bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructural and Magnetic Characterization of Ni Films with In-Plane Anisotropy Induced by Ion Bombardment During Growth
Authors: Lewis W. A. , Saffari H. , Farle M. , Kay E. , Hagstrom S. B. 
Published: March 2011

ABSTRACTNi films 250 to 1500 Å thick are prepared on polished amorphous quartz substrates in ultrahigh vacuum by ion beam sputter deposition. The growing film is bombarded simultaneously with Xe+ ions at an oblique angle of incidence. The structural and magnetic modifications are studied for different film thicknesses as a function of Xe+ ion energies (50–200 eV) and relative flux of arriving Ni atoms/Xe ions at the substrate. Lattice spacings and degree of texturing are determined by x-ray diffraction. Magnetic in-plane anisotropy is determined by longitudinal magneto-optic Kerr effect measurements. Our results show that an uniaxial in-plane magnetic anisotropy is induced with the hard magnetization direction parallel to the plane of incidence of the secondary Xe+ ions, and a (111) texture with an increased plane spacing of 0.5% is measured. The microstructure of the film and the magnitude of the anisotropy is sensitive to film thickness and flux ratio. For films prepared without secondary ion bombardment, the plane spacings correspond to those for bulk Ni, and isotropic magnetic behavior is observed.
Effect of Concurrent Ion Bombardment on Structure and Composition of Ion Sputter-Deposited Ni-Ti Thin Films
Authors: Grummon D. S. , Chang L. 
Published: March 2011

ABSTRACTThin films of approximately equiatomic NiTi have been produced by ion beam sputtering, and by ion beam assisted deposition (IBAD), using 0.1 and 0.5 keV argon ions at fluences giving ion/atom arrival ratios (R-ratios) ranging between 0.26 and 2.21. Ion beam sputtering produced amorphous films which showed several percent titanium loss relative to the alloy target composition. Concurrent irradiation of the growing films with argon ions accentuated the titanium depletion, and R-ratios greater than approximately 1.4 at an assist-beam energy of 0.5keV produced resputtering rates that exceeded the deposition rate. Analysis of experiments with assist-beam energies of 0.5 keV produced a value of 1.75 for εTi/εNi, the ratio of sputteryields for titanium and nickel, in an amorphous alloy film at approximately 325K. Though data for 0.1 keV assist-beam irradiation could be interpreted to yield a similar value for εTi/εNi, resputtering at these energies displayed unexpected dependencies on R-ratio, and is apparently sensitive to the assist-beam incidence angle as well as the R-ratio. No evidence of crystallization of the films was found for the R-ratios examined. However, concurrent ion irradiation produced phenomenological evidence of short range ordering. Nanophase precipitates observed in TEM foils from films produced by ion beam assisted deposition, discovered in previous work and there identified as Ni3Ti, have been found in fact to be titanium nitride.
Effects of Nitrogen Ion Energy on the Growth Mode of WN Films Deposited by Reactive Ion Beam Sputtering
Authors: Benhocine A.H. , Meyer F. , Eizenberg M. , Bouchier D. , Kianfar S. 
Published: March 2011

ABSTRACTWN films were deposited on clean Si substrates by Reactive Ion Beam Sputtering in a UHV system. The growth mode of the films as a function of the nitrogen ion energy was investigated by in situ Auger Electron Spectrometry. The energy of the incident ions was varied from 250 eV to 3 keV. We observed a significant nitridation of the silicon at the very beginning of the deposition. This nitridation is more pronounced for the lower energy and is more reduced for 2 keV-ions. It seems to follow the trend of the film composition: 250 eV-ions and 2 keV-ions result in N-rich films (N/W≈1) and W-rich films (N/W≈0.5), respectively. All these results are discussed in terms of sputtering yield, backscattering and sticking coefficient and are explained by taking into account: first, the interaction between the incident ions and the target, and second, the interaction between the species emitted by the target and the growing film.
Thermal and Collisional Effects on the Intrinsic Stress in Nitride Layers Deposited by Ion-Beam Based Techniques
Authors: Djouadi M.A. , BOUCHIER D. 
Published: March 2011

ABSTRACTIn IBAD BN and RIBSD Si3N4 layers deposited at room temperature, the internal stress can always be reduced below -1 GPa by a post-deposition annealing. When the deposition temperature is increased up to 600°C, the stress in Si3N4 layers is not significantly reduced and, in IBAD BN films, it is even greater than expected from the development of the thermal stress, which indicates that no relaxation of the stress occurs during deposition. This implies that the spatial extent of the ion peening effect may largely exceed the penetration depth of ions and of recoil atoms in the solid. In order to confirm this hypothesis, sequences of deposition/in situ annealing/deposition have been performed. In RIBSD films, the relaxation of the annealed sublayer can be observed. In IBAD films, the deposition of the upper layer results in an increase of the stress in the superficial zone of the annealed sublayer.
Investigation of titanium nitride films prepared by ion-beam-assisted deposition at high Ar+/Ti ratio
Authors: Hsieh J. H. , Bush D. E. , Erck R. A. , Fenske G. R. , Nichols F. A. 
Published: March 2011

