bluuebunny/crossref_metadata_2025_split huggingface dataset:
Residual Damage in Heavily Germanium-Doped Silicon
Authors: Demirlioğlu Esin , Aronowitz Sheldon , Su David 
Published: March 2011

ABSTRACTCross-sectional transmission electron microscopy (XTEM) studies have shown that two distinct damage regions are created when germanium is implanted into single-crystal silicon in high doses and subsequently annealed at high temperatures. The first layer extends approximately 90–95 nm into silicon for an implant energy of 120 keV. The second region is an end-of-range damage region located 200 nm from the silicon surface for the same implantation energy. Neither low-dose, low-energy boron implantation nor the type of cap layers used during annealing alter the damage pattern. Although the dose of the Ge implants is the major factor in the formation of the continuous damage layer, high oxygen concentration at the surface may also contribute to this effect.
The Enhanced Outdiffusion and Its Influence on the Impurity Behavior in the Implanted Si at Rapid Electron Beam Annealing
Authors: Kagadey V. A. , Lebedeva N. I. , Proskurovsky D. I. , Yakovleva L. V. 
Published: March 2011

ABSTRACTThe paper presents the results of a comprehensive study of the outdif-fusion of volatile impurities (P, As, Sb) from originally amorphous ion-implanted layers (IILs) of Si at rapid electron-beam heating in vacuum. The phenomenon of enhanced outdiffusion has been discovered and the activation energy of this process has been measured. It has been established that there exists an interconnection between the process of activation, deactivation, diffusion and segregation of the impurity in IIL and its outdiffusion. A qualitative model of the process determining this interconnection has been proposed. The reasons for the lowering of the potential barrier at the IIL-vacuum interface determining the abnormally high rates of vaporization of the impurity have been supposed.
Defect Elimination by MeV Ion Implantation
Authors: Saito S. , Kumagai M. , Kondolt T. 
Published: March 2011

ABSTRACTIn the p-type shallow junction formation using B+ implantation, preamorphaization is an essential technique to suppress B+ channeling. The crucial problem in this process is defect formation at an amorphous-crystal(a-c) interface. We have demonstrated that MeV ion implantation is effective to reduce defects for shallow junction formation. F+ preimplantation at 40 KeV with 1×l015 cm−2 was effective to form p-type shallow junctions by B+ implantation at 10 KeV with 5×1015cm−2. However, defect formation induced boron diffusion and also leakage current increase. These problems were overcome by MeV ion implantation at 1 MeV F+ or Si+ with 5x×1015 cm−2, followed by rapid thermal annealing at 1000–1100°C for 10 seconds. In the P preimplanted samples, followed by MeV ion implantation, defects at the a-c interface can be reduced and an about 50 % shallower junction depth was obtained, compared with just B+ implanted samples. The results indicate that MeV ion implantation is effective to form a shallow junction with a low leakage current.
Computer Simulation of Channeling Effects in Ion Implantation
Authors: Posselt Matthias 
Published: March 2011

ABSTRACTOur binary collision code Crystal-TRIM is applied to simulate 1 MeV P+ implantation into single-crystalline silicon at ion incidence into the [100] axial channel direction and doses between 2 × 1013 cm−2 and 6.7 × 1014 cm−2. The maximum penetration depth of the ions is determined by the electronic stopping of the well-channeled particles. The shape of the range distributions depends on (i) the thin amorphous surface layer on silicon, (ii) the radiation-induced production of vacancies and interstitials, and (iii) the static atomic disorder due to electronic energy deposition. The comparison of experimental data with results of computer simulations shows that at low doses at least the influence of the first two factors has to be considered. At higher doses the radiation damage due to nuclear energy deposition dominates the other effects.
High-Effective Ion-Implanted 6H-SiC Light Emitting Diodes with λmax=535nm
Authors: Suvorov A. V. , Ivanov P. A. , Makarov V. N. , Plotkin D. A. , Ioffe A. 
Published: March 2011

ABSTRACTThe p-n structures was formed by the implantation of Al ions into 6H-SiC n-type films and the thermal annealing. An energy of ions was in the range of 40–90 KeV, an annealing temperature -1700–2100K. We investigated the influence of implantation conditions over the defects electroluminescence of the obtained structures.After fabricating contacts and mesa-structures with areas 500–500μm our devices showed under the current of 20 mW:- integral light power 20μW,- λmax=535 nm, δλmax=80nm.For the first time was fabricated the green electroluminescence source on SiC with the value of efficiency approximated to one of the A3B5 structures, and after encapsulating it will be possible to obtain LEDs with an integral light power up to 80–100μW.
Ion Beam Synthesis of IrSi3 by Implantation of 2 MeV Ir Ions+
Authors: Sjoreen T. P. , Hinneberg H.-J. , Chisholm M. F. 
Published: March 2011

