOS process. As device dimensions scale, the influence of poly-depletion and short channel effect control on device performance continues to become more significant. Increasing gate electrode doping via high dose ion implantation is a standard method for reducing poly-depletion. Poly-silicon gate doping with the molecular ion B18H22 offers throughput advantages over monatomic B ion implantation. For instance each molecular ion introduces 18-B atoms, thereby reducing the implant dose. In addition, each B constituent of the molecular ion is implanted with 1/20th the ion energy, making it possible to achieve low energy dopant distribution while taking advantage of higher beam energy currents. In this work, B18H22 implantation conditions (energy, dose) were matched to those of the standard B+ process of record (POR) used for gate electrode doping. We show that the poly-depletion, threshold voltage, and yield of devices implanted with B18H22 are comparable to those implanted with the POR. We combine this device results with materials data to demonstrate that the high dose implants necessary to form p-type gate electrodes with minimum poly-depletion can be achieved with B18H22 ion implants without impacting the device performance.

  20. Ion Acoustic Waves in Ultracold Neutral Plasmas

    SciTech Connect

    Castro, J.; McQuillen, P.; Killian, T. C.

    2010-08-06

    We photoionize laser-cooled atoms with a laser beam possessing spatially periodic intensity modulations to create ultracold neutral plasmas with controlled density perturbations. Laser-induced fluorescence imaging reveals that the density perturbations oscillate in space and time, and the dispersion relation of the oscillations matches that of ion acoustic waves, which are long-wavelength, electrostatic, density waves.

  1. Structure analysis of bimetallic Co-Au nanoparticles formed by sequential ion implantation

    NASA Astrophysics Data System (ADS)

    Chen, Hua-jian; Wang, Yu-hua; Zhang, Xiao-jian; Song, Shu-peng; chen, Hong; Zhang, Ke; Xiong, Zu-zhao; Ji, Ling-ling; Dai, Hou-mei; Wang, Deng-jing; Lu, Jian-duo; Wang, Ru-wu; Zheng, Li-rong

    2016-08-01

    Co-Au alloy Metallic nanoparticles (MNPs) are formed by sequential ion implantation of Co and Au into silica glass at room temperature. The ion ranges of Au ions implantation process have been displayed to show the ion distribution. We have used the atomic force microscopy (AFM) and transmission electron microscopy (TEM) to investigate the formation of bimetallic nanoparticles. The extended X-ray absorption fine structure (EXAFS) has been used to study the local structural information of bimetallic nanoparticles. With the increase of Au ion implantation, the local environments of Co ions are changed enormously. Hence, three oscillations, respectively, Co-O, Co-Co and Co-Au coordination are determined.

  2. The effect of platform switching on the levels of metal ion release from different implant-abutment couples.

    PubMed

    Alrabeah, Ghada O; Knowles, Jonathan C; Petridis, Haralampos

    2016-01-01

    The improved peri-implant bone response demonstrated by platform switching may be the result of reduced amounts of metal ions released to the surrounding tissues. The aim of this study was to compare the levels of metal ions released from platform-matched and platform-switched implant-abutment couples as a result of accelerated corrosion. Thirty-six titanium alloy (Ti-6Al-4V) and cobalt-chrome alloy abutments were coupled with titanium cylinders forming either platform-switched or platform-matched groups (n=6). In addition, 18 unconnected samples served as controls. The specimens were subjected to accelerated corrosion by static immersion in 1% lactic acid for 1 week. The amount of metal ions ion of each test tube was measured using inductively coupled plasma mass spectrometry. Scanning electron microscope (SEM) images and energy dispersive spectroscopy X-ray analyses were performed pre- and post-immersion to assess corrosion at the interface. The platform-matched groups demonstrated higher ion release for vanadium, aluminium, cobalt, chrome, and molybdenum compared with the platform-switched groups (P<0.05). Titanium was the highest element to be released regardless of abutment size or connection (P<0.05). SEM images showed pitting corrosion prominent on the outer borders of the implant and abutment platform surfaces. In conclusion, implant-abutment couples underwent an active corrosion process resulting in metal ions release into the surrounding environment. The highest amount of metal ions released was recorded for the platform-matched groups, suggesting that platform-switching concept has a positive effect in reducing the levels of metal ion release from the implant-abutment couples. PMID:27357323

  3. Ion beam control in laser plasma interaction

    NASA Astrophysics Data System (ADS)

    Kawata, S.; Izumiyama, T.; Sato, D.; Nagashima, T.; Takano, M.; Barada, D.; Gu, Y. J.; Ma, Y. Y.; Kong, Q.; Wang, P. X.; Wang, W. M.

    2016-03-01

    By a two-stage successive acceleration in laser ion acceleration, our 2.5-dimensional particle-in-cell simulations demonstrate a remarkable increase in ion energy by a few hundreds of MeV; the maximum proton energy reaches about 250MeV. The ions are accelerated by the inductive continuous post-acceleration in a laser plasma interaction together with the target normal sheath acceleration and the breakout afterburner mechanism. An intense short-pulse laser generates a strong current by high-energy electrons accelerated, when an intense short- pulse laser illuminates a plasma target. The strong electric current creates a strong magnetic field along the high-energy electron current in the plasma. During the increase phase in the magnetic field strength, the moving longitudinal inductive electric field is induced by the Faraday law, and accelerates the forward-moving ions continously. The multi-stage acceleration provides a unique controllability in the ion energy and its quality.

  4. Surface modification of titanium and titanium alloys by ion implantation.

    PubMed

    Rautray, Tapash R; Narayanan, R; Kwon, Tae-Yub; Kim, Kyo-Han

    2010-05-01

    Titanium and titanium alloys are widely used in biomedical devices and components, especially as hard tissue replacements as well as in cardiac and cardiovascular applications, because of their desirable properties, such as relatively low modulus, good fatigue strength, formability, machinability, corrosion resistance, and biocompatibility. However, titanium and its alloys cannot meet all of the clinical requirements. Therefore, to improve the biological, chemical, and mechanical properties, surface modification is often performed. In view of this, the current review casts new light on surface modification of titanium and titanium alloys by ion beam implantation.

  5. Diffusion of ion implanted aluminum in silicon carbide

    SciTech Connect

    Tajima, Y.; Kijima, K.; Kingery, W.D.

    1982-09-01

    Diffusion of aluminum in silicon carbide was studied by Al implantation into single crystal SiC and subsequent profile analyses by secondary ion mass spectrometry (SIMS). The bulk diffusion coefficient of Al at temperatures between 1350 and 1800 /sup 0/C was determined to be D(cm/sup 2//s) = 1.3 x 10/sup -8/ exp (-231 kJ/mol/RT). The results were characterized by a low activation energy and a low pre-exponential constant compared with previously reported results. Dislocation enhanced diffusion was suggested from the appearance of the tails observed in the annealed concentration profiles.

  6. Pulsed-electron-beam annealing of ion-implantation damage

    NASA Technical Reports Server (NTRS)

    Greenwald, A. C.; Kirkpatrick, A. R.; Little, R. G.; Minnucci, J. A.

    1979-01-01

    Short-duration high-intensity pulsed electron beams have been used to anneal ion-implantation damage in silicon and to electrically activate the dopant species. Lattice regrowth and dopant activation were determined using He(+)-4 backscattering, SEM, TEM, and device performance characteristics as diagnostic techniques. The annealing mechanism is believed to be liquid-phase epitaxial regrowth initiating from the substrate. The high-temperature transient pulse produced by the electron beam causes the dopant to diffuse rapidly in the region where the liquid state is achieved.

  7. Productivity Improvement for the SHX--SEN's Single-Wafer High-Current Ion Implanter

    SciTech Connect

    Ninomiya, Shiro; Ochi, Akihiro; Kimura, Yasuhiko; Yumiyama, Toshio; Kudo, Tetsuya; Kurose, Takeshi; Kariya, Hiroyuki; Tsukihara, Mitsukuni; Ishikawa, Koji; Ueno, Kazuyoshi

    2011-01-07

    Equipment productivity is a critical issue for device fabrication. For ion implantation, productivity is determined both by ion current at the wafer and by utilization efficiency of the ion beam. Such improvements not only result in higher fabrication efficiency but also reduce consumption of both electrical power and process gases. For high-current ion implanters, reduction of implant area is a key factor to increase efficiency. SEN has developed the SAVING system (Scanning Area Variation Implantation with Narrower Geometrical pattern) to address this opportunity. In this paper, three variations of the SAVING system are introduced along with discussion of their effects on fab productivity.

  8. The ion implantation-induced properties of one-dimensional nanomaterials

    PubMed Central

    2013-01-01

    Nowadays, ion implantation is an extensively used technique for material modification. Using this method, we can tailor the properties of target materials, including morphological, mechanical, electronic, and optical properties. All of these modifications impel nanomaterials to be a more useful application to fabricate more high-performance nanomaterial-based devices. Ion implantation is an accurate and controlled doping method for one-dimensional nanomaterials. In this article, we review recent research on ion implantation-induced effects in one-dimensional nanostructure, such as nanowires, nanotubes, and nanobelts. In addition, the optical property of single cadmium sulfide nanobelt implanted by N+ ions has been researched. PMID:23594476

  9. Mass and energy deposition effects of implanted ions on solid sodium formate

    NASA Astrophysics Data System (ADS)

    Wang, Xiangqin; Shao, Chunlin; Yao, Jianming; Yu, Zengliang

    2000-07-01

    Solid sodium formate was implanted by low energy N +, H +, and Ar + ions. Measured with electron paramagnetic resonance (EPR) and Fourier-transform infrared (FT-IR), it was observed that new CH 2, CH 3 groups and COO - radical ion were produced in the implanted sodium formate. Analyzing with the highly sensitive ninhydrin reaction, it was found that a new NH 2 functional group was formed upon N + ion implantation, and its yield increased along with implantation dose but decreased with the ion's energy.

  10. Research and Technology Transfer Ion Implantation Technology for Specialty Materials: Proceedings of a joint workshop

    NASA Astrophysics Data System (ADS)

    Reeber, Robert R.

    1991-02-01

    The ion implantation research and technology transfer workshop brought together a diverse group of academic, industrial, and government participants. Several key issues highlighted were: (1) a need exists for new technology transfer infrastructures between universities, research labs and industry; (2) ion implantation technology has promise for several Army and industry applications because of environmental concerns and technological benefits; (3) the U.S. ion implantation industry is primarily service oriented; and (4) the cost of ion implantation technology could be significantly reduced if larger scale production equipment was available for on-line processing. A need exists in the U.S. for mechanisms and funds to develop such equipment.

  11. Dose Control System in the Optima XE Single Wafer High Energy Ion Implanter

    SciTech Connect

    Satoh, Shu; Yoon, Jongyoon; David, Jonathan

    2011-01-07

    Photoresist outgassing can significantly compromise accurate dosimetry of high energy implants. High energy implant even at a modest beam current produces high beam powers which create significantly worse outgassing than low and medium energy implants and the outgassing continues throughout the implant due to the low dose in typical high energy implant recipes. In the previous generation of high energy implanters, dose correction by monitoring of process chamber pressure during photoresist outgassing has been used. However, as applications diversify and requirements change, the need arises for a more versatile photoresist correction system to match the versatility of a single wafer high energy ion implanter. We have successfully developed a new dosimetry system for the Optima XE single wafer high energy ion implanter which does not require any form of compensation due to the implant conditions. This paper describes the principles and performance of this new dose system.

  12. Phase-mixing of ion plasma modes in pair-ion plasmas

    SciTech Connect

    Pramanik, Sourav; Chakrabarti, Nikhil

    2015-05-15

    Nonlinear interaction between two electrostatic normal modes of a warm pair-ion plasma, viz., ion plasma mode (Langmuir mode) and ion acoustic mode has been analyzed by employing a perturbation technique. It is shown that a gradual loss of phase coherence in the excited Langmuir wave dynamics (phase-mixing) occurs in such a plasma, leading to wave-breaking at arbitrarily low wave amplitudes. Nonlinear results provide an approximate expression for the phase-mixing time which is found to increase with the increase of the ratio of acoustic frequency to Langmuir frequency. The results of our investigation are expected to be relevant to the laboratory produced paired fullerene-ion plasmas.

  13. Friction and Wear Properties of As-deposited and Carbon Ion-implanted Diamond Films

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1994-01-01

    Recent work on the friction and wear properties of as-deposited and carbon ion-implanted diamond films was reviewed. Diamond films were produced by the microwave plasma chemical vapor deposition (CVD) technique. Diamond films with various grain sizes and surface roughnesses were implanted with carbon ions at 60 ke V ion energy, resulting in a dose of 1.2310(exp 17) carbon ions/cm(exp 2). Various analytical techniques, including Raman spectroscopy, proton recoil analysis, Rutherford backscattering, transmission and scanning electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffraction, were utilized to characterize the diamond films. Sliding friction experiments were conducted with a polished natural diamond pin in contact with diamond films in the three environments: humid air (40 percent relative humidity), dry nitrogen (less than 1 percent relative humidity), and ultrahigh vacuum (10(exp -7) Pa). The CVD diamond films indeed have friction and were properties similar to those of natural diamond in the three environments. The as-deposited, fine-grain diamond films can be effectively used as self-lubricating, wear-resistant coatings that have low coefficients of friction (0.02 to 0.04) and low wear rates (10(exp -7) to 10(exp -8)mm(exp 3)/N-m) in both humid air and dry nitrogen. However, they have high coefficients of friction (1.5 to 1.7) and a high wear rate (10(exp -4)mm(exp 3/N-m) in ultrahigh vacuum. The carbon ion implanation produced a thin surficial layer (less than 0.1 micron thick) of amorphous, nondiamond carbon on the diamond films. In humid air and dry nitrogen, the ion-implanted, fine- and coarse-grain diamond films have a low coefficient of friction (around 0.1) and a low wear rate (10(exp -7)mm(exp 3/N-m). Even in ultrahigh vacuum, the presence of the nondiamond carbon layer reduced the coefficient of friction of fine-grain diamond films to 0.1 or lower and the wear rate to 10(exp -6)mm(exp 3)/N-m. Thus, the carbon ion-implanted, fine

  14. Ion beam technology applications study. [ion impact, implantation, and surface finishing

    NASA Technical Reports Server (NTRS)

    Sellen, J. M., Jr.; Zafran, S.; Komatsu, G. K.

    1978-01-01

    Specific perceptions and possible ion beam technology applications were obtained as a result of a literature search and contact interviews with various institutions and individuals which took place over a 5-month period. The use of broad beam electron bombardment ion sources is assessed for materials deposition, removal, and alteration. Special techniques examined include: (1) cleaning, cutting, and texturing for surface treatment; (2) crosslinking of polymers, stress relief in deposited layers, and the creation of defect states in crystalline material by ion impact; and (3) ion implantation during epitaxial growth and the deposition of neutral materials sputtered by the ion beam. The aspects, advantages, and disadvantages of ion beam technology and the competitive role of alternative technologies are discussed.

  15. Metal ion implantation in inert polymers for strain gauge applications

    NASA Astrophysics Data System (ADS)

    Di Girolamo, Giovanni; Massaro, Marcello; Piscopiello, Emanuela; Tapfer, Leander

    2010-10-01

    Metal ion implantation in inert polymers may produce ultra-thin conducting films below the polymer surface. These subsurface films are promising structures for strain gauge applications. To this purpose, polycarbonate substrates were irradiated at room temperature with low-energy metal ions (Cu + and Ni +) and with fluences in the range between 1 × 10 16 and 1 × 10 17 ions/cm 2, in order to promote the precipitation of dispersed metal nanoparticles or the formation of a continuous thin film. The nanoparticle morphology and the microstructural properties of polymer nanocomposites were investigated by glancing-incidence X-ray diffraction and transmission electron microscopy (TEM) measurements. At lower fluences (<5 × 10 16 ions/cm 2) a spontaneous precipitation of spherical-shaped metal nanoparticles occurred below the polymer top-surface (˜50 nm), whereas at higher fluences the aggregation of metal nanoparticles produced the formation of a continuous polycrystalline nanofilm. Furthermore, a characteristic surface plasmon resonance peak was observed for nanocomposites produced at lower ion fluences, due to the presence of Cu nanoparticles. A reduced electrical resistance of the near-surface metal-polymer nanocomposite was measured. The variation of electrical conductivity as a function of the applied surface load was measured: we found a linear relationship and a very small hysteresis.

  16. Transient enhanced diffusion in ion-implanted silicon

    SciTech Connect

    Pennycook, S.J.; Culbertson, R.J.

    1987-03-01

    We discuss the transient-enhanced diffusion of Sb, As, P, In, Ga, and B in ion-implanted Si, where the near-surface region has been amorphized by the dopant or by a self-implantation process. With Sb, a large transient diffusion enhancement is observed proportional to dopant concentration. For Sb, As, P, and In, the enhancement follows the relative interstitialcy diffusion coefficient. We believe this behavior is caused by stable implantation-induced point defects present in the amorphous surface layer, which decay during thermal processing to release high concentrations of self-interstitials. This process occurs in competition with the solid phase epitaxial (SPE) growth process, and for high dopant concentrations can occur in the amorphous phase ahead of the crystallization front. We believe this may be the origin of the dopant redistribution which can occur during SPE growth, which sets the upper limit to the dopant concentration which can be incorporated in the lattice by SPE growth. These effects are reduced for Ga and are absent for B, although transient enhanced diffusion of these species can still occur from defects emitted from the damaged crystal underlying the original amorphous/crystalline interface.

  17. Ion-implanted high microwave power indium phosphide transistors

    NASA Technical Reports Server (NTRS)

    Biedenbender, Michael D.; Kapoor, Vik J.; Messick, Louis J.; Nguyen, Richard

    1989-01-01

    Encapsulated rapid thermal annealing (RTA) has been used in the fabrication of InP power MISFETs with ion-implanted source, drain, and active-channel regions. The MISFETs had a gate length of 1.4 microns. Six to ten gate fingers per device, with individual gate finger widths of 100 or 125 microns, were used to make MISFETs with total gate widths of 0.75, 0.8, or 1 mm. The source and drain contact regions and the channel region of the MISFETs were fabricated using Si implants in InP at energies from 60 to 360 keV with doses of (1-560) x 10 to the 12th/sq cm. The implants were activated using RTA at 700 C for 30 sec in N2 or H2 ambients using an Si3N4 encapsulant. The high-power high-efficiency MISFETs were characterized at 9.7 GHz, and the output microwave power density for the RTA conditions used was as high as 2.4 W/mm. For a 1-W input at 9.7 GHz gains up to 3.7 dB were observed, with an associated power-added efficiency of 29 percent and output power density 70 percent greater than that of GaAs MESFETs.

  18. Ion Implant Technology for Intermediate Band Solar Cells

    NASA Astrophysics Data System (ADS)

    Olea, Javier; Pastor, David; Luque, María Toledano; Mártil, Ignacio; Díaz, Germán González

    This chapter describes the creation of an Intermediate Band (IB) on single crystal silicon substrates by means of high-dose Ti implantation and subsequent Pulsed Laser Melting (PLM). The Ti concentration over the Mott limit is confirmed by Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) measurements and the recovery of the crystallinity after annealing by means of Glancing Incidence X Ray Diffraction (GIXRD) and Transmission Electron Microscopy (TEM). Rutherford Backscattering Spectroscopy (RBS) measurements show that most of the atoms are located interstitially. Analysis of the sheet resistance and mobility measured using the van der Pauw geometry shows a temperature-dependent decoupling between the implanted layer and the substrate. This decoupling and the high laminated conductivity of the implanted layer could not be explained except if we assume that an IB has been formed in the semiconductor. A specific model for the bilayer electrical behaviour has been developed. The fitting of this model and also the simulation of the sheet resistance with the ATLAS code allow to determine that the IB energetic position is located around 0.36-0.38 eV below the conduction band. Carriers at the IB have a density very similar to the Ti concentration and behave as holes with mobilities as low as 0.4 cm2 Vs- 1.

  19. Sputtering erosion in ion and plasma thrusters

    NASA Technical Reports Server (NTRS)

    Ray, Pradosh K.

    1995-01-01

    An experimental set-up to measure low-energy (below 1 keV) sputtering of materials is described. The materials to be bombarded represent ion thruster components as well as insulators used in the stationary plasma thruster. The sputtering takes place in a 9 inch diameter spherical vacuum chamber. Ions of argon, krypton and xenon are used to bombard the target materials. The sputtered neutral atoms are detected by a secondary neutral mass spectrometer (SNMS). Samples of copper, nickel, aluminum, silver and molybdenum are being sputtered initially to calibrate the spectrometer. The base pressure of the chamber is approximately 2 x 10(exp -9) Torr. the primary ion beam is generated by an ion gun which is capable of delivering ion currents in the range of 20 to 500 nA. The ion beam can be focused to a size approximately 1 mm in diameter. The mass spectrometer is positioned 10 mm from the target and at 90 deg angle to the primary ion beam direction. The ion beam impinges on the target at 45 deg. For sputtering of insulators, charge neutralization is performed by flooding the sample with electrons generated from an electron gun. Preliminary sputtering results, methods of calculating the instrument response function of the spectrometer and the relative sensitivity factors of the sputtered elements will be discussed.

