bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computer Simulation of Scattered Ion and Sputtered Species Effects in Ion Beam Sputter-Deposition of High Temperature Superconducting Thin Films
Authors: Krauss Alan R. , Auclello Orlando 
Published: March 2011

ABSTRACTIon beam sputter-deposition is a technique currently used by many groups to produce single and multicomponent thin films. This technique provides several advantages over other deposition methods, which include the capability for yielding higher film density, accurate stoichiometry control, and smooth surfaces. However, the relatively high kinetic energies associated with ion beam sputtering may lead to difficulties if the process is not properly controlled. Computer simulations have been performed to determine net deposition rates, as well as the secondary erosion, lattice damage, and gas implantation in the films, associated with primary ions scattered from elemental Y, Ba and Cu targets used to produce high temperature superconducting Y-Ba-Cu-O films. The simulations were performed using the TRIM code for different ion masses and kinetic energies, and different deposition geometries. Results are presented for primary beams of Ar+, Kr+ and Xe+ incident on Ba and Cu targets at 0° and 45° with respect to the surface normal, with the substrate positioned at 0° and 45°. The calculations indicate that the target composition, mass and kinetic energy of the primary beam, angle of incidence on the target, and position and orientation of the substrate affect the film damage and trapped primary beam gas by up to 5 orders of magnitude.
Fabrication of P-Type Cuinse2 Thin Film by MBD Using ECR Excited Nitrogen Ion Source
Authors: Nishitani M. , Negami T. , Terauchi M. , Wada T. , Hirao T. 
Published: March 2011

ABSTRACTPolycrystalline CuInSe2 thin films were prepared by coevaporation of the elements under the irradiation of nitrogenions excited by ECR plasma. Nitrogen atoms were doped uniformly in the obtained CuInSe2 films according to the SIMS analysis. The films showed p-type conduction even in the slightly In-rich region where the coevaporation films without the irradiation of nitrogen ions showed n-type conduction. These results show that p-type CuInSe2 thin films even in the slightly In-rich region can be fabricated by the irradiation of ECR excited nitrogen ions during its ternary coevaporation process.
Defect Structure of SiON Films Prepared by ECR Plasma CVD Method
Authors: Izumi T. , Matsumori T. , Kitagawa M. , Hirao T. 
Published: March 2011

ABSTRACTThe defect structure of silicon oxynitride films prepared by the ECR Plasma CVD method have been studied by ESR(electron spin resonance) method. The ESR analysis revealed the presence of three paramagnetic defects,that is, Si dangling bonds(g=2.0055 ΔHpp=8 Oe), Si dangling bonds with N atom neighbors(g=2.004, ΔHpp=12 Oe) and E-center(g=2.0016, ΔHpp=4 Oe). These centers strongly depend on the deposition conditions, such as gas flow rate, and microwave powers. The defect density is minimum for the deposition condition of SiON films, under the gas flow O2 /(N2 +02)ratio of 1/3, gas pressure of 8.3x10−4Torr and microwave power of 50OW.
Compositional Determinations of Oxide-Nitride-Oxide Stacked Dielectric
Authors: Waytena G.L. , Hren J. , Weiss J.K. , Rez P. , Fountain G.G. , Hattangady S.V. 
Published: March 2011

ABSTRACTElectron holography, and high spatial resolution (17Å) computer controlled Parallel Electron Energy Loss Spectrometry (PEELS) were used to probe the structure of and chemical profile across a thin silicon Oxide-Nitride-Oxide (ONO) layered structure of nominal width 10Å-50Å-10Å. We found that the layer widths are on the average 13Å-28Å-18Å, the first oxide layer was discontinuous, and the second oxide layer contained nitrogen. The nitride layer had a silicon to nitrogen concentration ratio of 1.0 ± 0.1. These results show, for the first time, the power of holography in characterizing thin, light element, amorphous layers and the importance of computer controlled parallel energy loss line scans for obtaining analytical information at the highest spatial resolution with minimum dose.
Low Energy Si Bombardment Effects on Epitaxial Si Growth
Authors: Kitabatake Makoto , Greene J. E. 
Published: March 2011

