bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamics of Polyatomic Molecules in Porous Silica
Authors: Brodka A. , Zerda T.W. 
Published: March 2011

AbstractThe liquid-solid phase transition of cyclohexane in small pores of sol-gel glass is studied by computer simulation. A cavity model is obtained by placing silica clusters at the corners of a cubic box. A molecule inside the cavity is approximated by an assembly of six Lennard-Jones (LJ) potentials. Translational and rotational motions of C6H12 are studied in the temperature range from 190 K to 333 K. Supercooling is observed and the freezing temperature is depressed in comparison to the bulk phase.
Refractoriness of High-Current and Low Acceleration Voltage Arsenic-Ion Implanted Polycrystalline Silicon Against Fluorine Chemistry
Authors: Saito Yasuyuki 
Published: March 2011

ABSTRACTThe author observed that both high-current-ion-beam and low-accelerationvoltage arsenic-implanted polycrystalline silicon-film surfaces are resistant to radical-fluorine-gas-etching. If we accept the simple assumption that a depth profile of concentration distribution of the implanted high-dose As atoms in polycrystalline Si film can be expressed with a standardized distribution function in the previous report of S. Furukawa, H. matsumura, and H. Ishiwara [Jpn. J. Appl. Phys. 11, 134 (1972)], we can take the premise that the chemical bonding reaction itself between radical-fluorine atoms and silicon atoms is prevented rather than that the covering of an arsenic- metal thin layer like amorphous state prevents the chemical bonding- reaction. We present a model of the prevention Si-F bond formation by high-dose arsenic implantation at low acceleration voltage. The model seems to be related to potential barrier increase and lattice vibration suppression for electromagnetic force-phonon interaction.
Computer Simulations of Cluster-Solid Interactions: Energetic Clusters and Soft Landings
Authors: Ghaly Mai , Averback R. S. 
Published: March 2011

ABSTRACTThe interaction of small energetic clusters of Cu atoms with Cu surfaces has been investigated by molecular dynamics computer simulations. The simulations are fully dynamical and three dimensional; they employ embedded atom method potentials. The simulations described here are an extension of our past work on cluster solid interactions [1]. In this work, the effects of the angle of incidence, energy, size and temperature of the cluster are examined. In addition, soft landings of Cu clusters on Cu are simulated.
Raman Spectroscopy Analysis of Nitrogen Ion Implantation in Silicon and Correlation with Transmission Electron Microscopy
Authors: PéRez-Rodríguez A. , Romano-Rodríguez A. , Morante J. R. , Esteve J. , Montserrat J. 
Published: March 2011

ABSTRACTIn this work Si samples implanted with nitrogen (N+ or N2+) at a dose of 1017 cm−2 are characterized by Raman spectroscopy and cross section transmission electron microscopy (XTEM). The correlation between the Raman spectra obtained with different excitation wavelengths and XTEM observations allows to determine the structural features related to the layers contributing to the total spectra. The evolution of these features with the annealing treatments (up to 1150°C) is studied. The results obtained show, after the annealing treatment at the highest temperature, the presence of silicon nitride precipitates in the silicon subsurface region, and the formation of a nitrogen rich polycrystalline Si layer with Si3N4 grains. The Raman spectra from the subsurface region show a remaining shift of -0.15 cm−1 when compared to the spectra from unimplanted Si. This shift, together with the similar shape of both Raman lines, suggests the presence in this region of an average tensile stress of 37.5 MPa.
Ultra-Shallow P+/N Junctions Formed by SiF4 Preamorphization and BF3 Implantation Using Plasma Immersion Ion Implantation
Authors: Jones Erin C. , Im Seongil , Cheung Nathan W. 
Published: March 2011

ABSTRACTSub-100 nm P+/N junctions are fabricated by implanting wafers in the plasma immersion ion implantation system (PIII). Ions from SiF4 and BF3 plasmas are implanted at energies from 4–6 keV and 2 keV, respectively. The amorphous region formed by SiF4 im-plantion is shown to be effective in slowing B diffusion during a 10 sec, 1060°C rapid thermal anneal step. Channeling and transmission electron microscopy studies show the recrys-tallized amorphous region is comparable in quality to an unprocessed Si wafer, and the implantation and annealing sequence has no detrimental effects on the physical or electrical characteristics of fabricated devices. Diodes have forward ideality factors of 1.05 to 1.06 and reverse leakage as low as 2 nA/cm2 in the diode bulk at -5 V applied bias.
Retardation and Enhancement in Lateral Solid Phase Epitaxy of Si on SiO2 by MeV Electron Beam Irradiation
Authors: Saito S. , Okabayashi H. , Mori H. , Komatsu M. 
Published: March 2011