  20. Electron-less negative ion extraction from ion-ion plasmas

    SciTech Connect

    Rafalskyi, Dmytro; Aanesland, Ane

    2015-03-09

    This paper presents experimental results showing that continuous negative ion extraction, without co-extracted electrons, is possible from highly electronegative SF{sub 6} ion-ion plasma at low gas pressure (1 mTorr). The ratio between the negative ion and electron densities is more than 3000 in the vicinity of the two-grid extraction and acceleration system. The measurements are conducted by both magnetized and non-magnetized energy analyzers attached to the external grid. With these two analyzers, we show that the extracted negative ion flux is almost electron-free and has the same magnitude as the positive ion flux extracted and accelerated when the grids are biased oppositely. The results presented here can be used for validation of numerical and analytical models of ion extraction from ion-ion plasma.

  1. Ni ion release, osteoblast-material interactions, and hemocompatibility of hafnium-implanted NiTi alloy.

    PubMed

    Zhao, Tingting; Li, Yan; Zhao, Xinqing; Chen, Hong; Zhang, Tao

    2012-04-01

    Hafnium ion implantation was applied to NiTi alloy to suppress Ni ion release and enhance osteoblast-material interactions and hemocompatibility. The auger electron spectroscopy, x-ray photoelectron spectroscopy, and atomic force microscope results showed that a composite TiO(2)/HfO(2) nanofilm with increased surface roughness was formed on the surface of NiTi, and Ni concentration was reduced in the superficial surface layer. Potentiodynamic polarization tests displayed that 4 mA NiTi sample possessed the highest E(br) - E(corr), 470 mV higher than that of untreated NiTi, suggesting a significant improvement on pitting corrosion resistance. Inductively coupled plasma mass spectrometry tests during 60 days immersion demonstrated that Ni ion release rate was remarkably decreased, for example, a reduction of 67% in the first day. The water contact angle increased and surface energy decreased after Hf implantation. Cell culture and methyl-thiazol-tetrazolium indicated that Hf-implanted NiTi expressed enhanced osteoblasts adhesion and proliferation, especially after 7 days culture. Hf implantation decreased fibrinogen adsorption, but had almost no effect on albumin adsorption. Platelets adhesion and activation were suppressed significantly (97% for 4 mA NiTi) and hemolysis rate was decreased by at least 57% after Hf implantation. Modified surface composition and morphology and decreased surface energy should be responsible for the improvement of cytocompatibility and hemocompatibility.

  2. Damage formation in SiC ion implanted at 625 K

    NASA Astrophysics Data System (ADS)

    Wendler, E.; Schöppe, Ph.; Bierschenk, Th.; Milz, St.; Wesch, W.; van der Berg, N. G.; Friedland, E.; Malherbe, J. B.

    2012-09-01

    Damage formation in 4H-SiC during ion implantation at 625 K is studied applying Rutherford backscattering spectrometry (RBS) in channeling configuration. For comparison two selected samples are analyzed by cross section transmission electron microscopy (TEM). The results for dual implantation of the self-ions Si and C are compared with those obtained for Ag ion implantation. It is found that the evolution of damage as a function of the number of displacements per lattice atom proceeds in two steps and is almost independent of the ion species implanted. The second significant increase of the damage concentration starts obviously when the relative volume increase introduced by the implanted ions exceeds a critical value of about 6 × 10-3. The damage produced at high ion fluences consists of point defect clusters, and probably, extended defects.

  3. Characterization and control of wafer charging effects during high-current ion implantation

    SciTech Connect

    Current, M.I.; Lukaszek, W.; Dixon, W.; Vella, M.C.; Messick, C.; Shideler, J.; Reno, S.

    1994-02-01

    EEPROM-based sense and memory devices provide direct measures of the charge flow and potentials occurring on the surface of wafers during ion beam processing. Sensor design and applications for high current ion implantation are discussed.

  4. Influence of the chemical nature of implanted ions on the structure of a silicon layer damaged by implantation

    SciTech Connect

    Shcherbachev, K. D. Voronova, M. I.; Bublik, V. T.; Mordkovich, V. N. Pazhin, D. M.; Zinenko, V. I.; Agafonov, Yu. A.

    2013-12-15

    The influence of the implantation of silicon single crystals by fluorine, nitrogen, oxygen, and neon ions on the distribution of strain and the static Debye-Waller factor in the crystal lattice over the implanted-layer depth has been investigated by high-resolution X-ray diffraction. The density depth distribution in the surface layer of native oxide has been measured by X-ray reflectometry. Room-temperature implantation conditions have ensured the equality of the suggested ranges of ions of different masses and the energies transferred by them to the target. It is convincingly shown that the change in the structural parameters of the radiation-damaged silicon layer and the native oxide layer depend on the chemical activity of the implanted ions.

  5. In-situ observation of sputtered particles for carbon implanted tungsten during energetic isotope ion implantation

    SciTech Connect

    Oya, Y.; Sato, M.; Uchimura, H.; Okuno, K.; Ashikawa, N.; Sagara, A.; Yoshida, N.; Hatano, Y.

    2015-03-15

    Tungsten is a candidate for plasma facing materials in future fusion reactors. During DT plasma operations, carbon as an impurity will bombard tungsten, leading to the formation of tungsten-carbon (WC) layer and affecting tritium recycling behavior. The effect of carbon implantation for the dynamic recycling of deuterium, which demonstrates tritium recycling, including retention and sputtering, has been investigated using in-situ sputtered particle measurements. The C{sup +} implanted W, WC and HOPG were prepared and dynamic sputtered particles were measured during H{sub 2}{sup +} irradiation. It has been found that the major hydrocarbon species for C{sup +} implanted tungsten is CH{sub 3}, while for WC and HOPG (Highly Oriented Pyrolytic Graphite) it is CH{sub 4}. The chemical state of hydrocarbon is controlled by the H concentration in a W-C mixed layer. The amount of C-H bond and the retention of H trapped by carbon atom should control the chemical form of hydrocarbon sputtered by H{sub 2}{sup +} irradiation and the desorption of CH{sub 3} and CH{sub 2} are due to chemical sputtering, although that for CH is physical sputtering. The activation energy for CH{sub 3} desorption has been estimated to be 0.4 eV, corresponding to the trapping process of hydrogen by carbon through the diffusion in W. It is concluded that the chemical states of hydrocarbon sputtered by H{sub 2}{sup +} irradiation for W is determined by the amount of C-H bond on the W surface. (authors)

  6. Peripheral nerve regeneration through a silicone chamber implanted with negative carbon ions: Possibility to clinical application

    NASA Astrophysics Data System (ADS)

    Ikeguchi, Ryosuke; Kakinoki, Ryosuke; Tsuji, Hiroshi; Yasuda, Tadashi; Matsuda, Shuichi

    2014-08-01

    We investigated whether a tube with its inner surface implanted with negative-charged carbon ions (C- ions) would enable axons to extend over a distance greater than 10 mm. The tube was found to support nerves regenerating across a 15-mm-long inter-stump gap. We also investigated whether a C- ion-implanted tube pretreated with basic fibroblast growth factor (bFGF) promotes peripheral nerve regeneration. The C- ion implanted tube accelerated nerve regeneration, and this effect was enhanced by bFGF. Silicone treated with C- ions showed increased hydrophilic properties and cellular affinity, and axon regeneration was promoted with this increased biocompatibility.

  7. Improve the corrosion and cytotoxic behavior of NiTi implants with use of the ion beam technologies

    SciTech Connect

    Meisner, L. L. Meisner, S. N.; Matveeva, V. A.; Matveev, A. L.

    2015-11-17

    The corrosion resistance behavior and cytotoxicity of binary NiTi-base alloy specimens subjected to surface modification by silicon ion beams and the proliferative ability of mesenchymal stem cells (MSC) of rat marrow on an ion-implanted surface of the alloy have been studied. The silicon ion beam processing of specimen surfaces is shown to bring about a nearly two-fold improvement in the corrosion resistance of the material to attack by acqueous solutions of NaCl and human plasma and a drastic decrease in the nickel concentration after immersion of the specimens into the solutions for ∼3400 and ∼6000 h, respectively. It is found that MSC proliferation strongly depends on the surface structure, roughness and chemical condition of NiTi implants.

  8. Improve the corrosion and cytotoxic behavior of NiTi implants with use of the ion beam technologies

    NASA Astrophysics Data System (ADS)

    Meisner, L. L.; Matveeva, V. A.; Meisner, S. N.; Matveev, A. L.

    2015-11-01

    The corrosion resistance behavior and cytotoxicity of binary NiTi-base alloy specimens subjected to surface modification by silicon ion beams and the proliferative ability of mesenchymal stem cells (MSC) of rat marrow on an ion-implanted surface of the alloy have been studied. The silicon ion beam processing of specimen surfaces is shown to bring about a nearly two-fold improvement in the corrosion resistance of the material to attack by acqueous solutions of NaCl and human plasma and a drastic decrease in the nickel concentration after immersion of the specimens into the solutions for ˜3400 and ˜6000 h, respectively. It is found that MSC proliferation strongly depends on the surface structure, roughness and chemical condition of NiTi implants.

  9. Passive mechanisms of surfaces produced by ion-beam mixing and ion implantation. Annual report, October 1988-November 1989

    SciTech Connect

    Natishan, P.M.; McCafferty, E.; Hubler, G.K.

    1990-05-01

    The corrosion behavior of Mo-Al, Cr-Al and Cr-Mo-Al surface alloys produced by ion implantation and ion beam mixing was examined in deaerated, 0.1M NaC1. The polarization behavior of the ion implanted samples was similar to that of Al and the pitting potentials of the ion implanted samples were 115 to 155 mV higher than that of Al. From the standpoint of the Ph sub pzc model this behavior would be explained by the presence of the implanted cations in the stable oxide lattice. There was incomplete mixing of the coating and substrate for the ion beam mixed samples, and the mixed elements remained almost entirely in the metallic state so that the desired mixed oxide films were not formed. Ion beam mixing did impart additional stability compared to as-deposited samples since themixing process produced more compact coatings.

  10. Extraction and Acceleration of Ions from an Ion-Ion Plasma

    SciTech Connect

    Popelier, Lara; Aanesland, Ane; Chabert, Pascal

    2011-09-26

    Extraction and acceleration of positive and negative ions from a strong electronegative plasma and from an ion-ion plasma is investigated in the PEGASES thruster, working with SF{sub 6}. The plasma is generated in a cylindrical quartz tube terminated by metallic endplates. The electrons are confined by a static magnetic field along the axis of the cylinder. The electron mobility along the field is high and the electrons are determining the sheaths in front of the endplates. The core plasma potential can therefore be controlled by the bias applied to the endplates. An ion-ion plasma forms at the periphery as a result of electron confinement and ions can freely diffuse along the perpendicular direction or extraction axis. Langmuir probe and RFEA measurements are carried out along this axis. The measured ion energy distributions shows a single peak centered around a potential consistent with the plasma potential and the peak position could be controlled with a positive voltage applied to the endplates. When the endplates are biased negatively, the plasma potential saturates and remained close to 15 V. A beam of negatively charged particles can be observed under certain conditions when the endplates were biased negatively.

  11. Very Large Area/Volume Microwave ECR Plasma and Ion Source

    NASA Technical Reports Server (NTRS)

    Foster, John E. (Inventor); Patterson, Michael J. (Inventor)

    2009-01-01

    The present invention is an apparatus and method for producing very large area and large volume plasmas. The invention utilizes electron cyclotron resonances in conjunction with permanent magnets to produce dense, uniform plasmas for long life ion thruster applications or for plasma processing applications such as etching, deposition, ion milling and ion implantation. The large area source is at least five times larger than the 12-inch wafers being processed to date. Its rectangular shape makes it easier to accommodate to materials processing than sources that are circular in shape. The source itself represents the largest ECR ion source built to date. It is electrodeless and does not utilize electromagnets to generate the ECR magnetic circuit, nor does it make use of windows.

  12. Annealing of PEEK, PET and PI implanted with Co ions at high fluencies

    NASA Astrophysics Data System (ADS)

    Mackova, A.; Malinsky, P.; Miksova, R.; Pupikova, H.; Khaibullin, R. I.; Valeev, V. F.; Svorcik, V.; Slepicka, P.

    2013-07-01

    The properties of implanted polymers strongly depend on the implantation ion fluence and on the properties of the implanted atoms. The stability of synthesized nano-structures during further technological steps like annealing is of importance for their possible applications. Polyimide (PI), polyetheretherketone (PEEK), and polyethyleneterephtalate (PET) were implanted with 40 keV Co+ ions at room temperature at fluences ranging from 0.2 × 1016 cm-2 to 1.0 × 1017 cm-2 and annealed at a temperature of 200 °C. The implanted depth profiles of as-implanted and annealed samples, determined by the RBS method, were compared with the results of SRIM 2012 simulations. The structural and compositional changes of the implanted and subsequently annealed polymers were characterized by RBS and UV-vis spectroscopy. The surface morphology of as-implanted and annealed samples was examined by the AFM method and their electrical properties by sheet resistance measurement.

  13. The biomedical properties of polyethylene terephthalate surface modified by silver ion implantation

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Li, Jianxin; Shen, Liru; Ling, Ren; Xu, Zejin; Zhao, Ansha; Leng, Yongxiang; Huang, Nan

    2007-04-01

    Polyethylene terephthalate (PET) film is modified by Ag ion implantation with a fluence 1 × 1016 ions/cm2. The results of X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) indicate that silver has been successfully implanted into the surface of PET. The PET samples modified by silver ion implantation have significantly bactericidal property. The capacity of the staphylococcus epidermidis (SE) adhered on the Ag+ implanted PET surface is 5.3 × 106 CFU/ml, but the capacity of the SE adhered on the untreated PET film is 2.23 × 107 CFU/ml. The thromboembolic property is evaluated by in vitro platelet adhesion test, and there is not statistically difference between the untreated PET and the Ag+ implanted PET for the number of adhered and activated platelets. The PET implanted by silver ion has not acute toxicity to endothelial cell (EC) which was evaluated by the release of lactate dehydrogenase (LDH) test.

  14. Recrystallization and reactivation of dopant atoms in ion-implanted silicon nanowires.

    PubMed

    Fukata, Naoki; Takiguchi, Ryo; Ishida, Shinya; Yokono, Shigeki; Hishita, Shunichi; Murakami, Kouichi

    2012-04-24

    Recrystallization of silicon nanowires (SiNWs) after ion implantation strongly depends on the ion doses and species. Full amorphization by high-dose implantation induces polycrystal structures in SiNWs even after high-temperature annealing, with this tendency more pronounced for heavy ions. Hot-implantation techniques dramatically suppress polycrystallization in SiNWs, resulting in reversion to the original single-crystal structures and consequently high reactivation rate of dopant atoms. In this study, the chemical bonding states and electrical activities of implanted boron and phosphorus atoms were evaluated by Raman scattering and electron spin resonance, demonstrating the formation of p- and n-type SiNWs.

  15. Estimate of the concentration of implanted ions in solid substrates using a web application

    NASA Astrophysics Data System (ADS)

    Rivera, F. H. Vera; Pérez Gutiérrez, B. R.; Dulce-Moreno, H. J.; Duran-Flórez, F.; Niño, E. D. V.

    2016-08-01

    The three-dimensional ionic implantation technique (3DII) is used to modify the surface of solid metal by electric discharges pulsed of high voltage at low pressures. Knowing the density of ions implanted in the surface of a functional element, in a faster and estimated way, will help to optimize the surface treatment technique. Therefore, a web application was developed which from experimental parameters established in a process 3DII estimates the concentration of ions implanted in solid metal substrates. The results obtained in this research work demonstrate the feasibility of the computational web tool to perfect the experiments of surface modification by ion implantation.

  16. Modification of anti-bacterial surface properties of textile polymers by vacuum arc ion source implantation

    NASA Astrophysics Data System (ADS)

    Nikolaev, A. G.; Yushkov, G. Yu.; Oks, E. M.; Oztarhan, A.; Akpek, A.; Hames-Kocabas, E.; Urkac, E. S.; Brown, I. G.

    2014-08-01

    Ion implantation provides an important technology for the modification of material surface properties. The vacuum arc ion source is a unique instrument for the generation of intense beams of metal ions as well as gaseous ions, including mixed metal-gas beams with controllable metal:gas ion ratio. Here we describe our exploratory work on the application of vacuum arc ion source-generated ion beams for ion implantation into polymer textile materials for modification of their biological cell compatibility surface properties. We have investigated two specific aspects of cell compatibility: (i) enhancement of the antibacterial characteristics (we chose to use Staphylococcus aureus bacteria) of ion implanted polymer textile fabric, and (ii) the "inverse" concern of enhancement of neural cell growth rate (we chose Rat B-35 neuroblastoma cells) on ion implanted polymer textile. The results of both investigations were positive, with implantation-generated antibacterial efficiency factor up to about 90%, fully comparable to alternative conventional (non-implantation) approaches and with some potentially important advantages over the conventional approach; and with enhancement of neural cell growth rate of up to a factor of 3.5 when grown on suitably implanted polymer textile material.

  17. Near-surface recrystallization of the amorphous implanted layer of ion implanted 6H-SiC

    NASA Astrophysics Data System (ADS)

    Kuhudzai, R. J.; van der Berg, N. G.; Malherbe, J. B.; Hlatshwayo, T. T.; Theron, C. C.; Buys, A. V.; Botha, A. J.; Wendler, E.; Wesch, W.

    2014-08-01

    The recrystallization and subsequent crystal growth during annealing of amorphous surface layers on 6H-SiC produced by ion implantation is investigated. Amorphous surface layers were produced by ion implantation of 360 keV ions of iodine, silver, xenon, cesium and strontium into single crystalline 6H-silicon carbide samples. The ion fluence for all the implantations were in the order of 1016 cm-2. Vacuum annealing of the damaged silicon carbide samples was then performed. The microstructure of SiC surfaces before and after annealing was investigated using a high resolution field emission scanning electron microscope (SEM). SEM analysis was complimented by Atomic Force Microscopy (AFM). SEM images acquired by an in-lens detector using an accelerating voltage of 2 kV show nano-crystallites developed for all implanted samples after annealing. Larger and more faceted crystallites along with elongated thin crystallites were observed for iodine and xenon implanted 6H-SiC. Crystallites formed on surfaces implanted with strontium and cesium were smaller and less faceted. Strontium, silver and cesium implanted samples also exhibited more cavities on the surface. AFM was used to evaluate the effect of annealing on the surface roughness. For all the amorphous surfaces which were essentially featureless, the root mean square (rms) roughness was approximately 1 nm. The roughness increased to approximately 17 nm for the iodine implanted sample after annealing with the surface roughness below this value for all the other samples. AFM also showed that the largest crystals grew to heights of about 17, 20, 45, 50 and 65 nm for Sr, Cs, Ag, Xe and I implanted samples after annealing at 1200 °C for 5 h respectively. SEM images and AFM analysis suggest that iodine is more effective in promoting crystal growth during the annealing of bombardment-induced amorphous SiC layers than the rest of the ions we implanted. In samples of silicon carbide co-implanted with iodine and silver, few

  18. Fundamental plasma emission involving ion sound waves

    NASA Technical Reports Server (NTRS)

    Cairns, Iver H.

    1987-01-01

    The theory for fundamental plasma emission by the three-wave processes L + or - S to T (where L, S and T denote Langmuir, ion sound and transverse waves, respectively) is developed. Kinematic constraints on the characteristics and growth lengths of waves participating in the wave processes are identified. In addition the rates, path-integrated wave temperatures, and limits on the brightness temperature of the radiation are derived.

  19. Effects of fluoride-ion-implanted titanium surface on the cytocompatibility in vitro and osseointegatation in vivo for dental implant applications.