ABSTRACTMolecular dynamics simulations were used to follow low-energy ion/surface interactions in Si MBE including kinetic energy redistribution in the lattice as a function of time, projectile and lattice atom trajectories, and the nature, number, and depth of residual defects. The simulations were carried out using the Tersoff many-body potential for Si. Irradiation events were initiated with 10 and 50 eV Si atoms incident normal to the Si(001)2xl surface at an array of points in the primitive surface unit cell. Epitaxy, exchange reactions, and defect (vacancy and interstitial) formations were observed. Quasidynamic simulations suggested that the interstitials preferentially diffuse toward the surface and are annealed out over times corresponding to monolayer deposition at typical Si MBE growth temperatures.
Characterization of In Situ P-Type and N-Type Doped Si and GeXSi1−X Films Grown by Low Temperature Remote Plasma Chemical Vapor Deposition
Authors: Thomas S. , Irby J. , Kinosky D. , Qian R. , Iqbal I. , Mahajan A. , Banerjee S. , Tasch A. , Magee C. 
Published: March 2011

ABSTRACTLow temperature Si and Si1−xGex epitaxy is one of the major thrusts in the trend towards low temperature Si processing for future generation ULSI circuits and novel Si-based devices. A remote plasma-enhanced chemical vapor deposition (RPCVD) technique has been developed to achieve Si homoepitaxy and Si1−xGex heteroepitaxy at low temperatures (≤450'C). P-type films have been grown by introducing 90 ppm or 5000 ppm B2H6/He into the system during the growth process to achieve in situ electrically active boron doping. A mesa diode structure with minimal thermal budget in the fabrication process has been employed to evaluate the properties of the boron-doped Si and Si1−xGex films grown at 450°C by RPCVD. Leakage current densities are reduced for diodes grown at 14–18 W (40–50 Å/min. growth rates) compared to similar devices grown at 6.6 W (5 Å/min.). N-type films have been grown by the introduction of 50 ppm PH3/He. Secondary ion mass spectroscopy (SIMS) has been employed to analyze the boron and phosphorus incorporation efficiencies and doping profiles under different conditions. Boron and phosphorus doping profile transitions as sharp as 50–100 Å/decade have been achieved. Transmission electron microscopy (TEM) has been used to investigate the microstructure of the B-doped films.
The Role of Ion Beam Assisted Surface Chemistry in Etching: Adsorption and Reactions of ALKYL Halides
Authors: Marshall Duncan , Jackman Richard B. 
Published: March 2011

ABSTRACTThe form of ideal surface chemistry that is necessary for chemically assisted ion beam etching (CAIBE), with particular reference to in-situ processing is considered. Whilst to date CAIBE has been almost exclusively carried out with chlorine, distinct advantages exist if a compound that which displays spontaneous reactivity which is limited to one or two monolayers can be used. The role of alkyl halides in this scenario has been investigated through the use of surface spectroscopic probes to investigate the microscopic chemical and ion beam assisted reactivity that may be achieved. Dichloroethane has been found to display promising behaviour.
Synthesis of Cupric Oxide Films using Mass-Separated Low-Energy O+ Beams
Authors: Kita R. , Hase T. , Itti R. , Sasaki M. , Morishita T. 
Published: March 2011

ABSTRACTWe report the epitaxial growth of CuO thin films prepared by lowenergy and high-density O+ ion beams mass-separated from an oxygen plasma. We have successfully produced O+ beams of 50 μA/cm2 while maintaining an ambient pressure of 3×10−9 Torr during the growth. CuO grows on MgO(100) with epitaxial relationship of (111)CuO // (100)MgO and [110]CuO // [110]MgO at room temperature and even under conditions where the flux density of O+ beams is at least one order of magnitude lower than the minimum flux density of O2 required to form CuO.
Advanced Ion Beam Material Processing Projects in Japan
Authors: Yamada Isao 
Published: March 2011

ABSTRACTR&D projects of ion beam systems and ion beam process technology have been conducted under the National Research and Development Program known as the “Large-Scale project”. The project includes development of five large-scale ion beam systems and their application for surface modifications. Under another program called the National Research Facility Development Project, the Ion Engineering Center Corporation has been established in order to promote industrial applications of ion beam processes. This paper reviews those projects and recent progress on development of large-scale ion beam systems and related materials processing technology. Major research projects which have been funded by the Ministry of Education for ion beam related researches are also reviewed.
Atomic and Molecular Beam Studies of Etching and Related Surface Chemistries
Authors: Coburn J.W. 
Published: March 2011