ABSTRACTWe have demonstrated the high energy (MeV) electron beam irradiation effects on lateral solid phase epitaxy (L-SPE) of Si-on-insulator (SOI). Thinned samples were set on a hot stage in a 2 MeV electron microscope and L-SPE growth under 2 MeV electron irradiation conditions was monitored in-situ by using the same microscope. L-SPE growth rate for the irradiation dose of 1021 cm−2 was enhanced by about 1.5 times greater than that under unirradiated condition. For electron beam irradiation doses higher than about 1023 cm−2, L-SPE growth was suppressed. Displacement of Si atoms, contamination effect and ionization effect are discussed as causes for the growth rate retardation and enhancement of L-SPE by electron beam irradiation.
Computer Simulation of Heat Flow Induced by Laser Irradiation in Presence of Heat Sinks or Sources
Authors: Tosto Sebastiano 
Published: March 2011

ABSTRACTThe paper concerns the computer simulation of heat flow induced on matter by laser irradiation in presence of heat sources or sinks. The model is 3D analytical and accounts for the dependence of thermal properties of matter on temperature. The results describe in particular the effect of a heat source due to a local phase change or solid state reaction releasing energy in a point of the laser affected zone. The purpose of the paper is to evidence how this additional energy affects the thermal field and then the heating and cooling rates. PACS 47.25.-Qv
A Mössbauer Study on Solid Krypton Precipitates in Aluminium and Silicon
Authors: Greuter M. J. W. , Niesen L. , Van Veen A. 
Published: March 2011

ABSTRACTMössbauer spectroscopy on the 9.4 keV transition in 83Kr is used to study inert gases in metals and semiconductors. An absorber was made by implanting 83Kr at 110 keV in Al foils to a total dose of 1.7· 1016 Kr cm−2, leading to the formation of small precipitates (bubbles). Spectra on the as-implanted sample were taken as a function of temperature for three 83RbI sources which differ in line shape due to a different water content. A model is presented to extract the absorber parameters from the spectra in a consistent way, in spite of the different sources used. The spectra of Kr bubbles in Al produced by high dose implantation show two components: a single line from Kr inside the bubble and a quadrupole split component from Kr at the Kr-Al interface. The total absorption area could be fitted very well assuming a simple Debye model, yielding a Debye temperature of ΘDT = 101(2) K. For the individual components we obtained Debye temperatures of ΘDQ = 98(6) K and ΘDS = 90(10) K. The isomer shift of the bulk fraction is significantly larger than that of a solid Kr layer at ambient pressure, reflecting the fact that the s-density increases under compression. The size of the precipitates can be estimated to be 1.5–1.8 nm. Thin KrSi films, produced by Kr plasma sputter deposition, were characterized using cross-sectional X-ray analysis. The results clearly show two different layers. Presumably, the film grows at first as c-Si with a low Kr concentration, but after having reached a certain critical thickness, further growth proceeds as a-Si with a high Kr concentration. For Mössbauer spectroscopy an absorber of 83KrSi was made by plasma deposition on an Al foil. The spectra can be fitted with a single line and a quadrupole component, both with isomer shifts much larger than found in the case of small Kr bubbles in Al. No change in the total absorbed area was observed from 4.2 to 200 K indicating a lower limit of 250 k for the Debye temperature. Both observations indicate that the Kr resides in very small clusters.
Cross-Sectional TEM Studies of DIGM in Irradiated Au-Cu Bilayers
Authors: Gao Yuzun , Alexander Dale E. , Rehn L. E. 
Published: March 2011

ABSTRACTCross-sectional transmission electron microscopy was used to study diffusion-induced grain boundary migration (DIGM) in irradiated and annealed Au/Cu bilayers. Using this technique, in combination with small probe X-ray energy dispersive spectroscopy, DIGM alloyed zones in Au were identified in an irradiated sample.
HREM of Electron Irradiated Quartz
Authors: Qin L. C. , Hobbs L. W. 
Published: March 2011

ABSTRACTIn situ electron irradiation has been carried out in transmission electron microscopes to monitor the dynamic evolution of α-quartz during the transition to the metamict state from the crystalline state. Crystals of different orientations were examined. HREM images were digitized and Fourier transformed to monitor degradation of periodicities. The final uniform metamict structure was characterized by radial distribution functions obtained from energy-filtered electron diffraction.
A Vibrational Analysis of Au Implanted Al2O3 Single Crystals: Ion and Thermal Annealing Effects
Authors: Henderson D. O. , Morgan S. H. , Mu R. , Chen N. , Magruder R. H. , White C. W. , Zuhr R. A. 
Published: March 2011