ABSTRACTThe formation of a buried IrSi3 layer in (111) oriented Si by ion implantation and annealing has been studied at an implantation energy of 2 MeV for substrate temperatures of 450–550°C. Rutherford backscattering (RBS), ion channeling and cross-sectional transmission electron microscopy showed that a buried epitaxial IrSi3 layer is produced at 550°C by implanting ≥ 3.4 × 1017 Ir/cm2 and subsequently annealing for 1 h at 1000°C plus 5 h at 1100°C. At a dose of 3.4 × 1017 Ir/cm2, the thickness of the layer varied between 120 and 190 nm and many large IrSi3 precipitates were present above and below the film. Increasing the dose to 4.4 × 1017 Ir/cm2 improved the layer uniformity at the expense of increased lattice damage in the overlying Si. RBS analysis of layer formation as a function of substrate temperature revealed the competition between the mechanisms for optimizing surface crystallinity vs. IrSi3 layer formation. Little apparent substrate temperature dependence was evident in the as-implanted state but after annealing the crystallinity of the top Si layer was observed to deteriorate with increasing substrate temperature while the precipitate coarsening and coalescence improved.
Optical Bleaching of Bismuth Implanted Silica Glass: A Threshold Effect
Authors: Park S. Y. , Magruder R. H. , Weeks R. A. , Zuhr R. A. 
Published: March 2011

ABSTRACTThe near surface regions of high purity silica glass discs, Spectrosil A, were modified by implantation with bismuth ions at 160 keV and room temperature. The glasses implanted with a nominal dose of 6×1016 Bi/cm2 at ∼5 μA/cm2 were subsequently bleached with a 5.0 eV KrF pulsed excimer laser. The laser had an average pulse duration of -20 ns and repetition rate of 10 Hz. It was found that the bleaching was dependent upon the power density of the laser for a constant total integrated energy. Ion backscattering and optical absorption measurements were made before and after laser irradiation. Large changes in optical density and depth distribution of the implanted ions were observed at power densities of ≥45 mJ/cm2-pulse. On the basis of our experimental results, the onset of the threshold for bleaching of silica glass implanted with 6×1016 Bi/cm2 at 160 keV and at room temperature is between 30 and 45 mJ/cm2-pulse.
Characterization of Thermal Annealed Bi Implanted Silica
Authors: Morgan S. H. , Henderson D. O. , Pan Z. , Magruder R. H. , Zuhr R. A. 
Published: March 2011

ABSTRACTOptical and infrared reflection spectra for Bi implanted silica are reported as a function of dose and thermal annealing. A series of high purity silica samples were implanted with Bi ions at an energy of 350 KeV. Doses were 1 × 1016 and 1.0 × 1017ions/cm2 at 5μamps/cm2. The samples were subsequently thermally annealed at 400, 600 and 800 C. The optical absorption from 6.2 to 1.8 eV and infrared reflectance from 5000 to 450 cm”−1 were measured before and after annealing. Effects of thermal annealing are strongly dependent on Bi content.
Characterization of Diamond Amorphized by Ion Implantation
Authors: Allen William R. , Lee Eal H. 
Published: March 2011

ABSTRACTSingle crystal diamond has been implanted at 1 MeV with 2×1020 Ar/m2. Rutherford backscattering spectrometry in a channeled geometry revealed a broad amorphized region underlying a thin, partially crystalline layer. Raman spectroscopy disclosed modifications in the bonding characteristic of the appearance of non-diamond carbon. The complementary nature of the two analysis techniques is demonstrated. The Knoop hardness of the implanted diamond was reduced by implantation.
Design of a Large-Scale Plasma Source Ion Implantation Experiment
Authors: Wood B. P. , Scheuer J. T. , Nastasi M. A. , Olsher R. H. , Reass W. A. , Henins I. , Rej D. J. 
Published: March 2011