    PubMed

    Wang, Xue-jin; Liu, Hui-ying; Ren, Xiang; Sun, Hui-yan; Zhu, Li-ying; Ying, Xiao-xia; Hu, Shu-hai; Qiu, Ze-wen; Wang, Lang-ping; Wang, Xiao-feng; Ma, Guo-wu

    2015-12-01

    As an attractive technique for the improvement of biomaterials, Plasma immersion ion implantation (PIII) has been applied to modifying the titanium material for dental implant application. The present study investigated the cytocompatibility and early osseointegration of fluoride-ion-implanted titanium (F-Ti) surface and implants, both characterizing in their composition of titanium oxide and titanium fluoride. The cytocompatibility of F-Ti was evaluated in vitro by using scanning electron microscope, Cell Counting Kit-8 assay, alkaline phosphatase activity assay, and quantitative real-time polymerase chain reaction. The results showed that the F-Ti weakened the effects that Porphyromonas gingivalis exerted on the MG-63 cells in terms of morphology, proliferation, differentiation, and genetic expression when MG-63 cells and Porphyromonas gingivalis were co-cultured on the surface of F-Ti. Meanwhile, the osteogenic activity of F-Ti implants was assessed in vivo via evaluating the histological morphology and estimating histomorphometric parameters. The analysis of toluidine blue staining indicated that the new bone was more mature in subjects with F-Ti group, which exhibited the Haversian system, and the mean bone-implant contact value of F-Ti group was slightly higher than that of cp-Ti group (p>0.05). Fluorescence bands were wider and brighter in the F-Ti group, and the intensity of fluorochromes deposited at the sites of mineralized bone formation was significantly higher for F-Ti surfaces than for cp-Ti surfaces, within the 2nd, 3rd and 4th weeks (p<0.05). An indication is that the fluoride modified titanium can promote cytocompatibility and early osseointegration, thus providing a promising alternative for clinical use.

  20. Influence of irradiation spectrum and implanted ions on the amorphization of ceramics

    SciTech Connect

    Zinkle, S.J.; Snead, L.L.

    1996-04-01

    Amorphization cannot be tolerated in ceramics proposed for fusion energy applications due to the accompanying large volume change ({approx} 15% in SiC) and loss of strength. Ion beam irradiations at temperatures between 200 K and 450 K were used to examine the likelihood of amorphization in ceramics being considered for the structure (SiC) and numerous diagnostic and plasma heating systems (MgAl{sub 2}O{sub 4}, Al{sub 2}O{sub 3}, MgO, Si{sub 3}N{sub 4}) in fusion energy systems. The microstructures were examined following irradiation using cross-section transmission electron microscopy. The materials in this study included ceramics with predominantly covalent bonding (SiC, Si{sub 3}N{sub 4}) and predominantely ionic bonding (MgAl{sub 2}O{sub 4}, Al{sub 2}O{sub 3}, MgO). The samples were irradiated with a variety of ion beams (including some simultaneous dual ion beam irradiations) in order to investigate possible irradiation spectrum effects. The ion energies were >0.5 MeV in all cases, so that the displacement damage effects could be examined in regions well separated from the implanted ion region.

  1. Negative ion extraction from hydrogen plasma bulk

    SciTech Connect

    Oudini, N.; Taccogna, F.; Minelli, P.

    2013-10-15

    A two-dimensional particle-in-cell/Monte Carlo collision model has been developed and used to study low electronegative magnetized hydrogen plasma. A configuration characterized by four electrodes is used: the left electrode is biased at V{sub l} = −100 V, the right electrode is grounded, while the upper and lower transversal electrodes are biased at an intermediate voltage V{sub ud} between 0 and −100 V. A constant and homogeneous magnetic field is applied parallel to the lateral (left/right) electrodes. It is shown that in the magnetized case, the bulk plasma potential is close to the transversal electrodes bias inducing then a reversed sheath in front of the right electrode. The potential drop within the reversed sheath is controlled by the transversal electrodes bias allowing extraction of negative ions with a significant reduction of co-extracted electron current. Furthermore, introducing plasma electrodes, between the transversal electrodes and the right electrode, biased with a voltage just above the plasma bulk potential, increases the negative ion extracted current and decreases significantly the co-extracted electron current. The physical mechanism on basis of this phenomenon has been discussed.

  2. Thermal Behaviour of W+C Ion Implanted Ultra High Molecular Weight Polyethylene (UHMWPE)

    SciTech Connect

    Urkac, E. Sokullu; Oztarhan, A.; Tihminlioglu, F.; Ila, D.; Chhay, B.; Muntele, C.; Budak, S.; Oks, E.; Nikolaev, A.

    2009-03-10

    The aim of this work was to examine thermal behavior of the surface modified Ultra High Molecular Weight Poly Ethylene (UHMWPE ) in order to understand the effect of ion implantation on the properties of this polymer which is widely used especially for biomedical applications. UHMWPE samples were Tungsten and Carbon (W+C) hybrid ion implanted by using Metal Vapour Vacuum Arc (MEVVA) ion implantation technique with a fluence of 10 17 ions/cm2 and extraction voltage of 30 kV. Untreated and surface-treated samples were investigated by Rutherford Back Scattering (RBS) Analysis, Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) Spectrometry, Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). This study has shown that ion implantation represents a powerful tool on modifying thermal properties of UHMWPE surfaces. This combination of properties can make implanted UHMWPE a preferred material for biomedical applications.

  3. Surface stiffening and enhanced photoluminescence of ion implanted cellulose - polyvinyl alcohol - silica composite.

    PubMed

    Shanthini, G M; Sakthivel, N; Menon, Ranjini; Nabhiraj, P Y; Gómez-Tejedor, J A; Meseguer-Dueñas, J M; Gómez Ribelles, J L; Krishna, J B M; Kalkura, S Narayana

    2016-11-20

    Novel Cellulose (Cel) reinforced polyvinyl alcohol (PVA)-Silica (Si) composite which has good stability and in vitro degradation was prepared by lyophilization technique and implanted using N(3+) ions of energy 24keV in the fluences of 1×10(15), 5×10(15) and 1×10(16)ions/cm(2). SEM analysis revealed the formation of microstructures, and improved the surface roughness on ion implantation. In addition to these structural changes, the implantation significantly modified the luminescent, thermal and mechanical properties of the samples. The elastic modulus of the implanted samples has increased by about 50 times compared to the pristine which confirms that the stiffness of the sample surface has increased remarkably on ion implantation. The photoluminescence of the native cellulose has improved greatly due to defect site, dangling bonds and hydrogen passivation. Electric conductivity of the ion implanted samples was improved by about 25%. Hence, low energy ion implantation tunes the mechanical property, surface roughness and further induces the formation of nano structures. MG63 cells seeded onto the scaffolds reveals that with the increase in implantation fluence, the cell attachment, viability and proliferation have improved greatly compared to pristine. The enhancement of cell growth of about 59% was observed in the implanted samples compared to pristine. These properties will enable the scaffolds to be ideal for bone tissue engineering and imaging applications. PMID:27561534

  4. Surface stiffening and enhanced photoluminescence of ion implanted cellulose - polyvinyl alcohol - silica composite.

    PubMed

    Shanthini, G M; Sakthivel, N; Menon, Ranjini; Nabhiraj, P Y; Gómez-Tejedor, J A; Meseguer-Dueñas, J M; Gómez Ribelles, J L; Krishna, J B M; Kalkura, S Narayana

    2016-11-20

    Novel Cellulose (Cel) reinforced polyvinyl alcohol (PVA)-Silica (Si) composite which has good stability and in vitro degradation was prepared by lyophilization technique and implanted using N(3+) ions of energy 24keV in the fluences of 1×10(15), 5×10(15) and 1×10(16)ions/cm(2). SEM analysis revealed the formation of microstructures, and improved the surface roughness on ion implantation. In addition to these structural changes, the implantation significantly modified the luminescent, thermal and mechanical properties of the samples. The elastic modulus of the implanted samples has increased by about 50 times compared to the pristine which confirms that the stiffness of the sample surface has increased remarkably on ion implantation. The photoluminescence of the native cellulose has improved greatly due to defect site, dangling bonds and hydrogen passivation. Electric conductivity of the ion implanted samples was improved by about 25%. Hence, low energy ion implantation tunes the mechanical property, surface roughness and further induces the formation of nano structures. MG63 cells seeded onto the scaffolds reveals that with the increase in implantation fluence, the cell attachment, viability and proliferation have improved greatly compared to pristine. The enhancement of cell growth of about 59% was observed in the implanted samples compared to pristine. These properties will enable the scaffolds to be ideal for bone tissue engineering and imaging applications.

  5. Gas-induced swelling of beryllium implanted with deuterium ions

    NASA Astrophysics Data System (ADS)

    Chernikov, V. N.; Alimov, V. Kh.; Markin, A. V.; Gorodetsky, A. E.; Kanashenko, S. L.; Zakharov, A. P.; Kupriyanov, I. B.

    1996-10-01

    An extensive TEM study of the microstructure of Be TIP-30 irradiated with 3 and 10 keV D ions up to fluences, Φ, in the range from 3 × 10 20 to 8 × 10 21 D/m 2 at temperatures, Tirr = 300, 500 and 700 K has been carried out. Depth distributions of deuterium in a form of separate D atoms and D 2 molecules have been investigated by means of SIMS (secondary ion mass spectrometry) and RGA (residual gas analysis) methods, correspondingly. D ion implantation is accompanied by blistering and gives rise to processes of gas-induced cavitation which are very sensitive to the irradiation temperature. At Tirr = 300 K tiny gas bubbles (about 1 nm in size) pressurized with molecular deuterium are developed with parameters resembling those of helium bubbles in Be. Irradiation at Tirr ≥ 500 K leads to the appearance of coarse deuterium-filled cavities which can form in sub-surface layers different kinds of oblate labyrinth structures. Questions of reemission, thermal desorption and trapping of deuterium in Be have been discussed.

  6. Negative ion source with hollow cathode discharge plasma

    DOEpatents

    Hershcovitch, Ady; Prelec, Krsto

    1983-01-01

    A negative ion source of the type where negative ions are formed by bombarding a low-work-function surface with positive ions and neutral particles from a plasma, wherein a highly ionized plasma is injected into an anode space containing the low-work-function surface. The plasma is formed by hollow cathode discharge and injected into the anode space along the magnetic field lines. Preferably, the negative ion source is of the magnetron type.

  7. Negative ion source with hollow cathode discharge plasma

    DOEpatents

    Hershcovitch, A.; Prelec, K.

    1980-12-12

    A negative ion source of the type where negative ions are formed by bombarding a low-work-function surface with positive ions and neutral particles from a plasma, wherein a highly ionized plasma is injected into an anode space containing the low-work-function surface is described. The plasma is formed by hollow cathode discharge and injected into the anode space along the magnetic field lines. Preferably, the negative ion source is of the magnetron type.

  8. Target dependent femtosecond laser plasma implantation dynamics in enabling silica for high density erbium doping

    PubMed Central

    Chandrappan, Jayakrishnan; Murray, Matthew; Kakkar, Tarun; Petrik, Peter; Agocs, Emil; Zolnai, Zsolt; Steenson, D.P.; Jha, Animesh; Jose, Gin

    2015-01-01

    Chemical dissimilarity of tellurium oxide with silica glass increases phase separation and crystallization tendency when mixed and melted for making a glass. We report a novel technique for incorporating an Er3+-doped tellurite glass composition into silica substrates through a femtosecond (fs) laser generated plasma assisted process. The engineered material consequently exhibits the spectroscopic properties of Er3+-ions, which are unachievable in pure silica and implies this as an ideal material for integrated photonics platforms. Formation of a well-defined metastable and homogeneous glass structure with Er3+-ions in a silica network, modified with tellurite has been characterized using high-resolution cross-sectional transmission electron microscopy (HRTEM). The chemical and structural analyses using HRTEM, Rutherford backscattering spectrometry (RBS) and laser excitation techniques, confirm that such fs-laser plasma implanted glasses may be engineered for significantly higher concentration of Er3+-ions without clustering, validated by the record high lifetime-density product 0.96 × 1019 s.cm−3. Characterization of planar optical layers and photoluminescence emission spectra were undertaken to determine their thickness, refractive indices and photoluminescence properties, as a function of Er3+ concentration via different target glasses. The increased Er3+ content in the target glass enhance the refractive index and photoluminescence intensity of the modified silica layer whilst the lifetime and thickness decrease. PMID:26370060

  9. Ion implantation of erbium into polycrystalline cadmium telluride

    SciTech Connect

    Ushakov, V. V. Klevkov, Yu. V.; Dravin, V. A.

    2015-05-15

    The specific features of the ion implantation of polycrystalline cadmium telluride with grains 20–1000 μm in dimensions are studied. The choice of erbium is motivated by the possibility of using rare-earth elements as luminescent “probes” in studies of the defect and impurity composition of materials and modification of the composition by various technological treatments. From the microphotoluminescence data, it is found that, with decreasing crystal-grain dimensions, the degree of radiation stability of the material is increased. Microphotoluminescence topography of the samples shows the efficiency of the rare-earth probe in detecting regions with higher impurity and defect concentrations, including regions of intergrain boundaries.

  10. Intravascular brachytherapy with radioactive stents produced by ion implantation

    NASA Astrophysics Data System (ADS)

    Golombeck, M.-A.; Heise, S.; Schloesser, K.; Schuessler, B.; Schweickert, H.

    2003-05-01

    About 1 million patients are treated for stenosis of coronary arteries by percutaneous balloon angioplasty annually worldwide. In many cases a so called stent is inserted into the vessel to keep it mechanically open. Restenosis is observed in about 20-30% of these cases, which can be treated by irradiating the stented vessel segment. In our approach, we utilized the stent itself as radiation source by ion implanting 32P. Investigations of the surface properties were performed with special emphasis on activity retention. Clinical data of about 400 patients showed radioactive stents can suppress instent restenosis, but a so called edge effect appeared, which can be avoided by the new "drug eluting stents".

  11. Ion beam sputter modification of the surface morphology of biological implants

    NASA Technical Reports Server (NTRS)

    Weigand, A. J.; Banks, B. A.

    1976-01-01

    The surface chemistry and texture of materials used for biological implants may significantly influence their performance and biocompatibility. Recent interest in the microscopic control of implant surface texture has led to the evaluation of ion beam sputtering as a potentially useful surface roughening technique. Ion sources, similar to electron bombardment ion thrusters designed for propulsive applications, are used to roughen the surfaces of various biocompatible alloys or polymer materials. These materials are typically used for dental implants, orthopedic prostheses, vascular prostheses, and artificial heart components. Masking techniques and resulting surface textures are described along with progress concerning evaluation of the biological response to the ion beam sputtered surfaces.

  12. Ion-beam-sputter modification of the surface morphology of biological implants

    NASA Technical Reports Server (NTRS)

    Weigand, A. J.; Banks, B. A.

    1977-01-01

    The surface chemistry and texture of materials used for biological implants may significantly influence their performance and biocompatibility. Recent interest in the microscopic control of implant surface texture has led to the evaluation of ion-beam sputtering as a potentially useful surface roughening technique. Ion sources, similar to electron-bombardment ion thrusters designed for propulsive applications, are used to roughen the surfaces of various biocompatible alloys or polymer materials. These materials are typically used for dental implants, orthopedic prostheses, vascular prostheses, and artificial heart components. Masking techniques and resulting surface textures are described along with progress concerning evaluation of the biological response to the ion-beam-sputtered surfaces.

  13. Open questions in electronic sputtering of solids by slow highly charged ions with respect to applications in single ion implantation

    SciTech Connect

    Schenkel, T.; Rangelow, I.W.; Keller, R.; Park, S.J.; Nilsson, J.; Persaud, A.; Radmilivitc, V.R.; Liddle, J.A.; Grabiec, P.; Bokor, J.; Schneider, D.H.

    2003-07-16

    In this article we discuss open questions in electronic sputtering of solids by slow, highly charged ions in the context of their application in a single ion implantation scheme. High yields of secondary electrons emitted when highly charged dopant ions impinge on silicon wafers allow for formation of non-Poissonian implant structures such as single atom arrays. Control of high spatial resolution and implant alignment require the use of nanometer scale apertures. We discuss electronic sputtering issues on mask lifetimes, and damage to silicon wafers.

  14. A simple ion implanter for material modifications in agriculture and gemmology

    NASA Astrophysics Data System (ADS)

    Singkarat, S.; Wijaikhum, A.; Suwannakachorn, D.; Tippawan, U.; Intarasiri, S.; Bootkul, D.; Phanchaisri, B.; Techarung, J.; Rhodes, M. W.; Suwankosum, R.; Rattanarin, S.; Yu, L. D.

    2015-12-01

    In our efforts in developing ion beam technology for novel applications in biology and gemmology, an economic simple compact ion implanter especially for the purpose was constructed. The designing of the machine was aimed at providing our users with a simple, economic, user friendly, convenient and easily operateable ion implanter for ion implantation of biological living materials and gemstones for biotechnological applications and modification of gemstones, which would eventually contribute to the national agriculture, biomedicine and gem-industry developments. The machine was in a vertical setup so that the samples could be placed horizontally and even without fixing; in a non-mass-analyzing ion implanter style using mixed molecular and atomic nitrogen (N) ions so that material modifications could be more effective; equipped with a focusing/defocusing lens and an X-Y beam scanner so that a broad beam could be possible; and also equipped with a relatively small target chamber so that living biological samples could survive from the vacuum period during ion implantation. To save equipment materials and costs, most of the components of the machine were taken from decommissioned ion beam facilities. The maximum accelerating voltage of the accelerator was 100 kV, ideally necessary for crop mutation induction and gem modification by ion beams from our experience. N-ion implantation of local rice seeds and cut gemstones was carried out. Various phenotype changes of grown rice from the ion-implanted seeds and improvements in gemmological quality of the ion-bombarded gemstones were observed. The success in development of such a low-cost and simple-structured ion implanter provides developing countries with a model of utilizing our limited resources to develop novel accelerator-based technologies and applications.

  15. Modelling of Ion Cyclotron Wall Conditioning plasmas

    NASA Astrophysics Data System (ADS)

    Douai, D.; Wauters, T.; Lyssoivan, A.; Marchuk, O.; Wünderlich, D.; Brémond, S.; Lombard, G.; Mollard, P.; Pegourié, B.; Van Oost, G.

    2011-12-01

    Ion Cyclotron Wall Conditioning (ICWC) is envisioned in ITER to clean the wall from impurities, to control the wall isotopic ratio and the hydrogen recycling in the presence of the toroidal magnetic field. Various experiments and modelling are advancing to consolidate this technique. In this contribution the modeling of ICWC is presented, which can be divided in two parts: plasma description and plasma wall interaction. Firstly a 0D plasma model, based on a set of energy and particle balance equations for Maxwellian Hydrogen and Helium species, is presented. The model takes into account elementary collision processes, coupled RF power, particle confinement, wall recycling, and active gas injection and pumping. The RF plasma production process is based mainly on electron collisional ionization. The dependency of the plasma parameters, the Hydrogen and Helium partial pressures and neutral or ionic fluxes on pressure and RF power are quantitatively in good agreement with those obtained experimentally on TORE SUPRA. Secondly an extension of the 0D model including the description of the wall interaction is presented and compared to TORE SUPRA multi-pulse ICWC discharges.

  16. High Curie temperature drive layer materials for ion-implanted magnetic bubble devices

    NASA Technical Reports Server (NTRS)

    Fratello, V. J.; Wolfe, R.; Blank, S. L.; Nelson, T. J.

    1984-01-01

    Ion implantation of bubble garnets can lower the Curie temperature by 70 C or more, thus limiting high temperature operation of devices with ion-implanted propagation patterns. Therefore, double-layer materials were made with a conventional 2-micron bubble storage layer capped by an ion-implantable drive layer of high Curie temperature, high magnetostriction material. Contiguous disk test patterns were implanted with varying doses of a typical triple implant. Quality of propagation was judged by quasistatic tests on 8-micron period major and minor loops. Variations of magnetization, uniaxial anisotropy, implant dose, and magnetostriction were investigated to ensure optimum flux matching, good charged wall coupling, and wide operating margins. The most successful drive layer compositions were in the systems (SmDyLuCa)3(FeSi)5O12 and (BiGdTmCa)3(FeSi)5O12 and had Curie temperatures 25-44 C higher than the storage layers.

  17. Swelling or erosion on the surface of patterned GaN damaged by heavy ion implantation

    SciTech Connect

    Gao, Yuan; Lan, Chune; Xue, Jianming; Yan, Sha; Wang, Yugang; Xu, Fujun; Shen, Bo; Zhang, Yanwen

    2010-06-08

    Wurtzite undoped GaN epilayers (0 0 0 1) was implanted with 500 keV Au+ ions at room temperature under different doses, respectively. Ion implantation was performed through photoresist masks on GaN to produce alternating strips. The experimental results showed that the step height of swelling and decomposition in implanted GaN depended on ion dose and annealing temperature, i.e., damage level and its evolution. This damage evolution is contributed to implantation-induced defect production, and defect migration/accumulation occurred at different levels of displacement per atom. The results suggest that the swelling is due to the formation of porous structures in the amorphous region of implanted GaN. The decomposition of implanted area can be attributed to the disorder saturation and the diffusion of surface amorphous layer.