ABSTRACTThe implantation of Au into Al2O3 leads to disruption of the crystal order producing an amorphous layer. Annealing the implanted crystals at 1373 K restores the crystallinity and also imparts a purple color to the implanted layer which is attributed to a surface plasmon resulting from the formation of Au colloids.
Investigation of Ion Beam Mixing of Iron Marker Layers in Aluminum Oxide by RBS
Authors: Cooper Elizabeth A. , Nastasi Michael , Sickafus Kurt E. 
Published: March 2011

ABSTRACTThin films made with a thin embedded marker layer of iron or iron oxide in amorphous alumina were ion mixed with 210 keV Ar over a temperature range of RT to 750°C in vacuum. The dose range was 5×l015-7×l016ions/cm2with an average dose rate of 4.5×1012ions/cm2-sec. The resulting marker distributions were analyzed using RBS. Spreading of the iron RBS peak due to mixing into the alumina matrix was observed in the Fe2O3marker samples and was clearly seen to be a function of temperature (>400°C) and dose, whereas for the Fe marker sample, no such temperature dependence was observed. An activation energy for the thermally assisted ion mixing in the Fe2O3marker sample was determined to be 0.69 eV in comparison to an activation energy of 1.77 eV for samples that underwent only a thermal treatment.
Ion-Beam Amortization of Ca2La2(SiO4)6O2 Single Crystals
Authors: Weber William J. , Wang Lu-Min 
Published: March 2011

ABSTRACTSingle crystals of Ca2La8(SiO4)6O2 were irradiated with 1.5 MeV Xe+, 1.5 MeV Kr+, 1.0 MeV Ar+ and 0.8 MeV Ne+ ions to investigate the effects of recoil-energy spectrum, temperature, and crystallographic orientation on irradiation-induced amorphization. The irradiations were carried out using the HVEM-Tandem Facility at Argonne National Laboratory. The structural changes and the ion fluence for complete amorphization in the electron transparent thickness of the specimens were determined by in situ transmission electron microscopy. The displacement dose determined for complete amorphization was approximately 0.6 dpa for the Xe+, Kr+, and Ar+ ion irradiations but increased to 1.4 dpa for the Ne+ ion irradiations, which may reflect an effect of lower recoil energies. The ion fluence for complete amorphization increased exponentially with temperature over the range from 25 to 400°C. Amorphization was not observed at 500°C. The activation energy associated with this simultaneous annealing process was estimated to be 0.13 eV, and the critical amorphization temperature was estimated to be 438°C for the 1.5 MeV Kr+ irradiations.
Temperature Dependence of the Kinetics of Silicon Amorphization by He Ion Implantation
Authors: Laânab L. , Roumili A. , Faye M. M. , Gessinn N. , Claverie A. 
Published: March 2011

ABSTRACTWe have studied by XTEM the kinetics of Si amorphization by light ion implantation (He) as a function of substrate temperature. The analysis of these kinetics has been performed within the framework of the “Critical Damage Energy Density” model which is shown to apply for temperatures up to 250 K. There is a drastic change in the efficiency of the amorphization process at about 175 K. These results are discussed and explained by considering the different types of defects (I, V, I2, V2, complexes…) that can be stabilized in c-Si depending on the temperature. Above 150 K, the amorphization proceeds through the accumulation of interstitials and vacancies while at higher temperature it proceeds through the accumulation of di-interstitials and di-vacancies left in the network after annihilation and recombination of the Frenkel pairs created by the bombardment.
Crystallization of Tin-Implanted Amorphous Silicon Thin Films
Authors: Lin Fuyu , Hatalis Miltiadis K. 
Published: March 2011

ABSTRACTThe crystallization of Sn-implanted amorphous silicon was studied as a function of tin implant dose and annealing conditions by transmission electron microscopy. The films were implanted at an energy of 110 keV with a dose in the range of 5 × 1014 to 5×1016 cm−2 and were annealed at a temperature in the range of 450°C to 550°C. An enhanced rate of crystallization in amorphous Si-Sn films compared to the non-implanted amorphous silicon films during thermal annealing was observed. The crystallization process of Si films implanted with tin at a dose of 2.5×1016 cm−2 or less is very similar to unimplanted silicon films except higher nucleation rates and shorter crystallization time were observed with increasing tin dose. Films implanted with tin at a dose of 2.5×1016 cm−2 or more display extremely rapid crystallization (3 hours at 450°C) and very fine grain structure (10 nm); no substantial grain growth has been observed during lurther annealing, but some single crystal-like areas were formed. In-situ annealing of silicon implanted to 5×1016 cm−2 showed that the crystallization process is enhanced by the formation of the liquid tin phase.
Roughness Effects During Focused Ion Beam Repair of X-Ray Masks with Polycrystalline Tungsten Absorbers
Authors: Kola R. R. , Celler G. K. , Harriott L R. 
Published: March 2011