ABSTRACTResults will be presented using a new ultrahigh vacuum system designed to investigate the complex surface chemistries prevailing in plasma-assisted etching processes which use more than one halogen or halogen-hydrogen gas mixtures. In this new apparatus, two separate controllable beams of atoms can be directed onto a surface and energetic ion bombardment of the surface can be introduced. Neutral species evolved or reflected from the surface are monitored with modulated beam mass spectrometry. Etch rates as small as 10−3 Å/sec can be detected. The chemical systems which have been used are Si-F-Cl, Si-F-H and Si-CI-H and some unexpected phenomena observed with these systems will be described. Some catalytic reactions have also been observed with these gases in the presence of polycrystalline Ni and Pd surfaces and another example of an oscillatory surface reaction has been found.
Edge-On Ion Irradiation of Electron Microscope Specimens
Authors: Otero Mauro P. , Allen Charles W. 
Published: March 2011

ABSTRACTA special technique is described for in situ transmission electron microscope (TEM) experiments involving simultaneous ion irradiation, in which the resultant phenomena are observed as in a cross-section TEM specimen. That is, instead of ion-irradiating the film or foil specimen normal to the major surfaces and observing in plan view (i.e., in the same direction), the specimen is irradiated edge-on (i.e., parallel to the major surfaces) and is observed normal to the depth direction with respect to the irradiation. The results of amorphization of Si, irradiated in this orientation by 1 or 1.5 MeV Kr, are presented and briefly compared with the usual plan view observations. The limitations of the technique are discussed and several experiments which might profitably employ this technique are suggested.
Amorphization of PLZT Material by 1.5 MeV Krypton Ion Irradiation with In Situ TEM Observation
Authors: Wang L.M. , Wu A.Y. , Ewing R.C. 
Published: March 2011

ABSTRACTPLZT 9/65/35 single crystals were irradiated with 1.5 MeV krypton ions at 25–450°C in the HVEM-Tandem Facility at Argonne National Laboratory. In-situ TEM was performed during irradiation in order to determine the critical amorphization dose. At room temperature, the material was completely amorphized after a dose of only 1.9×1014 ions/cm2, less than one fifth of the critical amorphization dose for silicon (1×1015 ions/cm2). The critical amorphization dose for the PLZT material increased with increasing irradiation temperature. At 450°C, amorphization was not observed after a dose of 1.1×10 15ions/cm2.
Optical Technique for Characterization of High Energy Ion Implanted Materials
Authors: Aizenberg Gustavo E , Swart Pieter L , Lacquet Beatrys M 
Published: March 2011

ABSTRACTA new method for the characterization of high energy ion-implanted materials has been developed. The refractive index and thickness of the amorphous layer produced by ion-implantation as well as the recrystallized layer formed by annealing of the ionimplanted samples can be determined by means of this non-destructive optical technique.For frequencies where the carriers do not respond, the measured reflectance is bilinear transformed, and further digital signal processing yields information about thickness and refractive index of the abovementioned layers. When working at optical frequencies where the carriers can respond to the electromagnetic field the physical position of the peak concentration follows directly from the processed reflectance data. Simulated and experimental data have been analyzed. The position of the boundaries between the amorphous, recrystallized and substrate zones, as well as the position of the carrier concentration peak can be determined for various steps of annealing. The algorithm has the advantage of being simple and time efficient.
Radiolytic Modification of Gas Sensor Surface Chemistry
Authors: Sofield C J , Guppy R M , Merdrignac O M , Moseley P T , Moore V J , Peat R 
Published: March 2011

ABSTRACTThe surfaces of thin films of tin dioxide prepared by radio frequency sputtering have been driven to react with nitrogen by exposure to a proton beam in an atmosphere containing nitrogen gas. Such modification of the composition of the free surfaces of the films modifies their gas response characteristics substantially.The effects of modifying the surface of tin dioxide by exposure to proton beams in air have been demonstrated for thin films prepared both by tputtering and by dip coating with a sol.
The Effect of Atomic Mixing on the Depth Profiles of Metal Markers in Silicon
Authors: King B. V. , Tonn D. G. , Tsong I.S.T. , Leavitt J. A. 
Published: March 2011