  18. Plasma-sprayed coating of hydroxyapatite on metal implants--a review.

    PubMed

    Talib, R J; Toff, M R M

    2004-05-01

    Metal implants such as titanium, stainless steel and Co-Cr-Mo are used for load bearing purposes such as hip joint prostheses, fixing plates and dental root implants. For practical application, plasma-sprayed coatings of hydroxyapatite (HA) on metal implants are applied to promote early formation of strong bonds between metal implant and living bone. Plasma spray coating involves heating of HA material to a semi-molten or molten state and then propels its to a metal substrate. The plasma flame temperature is in the range of 6,000 degrees C to 16,000 degrees C but the surface temperature of the substrate rarely exceeds 150 degrees C. The HA materials are feed into the spray gun in the form of powders. Furthermore, this paper will discuss the processes of plasma-sprayed coating of HA on various types of metal implants.

  19. N and Cr ion implantation of natural ruby surfaces and their characterization

    NASA Astrophysics Data System (ADS)

    Rao, K. Sudheendra; Sahoo, Rakesh K.; Dash, Tapan; Magudapathy, P.; Panigrahi, B. K.; Nayak, B. B.; Mishra, B. K.

    2016-04-01

    Energetic ions of N and Cr were used to implant the surfaces of natural rubies (low aesthetic quality). Surface colours of the specimens were found to change after ion implantation. The samples without and with ion implantation were characterized by diffuse reflectance spectra in ultra violet and visible region (DRS-UV-Vis), field emission scanning electron microscopy (FESEM), selected area electron diffraction (SAED) and nano-indentation. While the Cr-ion implantation produced deep red surface colour (pigeon eye red) in polished raw sample (without heat treatment), the N-ion implantation produced a mixed tone of dark blue, greenish blue and violet surface colour in the heat treated sample. In the case of heat treated sample at 3 × 1017 N-ions/cm2 fluence, formation of colour centres (F+, F2, F2+ and F22+) by ion implantation process is attributed to explain the development of the modified surface colours. Certain degree of surface amorphization was observed to be associated with the above N-ion implantation.

  20. Influence of plasma immersion titanium implantation on hydrogenation and mechanical properties of Zr-2.5Nb

    NASA Astrophysics Data System (ADS)

    Kashkarov, E. B.; Nikitenkov, N. N.; Syrtanov, M. S.; Sutygina, A. N.; Shulepov, I. A.; Lider, A. M.

    2016-05-01

    This paper describes the effect of plasma immersion ion implantation (PIII) of titanium on hydrogenation behavior and mechanical properties of Zr-2.5Nb alloy. Surface morphology and depth distribution of elements in the surface layer of the samples were analyzed by scanning electron (SEM) and atomic force microscopy (AFM), and glow-discharge optical emission spectroscopy (GDOES). Hydrogenation was performed at 673 K temperature and 2 atm pressure. It was found that after titanium implantation a diffusion barrier is formed, accumulating hydrogen and preventing hydrogen penetration in the sample volume. The microdroplet content significantly influences the hydrogenation behavior of the zirconium alloy. Hydrogen sorption rate decreased 18.3 times and 4.3 times using filtered and unfiltered PIII, respectively. The mechanical properties of titanium-implanted zirconium layer were improved. The degradation of the mechanical properties after hydrogenation was revealed.

  1. Study on the Growth and the Photosynthetic Characteristics of Low Energy C+ Ion Implantation on Peanut

    PubMed Central

    Han, Yuguo; Xu, Lei; Yang, Peiling; Ren, Shumei

    2013-01-01

    Employing the Nonghua 5 peanut as experimental material, the effects of low energy C+ ion implantation on caulis height, root length, dry weight, photosynthetic characteristics and leaf water use efficiency (WUE) of Peanut Ml Generation were studied. Four fluences were observed in the experiment. The results showed that ion implantation harmed the peanut seeds because caulis height, root length and dry weight all were lower in the treatments than in CK, and the harm was aggravated with the increase of ion fluence. Both Pn and Tr show a saddle-shape curve due to midday depression of photosynthesis. Low fluence of low energy C+ ion implantation could increase the diurnal average Pn of peanut. The diurnal variation of Tr did not change as significantly as Pn. The light saturation point (LSP) was restrained by the ions. After low energy C+ ion implantation, WUE was enhanced. When the fluence increased to a certain level, the WUE began to decrease. PMID:23861939

  2. Surface hardness changes induced by O-, Ca- or P-ion implantation into titanium.

    PubMed

    Ikeyama; Nakao; Morikawa; Yokogawa; Wielunski; Clissold; Bell

    2000-12-30

    Titanium or titanium alloys are very attractive biomedical materials. Biocompatible elements of oxygen, calcium and phosphorus were implanted into titanium and changes of surface hardness were measured using an ultra micro indenter (UMIS-2000). A multiple load-partial unload procedure that can reveal a hardness versus depth profile was adopted. Depth profiles of concentration of implanted ions were obtained by SIMS measurement. For O and P implantation, it is observed that the hardness increases with the increases in the dose. O implantation produced the largest increase in hardness, up to 2.2 times higher than the unimplanted titanium. On the other hand, Ca implantation produced only a small increase in the hardness that was independent of the ion dose. The surface oxide layer of a Ca implanted titanium sample was much thicker than the unimplanted samples or those implanted with O and P ions. The depth of maximum hardness increases with increasing energy of implanted ions. The depths of the maximum hardness occur at indentation depths of one-third to one-eighth of the mean ranges of implanted ions.

  3. Estimation of Protein Absorption on Polymer Material by Carbon-Negative Ion Implantation

    NASA Astrophysics Data System (ADS)

    Yamada, Tetsuya; Tsuji, Hiroshi; Hattori, Mitsutaka; Sommani, Piyanuch; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo

    Selective cell attachment on carbon-negative-ion implanted region of polystyrene was already reported by the authors. However, the selectivity and adhesion strength in the cell pattering were partially insufficient. The adhesive proteins called extracellular matrix (ECM), in general, intervene between cell and substrate surface in the cell attachment on the solid surface. Therefore, we considered to obtain clearer selective cell attachment with tighter binding strength on the implanted region of polystyrene when these adhesive proteins precedently adsorbed on the implanted region of polystyrene. In this paper, we have investigated adsorption properties of three kinds of adhesive proteins (gelatin, fibronectin, laminin) and cell attachment properties on precedent protein adsorbed surface of polystyrene modified by carbon negative-ion implantation. Carbon negative ions were implanted into polystyrene at energy of 10 keV with dose in a range of 1×1014~1×1016 ions/cm2. After implantation, the samples were dipped in the protein solutions for 2 hours. Then, the protein adsorption ratio between implanted and unimplanted regions was evaluated by detecting amount of nitrogen atoms on the surface by X-ray photoelectron spectroscopy (XPS). As a result, the protein-precedently-absorbed sample implanted at dose more than 3×1015 ions/cm2 showed the large gelatin adsorption ratio of more than 2, where the much densely populated cell-attachment was observed more than that on the implanted region of polystyrene without precedent adsorption of protein after cell culture.

  4. Three-layer photocarrier radiometry model of ion-implanted silicon wafers

    NASA Astrophysics Data System (ADS)

    Li, Bincheng; Shaughnessy, Derrick; Mandelis, Andreas; Batista, Jerias; Garcia, Jose

    2004-06-01

    A three-dimensional three-layer model is presented for the quantitative understanding of the infrared photocarrier radiometry (PCR) response of ion-implanted semiconductors, specifically Si. In addition to the implanted layer and intact substrate normally assumed in all existing two-layer theoretical models to describe the photothermal response of ion-implanted semiconductors, a surface layer is considered in this three-layer model to represent a thin, less severally damaged region close to the surface. The effects on the PCR signal of several structural, transport, and optical properties of ion-implanted silicon wafers affected significantly by the ion implantation process (minority carrier lifetime, diffusion coefficient, optical absorption coefficient, thickness of the implanted layer, and front surface recombination velocity) are discussed. The dependence of the PCR signal on the ion implantation dose is theoretically calculated and compared to experimental results. Good agreement between experimental data and theoretical calculations is obtained. Both theoretical and experimental results show the PCR dependence on dose can be separated into four regions with the transition across each region defined by the implantation-induced electrical and optical degrees of damage, respectively, as the electrical and optical damage occurs at different dose ranges. It is also shown that the PCR amplitude decreases monotonically with increasing implantation dose. This monotonic dependence provides the potential of the PCR technique for industrial applications in semiconductor metrology.

  5. Ion-implanted PLZT ceramics: a new high-sensitivity image storage medium

    SciTech Connect

    Peercy, P.S.; Land, C.E.

    1980-01-01

    Results were presented of our studies of photoferroelectric (PFE) image storage in H- and He-ion implanted PLZT (lead lanthanum zirconate titanate) ceramics which demonstrate that the photosensitivity of PLZT can be significantly increased by ion implantation in the ceramic surface to be exposed to image light. More recently, implantations of Ar and Ar + Ne into the PLZT surface have produced much greater photosensitivity enhancement. For example, the photosensitivity after implantation with 1.5 x 10/sup 14/ 350 keV Ar/cm/sup 2/ + 1 x 10/sup 15/ 500 keV Ne/cm/sup 2/ is increased by about four orders of magnitude over that of unimplanted PLZT. Measurements indicate that the photosensitivity enhancement in ion-implanted PLZT is controlled by implantation-produced disorder which results in marked decreases in dielectric constant and dark conductivity and changes in photoconductivity of the implanted layer. The effects of Ar- and Ar + Ne-implantation are presented along with a phenomenological model which describes the enhancement in photosensitivity obtained by ion implantation. This model takes into account both light- and implantation-induced changes in conductivity and gives quantitative agreement with the measured changes in the coercive voltage V/sub c/ as a function of near-uv light intensity for both unimplanted and implanted PLZT. The model, used in conjunction with calculations of the profiles of implantation-produced disorder, has provided the information needed for co-implanting ions of different masses, e.g., Ar and Ne, to improve photosensitivity.

  6. Ion-plasma gun for ion-milling machine

    DOEpatents

    Kaminsky, Manfred S.; Campana, Jr., Thomas J.

    1976-01-01

    An ion gun includes an elongated electrode with a hollow end portion closed by a perforated end plate. The end plate is positioned parallel to a perforated flat electrode of opposite electrical polarity. An insulated sleeve encompasses the elongated electrode and extends outwardly from the perforated end towards the flat electrode. The sleeve length is separated into two portions of different materials. The first is formed of a high-temperature material that extends over the hollow portion of the elongated electrode where the arc is initiated by a point source electrode. The second sleeve portion extending over the remainder of the elongated electrode is of a resilient material for enhanced seal-forming ability and retention of plasma gas. Perforations are arranged in the flat electrode in a mutually opposing triangular pattern to project a plasma beam having a generally flat current profile towards a target requiring precision milling.

  7. Effect of phosphorus-ion implantation on the corrosion resistance and biocompatibility of titanium.

    PubMed

    Krupa, D; Baszkiewicz, J; Kozubowski, J A; Barcz, A; Sobczak, J W; Biliński, A; Lewandowska-Szumieł, M; Rajchel, B

    2002-08-01

    This work presents data on the structure and corrosion resistance of titanium after phosphorus-ion implantation with a dose of 10(17)P/cm2. The ion energy was 25keV. Transmission electron microscopy was used to investigate the microstructure of the implanted layer. The chemical composition of the surface layer was examined by X-ray photoelectron spectroscopy and secondary ion mass spectrometry. The corrosion resistance was examined by electrochemical methods in a simulated body fluid at a temperature of 37 C. Biocompatibility tests in vitro were performed in a culture of human derived bone cells in direct contact with the materials tested. Both, the viability of the cells determined by an XTT assay and activity of the cells evaluated by alkaline phosphatase activity measurements in contact with implanted and non-implanted titanium samples were detected. The morphology of the cells spread on the surface of the materials examined was also observed. The results confirmed the biocompatibility of both phosphorus-ion-implanted and non-implanted titanium under the conditions of the experiment. As shown by transmission electron microscope results, the surface layer formed during phosphorus-ion implantation was amorphous. The results of electrochemical examinations indicate that phosphorus-ion implantation increases the corrosion resistance after short-term as well as long-term exposures.

  8. A double-plasma source of continuous bipolar ion-ion beam

    SciTech Connect

    Dudin, S. V.; Rafalskyi, D. V.

    2013-01-21

    A double-plasma source capable of the generation of a continuous bipolar ion-ion beam is described. The quasi-neutral ion-ion flow to an extraction electrode is formed in the system containing primary inductively coupled plasma separated from a secondary plasma by an electrostatic grid-type filter. The total current of each ion species to the 250 mm diameter extraction electrode is about 80 mA; the electron current does not exceed 30% of the ion current. Method of positive/negative ion current ratio control is proposed, allowing the ion currents ratio variation in wide range.

  9. Swift and heavy ion implanted chalcogenide laser glass waveguides and their different refractive index distributions

    SciTech Connect

    Qiu Feng; Narusawa, Tadashi; Zheng Jie

    2011-02-10

    Planar waveguides have been fabricated in Nd- or Ho-doped gallium lanthanum sulfide laser glasses by 60 MeV Ar or 20 MeV N ion implantation. The refractive index profiles were reconstructed based on the results of prism coupling. The Ar implanted waveguides exhibit an approximate steplike distribution, while the N implanted ones show a ''well + barrier'' type. This difference can be attributed to the much lower dose of Ar ions. After annealing, the N implanted waveguides can support two modes at 1539 nm and have low propagation loss, which makes them candidates for novel waveguide lasers.

  10. MAGNESIUM PRECIPITATION AND DIFUSSION IN Mg+ ION IMPLANTED SILICON CARBIDE

    SciTech Connect

    Jiang, Weilin; Jung, Hee Joon; Kovarik, Libor; Wang, Zhaoying; Roosendaal, Timothy J.; Zhu, Zihua; Edwards, Danny J.; Hu, Shenyang Y.; Henager, Charles H.; Kurtz, Richard J.; Wang, Yongqiang

    2015-03-02

    As a candidate material for fusion reactor applications, silicon carbide (SiC) undergoes transmutation reactions under high-energy neutron irradiation with magnesium as the major metallic transmutant; the others include aluminum, beryllium and phosphorus in addition to helium and hydrogen gaseous species. Calculations by Sawan et al. predict that at a dose of ~100 dpa (displacements per atom), there is ~0.5 at.% Mg generated in SiC. The impact of these transmutants on SiC structural stability is currently unknown. This study uses ion implantation to introduce Mg into SiC. Multiaxial ion-channeling analysis of the as-produced damage state indicates a lower dechanneling yield observed along the <100> axis. The microstructure of the annealed sample was examined using high-resolution scanning transmission electron microscopy. The results show a high concentration of likely non-faulted tetrahedral voids and possible stacking fault tetrahedra near the damage peak. In addition to lattice distortion, dislocations and intrinsic and extrinsic stacking faults are also observed. Magnesium in 3C–SiC prefers to substitute for Si and it forms precipitates of cubic Mg2Si and tetragonal MgC2. The diffusion coefficient of Mg in 3C–SiC single crystal at 1573 K has been determined to be 3.8 ± 0.4E-19 m2/s.

  11. Effect of phosphorous ion implantation on the mechanical properties and bioactivity of hydroxyapatite.

    PubMed

    Kobayashi, Satoshi; Muramatsu, Takehiro; Teranishi, Yoshikazu

    2015-01-01

    Hydroxyapatite (HA) has ability of bone-like apatite formation, which consists with chemical interaction between the surface of HA and ions included in body fluid. Thus, proper surface modification might enhance the function. In the present study, the effect of phosphorous ion implantation on mechanical properties and bioactivity of HA was investigated. In order to clarify the effect of ion implantation dose, ion dose of 1 × 10(12), 1 × 10(13) and 1 × 10(14) ions/cm(2) were selected. Mechanical properties and bioactivity were evaluated in 4-point bending tests and immersion test in simulated body fluid. Bending strength was reduced due to ion implantation. The amount of decreasing strength was similar regardless of ion implantation dose. Bone-like apatite formation was slightly delayed with ion implantation, however, improvement in interfacial strength between bone-like apatite layer and the base HA was indicated. From the results, the possibility of phosphorous ion implantation for enhancement of bioactivity of HA was proved.

  12. Effective dopant activation via low temperature microwave annealing of ion implanted silicon

    NASA Astrophysics Data System (ADS)

    Zhao, Zhao; David Theodore, N.; Vemuri, Rajitha N. P.; Das, Sayantan; Lu, Wei; Lau, S. S.; Alford, T. L.

    2013-11-01

    Susceptor-assisted microwave annealing enables effective dopant activation, at low temperatures, in ion-implanted Si. Given similar thermal budgets for microwave annealing and rapid thermal annealing (RTA), sheet resistances of microwave annealed Si, with either B+ or P+ implants, are lower than the values obtained using RTA. The fraction of dopants activated is as high as 18% for B+ implants and 64% for P+ implants. Dopant diffusion is imperceptible after microwave annealing, but significant after RTA, for P+ implanted Si samples with the same dopant activation. Microwave annealing achieves such properties using shorter anneal times and lower peak temperatures compared to RTA.

  13. 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.

  14. Magnetic plasma confinement for laser ion source.

    PubMed

    Okamura, M; Adeyemi, A; Kanesue, T; Tamura, J; Kondo, K; Dabrowski, R

    2010-02-01

    A laser ion source (LIS) can easily provide a high current beam. However, it has been difficult to obtain a longer beam pulse while keeping a high current. On occasion, longer beam pulses are required by certain applications. For example, more than 10 micros of beam pulse is required for injecting highly charged beams to a large sized synchrotron. To extend beam pulse width, a solenoid field was applied at the drift space of the LIS at Brookhaven National Laboratory. The solenoid field suppressed the diverging angle of the expanding plasma and the beam pulse was widened. Also, it was observed that the plasma state was conserved after passing through a few hundred gauss of the 480 mm length solenoid field.

  15. Surface modification of poly(propylene carbonate) by oxygen ion implantation

    NASA Astrophysics Data System (ADS)

    Zhang, Jizhong; Kang, Jiachen; Hu, Ping; Meng, Qingli

    2007-04-01

    Poly(propylene carbonate) (PPC) was implanted by oxygen ion with energy of 40 keV. The influence of experimental parameters was investigated by varying ion fluence from 1 × 10 12 to 1 × 10 15 ions/cm 2. XPS, SEM, surface roughness, wettability, hardness, and modulus were employed to investigate structure and properties of the as-implanted PPC samples. Eight chemical groups, i.e., carbon, C sbnd H, C sbnd O sbnd C, C sbnd O, O sbnd C sbnd O, C dbnd O, ?, and ? groups were observed on surfaces of the as-implanted samples. The species and relative intensities of the chemical groups changed with increasing ion fluence. SEM images displayed that irradiation damage was related strongly with ion fluence. Both surface-recovering and shrunken behavior were observed on surface of the PPC sample implanted with fluence of 1 × 10 15 ions/cm 2. As increasing ion fluence, the surface roughness of the as-implanted PPC samples increased firstly, reached the maximum value of 159 nm, and finally decreased down the minimum value. The water droplet contact angle of the as-implanted PPC samples changed gradually with fluence, and reached the minimum value of 70° with fluence of 1 × 10 15 ions/cm 2. The hardness and modulus of the as-implanted PPC samples increased with increasing ion fluence, and reached their corresponding maximum values with fluence of 1 × 10 15 ions/cm 2. The experimental results revealed that oxygen ion fluence closely affected surface chemical group, morphology, surface roughness, wettability, and mechanical properties of the as-implanted PPC samples.

  16. Compressive and rarefactive ion acoustic solitons in a magnetized two-ion component plasma

    NASA Astrophysics Data System (ADS)

    Ur-Rehman, Hafeez; Mahmood, S.; Aman-ur-Rehman

    2014-10-01

    The formation of compressive (hump) and rarefactive (dip) ion acoustic solitons is studied in magnetized O+- H+- e and O+- H-- e plasmas. The hydrodynamics equations are described for cold heavy (oxygen) ions, warm light (hydrogen) ions and isothermal Boltzmann distributed electrons along with Poisson equations in the presence of a magnetic field. The reductive perturbation method is used to derive the nonlinear Zakharov-Kuznetsov (ZK) equation for an ion acoustic wave in magnetized two-ion component plasma. It is found that two modes of ion acoustic waves with fast and slow speeds can propagate in the linear limit in such a plasma. It is noticed that, in the case of positively charged light hydrogen ions O+- H+- e plasmas, the slow ion acoustic wave solitons formed both potential hump as well as dip structures, while fast ion acoustic wave solitons give only hump structures. However in the case of negatively charged light hydrogen ions O+- H-- e plasmas, the slow ion acoustic wave solitons formed potential hump structures while fast ion acoustic wave solitons produce dip structures. The variations in the amplitude and width of the nonlinear slow and fast ion acoustic wave structures with density, temperature of light ions and magnetic field intensity are obtained in magnetized two-ion component plasmas. The magnetic field has its effect only on the width of the nonlinear ion acoustic wave structures in two-ion component plasmas.