ABSTRACTIn Plasma Source Ion Implantation (PSII), a target to be implanted is immersed in a weakly ionized plasma and pulsed to a high negative voltage. Ions in the plasma are accelerated toward the target and implanted in its surface, thereby modifying the properties of the surface. Experimental results reported in the literature have generally been for small targets. We present here the design of a large-scale PSII experiment being assembled Los Alamos National Laboratory, in which we plan to implant targets with surface areas exceeding 1 m2 to doses of up to 5 × 1017 cm−2. In presenting this design, we use Monte Carlo and particle-in-cell simulations to examine sheath expansion, implant current and dose, secondary electron emission, target sputtering, implant depth, and x-ray emission resulting from secondary electrons hitting the vacuum chamber wall.
Microstructure of Heat-Affected Zone in Carbon Steel Irradiated by a Low-Energy High-Current Electron Beam
Authors: Ivanov Yu. F. , Itin V. I. , Lykov S. V. , Markov A. B. , Rotshtein V. P. 
Published: March 2011

ABSTRACTUsing X-ray structural analysis and transmission electron microscopy of thin layers we have studied the mechanism of heat-affected zone formation in as-hardened steel irradiated by a low-energy microsecond high-current electron beam. It has been found that the above zone consists of three characteristic layers. We have analysed the conditions of formation of this layers using thermal calculations.
Lattice Site of Helium Implanted in Si and Diamond
Authors: Allen William R. 
Published: March 2011

ABSTRACTSingle crystals of silicon and diamond were implanted at 300K with 70 keV 3He. Ion channeling analyses were executed by application of Rutherford backscattering spectrometry and nuclear reaction analysis. Helium exhibits a non-random lattice site in the channeling angular distributions for silicon and diamond. A major fraction of the implanted 3He was qualitatively identified to be near to the tetrahedral interstice in both materials.
Defect Creation and Electron Trapping in Single Crystal and Sintered Alumina by Electron Beam Irradiation
Authors: Carroll D. L. , Doering D. L. , Xiong-Skiba P. 
Published: March 2011

ABSTRACTElectron beam irradiation of oxides produces electron trapping states which store excess charge. Thermionic emission of this charge occurs during heating with emission peak temperatures related to binding mechanisms and energies. We present thermionic emission results which show both intrinsic and beam induced trapping states in OC-Al2O3 (sapphire) and sintered alumina. Five states have been identified with thermionic emission peaks at temperatures between -50°C and 500°C. Two states are electron beam induced and occur only for electron beam energies above fixed thresholds. These thresholds appear to correlate to with the Is core electron binding energies for oxygen and aluminum. The emission peaks from the sintered material are about 10 fold greater in intensity and slightly broadened in comparison to the single crystal. This suggests that structure plays an important role in charge trapping. Emission was also extremely sensitive to sample treatments such as annealing before electron irradiation.
Parameters for Nitrogen Diffusion in Ni, Ti, and Al Obtained from Implanted Bilayers
Authors: Bourdelle K. K. , Boerma D. O. 
Published: March 2011

ABSTRACTNi foils and samples consisting of bilayers of Ni or Fe on Al, Ti or Si were implanted at room temperature with 15N+ ions to fluences of around 1×l017 N/cm2. The concentration depth profiles of 15N were determined with nuclear reaction analysis before and after vacuum annealing. It was found that the penetrability for N atoms of the surface and the solid/solid interface plays an important role in the N redistribution during implantation or annealing. The formation of a nitride layer or nitride clusters in Ni and Fe was deduced. Parameters for N migration determined for the metals under investigation are discussed in terms of models.
Epitaxial Phase Formation of FeSi2 in an Fe-Implanted Si by Ion Irradiation and Rapid Thermal Annealing
Authors: Lin X. W. , Behar M. , Desimoni J. , Bemas H. , Swider W. , Liliental-Weber Z. , Washburn J. 
Published: March 2011

ABSTRACTSi (001) wafers were implanted at room temperature with 50-keV Fe ions to different doses and subsequently crystallized either by rapid thermal annealing (RTA) (900°C, 120 s) or by Si+ irradiation (500 keV, 320 °C). Transmission electron microscopy, as well as Rutherford backscattering and channeling, were used to study the phase formation of FeSi2 in Si. Depending on the implantation dose and the crystallization process, three phases of FeSi2 were produced. While RTA results in the formation of β-FeSi2, ion irradiation promotes the growth of either cubic FeSi2 phase for low implantation doses (< = 4 at.% Fe) or a-FeSi2 for high implantation doses (≈18 at.% Fe). All these phases of FeSi2 were found to grow epitaxially in the Si matrix and their orientation relationships relative to Si have been determined. The interfacial energy between FeSi2 and Si appears to be an important factor in determining the final structure of FeSi2.
Microstructure of Zr3Al After 2 MeV Proton Bombardment
Authors: Chen F. C. , Ardell A. J. , Pedraza D. F. , Buhl R. A. 
Published: March 2011