ABSTRACTAtomic mixing effects of sputter depth-profiles are modeled by a diffusion theory with a depth-dependent diffusion constant D. The model is compared to SIMS depth profiles, using 5 keV Ar+ bombardment of dilute thin-film multilayers of Al, Ag, Ti and Mo in silicon. The experimental values of D can be explained by cascade mixing and radiation enhanced diffusion within the cascade for Al, Ag and Ti markers but not for the Mo marker.
Microstructural Developments During Implantation of Metals
Authors: Potter D. I. , Ahmed M. , Lamond S. 
Published: March 2011

ABSTRACTThe chemical and microstructural changes caused by the direct implantation of solutes into metals are examined. The particular case involving Al+-ion implantation into nickel is treated in detail. Chemical composition profiles measured using Auger spectroscopy and Rutherford backscattering, and average near-surface chemical composition measured using an analytical electron microscope, are compared with model calculations. The microstructures that develop during implantation are investigated using transmission electron microscopy. For low fluences implanted near room temperature, these microstructures contain dislocations and dislocation loops. Dislocation loops, dislocations, and voids result from implantations at temperatures near 500°C. Higher fluences at these elevated temperatures produce precipitates when the composition of implanted solute lies in a two-phase region of the phase diagram. Implanted concentrations corresponding to intermetallic compounds produce continuous layers of these compounds. Room temperature, as compared to elevated temperature, implantation may produce the same phases at the appropriate concentrations, e.g. β'-NiAl, or different phases, depending on the relative stability of the phases involved.
The Development of the Amorphous Phase in NiTi During Heavy Ion or Electron Bombardment
Authors: Brimhall J. L. , Kissinger H. E. , Pelton A. R. 
Published: March 2011

ABSTRACTA supralinear dose dependence for the amorphous transformation was observed in NiTi during bombardment with 2.5 MeV Ni+ ions. These results are consistent with a mechanism that requires cascade overlap to obtain a critical defect density for the amorphous transformation. Direct amorphization in the cascades was not resolvable. The temperature dependence of the minimum dose required for complete amorphous transformation had the same form as that observed for amorphization of silicon. Amorphization caused by electron bombardment required a higher dose than by ion bombardment. Different degrees of homogeneity of the damage state between ions and electrons can explain the dose dependence on particle type.
Hvem and Internal Oxidation Studies of Lithiated Nickel
Authors: Seshan K. , Baldo P. , Wiedersich H. 
Published: March 2011

ABSTRACTPure, polycrystalline nickel samples were implanted with lithium to doses up to 5 × 1017 lithium ions per square centimeter, at a temperature of 500°C, such that the implantation damage would anneal. These samples were then prepared for electron microscopy and examined at 1 MeV, in the Argonne National Laboratory HVEM facility. It was observed that compared to pure nickel, the lithium implanted nickel showed a different radiation damage behaviour. A plausible explanation for the difference in behaviour is presented in this paper.The lithium implanted nickel, in the high dose samples, also showed an unusual form of precipitation. Electron microscopy revealed the precipitates to have truncated octahedral shapes with {111} planes for sides and {100} planes truncating the corners. They resemble voids and helium bubbles in nickel. The precipitates appear to be associated with dislocations. The lithium implanted nickel was internally oxidized in order to obtain evidence for the presence of lithium. Electron diffraction analysis of the internally oxidized lithiated nickel showed the presence of a topo-taxial compound being formed, with an ordered NaCl-structure. Possible interpretations of this diffraction pattern are discussed.
Epitaxial Crystallisation of Doped Amorphous Silicon
Authors: Elliman R.G. , Johnson S.T. , Short K.T. , Williams J.S. 
Published: March 2011

ABSTRACTThis paper outlines a model to account for the influence of doping and electronic processes on the solid phase epitaxial regrowth rate of ion implanted (100) silicon. In addition we present data which illustrates good quality epitaxial crystallisation of silicon at 400°C induced by He+ ion irradiation. We tentatively suggest that electronic energy-loss processes may be responsible for this behaviour.
Ion-Beam-Induced Damaging and Dynamic Annealing Processes in Silicon
Authors: Short K.T. , Chivers D.J. , Elliman R.G. , Liu J. , Pogany A.P. , Wagenfeld H. , Williams J.S. 
Published: March 2011