  17. Report on the workshop on Ion Implantation and Ion Beam Assisted Deposition

    NASA Astrophysics Data System (ADS)

    Dearnaley, G.

    1992-03-01

    This workshop was organized by the Corpus Christi Army Depot (CCAD), the major helicopter repair base within AVSCOM. Previous meetings had revealed a strong interest throughout DoD in ion beam technology as a means of extending the service life of military systems by reducing wear, corrosion, fatigue, etc. The workshop opened with an account by Dr. Bruce Sartwell of the successful application of ion implantation to bearings and gears at NRL, and the checkered history of the MANTECH Project at Spire Corporation. Dr. James Hirvonen (AMTL) continued with a summary of successful applications to reduce wear in biomedical components, and he also described the processes of ion beam-assisted deposition (IBAD) for a variety of protective coatings, including diamond-like carbon (DLC).

  18. Electrostatic ion-cyclotron waves in a two-ion component plasma

    NASA Technical Reports Server (NTRS)

    Suszcynsky, David M.; Merlino, Robert L.; D'Angelo, Nicola

    1988-01-01

    The excitation of electrostatic ion cyclotron (EIC) waves is studied in a single-ended Q machine in a two-ion component plasma (Ca+ and K+). Over a large range of relative concentrations of Cs+ and K+ ions, two modes are excited with frequencies greater than the respective cyclotron frequencies of the ions. The results are discussed in terms of a fluid theory of electrostatic ion cyclotron waves in a two-ion component plasma.

  19. Ion diffusion at interfaces in hot plasmas

    SciTech Connect

    Boercker, D.B.; Warren, K.; Haggin, G.

    1986-04-01

    There are many laboratory applications in which it is important to know how fast two hot, ionized materials mix across an initially sharp interface. The speed of this process is regulated by the interdiffusion coefficient for the species involved. In a previous work, a theoretical method for calculating the interdiffusion coefficient in a Binary Ionic Mixture (classical ions in a uniform, neutralizing background) was described and found to give excellent agreement with Molecular Dynamics estimates. The purpose of this report is to show how these results may be applied to a model of the plasma interface, including electric field effects, to give a good description of the mixing across it.

  20. Effect of dual ion implantation of calcium and phosphorus on the properties of titanium.

    PubMed

    Krupa, D; Baszkiewicz, J; Kozubowski, J A; Barcz, A; Sobczak, J W; Biliński, A; Lewandowska-Szumieł, M; Rajchel, B

    2005-06-01

    This study is concerned with the effect of dual implantation of calcium and phosphorus upon the structure, corrosion resistance and biocompatibility of titanium. The ions were implanted in sequence, first Ca and then P, both at a dose of 10(17) ions/cm2 at a beam energy of 25 keV. Transmission electron microscopy was used to investigate the microstructure of the implanted layer. The chemical composition of the implanted layer was examined by XPS and SIMS. The corrosion resistance was determined by electrochemical methods in a simulated body fluid (SBF) at a temperature of 37 degrees C. The biocompatibility tests were performed in vitro in a culture of human-derived bone cells (HDBC) in contact with the tested materials. The viability of the cells was determined by an XTT assay and their activity by the measurements of the alkaline phosphatase activity in contact with implanted and non-implanted titanium samples. The in vitro examinations confirmed that, under the conditions prevailing during the experiments, the biocompatibility of Ca + P ion-implanted titanium was satisfactory. TEM results show that the surface layer formed by the Ca + P implantation is amorphous. The corrosion resistance of titanium, examined by the electrochemical methods, appeared to be increased after the Ca + P ion implantation.

  1. Ion implantation modified stainless steel as a substrate for hydroxyapatite deposition. Part II. Biomimetic layer growth and characterization.

    PubMed

    Pramatarova, L; Pecheva, E; Krastev, V

    2007-03-01

    The interest in stainless steel as a material widely used in medicine and dentistry has stimulated extensive studies on improving its bone-bonding properties. AISI 316 stainless steel is modified by a sequential ion implantation of Ca and P ions (the basic ions of hydroxyapatite), and by Ca and P implantation and subsequent thermal treatment in air (600( composite function)C, 1 h). This paper investigates the ability of the as-modified surfaces to induce hydroxyapatite deposition by using a biomimetic approach, i.e. immersion in a supersaturated aqueous solution resembling the human blood plasma (the so-called simulated body fluid). We describe our experimental procedure and results, and discuss the physico-chemical properties of the deposed hydroxyapatite on the modified stainless steel surfaces. It is shown that the implantation of a selected combination of ions followed by the applied methodology of the sample soaking in the simulated body fluid yield the growth of hydroxyapatite layers with composition and structure resembling those of the bone apatite. The grown layers are found suitable for studying the process of mineral formation in nature (biomineralization).

  2. Long-range effect of ion implantation of Raex and Hardox steels

    NASA Astrophysics Data System (ADS)

    Budzyński, P.; Kamiński, M.; Droździel, A.; Wiertel, M.

    2016-09-01

    Ion implantation involves introduction of ionized atoms of any element (nitrogen) to metals thanks to the high kinetic energy that they acquired in the electric field. The distribution of nitrogen ions implanted at E = 65 keV energy and D = 1.1017 N+ /cm2 fluence in the steel sample and vacancies produced by them was calculated using the SRIM program. This result was confirmed by RBS measurements. The initial maximum range of the implanted nitrogen ions is ∼⃒0.17 μm. This value is relatively small compared to the influence of nitriding on the thickness surface layer of modified steel piston rings. Measurements of the friction coefficient during the pin-on-disc tribological test were performed under dry friction conditions. The friction coefficient of the implanted sample increased to values characteristic of an unimplanted sample after ca. 1500 measurement cycles. The depth of wear trace is ca. 2.4 μm. This implies that the thickness of the layer modified by the implantation process is ∼⃒2.4 μm and exceeds the initial range of the implanted ions by an order of magnitude. This effect, referred to as a long-range implantation effect, is caused by migration of vacancies and nitrogen atoms into the sample. This phenomenon makes ion implantation a legitimate process of modification of the surface layer in order to enhance the tribological properties of critical components of internal combustion engines such as steel piston rings.

  3. Optical characteristics of Cu-nanocluster layers assembled by ion implantation

    SciTech Connect

    Haglund, R.F. Jr.; Yang, L. . Dept. of Physics and Astronomy); Magruder, R.H. III; Wittig, J.E. . Dept. of Materials Science and Engineering); Zuhr, R.A. )

    1991-01-01

    We have generated cluster layers in solid insulating substrates by implanting Cu ions into fused silica, creating thin layers ({approximately} 150 nm) of nonoclusters over a diameter of order 2 cm. Transmission electron microscopy shows that the size and size distribution can be controlled by the parameters of the ion implantation. We report measurements of the optical properties and nonlinear index of the refraction on these unusual solid-phase cluster materials as a function of total implanted-ion dose. 7 refs., 8 figs.

  4. Influence of ion streaming instabilities on transport near plasma boundaries

    NASA Astrophysics Data System (ADS)

    Baalrud, Scott D.

    2016-04-01

    Plasma boundary layers are susceptible to electrostatic instabilities driven by ion flows in presheaths and, when present, these instabilities can influence transport. In plasmas with a single species of positive ion, ion-acoustic instabilities are expected under conditions of low pressure and large electron-to-ion temperature ratio ({{T}e}/{{T}i}\\gg 1 ). In plasmas with two species of positive ions, ion-ion two-stream instabilities can also be excited. The stability phase-space is characterized using the Penrose criterion and approximate linear dispersion relations. Predictions for how these instabilities affect ion and electron transport in presheaths, including rapid thermalization due to instability-enhanced collisions and an instability-enhanced ion-ion friction force, are briefly reviewed. Recent experimental tests of these predictions are discussed along with research needs required for further validation. The calculated stability boundaries provide a guide to determine the experimental conditions at which these effects can be expected.

  5. Microstructure of Co-doped TiO{sub 2}(110) rutile by ion implantation

    SciTech Connect

    Wang, C.M.; Shutthanandan, V.; Thevuthasan, S.; Droubay, T.; Chambers, S.A.

    2005-04-01

    Co-doped rutile TiO{sub 2} was synthesized by injecting Co ions into single crystal rutile TiO{sub 2} using high energy ion implantation. Microstructures of the implanted specimens were studied in detail using high-resolution transmission electron microscopy (HRTEM), energy dispersive x-ray spectroscopy, electron diffraction, and HRTEM image simulations. The spatial distribution and conglomeration behavior of the implanted Co ions, as well as the point defect distributions induced by ion implantation, show strong dependences on implantation conditions. Uniform distribution of Co ions in the rutile TiO{sub 2} lattice was obtained by implanting at 1075 K with a Co ion fluence of 1.25x10{sup 16} Co/cm{sup 2}. Implanting at 875 K leads to the formation of Co metal clusters. The precipitated Co metal clusters and surrounding TiO{sub 2} matrix exhibit the orientation relationships Co<110> parallel TiO{sub 2}[001] and Co{l_brace}111{r_brace} parallel TiO{sub 2}(110). A structural model representing the interface between Co metal clusters and TiO{sub 2} is developed based on HRTEM imaging and image simulations.

  6. Microstructure of Co-doped TiO₂ (110) Rutile by Ion Implantation

    SciTech Connect

    Wang, Chong M.; Shutthanandan, V.; Thevuthasan, Suntharampillai; Droubay, Timothy C.; Chambers, Scott A.

    2005-04-01

    Co-doped rutile TiO₂ was synthesized by injecting Co ions into single crystal rutile TiO₂ using high energy ion implantation. Microstructures of the implanted specimens were studied in detail using high-resolution transmission electron microscopy (HRTEM), energy dispersive x-ray spectroscopy (EDS), electron diffraction, and HRTEM image simulations. The spatial distribution and conglomeration behavior of the implanted Co ions, as well as the point defect distributions induced by ion implantation, show strong dependences on implantation conditions. Uniform distribution of Co ions in the rutile TiO₂ lattice was obtained by implanting at 1075 K with a Co ion fluence of 1.25x10¹⁶ Co/cm². Implanting at 875 K leads to the formation of Co metal clusters. The precipitated Co metal clusters and surrounding TiO₂ matrix exhibit the orientation relationships Co<110>//TiO₂[001] and Co{111}//TiO₂(110). A structural model representing the interface between Co metal clusters and TiO₂ is developed based on HRTEM imaging and image simulations.

  7. Blistering and cracking of LiTaO3 single crystal under helium ion implantation

    NASA Astrophysics Data System (ADS)

    Ma, Changdong; Lu, Fei; Ma, Yujie

    2015-03-01

    Blistering and cracking in LiTaO3 surface are investigated after 200-keV helium ion implantation and subsequent post-implantation annealing. Rutherford backscattering/channeling is used to examine the lattice damage caused by ion implantation. Blistering is observed through optical microscopy in a dynamic heating process. Atomic force microscopy and scanning electron microscopy measurements are used to detect the LiTaO3 surface morphology. Experimental results show that blistering and flaking are dependent on implantation fluence, beam current, and also annealing temperature. We speculate that the surface cracking of He+-implanted LiTaO3 results from the implantation-induced stress and compression.

  8. Origin of 'energetic' ions from laser-produced plasmas.

    NASA Technical Reports Server (NTRS)

    Ehler, W.; Linlor, W. I.

    1973-01-01

    A fast-ion current peak, measured with an ion collector placed in the path of an expanding laser-produced plasma, was identified as carbon, nitrogen, and oxygen contaminants which originated from a tungsten target surface.

  9. Ion acoustic shocks in magneto rotating Lorentzian plasmas

    SciTech Connect

    Hussain, S.; Akhtar, N.; Hasnain, H.

    2014-12-15

    Ion acoustic shock structures in magnetized homogeneous dissipative Lorentzian plasma under the effects of Coriolis force are investigated. The dissipation in the plasma system is introduced via dynamic viscosity of inertial ions. The electrons are following the kappa distribution function. Korteweg-de Vries Burger (KdVB) equation is derived by using reductive perturbation technique. It is shown that spectral index, magnetic field, kinematic viscosity of ions, rotational frequency, and effective frequency have significant impact on the propagation characteristic of ion acoustic shocks in such plasma system. The numerical solution of KdVB equation is also discussed and transition from oscillatory profile to monotonic shock for different plasma parameters is investigated.

  10. Shunting arc plasma source for pure carbon ion beam.

    PubMed

    Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse.

  11. Shunting arc plasma source for pure carbon ion beama)

    NASA Astrophysics Data System (ADS)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y.

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm2 at the peak of the pulse.

  12. Radiative transitions of excited ions moving slowly in plasmas

    SciTech Connect

    Hu, Hongwei Chen, Wencong; Li, Peng; Zhao, Yongtao; Zhou, Xianming; Li, Zhen; Li, Fuli; Dong, Chenzhong

    2014-12-15

    The electric dipole transitions of excited ions moving slowly in plasmas are studied. The results show that some transitions forbidden for excited ions at rest become allowed for moving excited ions. The transition rates change with varying speed of the ions. Forbidden transitions are strongly influenced by the speed, non-forbidden transitions are weakly influenced.

  13. Ion optical effects in a low pressure rf plasma

    SciTech Connect

    Oechsner, Hans; Paulus, Hubert

    2013-11-15

    Ion optical effects in low pressure gas discharges are introduced as a novel input into low pressure plasma technology. They are based on appropriate geometrical plasma confinements which enable a control of the shape of internal density and potential distributions and, hence, the ion motion in the plasma bulk. Such effects are exemplified for an electron cyclotron wave resonance plasma in Ar at 1–5 × 10{sup −3} millibars. The geometry of the plasma chamber is modified by a conical and a cylindrical insert. Computer simulations display spherical plasma density contours to be formed around the conical confinement. This effects an increase of the ratio of the ion currents into the conical and the cylindrical inserts which depends on the fourth power of the plasma electron temperature. A quantitative understanding of this behavior is presented. As another essential result, the shape of the internal plasma contours is found to be independent of the pressure controlled plasma parameters.

  14. Ion Implantation Angle Variation to Device Performance and the Control in Production

    SciTech Connect

    Zhao, Z.Y.; Hendrix, D.; Wu, L.Y.; Cusson, B.K.

    2003-08-26

    As the device features get smaller and aspect ratios of photoresist openings get steeper, shadowing effect has more impact on the performance of devices. Many of the traditional 7 deg. tilt implants have progressed to 0 deg. implants. But shadowing may still occur if the tilt angle deviates from normal direction. Some implants, such as halo implants, demand even more stringent angle control to reduce device performance variation. The demand for implant angle control and monitoring thus becomes more obvious and important. However, statistical process control (SPC) cannot be done on shadowing effect without special test structures. Channeling, on the other hand, provides good sensitivity in regard to implant angle changes. It is the authors' intention to introduce channeling implant in different channels to monitor the implant angle variation. The incoming <100> silicon wafers have a cut-angle spec of +/- 1.0 deg. This poses a difficulty if one wants to control the implant angle's accuracy within +/- 0.5 deg. Other measures have to be taken to ensure the consistency of test wafers and to have prompt diagnosis feedback when needed. This paper will discuss the effect of implant tilt angle on device parameters and how to control the angle variation in production. Correlations of implant tilt angle variation to ThermaWave, sheet resistance (Rs), Secondary Ion Mass Spectrometry (SIMS) and device parameters will be covered with certain implant conditions.

  15. Ion Implantation Angle Variation to Device Performance and the Control in Production

    NASA Astrophysics Data System (ADS)

    Zhao, Z. Y.; Hendrix, D.; Wu, L. Y.; Cusson, B. K.

    2003-08-01

    As the device features get smaller and aspect ratios of photoresist openings get steeper, shadowing effect has more impact on the performance of devices. Many of the traditional 7° tilt implants have progressed to 0° implants. But shadowing may still occur if the tilt angle deviates from normal direction. Some implants, such as halo implants, demand even more stringent angle control to reduce device performance variation. The demand for implant angle control and monitoring thus becomes more obvious and important. However, statistical process control (SPC) cannot be done on shadowing effect without special test structures. Channeling, on the other hand, provides good sensitivity in regard to implant angle changes. It is the authors' intention to introduce channeling implant in different channels to monitor the implant angle variation. The incoming <100> silicon wafers have a cut-angle spec of +/- 1.0°. This poses a difficulty if one wants to control the implant angle's accuracy within +/- 0.5°. Other measures have to be taken to ensure the consistency of test wafers and to have prompt diagnosis feedback when needed. This paper will discuss the effect of implant tilt angle on device parameters and how to control the angle variation in production. Correlations of implant tilt angle variation to ThermaWave™, sheet resistance (Rs), Secondary Ion Mass Spectrometry (SIMS) and device parameters will be covered with certain implant conditions.

  16. Rapid thermal annealing of Si 1- xGe x layers formed by germanium ion implantation

    NASA Astrophysics Data System (ADS)

    Xia, Z.; Saarilahti, J.; Ronkainen, H.; Eränen, S.; Suni, I.; Molarius, J.; Kuivalainen, P.; Ristolainen, E.; Tuomi, T.

    1994-05-01

    (100) Si samples, amorphized by implanting with 50, 70 and 100 keV 74Ge + ions at doses of the order of 1 × 10 16cm -2, have been recrystallized by rapid thermal annealing (RTA) with different temperature-time ( T- t) combinations. Monte Carlo calculations using TRIM-91 computer program were performed to estimate the depth of amorphized regions, implanted Ge distributions and recoil-implanted O depth profiles. The RBS channeling measurements show that fully epitaxial regrowth of implanted layers can be reached with proper rapid thermal processing. An empirical guide is presented for regrowing the implanted SiGe layers with RTA. The recoil-implanted oxygen in the implanted layers was measured by 16O(α,α) 16O RBS resonance channeling and SIMS.

  17. Investigation of Mn-implanted n-Si by low-energy ion beam deposition

    NASA Astrophysics Data System (ADS)

    Liu, Lifeng; Chen, Nuofu; Song, Shulin; Yin, Zhigang; Yang, Fei; Chai, Chunlin; Yang, Shaoyan; Liu, Zhikai

    2005-01-01

    Mn ions were implanted to n-type Si(0 0 1) single crystal by low-energy ion beam deposition technique with an energy of 1000 eV and a dose of 7.5×10 17 cm -2. The samples were held at room temperature and at 300 °C during implantation. Auger electron spectroscopy depth profiles of samples indicate that the Mn ions reach deeper in the sample implanted at 300 °C than in the sample implanted at room temperature. X-ray diffraction measurements show that the structure of the sample implanted at room temperature is amorphous while that of the sample implanted at 300 °C is crystallized. There are no new phases found except silicon both in the two samples. Atomic force microscopy images of samples indicate that the sample implanted at 300 °C has island-like humps that cover the sample surface while there is no such kind of characteristic in the sample implanted at room temperature. The magnetic properties of samples were investigated by alternating gradient magnetometer (AGM). The sample implanted at 300 °C shows ferromagnetic behavior at room temperature.

  18. Differential turbulent heating of different ions in electron cyclotron resonance ion source plasma

    SciTech Connect

    Elizarov, L.I.; Ivanov, A.A.; Serebrennikov, K.S.; Vostrikova, E.A.

    2006-03-15

    The article considers the collisionless ion sound turbulent heating of different ions in an electron cyclotron resonance ion source (ECRIS). The ion sound arises due to parametric instability of pumping wave propagating along the magnetic field with the frequency close to that of electron cyclotron. Within the framework of turbulent heating model the different ions temperatures are calculated in gas-mixing ECRIS plasma.

  19. Effect of calcium and phosphorus ion implantation on the corrosion resistance and biocompatibility of titanium.

    PubMed

    Krupa, D; Baszkiewicz, J; Kozubowski, J A; Lewandowska-Szumieł, M; Barcz, A; Sobczak, J W; Biliński, A; Rajchel, A

    2004-01-01

    This paper is concerned with the corrosion resistance and biocompatibility of titanium after surface modification by the ion implantation of calcium or phosphorus or calcium + phosphorus. Calcium and phosphorus ions were implanted in a dose of 10(17) ions/cm(2). The ion beam energy was 25 keV. The microstructure of the implanted layers was examined by TEM. The chemical composition of the surface layers was determined by XPS and SIMS. The corrosion resistance was examined by electrochemical methods in a simulated body fluid (SBF) at a temperature of 37 degrees C. The biocompatibility was evaluated in vitro. As shown by TEM results, the surface layers formed during calcium, phosphorus and calcium + phosphorus implantation were amorphous. The results of the electrochemical examinations (Stern's method) indicate that the calcium, phosphorus and calcium + phosphorus implantation into the surface of titanium increases its corrosion resistance in stationary conditions after short- and long-term exposures in SBF. Potentiodynamic tests show that the calcium-implanted samples undergo pitting corrosion during anodic polarisation. The breakdown potentials measured are high (2.5 to 3 V). The good biocompatibility of all the investigated materials was confirmed under the specific conditions of the applied examination, although, in the case of calcium implanted titanium it was not as good as that of non-implanted titanium.