ABSTRACTTungsten is emerging as the absorber material of choice for x-ray masks due to recent advances in the deposition of low stress films. For a practical technology, the masks must be free from defects. These defects may be in the form of excess or missing absorber. Finely focused ion beams have been used for defect repair on x-ray masks, both for removal of excess absorber material by physical sputtering and for addition of absorber material by ion-induced deposition. The eifect of ion channeling in polycrystalline tungsten films is spatially nonuniform material removal during sputtering. Different grains will have significantly different sputtering yields, depending on their orientation with respect to the direction of the ion beam. The repaired features then suffer from roughness on the bottoms and sidewalls of the sputter craters. We have investigated the use of XeF2 assisted sputtering with a 20 keV Ga+ focused ion beam to reduce this roughness. The chemical etching component of the material removal lessens the directional dependence and therefore the roughness during defect repair. It was also found that chromium etch rate was reduced in the presence of XeF2 gas while the etch rate of W was enhanced so that the removal rate of Cr is much less than that of W. We can take advantage of this etch selectivity by using a thin Cr layer under the W absorber as an etch stop layer to eliminate the roughness at the bottom of the features and a thin layer of Cr on top of the W as an etch mask for reducing the sidewall roughness.
Solute Trapping in Metals
Authors: Smith Patrick M. , Reitanot Riccardo , Aziz Michael J. 
Published: March 2011

ABSTRACTMany of the advances in rapid solidification processing of metallic alloys exploit the trapping of solute which occurs at high solidification velocities. The difficulty of performing experiments which measure such high solidification velocities in metals has until now prevented accurate measurements of solute trapping in these systems. We have observed the transition from near-equilibrium solute partitioning to solute trapping during solidification at m/s velocities in aluminum alloys, and have compared the predictions of various solute trapping models. Aluminum thin films deposited on insulators were ion-implanted with Sn, Cu, Ge, and In, and were pulsed-laser melted; plane-front solidification was achieved, and regrowth velocities of 0.6 m/s to 5 m/s were measured with the transient conductance technique. Of the existing solute trapping models, the Continuous Growth Model of Aziz was found to fit the observed dependence of the partition coefficient on solidification velocity more closely than any other single-parameter model. The diffusive speed, which locates the transition from solute partitioning to solute trapping, was found to vary from 6 m/s to 38 m/s for various solutes in aluminum. We have examined correlations between the diffusive speed in the Continuous Growth Model and known alloy properties in order to allow better estimates of the diffusive speed to be made for alloy systems in which it has not been measured; the relation between the diffusive speed and the equilibrium partition coefficient will be discussed.
The Effect of CU Intermediate Layer made by IBAD on the CU Surface Film of E–Gun Evaporation
Authors: Yang Jie , Wang Chen , Tao Kun , Fan Yudien 
Published: March 2011

ABSTRACTCu intermediate layers (IL) by argon ion beam assisted deposition(IBAD) between substrates and Cu surface films (SF) deposited by electron-gun were made and their effect on the microstructure and properties of the Cu surface films were studied. Primary deposition variables were ion energy and substrates type. Trends in crystallographic texture, crystal-size and resistivity of Cu surface films with different IBAD layers on different substrates are significantly different. Analyzed by RBS, and XRD, the IBAD intermediate layer changed the crystallinity of Cu SF and increased the interface adhesion between the Cu SF and substrate. The experimental results shows that films with lower resistivity and better interface adhesion could be obtained by IBAD- PVD combined technique. The mechanism of crystallographic texture formation is also discussed.
Study of Oxygen-Ion-Beam-Assisted Evaporated Aluminum Oxide Films
Authors: Franzen W. , Tetreault T. , Kosik W. , Croft W. , Hirvonen J. K. 
Published: March 2011