ABSTRACTWe have employed high resolution ion channeling and TEM methods to investigate the damage production and dynamic annealing processes which take place in (100) silicon bombarded at elevated temperatures. Two important observations have arisen from our results i) We have observed an amorphisation process for Sb-implanted silicon at 250°C which is more akin to amorphisation processes in metals, whereby the impurity (Sb) appears to influence the stability of amorphous zones associated with individual ion tracks. ii) We have demonstrated that previously amorphised layers in silicon can be recrystallised through a solid phase epitaxial process by subsequent bombardment with He+, Ar+ and Sb+ ions at substrate temperatures of 300–400°C, which are significantly below normal thermal regrowth temperatures of >500°C.
Characterization of N-Type Layers Formed in Si by Ion Implantation of Hydrogen
Authors: Wilson S. R. , Paulson W. M. , Krolikowski W. F. , Fathy D. , Gressett J. D. , Hamdi A. H. , Mcdaniel F. D. 
Published: March 2011

ABSTRACTSilicon wafers have been implanted with H+ (90 keV) to doses of 5.0E15/ cm2 and 2.OE16/cm2. The wafers were annealed in nitrogen at temperatures between 450 and 700°C for times between 10 and 60 min. The electrically active carrier profiles were measured by capacitance voltage and spreading resistance techniques. The residual damage was measured by TEM and RBS. The electrical measurements were essentially the same in both FZ and CZ silicon implying that oxygen is not playing a role in the donor formation which was observed. The donor concentration peaks near the projected range of the hydrogen after annealing at temperatures between 450–500°C. As reported previously 1000 H+ ions generate 1 donor in the implant peak. In addition, the donor concentration between the surface and Rp has increased more than a factor of 10 above the background concentration after a 450°C 10 min anneal. Anneals of 550°C for 30 min or more annihilates essentially all of the donors. The RBS results show small amounts of damage for the 5.0E15/cm2 implant dose but considerable crystal damage with a dose of 2.0E16/cm2, even after a 500°C, 30 min anneal. Cross-sectional TEM analysis of 500°C annealed samples showed a large number of small loops at depths corresonding to the depth of the peak electrical carrier concentration. The donors are directly correlated to the implant damage and resultant defects. SIMS data shows little diffusion for anneals of 500°C or less but after 550°C, 30 min the peak H concentration decreases by approximately a factor of 10.
Ion Mixing Processes
Authors: Nicolet Marc-A. , Banwell T. C. , Paine B. M. 
Published: March 2011

ABSTRACTWe consider ion mixing in the low temperature regime, where it is insensitive to temperature. Mixing of most thin markers is Gaussian, independent of irradiation flux, and varies linearly with fluence. However, the mixing in some media varies widely between markers of similar mass and appears to correlate with thermal diffusion constants. In bilayer systems, the profile of long-range mixing is exponential, and the number of mixed atoms scales linearly with fluence. This can be modeled successfully with simple collisional theory. Short range mixing scales with the square root of the fluence, but again shows strong correlations with known bulk chemical properties. We conclude that chemical driving forces and low energy transport mechanisms such as interstitial migration play major roles in ion mixing, even at low temperatures.
Spatial Correlation Interpretation of Effects of As+ Implantation on the Raman Spectra of GaAs
Authors: Aspnes D.E. , Tiong K.K. , Amirtharaj P.M. , Pollak F.H. 
Published: March 2011

ABSTRACTThe red shift and asymmetric broadening of the LO phonon mode of ion-implanted GaAs are both described quantitatively by a spatial correlation model based on a damage-induced relaxation of the momentum selection rule previously used by Richter, Wang, and Ley to describe similar effects in microcrystalline Si. The success of the model for a qualitatively different disorder microstructure suggests it may be possible to evaluate average sizes of crystallographically perfect regions in semiconductors from the phonon lineshapes of their Raman spectra.
Effects of Double-Implant on the Epitaxial Growth of Amorphous Silicon
Authors: Chen L.J. , Nieh C.W. 
Published: March 2011

ABSTRACTInvestigation has been made on the effects of double implant of BF2+−As+, BF2+−P+, B+−As+ and B+−P+ on the thermal annealing behaviors of silicon. For specimens with As+ or P+ as the major dopants, the annealing behaviors were similar to those singly implanted with As+ or P+. For samples with BF2+ or B+ as the major impurities, drastic changes in annealing characteristics were found in comparison with BF2+ or B+ single implant specimens. High density twins, including primary twins on all four {111{ planes and twelve types of secondary twins were observed in BF2+−As+ and BF2+−P+ double implant samples.