  20. Laser-induced fluorescence and nonlinear optical properties of ion-implanted fused silica

    SciTech Connect

    Becker, K.; Yang, L.; Haglund, R.F. Jr. . Dept. of Physics and Astronomy); Magruder, R.H.; Weeks, R.A. . Dept. of Materials Science and Engineering); Zuhr, R.A. )

    1990-01-01

    We report absorption, fluorescence and nonlinear optical properties of fused silica implanted with Ti, Cu and Bi and doses of 1{center dot}10{sup 15} ions/cm{sup 2} to 6{center dot}10{sup 16} ions/cm{sup 2} when irradiated with 532 nm laser light. The fluorescence spectrum is a broad band around 640 nm shows little variation for all ion species. Absorption as function of implanted dose shows a threshold for Ti between 1{center dot}10{sup 16} ions/cm{sup 2} and 6{center dot}10{sup 16} ions/cm{sup 2}. The nonlinear optical index is large, n{sub 2} > 10{sup {minus}5} esu. All measured quantities show a strong dependence on the implanted ion dose. The source of the nonlinearity, whether electronic or thermal, remains to be more completely determined. 9 refs., 4 figs.

  1. Nondiffusive transport regimes for suprathermal ions in turbulent plasmas

    NASA Astrophysics Data System (ADS)

    Bovet, A.; Fasoli, A.; Ricci, P.; Furno, I.; Gustafson, K.

    2015-04-01

    The understanding of the transport of suprathermal ions in the presence of turbulence is important for fusion plasmas in the burning regime that will characterize reactors, and for space plasmas to understand the physics of particle acceleration. Here, three-dimensional measurements of a suprathermal ion beam in the toroidal plasma device TORPEX are presented. These measurements demonstrate, in a turbulent plasma, the existence of subdiffusive and superdiffusive transport of suprathermal ions, depending on their energy. This result stems from the unprecedented combination of uniquely resolved measurements and first-principles numerical simulations that reveal the mechanisms responsible for the nondiffusive transport. The transport regime is determined by the interaction of the suprathermal ion orbits with the turbulent plasma dynamics, and is strongly affected by the ratio of the suprathermal ion energy to the background plasma temperature.

  2. Phosphorous ion implantation in C{sub 60} for the photovoltaic applications

    SciTech Connect

    Narayanan, K. L.; Yamaguchi, M.

    2001-06-15

    Thin films of C{sub 60} deposited on p-type Si(100) wafer are implanted with low energy phosphorous ions for the photovoltaic applications. An attempt has been made on the device fabrication with phosphorous ion implanted C{sub 60} films grown on the p-type Si wafer. The photovoltaic properties of the solar cell structure are discussed with the dark and illuminated J{endash}V characteristics. The efficiency of the structure in the multiple energy phosphorous ion implanted C{sub 60} film/p-Si heterojunction is found to be 0.01% under air mass 1.5 conditions. The low efficiency is attributed to the ion implantation induced damage effects and subsequent larger series resistance values. {copyright} 2001 American Institute of Physics.

  3. Singular waves in a magnetized pair-ion plasma

    SciTech Connect

    Samanta, Sukanta; Misra, Amar P.

    2009-07-15

    The existence of singular waves along the boundary of a magnetized pair-ion plasma is proved for both plasma-metal and plasma-vacuum interfaces. Such waves are shown to propagate at the points of intersection of the complex-zone boundary and the surface wave dispersion curve in a weakly magnetized plasma. The results could be relevant for negative ion plasmas in the laboratory and space as well as for the modeling of a plasma sustained by a traveling surface wave.

  4. Immobilization of extracellular matrix on polymeric materials by carbon-negative-ion implantation

    NASA Astrophysics Data System (ADS)

    Tsuji, Hiroshi; Sommani, Piyanuch; Muto, Takashi; Utagawa, Yoshiyuki; Sakai, Shun; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo

    2005-08-01

    Effects of ion implantation into polystyrene (PS), silicone rubber (SR) and poly-L-lactic acid (PLA) have been investigated for immobilization of extracellular matrix. Carbon negative ions were implanted into PS and SR sheets at various energies between 5-30 keV and various doses between 1.0 × 1014-1.0 × 1016 ions/cm2. Contact angles of pure water on C-implanted surfaces of PS and SR were decreased as increase in ion energy and in dose due to formation of functional groups such as OH and C-O. Selective attachment of nerve cells was observed on C-implanted them at 10 keV and 3 × 1015 ions/cm2 after in vitro cell culture of nerve cells of PC-12 h. Neurite outgrowth also extended over the implanted area. After dipping in a serum medium and in a fibronectin solution for 2 h, the detection of N 1s electrons by X-ray induced photoelectron spectroscopic (XPS) revealed a significant distinction of protein adhesion on the implanted area. Thus, immobilization of proteins on surface is used for considering the selective cell-attachment. For PLA, the selective attachment of cells and protein depended on the implantation conditions.

  5. Ion acoustic shock wave in collisional equal mass plasma

    SciTech Connect

    Adak, Ashish; Ghosh, Samiran; Chakrabarti, Nikhil

    2015-10-15

    The effect of ion-ion collision on the dynamics of nonlinear ion acoustic wave in an unmagnetized pair-ion plasma has been investigated. The two-fluid model has been used to describe the dynamics of both positive and negative ions with equal masses. It is well known that in the dynamics of the weakly nonlinear wave, the viscosity mediates wave dissipation in presence of weak nonlinearity and dispersion. This dissipation is responsible for the shock structures in pair-ion plasma. Here, it has been shown that the ion-ion collision in presence of collective phenomena mediated by the plasma current is the source of dissipation that causes the Burgers' term which is responsible for the shock structures in equal mass pair-ion plasma. The dynamics of the weakly nonlinear wave is governed by the Korteweg-de Vries Burgers equation. The analytical and numerical investigations revealed that the ion acoustic wave exhibits both oscillatory and monotonic shock structures depending on the frequency of ion-ion collision parameter. The results have been discussed in the context of the fullerene pair-ion plasma experiments.

  6. Ion acoustic shock wave in collisional equal mass plasma

    NASA Astrophysics Data System (ADS)

    Adak, Ashish; Ghosh, Samiran; Chakrabarti, Nikhil

    2015-10-01

    The effect of ion-ion collision on the dynamics of nonlinear ion acoustic wave in an unmagnetized pair-ion plasma has been investigated. The two-fluid model has been used to describe the dynamics of both positive and negative ions with equal masses. It is well known that in the dynamics of the weakly nonlinear wave, the viscosity mediates wave dissipation in presence of weak nonlinearity and dispersion. This dissipation is responsible for the shock structures in pair-ion plasma. Here, it has been shown that the ion-ion collision in presence of collective phenomena mediated by the plasma current is the source of dissipation that causes the Burgers' term which is responsible for the shock structures in equal mass pair-ion plasma. The dynamics of the weakly nonlinear wave is governed by the Korteweg-de Vries Burgers equation. The analytical and numerical investigations revealed that the ion acoustic wave exhibits both oscillatory and monotonic shock structures depending on the frequency of ion-ion collision parameter. The results have been discussed in the context of the fullerene pair-ion plasma experiments.

  7. Measurement of the ion drag force in a collisionless plasma with strong ion-grain coupling

    SciTech Connect

    Nosenko, V.; Fisher, R.; Merlino, R.; Khrapak, S.; Morfill, G.; Avinash, K.

    2007-10-15

    The ion drag force acting on dust grains was measured experimentally in a low-pressure Ar plasma in the regime of strong ion-grain coupling. Argon ions were drifting in the axial ambipolar electric field naturally present in a hot-filament dc discharge plasma. Following the method of Hirt et al. [Phys. Plasmas 11, 5690 (2004)], hollow glass microspheres were dropped into the plasma and allowed to fall due to gravity. The ion drag force was derived from the particle trajectory deflection from the vertical direction. The result is in reasonable agreement with a theoretical model that takes strong ion-grain coupling into account.

  8. Deformation characteristics of the near-surface layers of zirconia ceramics implanted with aluminum ions

    NASA Astrophysics Data System (ADS)

    Ghyngazov, S. A.; Vasiliev, I. P.; Frangulyan, T. S.; Chernyavski, A. V.

    2015-10-01

    The effect of ion treatment on the phase composition and mechanical properties of the near-surface layers of zirconium ceramic composition 97 ZrO2-3Y2O3 (mol%) was studied. Irradiation of the samples was carried out by accelerated ions of aluminum with using vacuum-arc source Mevva 5-Ru. Ion beam had the following parameters: the energy of the accelerated ions E = 78 keV, the pulse current density Ji = 4mA / cm2, current pulse duration equal τ = 250 mcs, pulse repetition frequency f = 5 Hz. Exposure doses (fluence) were 1016 и 1017 ion/cm2. The depth distribution implanted ions was studied by SIMS method. It is shown that the maximum projected range of the implanted ions is equal to 250 nm. Near-surface layers were investigated by X-ray diffraction (XRD) at fixed glancing incidence angle. It is shown that implantation of aluminum ions into the ceramics does not lead to a change in the phase composition of the near-surface layer. The influence of implanted ions on mechanical properties of ceramic near-surface layers was studied by the method of dynamic nanoindentation using small loads on the indenter P=300 mN. It is shown that in ion- implanted ceramic layer the processes of material recovery in the deformed region in the unloading mode proceeds with higher efficiency as compared with the initial material state. The deformation characteristics of samples before and after ion treatment have been determined from interpretation of the resulting P-h curves within the loading and unloading sections by the technique proposed by Oliver and Pharr. It was found that implantation of aluminum ions in the near-surface layer of zirconia ceramics increases nanohardness and reduces the Young's modulus.

  9. Enhancement of surface properties of SAE 1020 by chromium plasma immersion recoil implantation

    NASA Astrophysics Data System (ADS)

    Ueda, M.; Mello, C. B.; Beloto, A. F.; Rossi, J. O.; Reuther, H.

    2007-04-01

    SAE 1020 steel is commonly used as concrete reinforcement and small machine parts, but despite its good mechanical properties, as ductility, hardness and wear resistance, it is susceptible to severe corrosion. It is well known that chromium content above 12% in Fe alloys increases their corrosion resistance. In order to obtain this improvement, we studied the introduction of chromium atoms into the matrix of SAE 1020 steel by recoil implantation process using a plasma immersion ion implantation (PIII) system. Potentiodynamic scans showed that the presence of Cr film leads to a gain in the corrosion potential, from -650 mV to -400 mV. After PIII treatment, the corrosion potential increased further to -340 mV, but the corrosion current density presented no significant change. Vickers microhardness tests showed surface hardness increase of up to about 27% for the treated samples. Auger electron spectroscopy showed that, for a 30 nm film, Cr was introduced for about 20 nm into the steel matrix. Tribology tests, of pin-on-disk type, showed that friction coefficient of treated samples was reduced by about 50% and a change in wear mechanism, from adhesive to abrasive mode, occurred.

  10. Direction-dependent RBS channelling studies in ion implanted LiNbO3

    NASA Astrophysics Data System (ADS)

    Wendler, E.; Becker, G.; Rensberg, J.; Schmidt, E.; Wolf, S.; Wesch, W.

    2016-07-01

    Damage formation in ion implanted LiNbO3 was studied by Rutherford backscattering spectrometry (RBS) along various directions of the LiNbO3 crystal. From the results obtained it can be unambiguously concluded that Nb atoms being displaced during ion implantation preferably occupy the free octahedron sites of the LiNbO3 lattice structure and most likely also form NbLi antisite defects.

  11. Optical absorption in ion-implanted lead lanthanum zirconate titanate ceramics

    NASA Astrophysics Data System (ADS)

    Seager, C. H.; Land, C. E.

    1984-08-01

    Optical absorption measurements have been performed on unmodified and on ion-implanted lead lanthanum zirconate titanate ceramics using the photothermal deflection spectroscopy technique. Bulk absorption coefficients depend on the average grain size of the material while the absorption associated with the ion-damaged layers does not. The damage-induced surface absorptance correlates well with the photosensitivity observed in implanted PLZT devices, supporting earlier models for the enhanced imaging efficiency of the materials.

  12. Neutron activation analysis for reference determination of the implantation dose of cobalt ions

    SciTech Connect

    Garten, R.P.H.; Bubert, H.; Palmetshofer, L.

    1992-05-15

    The authors prepared depth profilling reference materials by cobalt ion implantation at an ion energy of 300 keV into n-type silicon. The implanted Co dose was then determined by instrumental neutron activation analysis (INAA) giving an analytical dynamic range of almost 5 decades and uncertainty of 1.5%. This form of analysis allows sources of error (beam spreading, misalignment) to be corrected. 70 refs., 3 tabs.

  13. Properties of ion-particle interaction and the ion drag force in complex (dusty) plasmas

    SciTech Connect

    Khrapak, Sergey A.

    2009-11-10

    In this paper a concise overview of recent results concerning the properties of ion-particle interaction and the ion drag force in complex (dusty) plasmas is presented. Two main theoretical approaches to calculate the ion drag force--binary collision and linear plasma response formalisms are discussed. When possible, theoretical results are compared with the results from experiments and numerical simulations.

  14. Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

    NASA Astrophysics Data System (ADS)

    Reichel, Christian; Feldmann, Frank; Müller, Ralph; Reedy, Robert C.; Lee, Benjamin G.; Young, David L.; Stradins, Paul; Hermle, Martin; Glunz, Stefan W.

    2015-11-01

    Passivated contacts (poly-Si/SiOx/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF2), the ion implantation dose (5 × 1014 cm-2 to 1 × 1016 cm-2), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iVoc) of 725 and 720 mV, respectively. For p-type passivated contacts, BF2 implantations into intrinsic a-Si yield well passivated contacts and allow for iVoc of 690 mV, whereas implanted B gives poor passivation with iVoc of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved Voc of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF2 implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with Voc of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts.

  15. The effects of ion implantation on the fatigue behavior of metals

    SciTech Connect

    Wang, Jih-Jong.

    1989-01-01

    The effects of ion implanatation on the fatigue behavior of metals were investigated. High stacking fault energy FCC materials of aluminum and copper, low stacking fault energy FCC material of austenitic stainless steel and HCP material of titanium were ion implanted by boron or nitrogen at energies of 50 KeV to 3 MeV. The doses were from 10{sup 15} ions/cm{sup 2} to 10{sup 17} ions/cm{sup 2}. Flexural bending fatigue experiments were conducted on both the implanted and unimplanted specimens. After fatiguing the surface topography was examined by optical microscopy and SEM, and the microstructure of the surface layer was investigated by TEM. At relatively small amplitudes, close to the fatigue limit, the ion-implanted surface layer suppresses the formation of persistent slip bands (PSB's). At higher stress-amplitudes the implanted layer is penetrated by dislocation-channels which develop into the equivalent of PSB's. For constant fatigue testing parameters the density of PSB's decreased with increasing implant dose, but the intensity of slip in the few dislocation-channel PSB's was increased. Cracks nucleated at these slip bands and propagated along them. A composite model is presented to qualitatively analyze the effect of ion implantation on fatigue strength.

  16. Quasi-periodic behavior of ion acoustic solitary waves in electron-ion quantum plasma

    NASA Astrophysics Data System (ADS)

    Sahu, Biswajit; Poria, Swarup; Narayan Ghosh, Uday; Roychoudhury, Rajkumar

    2012-05-01

    The ion acoustic solitary waves are investigated in an unmagnetized electron-ion quantum plasmas. The one dimensional quantum hydrodynamic model is used to study small as well as arbitrary amplitude ion acoustic waves in quantum plasmas. It is shown that ion temperature plays a critical role in the dynamics of quantum electron ion plasma, especially for arbitrary amplitude nonlinear waves. In the small amplitude region Korteweg-de Vries equation describes the solitonic nature of the waves. However, for arbitrary amplitude waves, in the fully nonlinear regime, the system exhibits possible existence of quasi-periodic behavior for small values of ion temperature.

  17. Scanning-electron-microscopy observations and mechanical characteristics of ion-beam-sputtered surgical implant alloys

    NASA Technical Reports Server (NTRS)

    Weigand, A. J.; Meyer, M. L.; Ling, J. S.

    1977-01-01

    An electron bombardment ion thruster was used as an ion source to sputter the surfaces of orthopedic prosthetic metals. Scanning electron microscopy photomicrographs were made of each ion beam textured surface. The effect of ion texturing an implant surface on its bond to bone cement was investigated. A Co-Cr-W alloy and surgical stainless steel were used as representative hard tissue implant materials to determine effects of ion texturing on bulk mechanical properties. Work was done to determine the effect of substrate temperature on the development of an ion textured surface microstructure. Results indicate that the ultimate strength of the bulk materials is unchanged by ion texturing and that the microstructure will develop more rapidly if the substrate is heated prior to ion texturing.

  18. Effect of implanted species on thermal evolution of ion-induced defects in ZnO

    SciTech Connect

    Azarov, A. Yu.; Rauwel, P.; Kuznetsov, A. Yu.; Svensson, B. G.; Hallén, A.; Du, X. L.

    2014-02-21

    Implanted atoms can affect the evolution of ion-induced defects in radiation hard materials exhibiting a high dynamic annealing and these processes are poorly understood. Here, we study the thermal evolution of structural defects in wurtzite ZnO samples implanted at room temperature with a wide range of ion species (from {sup 11}B to {sup 209}Bi) to ion doses up to 2 × 10{sup 16} cm{sup −2}. The structural disorder was characterized by a combination of Rutherford backscattering spectrometry, nuclear reaction analysis, and transmission electron microscopy, while secondary ion mass spectrometry was used to monitor the behavior of both the implanted elements and residual impurities, such as Li. The results show that the damage formation and its thermal evolution strongly depend on the ion species. In particular, for F implanted samples, a strong out-diffusion of the implanted ions results in an efficient crystal recovery already at 600 °C, while co-implantation with B (via BF{sub 2}) ions suppresses both the F out-diffusion and the lattice recovery at such low temperatures. The damage produced by heavy ions (such as Cd, Au, and Bi) exhibits a two-stage annealing behavior where efficient removal of point defects and small defect clusters occurs at temperatures ∼500 °C, while the second stage is characterized by a gradual and partial annealing of extended defects. These defects can persist even after treatment at 900 °C. In contrast, the defects produced by light and medium mass ions (O, B, and Zn) exhibit a more gradual annealing with increasing temperature without distinct stages. In addition, effects of the implanted species may lead to a nontrivial defect evolution during the annealing, with N, Ag, and Er as prime examples. In general, the obtained results are interpreted in terms of formation of different dopant-defect complexes and their thermal stability.

  19. Plasma mediated collagen-I-coating of metal implant materials to improve biocompatibility.

    PubMed

    Hauser, Joerg; Koeller, Manfred; Bensch, Sebastian; Halfmann, Helmut; Awakowicz, Peter; Steinau, Hans-Ulrich; Esenwein, Stefan

    2010-07-01

    This study describes the collagen-I coating of titanium and steel implants via cold low-pressure gas plasma treatment. To analyze the coatings in terms of biocompatibility osteoblast-like osteosarcoma cells and human leukocytes were cultivated on the metal surfaces. Two different implant materials were assessed (Ti6Al4V, X2CrNiMo18) and four different surface properties were evaluated: (a) plasma pretreated and collagen-I coated implant materials; (b) collagen-I dip-coated without plasma pretreatment; (c) plasma treated but not collagen-I coated; (d) standard implant materials served as control. The different coating characteristics were analyzed by scanning electron microscopy (SEM). For adhesion and viability tests calcein-AM staining of the cells and Alamar blue assays were performed. The quantitative analysis was conducted by computer assisted microfluorophotography and spectrometer measurements. SEM analysis revealed that stable collagen-I coatings could not be achieved on the dip-coated steel and titanium alloys. Only due to pretreatment with low-pressure gas plasma a robust deposition of collagen I on the surface could be achieved. The cell viability and cell attachment rate on the plasma pretreated, collagen coated surfaces was significantly (p < 0.017) increased compared to the non coated surfaces. Gas plasma treatment is a feasible method for the deposition of proteins on metal implant materials resulting in an improved biocompatibility in vitro. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010.

  20. Compact mass spectrometer for plasma discharge ion analysis

    DOEpatents

    Tuszewski, Michel G.