ABSTRACTThe ordered intermetallic Ll2 alloy Zr3Al was irradiated with 2 MeV protons at -124 °C to fluences up to 2 × 1015 H+/mm2 and at 250 °C to fluences up to 1 × 1015 H+/mm2. Defects with spherically symmetric strain fields were produced at both irradiation temperatures. They are of interstitial character at -124 °C and vacancy character at 250 °C. Disordering is induced at -124 °C, whereas irradiating at 250 °C initially lowers, then slightly raises, the degree of long-range order above its unirradiated value. Additional defects that appear as black spots were imaged using superlattice reflections in dark field. For the low-temperature irradiations they were seen at all doses, but were present at only the lowest close for the high-temperature irradiations. They are probably disordered zones, although some of the zones may be amorphous at the higher doses in the low-temperature irradiations.
Resolution Limits of Focused-Ion-Beam Resist Patterning
Authors: Kubena R. L. 
Published: March 2011

ABSTRACTWe have recently demonstrated the ability to focus a 50-keV Ga+ beam to an 8-nm-diameter spot diameter. This ultra-high resolution probe has been used to study the resolution limits of conventional resists for focused-ion-beam lithography. Lines and dots in poly (methylmethacrylate) resist as small as 7–8 nm have been formed with high throughput. In addition, no proximity effects have been observed for 25 to 30-nm size features on high-z substrates. However, for the smallest geometries obtainable, the pattern fidelity and resolution are most likely limited by ion scattering effects and statistical dose fluctuations. The use of lighter ions (such as He, Li, or Be) with lower sensitivity resists should, in principle, allow focused-ion-beam lithography to be extended to the sub-5 nm regime.
Creation of 3D Patterns in Si by Focused Ga-Ion Beam and Anisotropic Wet Chemical Etching
Authors: Chen Wei , Chen P. , Madhukar A. , Viswanathan R. , So J. 
Published: March 2011

ABSTRACTWe report the realization of free standing 3D structures as tall as ∼ 7μm with nano-scale thickness in Si using the technique of Ga focused ion beam implantation and sputtering followed by wet chemical etching. Some of the previously investigated subjects such as anisotropie etching behavior of crystalline Si and etch stop effect of Ga+implanted Si etched in certain anisotropie chemical etchants have been further explored with the emphasis on exploiting them in realizing free standing structures. The design and fabrication considerations in achieving such free standing structures are discussed and some typical structures fabricated by this technique are shown.
Novel Materials Synthesis Using an Intense Pulsed Ion Beam
Authors: Gautier D. C. , Muenchausen R. E. , Rej D. J. , Roberts B. F. , Johnston G. , Waganarr W. J. 
Published: March 2011

ABSTRACTInitial experiments on the evaporation from metallic and ceramic targets using a pulsed light ion beam source is reported. The source is an intense ion beam produced by a 1.2 MV, 300 kJ Anaconda generator which has been fitted with an extraction diode.Beam fluences of 10–20 J/cm2 give a deposition rate of about 30–50 nm per shot, for both brass and YBa2Cu3O7-x (1–2–3) targets. This is about 1000 times greater than comparable rates from pulsed laser deposition (PLD). Single-shot ablated 1–2–3 films, deposited on Si, were analyzed using RBS; the measured stoichiometry was close to 1–2–3 in favorable cases, but shot-to-shot reproducibili ty was poor.Approximately 1% of the available ion beam energy was utilized for these initial experiments. The potential for producing large area coatings from multi-cation targets and nanophase powders using pulsed ion beam deposition will be discussed.
Laser Solid-Phase-Epitaxy of Amorphous Si1−xGex layer on Si
Authors: Sogoh Yasunori , Murakami Kouicbi , Nasuda Kohzoh 
Published: March 2011

ABSTRACTLaser Solid-phase-epitaxy (SPE) of amorphous Si1−xGex layer on Si formed by the molecular beam deposition (MBD) method was successfully performed by cw-Kr laser irradiation. Laser SPE of small areas was achieved by Laser irradiations of short time durations and high power densities The strain in the Laser-SPE layers was evaluated by micro-Raman scattering. It is demonstrated that strained SiGe layers on Si can be grown in the central area of 10μm size within the area crystallized by Laser- SPE at a substrate temperature of 400°C after preannealing at 350°C for 15 to 30 minutes.
Ion Beam Sputtering of Erbium Doped Fluoroaluminate Glass Films
Authors: Moore M. W. , Davey S. T. , Rothwell W. J. M. , Cannard P. J. 
Published: March 2011