ABSTRACTAluminum oxide films have been deposited by electron-beam evaporation on heated substrates under oxygen ion bombardment. Substrates were crystalline silicon, grafoil and glass. Both substrat temperature and ion current density were changed for each deposition The films deposited on silicon were examined by spectroscopie ellipsometry which showed that for substrate temperatures between 70°C and 250°C the index of refraction, and therefore the film density, first rose and then decreased with increasing ion current density. Ai 400°C the index reached a plateau under these conditions. Study by Rutherford backscattering of films deposited on grafoil showed no significant correlation between oxygen-aluminum stoichiometry and fi; density, suggesting that the decrease in density for large ion currei is not due to oxygen-ion incorporation, as has been suggested in the past. The films deposited on glass at 400°C showed some evidence of crystallization.
Formation of buried α- and β- FeSi2 in (100) Si by high dose ion implantation
Authors: Maex K. , Lauwers A. , Van Hove M. , Vandervorst W. , Van Rossum M. 
Published: March 2011

ABSTRACTA study on ion beam synthesis of buried α- and β-FeSi2 in >100< Si is presented. Phase formation has been investigated as a function of implant and anneal temperature. Layer characterization was performed by RBS, XRD, resistivity, spreading resistance and Hall effect measurements. Orientation effects in the layers have been observed depending on the implant temperature. Transport measurements show that die holes are the majority carriers in the semiconducting layers.
Ion Beam Synthesis of Buried CoSi2 Layers in SiGe Alloys
Authors: Jebasinski R. , Mantl S. , Dieker Chr. , Dederichs H. , Vescan L. , Butz R. 
Published: March 2011

ABSTRACTSynthesis of buried, epitaxial CoSi2 layers in Si1−xGex alloys (x =0.48 and x = 0.09) by 100 and 150 keV Co+ ion implantation and subsequent rapid thermal annealing was studied by X-Ray diffraction, Rutherford backscattering spectroscopy, He ion channeling, Auger Eectron Spectroscopy and Transmission Electron Microscopy. Buried single-crystal CoSi2 layers in the Si0.91Ge0.09 alloy containing ≈ 1 at% Ge were formed. The suicide formation causes an outdiffusion of Ge leading to an increase in the Ge concentration of the adjacent SiGe layers. In contrast, in the Si0.52Ge0.48 alloy no buried suicide layers could be produced.
Correlation of Optical Properties and Structural Analysis for Cobalt Silicide Layers Buried in Silicon
Authors: Perry C. H. , Lu F. , Namavar F. , Maruska H. P. 
Published: March 2011

ABSTRACTThe optical reflectivity from buried and exposed CoSi2 layers produced by Co ion implantation of Si substrates has been measured over the energy range 0.012–6.2 eV (0.2- 100 μm). Both unannealed and annealed layers were investigated. The complex dielectric constant of the bare CoSi2 layer was obtained from a Kramers-Kronig analysis. The plasma frequency, carrier concentration and relaxation time of the buried CoSi2 layers were obtained from classical dispersion analyses of the multicomponent reflectivity data. The effective carrier concentration derived from the optical data and the measured chaneling from Rutherford back scattering correlated with anneal temperature.
The Structure of Rapidly Solidified Powders of Ni3Al and Ni3 Al + B + Ti
Authors: Baker I. , Ichishita F. , Schulson E.M. 
Published: March 2011

ABSTRACTPowders of stoichiometric Ni3Al and Ni3Al containing boron and titanium were produced by rapid solidification rate (RSR) processing. Most particles were found to be spherical; some had skins and some contained holes. Fractured particles were found, indicating possible brittleness. Particle size distributions were log-normal with an arithmetic mean particle size of 23.5μm. Both alloys exhibited a dendritic structure in which compositional differences were present. In addition, stoichiometric Ni3Al contained interdendritic lamellae. X-ray diffractometry indicated that the powders were only partially ordered.
High Strength Nickel-Chromium-Molybdenum Microcrystalline Alloy Via Rapid Solidification Technology (Rst)
Authors: Panchanathan V. 
Published: March 2011

ABSTRACTThere is a growing national need for development of new improved materials having superior corrosion resistance combined with high mechanical strength. This paper discusses the properties and corrosion behavior of a new nickel-chromium-molybdenum microcrystalline alloy made via rapid solidification powder process, making it suitable for potential applications in corrosive environments. The alloy, called Markomet 1119, has the following composition in weight percent:Bal Ni, 20.3Cr, 22.8Mo, 2.9Fe, 0.5B, 0.8C.This is prepared as rapidly solidified powder by the method of a melt-spinning-pulverization process. The powder is consoldated into rods by hot extrusion. The mechanical properties and corrosion tests carried out on Markomet 1119 are reported. The microstructural feature of the alloy as investigated by SEM is also reported.