    1997-01-01

    A mass spectrometer and methods for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector.

  1. Compact mass spectrometer for plasma discharge ion analysis

    DOEpatents

    Tuszewski, M.G.

    1997-07-22

    A mass spectrometer and methods are disclosed for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector. 7 figs.

  2. Non-mass-analyzed ion implantation from a solid phosphorus source

    NASA Technical Reports Server (NTRS)

    Spitzer, M. B.; Bunker, S. N.

    1982-01-01

    A phosphorus ion beam, extracted from a Freeman ion source charged with elemental phosphorus, has been investigated for use in solar cell fabrication. Mass spectroscopy of the beam indicates the absence of both minority-carrier lifetime degrading impurities and hydrogen. The ion beam, without mass analysis, was used for ion implantation of solar cells, and performance for all cells was found to be equivalent to mass-analyzed controls.

  3. Deterioration mechanisms of joint prosthesis materials. Several solutions by ion implantation surface treatments.

    PubMed

    Rieu, J; Pichat, A; Rabbe, L M; Chabrol, C; Robelet, M

    1990-07-01

    Materials for orthopaedic implants can fail for several combined reasons: corrosion, fatigue and wear for metals, wear and creep for polymers, fracture for ceramics. Some typical cases are analysed and it is demonstrated that ion implantation improves metals and polymers used for joint prosthesis. Implantations of nitrogen, oxygen and argon ions modify the structure of a 2-500 nm thick layer in the materials. The results of friction tests on the couple metal-polymer are correlated with the surface properties. PMID:2397260

  4. Precipitation in As-Ion-Implanted and Annealed InAs

    NASA Astrophysics Data System (ADS)

    Kim, Seon-Ju; Han, Haewook

    2001-11-01

    Low-energy As-ion-implanted InAs was examined using double-crystal X-ray diffraction and transmission electron microscopy. For uniform defect distribution, multiple implantations were made at 0.05-0.4 MeV with 4 × 1014-5× 1015 ions/cm2. After annealing at 600°C for 20 min, As precipitates were observed, and the implantation-induced strain was significantly reduced, showing the recovery of crystallinity. The density of the As precipitates was 7.4 × 1016 cm-3 and the mean diameter was 55 Å, which corresponds to a volume fraction of 1.1%.

  5. Method of making an ion-implanted planar-buried-heterostructure diode laser

    DOEpatents

    Brennan, Thomas M.; Hammons, Burrell E.; Myers, David R.; Vawter, Gregory A.

    1992-01-01

    Planar-buried-heterostructure, graded-index, separate-confinement-heterostructure semiconductor diode laser 10 includes a single quantum well or multi-quantum well active stripe 12 disposed between a p-type compositionally graded Group III-V cladding lever 14 and an n-type compositionally graded Group III-V cladding layer 16. The laser 10 includes an iion implanted n-type region 28 within the p-type cladding layer 14 and further includes an ion implanted p-type region 26 within the n-type cladding layer 16. The ion implanted regions are disposed for defining a lateral extent of the active stripe.

  6. Ion flux and ion distribution function measurements in synchronously pulsed inductively coupled plasmas

    SciTech Connect

    Brihoum, Melisa; Cunge, Gilles; Darnon, Maxime; Joubert, Olivier; Gahan, David; Braithwaite, Nicholas St. J.

    2013-03-15

    Changes in the ion flux and the time-averaged ion distribution functions are reported for pulsed, inductively coupled RF plasmas (ICPs) operated over a range of duty cycles. For helium and argon plasmas, the ion flux increases rapidly after the start of the RF pulse and after about 50 {mu}s reaches the same steady state value as that in continuous ICPs. Therefore, when the plasma is pulsed at 1 kHz, the ion flux during the pulse has a value that is almost independent of the duty cycle. By contrast, in molecular electronegative chlorine/chlorosilane plasmas, the ion flux during the pulse reaches a steady state value that depends strongly on the duty cycle. This is because both the plasma chemistry and the electronegativity depend on the duty cycle. As a result, the ion flux is 15 times smaller in a pulsed 10% duty cycle plasma than in the continuous wave (CW) plasma. The consequence is that for a given synchronous RF biasing of a wafer-chuck, the ion energy is much higher in the pulsed plasma than it is in the CW plasma of chlorine/chlorosilane. Under these conditions, the wafer is bombarded by a low flux of very energetic ions, very much as it would in a low density, capacitively coupled plasma. Therefore, one can extend the operating range of ICPs through synchronous pulsing of the inductive excitation and capacitive chuck-bias, offering new means by which to control plasma etching.

  7. Effect of MeV nitrogen ion implantation on the resistivity transition in Czochralski silicon wafers

    NASA Astrophysics Data System (ADS)

    Moon, Byeong-Sam; Lee, In-Ji; Park, Jea-Gun

    2012-12-01

    We investigated how MeV nitrogen ion implantation affects the resistivity transition in Czochralski (CZ) silicon wafers. After annealing at 800 °C for 20 h and again at 1000 °C for 10 h, the implanted nitrogen atoms accumulated in the projected range (R P ) for ion doses less than 5 × 1014 cm-2 whereas they accumulated at both R P /2 and R P at ion doses above 3 × 1015 cm-2. These results indicate that no resistivity transition was found at nitrogen ion doses less than 5 × 1013 cm-2 whereas n-/p or n+/p resistivity transition was shown at ion doses higher than 5 × 1014 cm-2. Many fewer than 1% of the implanted nitrogen atoms were ionized after the heat treatment. Thus, the resistivity of nitrogen-doped silicon wafers is more than 100 times higher than that of phosphorous-doped silicon wafers.

  8. Parallel Simulation of Ion Implantation for Multi-Component Targets Using Boltzmann Transport Equation

    NASA Astrophysics Data System (ADS)

    Wang, Shyh-Wei; Guo, Shuang-Fa

    1998-07-01

    A stepwise Boltzmann transport equation (BTE) simulation using non-uniform energy grid momentum matrix and exact nuclear scattering cross-section is successfully parallelized to simulate the ion implantation of multi-component targets. Assuming that the interactions of ion with different target atoms are independent, the scattering of ions with different components can be calculated concurrently by different processors. It is developed on CONVEX SPP-1000 and the software environment of parallel virtual machine (PVM) with a master-slave paradigm. A speedup of 3.3 has been obtained for the simulation of As ions implanted into AZ1350 (C6.2H6O1N0.15S0.06) which is composed of five components. In addition, our new scheme gives better agreement with the experimental results for heavy ion implantation than the conventional method using a uniform energy grid and approximated scattering function.

  9. Measurement of lattice damage caused by ion-implantation doping of semiconductors.

    NASA Technical Reports Server (NTRS)

    Hunsperger, R. G.; Wolf, E. D.; Shifrin, G. A.; Marsh, O. J.; Jamba, D. M.

    1971-01-01

    Discussion of two new techniques used to measure the lattice damage produced in GaAs by the implantation of 60 keV cadmium ions. In the first method, optical reflection spectra of the ion-implanted samples were measured in the wavelength range from 2000 to 4600 A. The decrease in reflectivity resulting from ion-implantation was used to determine the relative amount of lattice damage as a function of ion dose. The second technique employed the scanning electron microscope. Patterns very similar in appearance to Kikuchi electron diffraction patterns are obtained when the secondary and/or backscattered electron intensity is displayed as a function of the angle of incidence of the electron beam on a single crystal surface. The results of measurements made by both methods are compared with each other and with data obtained by the method of measuring lattice damage by Rutherford scattering of 1 MeV helium ions.

  10. Planar optical waveguides in Nd:BSO crystals fabricated by He and C ion implantation

    NASA Astrophysics Data System (ADS)

    Liu, Tao; Guo, Sha-Sha; Zhao, Jin-Hua; Guan, Jing; Wang, Xue-Lin

    2011-01-01

    Planar optical waveguides in Nd:BSO crystals were fabricated by the implantation of 500 keV He ions and 6.0 MeV C ions at two different substrate temperatures. The guiding modes were measured by the prism-coupling method with a He-Ne beam at 633 nm. The intensity calculation method (ICM) and reflectivity calculation method (RCM) were used for reconstructing refractive index profiles. The near-field intensity distribution of the waveguide, formed by He and C ions implanted after annealing at 300 °C, was measured by the end-face coupling setup. It was in reasonable agreement with the intensity of the waveguide mode simulated by the finite-difference beam propagation method (FD-BPM). The absorption spectra of the sample with He ions implanted at fluences of 3 × 1016 ions/cm2 were measured using a spectrophotometer.

  11. Surface engineering of a Zr-based bulk metallic glass with low energy Ar- or Ca-ion implantation.

    PubMed

    Huang, Lu; Zhu, Chao; Muntele, Claudiu I; Zhang, Tao; Liaw, Peter K; He, Wei

    2015-02-01

    In the present study, low energy ion implantation was employed to engineer the surface of a Zr-based bulk metallic glass (BMG), aiming at improving the biocompatibility and imparting bioactivity to the surface. Ca- or Ar-ions were implanted at 10 or 50 keV at a fluence of 8 × 10(15)ions/cm(2) to (Zr0.55Al0.10Ni0.05Cu0.30)99Y1 (at.%) BMG. The effects of ion implantation on material properties and subsequent cellular responses were investigated. Both Ar- and Ca-ion implantations were suggested to induce atom displacements on the surfaces according to the Monte-Carlo simulation. The change of atomic environment of Zr in the surface regions as implied by the alteration in X-ray absorption measurements at Zr K-edge. X-ray photoelectron spectroscopy revealed that the ion implantation process has modified the surface chemical compositions and indicated the presence of Ca after Ca-ion implantation. The surface nanohardness has been enhanced by implantation of either ion species, with Ca-ion implantation showing more prominent effect. The BMG surfaces were altered to be more hydrophobic after ion implantation, which can be attributed to the reduced amount of hydroxyl groups on the implanted surfaces. Higher numbers of adherent cells were found on Ar- and Ca-ion implanted samples, while more pronounced cell adhesion was observed on Ca-ion implanted substrates. The low energy ion implantation resulted in concurrent modifications in atomic structure, nanohardness, surface chemistry, hydrophobicity, and cell behavior on the surface of the Zr-based BMG, which were proposed to be mutually correlated with each other. PMID:25492195

  12. Signal Propagation in Collisional Plasma with Negative Ions

    SciTech Connect

    I. Kaganovich; S.V. Berezhnoi; C.B. Shin

    2000-12-18

    The transport of charged species in collisional currentless plasmas is traditionally thought of as a diffusion-like process. In this paper, it is demonstrated that, in contrast to two-component plasma, containing electrons and positive ions, the transport of additional ions in multi-species plasmas is not governed by diffusion, rather described by nonlinear convection. As a particular example, plasmas with the presence of negative ions have been studied. The velocity of a small perturbation of negative ions was found analytically and validated by numerical simulation. As a result of nonlinear convection, initially smooth ion density profiles break and form strongly inhomogeneous shock-like fronts. These fronts are different from collisionless shocks and shocks in fully ionized plasma. The structure of the fronts has been found analytically and numerically.

  13. Oblique Propagation of Ion Acoustic Solitons in Magnetized Superthermal Plasmas

    NASA Astrophysics Data System (ADS)

    Devanandhan, S.; Sreeraj, T.; Singh, S.; Lakhina, G. S.

    2015-12-01

    Small amplitude ion-acoustic solitons are studied in a magnetized plasma consisting of protons, doubly charged helium ions and superthermal electrons. The Korteweg-de-Vries-Zakharov-Kuznetsov (KdV-ZK) is derived to examine the properties of ion acoustic solitary structures observed in space plasmas. Our model is applicable for weakly magnetized plasmas. The results will be applied to the satellite observations in the solar wind at 1 AU where magnetized ion acoustic waves with superthermal electrons can exist. The effects of superthermality, temperature and densities on these solitary structures will be discussed.

  14. Ion holes in the hydrodynamic regime in ultracold neutral plasmas

    SciTech Connect

    McQuillen, P.; Castro, J.; Strickler, T.; Bradshaw, S. J.; Killian, T. C.

    2013-04-15

    We describe the creation of localized density perturbations, or ion holes, in an ultracold neutral plasma in the hydrodynamic regime, and show that the holes propagate at the local ion acoustic wave speed. We also observe the process of hole splitting, which results from the formation of a density depletion initially at rest in the plasma. One-dimensional, two-fluid hydrodynamic simulations describe the results well. Measurements of the ion velocity distribution also show the effects of the ion hole and confirm the hydrodynamic conditions in the plasma.

  15. Sheath structure in electronegative plasmas with finite positive ion temperature

    NASA Astrophysics Data System (ADS)

    Palop, J. I. Fernández; Ballesteros, J.; Hernández, M. A.; Crespo, R. Morales; del Pino, S. Borrego

    2004-05-01

    An earlier theoretical work, concerning the sheath structure in electronegative plasmas, is extended to include the effect of the positive ion thermal motion. A significant change is observed in the quantities characterizing the sheath with respect to the cold ion assumption. The sheath is contracted when the positive ion thermal motion is considered causing a decrease in the sheath thickness. The ion saturation current and the floating potential are shown to be distinguished quantities in plasma diagnosis of electronegative plasmas by using plane Langmuir probes.

  16. Decrease of Staphylococcal adhesion on surgical stainless steel after Si ion implantation

    NASA Astrophysics Data System (ADS)

    Braceras, Iñigo; Pacha-Olivenza, Miguel A.; Calzado-Martín, Alicia; Multigner, Marta; Vera, Carolina; Broncano, Luis Labajos-; Gallardo-Moreno, Amparo M.; González-Carrasco, José Luis; Vilaboa, Nuria; González-Martín, M. Luisa

    2014-08-01

    316LVM austenitic stainless steel is often the material of choice on temporal musculoskeletal implants and surgical tools as it combines good mechanical properties and acceptable corrosion resistance to the physiologic media, being additionally relatively inexpensive. This study has aimed at improving the resistance to bacterial colonization of this surgical stainless steel, without compromising its biocompatibility and resistance. To achieve this aim, the effect of Si ion implantation on 316LVM has been studied. First, the effect of the ion implantation parameters (50 keV; fluence: 2.5-5 × 1016 ions/cm2; angle of incidence: 45-90°) has been assessed in terms of depth profiling of chemical composition by XPS and nano-topography evaluation by AFM. The in vitro biocompatibility of the alloy has been evaluated with human mesenchymal stem cells. Finally, bacterial adhesion of Staphylococcus epidermidis and Staphylococcus aureus on these surfaces has been assessed. Reduction of bacterial adhesion on Si implanted 316LVM is dependent on the implantation conditions as well as the features of the bacterial strains, offering a promising implantable biomaterial in terms of biocompatibility, mechanical properties and resistance to bacterial colonization. The effects of surface composition and nano-topography on bacterial adhesion, directly related to ion implantation conditions, are also discussed.

  17. Modification of titanium and titanium dioxide surfaces by ion implantation: Combined XPS and DFT study

    NASA Astrophysics Data System (ADS)

    Boukhvalov, D. W.; Korotin, D. M.; Efremov, A. V.; Kurmaev, E. Z.; Borchers, Ch.; Zhidkov, I. S.; Gunderov, D. V.; Valiev, R. Z.; Gavrilov, N. V.; Cholakh, S. O.

    2015-04-01

    The results of XPS measurements (core levels and valence bands) of P+, Ca+, P+Ca+ and Ca+P+ ion implanted (E=30 keV, D=1x1017 cm-2) commercially pure titanium (cp-Ti) and first-principles density functional theory (DFT) calculations demonstrates formation of various structural defects in titanium dioxide films formed on the surface of implanted materials. We have found that for double implantation (Ti:P+,Ca+ and Ti:Ca+,P+) the outermost surface layer formed mainly by Ca and P, respectively, i.e. the implantation sequence is very important. The DFT calculations show that under P+ and Ca+P+ ion implantation the formation energies for both cation (P-Ti) and anion (P-O) substitutions are comparable which can induce the creation of [PO4]3- and Ti-P species. For Ca+ and P+Ca+-ion implantation the calculated formation energies correspond to Ca2+-Ti4+ cation substitution. This conclusion is in agreement with XPS Ca 2p and Ti 2p core levels and valence band measurements and DFT calculations of electronic structure of related compounds. The conversion of implanted ions to Ca2+ and [PO4]3- species provides a good biocompatibility of cp-Ti for further formation of hydroxyapatite.

  18. Trapped ion mode in toroidally rotating plasmas

    SciTech Connect

    Artun, M.; Tang, W.M.; Rewoldt, G.

    1995-04-01

    The influence of radially sheared toroidal flows on the Trapped Ion Mode (TIM) is investigated using a two-dimensional eigenmode code. These radially extended toroidal microinstabilities could significantly influence the interpretation of confinement scaling trends and associated fluctuation properties observed in recent tokamak experiments. In the present analysis, the electrostatic drift kinetic equation is obtained from the general nonlinear gyrokinetic equation in rotating plasmas. In the long perpendicular wavelength limit k{sub {tau}}{rho}{sub bi} {much_lt} 1, where {rho}{sub bi} is the average trapped-ion banana width, the resulting eigenmode equation becomes a coupled system of second order differential equations nmo for the poloidal harmonics. These equations are solved using finite element methods. Numerical results from the analysis of low and medium toroidal mode number instabilities are presented using representative TFTR L-mode input parameters. To illustrate the effects of mode coupling, a case is presented where the poloidal mode coupling is suppressed. The influence of toroidal rotation on a TFTR L-mode shot is also analyzed by including a beam species with considerable larger temperature. A discussion of the numerical results is presented.

  19. Synergistic Effects of Iodine and Silver Ions Co-Implanted in 6H-SiC

    SciTech Connect

    Kuhudzai, Remeredzai J.; Malherbe, Johan; Hlatshwayo, T. T.; van der Berg, N. G.; Devaraj, Arun; Zhu, Zihua; Nandasiri, Manjula I.

    2015-10-23

    Motivated by the aim of understanding the release of fission products through the SiC coating of fuel kernels in modern high temperature nuclear reactors, a fundamental investigation is conducted to understand the synergistic effects of implanted silver (Ag) and iodine (I) in 6H-SiC. The implantation of the individual species, as well as the co-implantation of 360 keV ions of I and Ag at room temperature in 6H-SiC and their subsequent annealing behavior has been investigated by Secondary Ion Mass Spectrometry (SIMS), Atom Probe Tomography (APT) and X-ray Photoelectron Spectroscopy (XPS). SIMS and APT measurements indicated the presence of Ag in the co-implanted samples after annealing at 1500 ºC for 30 hours in sharp contrast to the samples implanted with Ag only. In samples implanted with Ag only, complete loss of the implanted Ag was observed. However, for I only implanted samples, some iodine was retained. APT of annealed co-implanted 6H-SiC showed clear spatial association of Ag and I clusters in SiC, which can be attributed to the observed I assisted retention of Ag after annealing. Such detailed studies will be necessary to identify the fundamental mechanism of fission products migration through SiC coatings.

  20. Synergistic effects of iodine and silver ions co-implanted in 6H-SiC

    NASA Astrophysics Data System (ADS)

    Kuhudzai, R. J.; Malherbe, J. B.; Hlatshwayo, T. T.; van der Berg, N. G.; Devaraj, A.; Zhu, Z.; Nandasiri, M.

    2015-12-01

    Motivated by the aim of understanding the release of fission products through the SiC coating of fuel kernels in modern high temperature nuclear reactors, a fundamental investigation is conducted to understand the synergistic effects of implanted silver (Ag) and iodine (I) in 6H-SiC. The implantation of the individual species, as well as the co-implantation of 360 keV ions of I and Ag at room temperature in 6H-SiC and their subsequent annealing behaviour has been investigated by Secondary Ion Mass Spectrometry (SIMS), Atom Probe Tomography (APT) and X-ray Photoelectron Spectroscopy (XPS). SIMS and APT measurements indicated the presence of Ag in the co-implanted samples after annealing at 1500 °C for 30 h in sharp contrast to the samples implanted with Ag only. In samples implanted with Ag only, complete loss of the implanted Ag was observed. However, for I only implanted samples, some iodine was retained. APT of annealed co-implanted 6H-SiC showed clear spatial association of Ag and I clusters in SiC, which can be attributed to the observed I assisted retention of Ag after annealing. Such detailed studies will be necessary to identify the fundamental mechanism of fission products migration through SiC coatings.

  1. Suppression of ion-implantation induced porosity in germanium by a silicon dioxide capping layer

    NASA Astrophysics Data System (ADS)

    Tran, Tuan T.; Alkhaldi, Huda S.; Gandhi, Hemi H.; Pastor, David; Huston, Larissa Q.; Wong-Leung, Jennifer; Aziz, Michael J.; Williams, J. S.