ABSTRACTAr ion beam sputtering has been used to deposit fluoride glasses films up to a micron in thickness on silica and silicon substrates, Fluorozirconate films were found to be dark in colour, attributed to the presence of reduced chemical species. Fluoroaluminate films composed of fluorides less susceptible to reduction were clear and fluorescence from a layer doped with 2 wt% Er3+ is presented.
Angular Distribution of Electrons Elastically Scattered from Copper Surfaces, Polished and Textured by Argon Flux
Authors: Krainsky Isay L. 
Published: March 2011

ABSTRACTAngular distributions of the elastically scattered secondary electrons from two kinds of Cu surfaces, polished and textured by 2 keV Ar+ have been studied in the energy range from 50 eV to 2 keV. The results show that for the polished Cu surface the elastic scattering process is dominated by atomic scattering from single atoms (although, contributions from othei processes are also important). However when the textured surface was studied, new multiple peaks appeared on the angular distributions. Positions of these peaks for the various angles of incidence and primary energies indicate that their origin lies in the diffraction of the primary electrons on some kind of a polycrystalline structure. This structure is probably created by the process of recrystallization induced by ion sputtering similar to the sputtering induced crystallization process already known for some oxides and nonmetallic compounds.
Deep-Penetration Mechanism of Ion-Irradiation Defects in Al0.3Ga0.7As/GaAs Heterostructure Investigated by In Situ Hall Measurement
Authors: Kanayama Toshihiko , Takeuchi Yukihiro , Sugiyama Yoshinobu 
Published: March 2011

ABSTRACTTwo-dimensional electron gas 60–120-nm deep from the surface was irradiated with 10-keV Ar ions (projected range = 8.8 nm) and resulting change in the mobility was analyzed. Defect distribution thus obtained is exponential in depth with the larger penetration length for the lower irradiation temperature. In-situ Hall measurements revealed that the mobility decreases simultaneously with the irradiation at 90 K. Consequently, the deep penetration of defects is concluded to be mainly due to the ion channeling. Results of iso-chronal annealing indicate that thermal diffusion of the defect that affects the mobility takes place at around 340–400 K, whereas the mobility starts to recover at ∼120 K.
Shock Consolidation of Powders - Theory and Experiment
Authors: Vreeland T. , Kasiraj P. , Ahrens Thomas J. , Schwarz R. B. 
Published: March 2011

ABSTRACTA recently proposed model of shock consolidation of powders quantitatively predicts regimes of input energy and shock duration required to produce well-bonded compacts. A growing data base from shock experiments in which the shock wave and powder parameters of importance are controlled allows evaluation of the model.Rapidly solidified crystalline AISI 9310, and microcrystalline Markomet 3.11, as well as amorphous Markomet 1064 and crystalline Mo powders, have been consolidated by shocks up to 2 μsec duration. The formation of amorphous layers on Marko 3.11 particle surfaces indicates that surface melting and rapid solidification occurred. Decreasing amounts of amorphous structure are retained in Marko 3.11 and 1064 powder compacts with increasing shock energies. Significant improvement in Mo particle bonding is achieved by reducing surface oxides prior to shock consolidation.
Kinetics of Solidification at Rapid Rates
Authors: Peteves S.D. , Alvarez J. , Abbaschian G.J. 
Published: March 2011

ABSTRACTA novel technique was used to measure directly the interface temperature and growth rate during solidification of pure gallium. The technique utilizes the Seebeck emf generated across two solid-liquid interfaces to determine the interface supercooling and an optical microscope to measure the solidification rates. The growth rate measurements were made in the range of about 0.08 to 1400 μm/s for 1.59 to 3.6°C interface supercoolings (ΔT) on the (111) interface of high purity gallium in glass capillaries. A plot of logv vs. 1/T for dislocation-free interfaces followed two straight lines, one for higher than about 1 μm/s growth rates and the other for the lower rates. The data at the lower rates correspond to the lateral growth mechanism for which a single nucleus forms and spreads across the interface before formation of the next nucleus, while those at the higher solidification rates correspond to the lateral growth by the multi-nucleation and spreading mechanism.
Alloying Effects on the Hardness and Ductility of Metallic Glasses
Authors: Mordike B. L. , Hunger G. 
Published: March 2011

ABSTRACTHardness and ductility in Fe-M-B alloys were found to be directly dependent on the strength of the metal-metalloid bonding. This behaviour, as well as the annealing embrittlement, can be explained by the localized viscous flow model of heterogeneous deformation.