    2016-08-01

    Ion implantation with high ion fluences is indispensable for successful use of germanium (Ge) in the next generation of electronic and photonic devices. However, Ge readily becomes porous after a moderate fluence implant ( ˜1 ×1015 ion cm-2 ) at room temperature, and for heavy ion species such as tin (Sn), holding the target at liquid nitrogen (LN2) temperature suppresses porosity formation only up to a fluence of 2 ×1016 ion cm-2 . We show, using stylus profilometry and electron microscopy, that a nanometer scale capping layer of silicon dioxide significantly suppresses the development of the porous structure in Ge during a S n - implant at a fluence of 4.5 ×1016 ion cm-2 at LN2 temperature. The significant loss of the implanted species through sputtering is also suppressed. The effectiveness of the capping layer in preventing porosity, as well as suppressing sputter removal of Ge, permits the attainment of an implanted Sn concentration in Ge of ˜15 at.% , which is about 2.5 times the maximum value previously attained. The crystallinity of the Ge-Sn layer following pulsed-laser-melting induced solidification is also greatly improved compared with that of uncapped material, thus opening up potential applications of the Ge-Sn alloy as a direct bandgap material fabricated by an ion beam synthesis technique.

  2. Temperature dependent surface modification of T91 steel under 3.25 MeV Fe-ion implantation

    NASA Astrophysics Data System (ADS)

    Zhu, Huiping; Wang, Zhiguang; Cui, Minghuan; Li, Bingsheng; Gao, Xing; Sun, Jianrong; Yao, Cunfeng; Wei, Kongfang; Shen, Tielong; Pang, Lilong; Zhu, Yabin; Li, Yuanfei; Wang, Ji; Xie, Erqing

    2015-01-01

    Ion implantation is an established technique for modifying the surface properties of a wide range of materials. In this research, temperature dependent surface modification induced by Fe-ion implantation in T91 steel was investigated. The T91 samples were implanted with 3.25 MeV Fe-ions to fluence of 1.7 × 1016 ions/cm2 at room temperature, 300 and 450 °C, respectively. After implantation, the T91 samples were characterized by means of positron annihilation Doppler broadening spectroscopy (PADBS) and nano-indention technology (NIT). It was found that the concentration of open-volume defects in T91 samples decreased with increasing implantation temperature. From NIT analysis, it was found that all the samples were hardened after implantation and the hardness of the implanted T91 samples increased with increasing implantation temperature.

  3. Effects of sequential tungsten and helium ion implantation on nano-indentation hardness of tungsten

    SciTech Connect

    Armstrong, D. E. J.; Edmondson, P. D.; Roberts, S. G.

    2013-06-24

    To simulate neutron and helium damage in a fusion reactor first wall sequential self-ion implantation up to 13 dpa followed by helium-ion implantation up to 3000 appm was performed to produce damaged layers of {approx}2 {mu}m depth in pure tungsten. The hardness of these layers was measured using nanoindentation and was studied using transmission electron microscopy. Substantial hardness increases were seen in helium implanted regions, with smaller hardness increases in regions which had already been self-ion implanted, thus, containing pre-existing dislocation loops. This suggests that, for the same helium content, helium trapped in distributed vacancies gives stronger hardening than helium trapped in vacancies condensed into dislocation loops.

  4. Surface treatment of silicone rubber by carbon negative-ion implantation for nerve regeneration

    NASA Astrophysics Data System (ADS)

    Tsuji, Hiroshi; Izukawa, Masayoshi; Ikeguchi, Ryosuke; Kakinoki, Ryosuke; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo

    2004-07-01

    Surface treatment of silicone rubber by carbon negative ion-implantation was investigated for nerve regeneration by "tubulation". Silicone rubber had its surface property altered to be more hydrophilic by carbon negative-ion implantation. The extracellular matrices of proteins in culture medium adsorbed on the implanted surface rather than unimplanted ones. These improvements in wettability and adsorption properties of proteins were respected to contribute to the regeneration of a nerve-lacking system. An in vivo regeneration test of rat sciatic nerves with silicone-rubber tubes was performed. Using a tube in which the inner surface was implanted with carbon negative ions, the sciatic nerve was regenerated through the inter-stump gap of 15 mm between the proximal and distal nerve stumps and electrical stimulation was transported through the regenerated nerve. Thus, the nerve system was recovered. However, with the unimplanted tube, the nerve was not regenerated at all.

  5. Synthesis of (SiC){sub 3}N{sub 4} thin films by ion implantation

    SciTech Connect

    Uslu, C.; Lee, D.H.; Berta, Y.; Park, B.; Thadhani, N.N.; Poker, D.B.

    1993-12-31

    We have investigated the synthesis of carbon-silicon-nitride compounds by ion implantation. In these experiments, 100 keV nitrogen ions were implanted into polycrystalline {beta}-SiC (cubic phase) at various substrate temperatures and ion doses. These thin films were characterized by x-ray diffraction with a position-sensitive detector, transmission electron microscopy with chemical analysis, and Rutherford backscattering spectroscopy. The as-implanted samples show a buried amorphous layer at a depth of 170 nm. Peak concentration of nitrogen saturates at approximately 45 at. % with doses above {approximately} 9.0 {times} 10{sup 17} N/cm{sup 2} at 860{degree}C. These results suggest formation of a new phase by nitrogen implantation into {beta}-SiC.

  6. Fabrication of highly homogeneous surface-enhanced Raman scattering substrates using Ag ion implantation

    NASA Astrophysics Data System (ADS)

    Li, Wenqing; Xiao, Xiangheng; Dai, Zhigao; Wu, Wei; Cheng, Li; Mei, Fei; Zhang, Xingang; Jiang, Changzhong

    2016-06-01

    In recent times, surface-enhanced Raman scattering (SERS) has attracted attention for its excellent potential application in chemical and biological detection. In this work, we demonstrate that a highly homogeneous SERS substrate can be realized by Ag ion implantation and the subsequent annealing process. Both the implantation and annealing parameters have been optimized for a high sensitivity SERS substrate. The SERS measurement indicates that a sample implanted by 20 kV Ag ions with a dosage of 3  ×  1016 ions cm-2 exhibits the highest SERS activity. In addition, the SERS activity of the Ag-implanted substrates depends highly on the annealing temperature and time. Since none of the fabrication processes contain chemical reactions, our substrate is a clean system without any chemical residues.

  7. Selective nucleation induced by defect nanostructures: A way to control cobalt disilicide precipitation during ion implantation

    SciTech Connect

    Fortuna, F.; Nguyen, M.-A.; Ruault, M.-O.; Kirk, M. A.; Borodin, V. A.; Ganchenkova, M. G.

    2012-12-15

    In this paper, we show a way to control cobalt disilicide precipitation during Co ion implantation at high temperatures (650 Degree-Sign C) by affecting radiation defects involved in precipitate nucleation and growth. We demonstrate that the relative shares of different precipitate types nucleated by implantation are strongly affected by defect microstructures deliberately created in investigated samples prior to cobalt implantation. Especially interesting is the effect of a dense ensemble of extremely small (1-3 nm) cavities, which promotes the formation of a relatively uniform layer of coherent cobalt disilicide precipitates with a narrow size distribution. In order to better understand the mechanism of the microstructural influence on the precipitate nucleation modes during Co implantation, we investigate the disilicide precipitation using different implantation setups and compare the results with those for cavity-free Si specimens implanted in similar conditions.

  8. Resonance ultrasonic vibrations in Cz-Si wafers as a possible diagnostic technique in ion implantation

    NASA Astrophysics Data System (ADS)

    Zhao, Z. Y.; Ostapenko, S.; Anundson, R.; Tvinnereim, M.; Belyaev, A.; Anthony, M.

    2001-07-01

    The semiconductor industry does not have effective metrology for well implants. The ability to measure such deep level implants will become increasingly important as we progress along the technology road map. This work explores the possibility of using the acoustic whistle effect on ion implanted silicon wafers. The technique detects the elastic stress and defects in silicon wafers by measuring the sub-harmonic f/2 resonant vibrations on a wafer induced via backside contact to create standing waves, which are measured by a non-contact ultrasonic probe. Preliminary data demonstrates that it is sensitive to implant damage, and there is a direct correlation between this sub-harmonic acoustic mode and some of the implant and anneal conditions. This work presents the results of a feasibility study to assess and quantify the correspondent whistle effect to implant damage, residual damage after annealing and intrinsic defects.

  9. Fabrication and Characterization of Thin Film Ion Implanted Composite Materials for Integrated Nonlinear Optical Devices

    NASA Technical Reports Server (NTRS)

    Sarkisov, S.; Curley, M.; Williams, E. K.; Wilkosz, A.; Ila, D.; Poker, D. B.; Hensley, D. K.; Smith, C.; Banks, C.; Penn, B.; Clark, R.

    1998-01-01

    Ion implantation has been shown to produce a high density of metal colloids within the layer regions of glasses and crystalline materials. The high-precipitate volume fraction and small size of metal nanoclusters formed leads to values for the third-order susceptibility much greater than those for metal doped solids. This has stimulated interest in use of ion implantation to make nonlinear optical materials. On the other side, LiNbO3 has proved to be a good material for optical waveguides produced by MeV ion implantation. Light confinement in these waveguides is produced by refractive index step difference between the implanted region and the bulk material. Implantation of LiNbO3 with MeV metal ions can therefore result into nonlinear optical waveguide structures with great potential in a variety of device applications. We describe linear and nonlinear optical properties of a waveguide structure in LiNbO3-based composite material produced by silver ion implantation in connection with mechanisms of its formation.

  10. The Effect of Ag and Ag+N Ion Implantation on Cell Attachment Properties

    SciTech Connect

    Urkac, Emel Sokullu; Oztarhan, Ahmet; Gurhan, Ismet Deliloglu; Iz, Sultan Gulce; Tihminlioglu, Funda; Oks, Efim; Nikolaev, Alexey; Ila, Daryush

    2009-03-10

    Implanted biomedical prosthetic devices are intended to perform safely, reliably and effectively in the human body thus the materials used for orthopedic devices should have good biocompatibility. Ultra High Molecular Weight Poly Ethylene (UHMWPE) has been commonly used for total hip joint replacement because of its very good properties. In this work, UHMWPE samples were Ag and Ag+N ion implanted by using the Metal-Vapor Vacuum Arc (MEVVA) ion implantation technique. Samples were implanted with a fluency of 1017 ion/cm2 and extraction voltage of 30 kV. Rutherford Backscattering Spectrometry (RBS) was used for surface studies. RBS showed the presence of Ag and N on the surface. Cell attachment properties investigated with model cell lines (L929 mouse fibroblasts) to demonstrate that the effect of Ag and Ag+N ion implantation can favorably influence the surface of UHMWPE for biomedical applications. Scanning electron microscopy (SEM) was used to demonstrate the cell attachment on the surface. Study has shown that Ag+N ion implantation represents more effective cell attachment properties on the UHMWPE surfaces.

  11. The Effect of Ag and Ag+N Ion Implantation on Cell Attachment Properties

    NASA Astrophysics Data System (ADS)

    Urkac, Emel Sokullu; Oztarhan, Ahmet; Tihminlioglu, Funda; Gurhan, Ismet Deliloglu; Iz, Sultan Gulce; Oks, Efim; Nikolaev, Alexey; Ila, Daryush

    2009-03-01

    Implanted biomedical prosthetic devices are intended to perform safely, reliably and effectively in the human body thus the materials used for orthopedic devices should have good biocompatibility. Ultra High Molecular Weight Poly Ethylene (UHMWPE) has been commonly used for total hip joint replacement because of its very good properties. In this work, UHMWPE samples were Ag and Ag+N ion implanted by using the Metal-Vapor Vacuum Arc (MEVVA) ion implantation technique. Samples were implanted with a fluency of 1017 ion/cm2 and extraction voltage of 30 kV. Rutherford Backscattering Spectrometry (RBS) was used for surface studies. RBS showed the presence of Ag and N on the surface. Cell attachment properties investigated with model cell lines (L929 mouse fibroblasts) to demonstrate that the effect of Ag and Ag+N ion implantation can favorably influence the surface of UHMWPE for biomedical applications. Scanning electron microscopy (SEM) was used to demonstrate the cell attachment on the surface. Study has shown that Ag+N ion implantation represents more effective cell attachment properties on the UHMWPE surfaces.

  12. Kinetic study of ion-acoustic plasma vortices

    SciTech Connect

    Khan, S. A.; Aman-ur-Rehman; Mendonca, J. T.

    2014-09-15

    The kinetic theory of electron plasma waves with finite orbital angular momentum has recently been introduced by Mendonca. This model shows possibility of new kind of plasma waves and instabilities. We have extended the theory to ion-acoustic plasma vortices carrying orbital angular momentum. The dispersion equation is derived under paraxial approximation which exhibits a kind of linear vortices and their Landau damping. The numerical solutions are obtained and compared with analytical results which are in good agreement. The physical interpretation of the ion-acoustic plasma vortices and their Landau resonance conditions are given for typical case of Maxwellian plasmas.

  13. Solitons in a relativistic plasma with negative ions--

    SciTech Connect

    Das, G.C. ); Karmakar, B. ); Ibohanbi Singh, KH. )

    1990-02-01

    The interaction of the nonlinearity and the dispersiveness causing the solitary waves are studied in a relativistic plasma with negative ions through the derivation of a nonlinear partial differential equation known as the Korteweg-Devries (K-DV) equation. The negative ions play a salient feature on the existence and behavior of the solitons and could be of interest in laboratory plasmas. First, the observations are made in a nonisothermal plasma, and later the reduction to the nonisothermality of the plasma shows entirely different characteristics as compared to the solitons in the isothermal plasmas. A comparison with the various solutions has been emphasized.

  14. "Super-acceleration" of ions in a stationary plasma discharge

    NASA Astrophysics Data System (ADS)

    Bardakov, Vladimir; Ivanov, Sergey; Kazantsev, Alexander; Strokin, Nikolay; Stupin, Aleksey

    2016-10-01

    We report on the detection of the acceleration effect of the bulk of ions in a stationary plasma E × B discharge to energies exceeding considerably the value equivalent to the discharge voltage. We determined the conditions necessary for the generation of high-energy ions, and ascertained the influence exerted on the value of the ion energies by pressure (flow rate) and the kind of plasma-producing gas, and by the value of discharge current. The possible acceleration mechanism is suggested.

  15. Quantitative secondary ion mass spectrometric analysis of secondary ion polarity in GaN films implanted with oxygen

    NASA Astrophysics Data System (ADS)

    Hashiguchi, Minako; Sakaguchi, Isao; Adachi, Yutaka; Ohashi, Naoki

    2016-10-01

    Quantitative analyses of N and O ions in GaN thin films implanted with oxygen ions (16O+) were conducted by secondary ion mass spectrometry (SIMS). Positive (CsM+) and negative secondary ions extracted by Cs+ primary ion bombardment were analyzed for oxygen quantitative analysis. The oxygen depth profiles were obtained using two types of primary ion beams: a Gaussian-type beam and a broad spot beam. The oxygen peak concentrations in GaN samples were from 3.2 × 1019 to 7.0 × 1021 atoms/cm3. The depth profiles show equivalent depth resolutions in the two analyses. The intensity of negative oxygen ions was approximately two orders of magnitude higher than that of positive ions. In contrast, the O/N intensity ratio measured using CsM+ molecular ions was close to the calculated atomic density ratio, indicating that the SIMS depth profiling using CsM+ ions is much more effective for the measurements of O and N ions in heavy O-implanted GaN than that using negative ions.

  16. Ion-implanted polytetrafluoroethylene enhances Saccharomyces cerevisiae biofilm formation for improved immobilization.

    PubMed

    Tran, Clara T H; Kondyurin, Alexey; Hirsh, Stacey L; McKenzie, David R; Bilek, Marcela M M

    2012-11-01

    The surface of polytetrafluoroethylene (PTFE) was modified using plasma immersion ion implantation (PIII) with the aim of improving its ability to immobilize yeast. The density of immobilized cells on PIII-treated and -untreated PTFE was compared as a function of incubation time over 24 h. Rehydrated yeast cells attached to the PIII-treated PTFE surface more rapidly, with higher density, and greater attachment strength than on the untreated surface. The immobilized yeast cells were removed mechanically or chemically with sodium hydroxide and the residues left on the surfaces were analysed with Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS). The results revealed that the mechanism of cell attachment on both surfaces differs and a model is presented for each. Rapid attachment on the PIII-treated surface occurs through covalent bonds of cell wall proteins and the radicals on the treated surface. In contrast, on the untreated surface, only physisorbed molecules were found in the residue and lipids were more highly concentrated than proteins. The presence of lipids in the residue was found to be a consequence of damage to the plasma membrane during the rehydration process and the increased cell stress was also apparent by the amount of Hsp12 in the protein residue. The immobilized yeast cells on PIII-treated PTFE were found to be as active as yeast cells in suspension.

  17. Transverse ion heating in multicomponent plasmas. [in ionosphere

    NASA Technical Reports Server (NTRS)

    Ashour-Abdalla, M.; Okuda, H.; Kim, S. Y.

    1987-01-01

    A new mechanism is proposed for plasma modes which can occur only in a multicomponent plasma and not in pure electron-ion plasma. The addition of ions creates a new instability near the ion-ion hybrid mode whose frequency is adequate for the wave to interact with oxygen ions. To study heating of ions (such as ionospheric oxygen ions) in presence of auroral electrons, several numerical simulations were carried out using a one-dimensional electrostatic code in a magnetic field. It was found that in the presence of electrons drifting along auroral field lines into the ionosphere, the ion-ion hybrid mode can be driven unstable when the electron drift speed is too small to excite the lower hybrid instability. Since the ion-ion mode has a smaller frequency than that of the lower hybrid waves, it can couple to the heavy ions, resulting in a substantial heating of heavy ions; on the other hand, because of their frequencies, the lower hybrid waves can accelerate only light ion species.

  18. Use of low-energy hydrogen ion implants in high-efficiency crystalline-silicon solar cells

    NASA Technical Reports Server (NTRS)

    Fonash, S. J.; Sigh, R.; Mu, H. C.

    1986-01-01

    The use of low-energy hydrogen implants in the fabrication of high-efficiency crystalline silicon solar cells was investigated. Low-energy hydrogen implants result in hydrogen-caused effects in all three regions of a solar cell: emitter, space charge region, and base. In web, Czochralski (Cz), and floating zone (Fz) material, low-energy hydrogen implants reduced surface recombination velocity. In all three, the implants passivated the space charge region recombination centers. It was established that hydrogen implants can alter the diffusion properties of ion-implanted boron in silicon, but not ion-implated arsenic.

  19. Spatial variation of plasma parameters and ion acceleration in an inductive plasma system

    SciTech Connect

    Volynets, V.N.; Park, Wontaek; Tolmachev, Yu.N.; Pashkovsky, V.G.; Yoo, Jinwoo

    2006-02-15

    Plasma parameters of inductively coupled plasma system with an annular plasma source have been studied experimentally. At low pressures (about 1 mTorr), electron temperature inside the plasma source is rather high (8-13 eV) and is much greater than in the diffusion (main) chamber (4-5 eV). The plasma potential inside the source is also much higher than in the main chamber. There is a rapid drop of the electron temperature and plasma potential at the boundary between the plasma source and the main chamber. The drop of the plasma potential at the boundary (about 20 V) means the existence of a strong axial electric field, which retards the electrons inside the plasma source and accelerates the ions from the source into the main chamber. Measurements of ion energy distributions in the main chamber volume reveal the existence of ions with kinetic energies about 15 eV.

  20. Impact of Ion Implantation on Licorice (Glycyrrhiza uralensis Fisch) Growth and Antioxidant Activity Under Drought Stress

    NASA Astrophysics Data System (ADS)

    Liu, Jingnan; Tong, Liping; Shen, Tongwei; Li, Jie; Wu, Lijun; Yu, Zengliang

    2007-06-01

    Low energy ion beams are known to have stimulation effects on plant generation and to improve plants' intrinsic quality. In the present study, the growth and physiological index of licorice implanted with 0, 8, 10, 12 and 14× (2.6×1015) ions/cm2 were investigated under well-watered and drought-stress conditions. The results showed that a proper dose of ion implantation was particularly efficient in stimulating the licorice growth and improving the plant biomass significantly in both the well-watered and drought-stress conditions. The physiological results of licorice measured by leaf water potential, lipid oxidation, soluble protein and antioxidant system showed a significant correlation between ion implantation and water regime except for leaf water potential. Therefore, the study indicated that ion implantation can enhance licorice's drought tolerance by increasing the activity of superoxide dismutase (SOD), catalase (CAT) and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging ability to lower oxidative damage to lipids in plants. Ion beam implantation, therefore, provides an alternative method to enhance licorice drought tolerance.