ABSTRACTTitanium nitride films were prepared by reactive ion beam assisted deposition (RIBAD) with Ar+/Ti ratios ranging from 1.0 to 2.3. The compositions, phases and textures of these films were studied by AES and XRD as a function of Ar+/Ti ratio and nitrogen partial pressure. The results indicate that the IBAD titanium nitride films deposited at high Ar+/Ti ratio and low nitrogen partial pressure may have reduced nitrogen concentration, (200) preferred orientation, and possibly contain the Ti2N phase.
Molecular Dynamics Simulations of Ion Beam Mixing at Subthreshold Energies in Metallic Superlattices Structural Effects
Authors: Mazzone A. M. 
Published: March 2011

ABSTRACTThis work presents results of molecular dynamics simulations of the intermixing of a heterostructure formed by a Fe-Ag bilayer of thickness of few tens of Å. The intermixing is generated by As+ ions with energy of few eV. It has been found that the structure of the lattice has profound effects on mixing and disordering.
Physical and Chemical Effects of Focused Ga-Ion Beam on GaAs (100)
Authors: Chen Wei , Chen P. , Viswanathan R. , Madhukar A. , Chen Jun , Kaviani Kian , Xie Q. , Hu Kezhong 
Published: March 2011

ABSTRACTGa droplet formation on GaAs(100) substrates milled by focused Ga ion beam is studied using scanning electron microscopy and scanning Auger microscopy. It is found that Ga droplet formation requires a threshold Ga+ dose of ∽ 1016/cm 2 and is closely correlated to the formation of Ga overlayer at the milled surface and the increase in Ga concentration by ∽ 32% in the subsurface region. The Ga droplet evolution appears to be driven by the instantaneous energy deposited continuously by the ions.
Temperature Dependence of Ion-Beam-Induced In-Plane Stress in Silicon
Authors: Yuan J. Z. , Hartmann R. , Verner I. V. , Corbett J. W. 
Published: March 2011

ABSTRACTExperiments were conducted to determine the sample temperature dependence of ion-beaminduced in-plane stress in silicon. Implantations were carried out for B+, Ar+ and Ti+ at various dose ranges and different silicon temperatures. The ion-beam-induced surface stress was measured by using a newly developed technique, which has a high sensitivity. A large abnormal stress was observed for B+ implantation at room temperature. The results show that the silicon temperature has a significant effect on the ion-beam-induced stress. The influence of temperature on stress curves were presented. This effect is consistent with the temperature effect on the ionbeam-induced amorphization of silicon. However, the effect on chemically active ions, such as B+, is significant, indicating that some preferable temperature can be used for minimizing ionimplantation-induced stress.
Correlation between Chemical Modification and Generated Refractive Index on Ion Implanted PMMA
Authors: Kallweit R. , Roll U. , Eichinger P. , Strack H. , Pöcker A. 
Published: March 2011

ABSTRACTThe optical characteristics of polymethylmetacrylate (PMMA) can be changed selectively with the aid of ion implantation. This can be explained by the manner in which the chain molecules are decomposed by the bombardment. New binding states can be identified by means of XPS on the irradiated surface and traced throughout the implantation depth using dynamic SIMS. In order to avoid chemical reactions, inert gas ions, ranging from He to Xe, have been implanted at energies between 100 keV and 380 keV, and fluences from 1 × 1013 /cm2 to 7 × 1015 /cm2. The results indicate a correlation of the refractive index and the surface layer contraction with surface CH- and COH-groups generation (XPS) and with in-depth damage described by the emission of secondary ions with masses 26 and 42 (SIMS), assigned to (CH2)- and (C2OH2)-.
Oxygen-Doped-Silicon/Silicon Heterointerfaces by Ion Implantation
Authors: Srikanth K. , Ashok S. 
Published: March 2011

ABSTRACTWe have investigated oxygen ion implantation at substoichiometric doses for bandgap modification in silicon. Redistribution of the oxygen atoms during the high temperature anneal results in sharp interfaces aiding the formation of a heterojunction. A most interesting observation is the presence of donors in the vicinity of the implanted region, resulting in extensive counterdoping. Mesa type diodes on the implanted sample exhibit excellent rectification with a diode ideality factor n of 1.2 and a reverse saturation current density of 1 × 10−8 A/cm 2. The near surface region is shown to be crucial for achieving the high rectification behavior.
Detailed Model of the Afterglow Region of a Microwave Generated Oxygen Plasma
Authors: Chou Chin-Hao , Wei Ta-Chin , Phillips Jonathan 
Published: March 2011

ABSTRACTA one dimensional mass continuity equation was used to model a low pressure, high radical concentration, non-isothermal oxygen afterglow reactor. The mathematics are very similar to those used to model flames. It was shown that the model, with no adjustable parameters, yielded very good agreement with experimental measures of O-atom flux. The model was manipulated to study the influence of temperature profile, pressure, homogeneous and heterogeneous kinetics, O-atom generation and flow rate on the afterglow plasma.
New Approaches for Dry Etching Metal Oxides at low Temperature and High Rates
Authors: Rousseau Francois , Jain A. , Perry L. , Farkas J. , Kodas T. T. , Hampden-Smith M. J. , Paffett M. , Muenchausen R. 
Published: March 2011

ABSTRACTThe reactions of metal oxides including CuO, ZnO, V2O5, and PbO with 1,1,1,5,5,5-hexaflouro- 2,4-pentanedione (hfacH) were investigated. A hot-wall reactor was used to react hfacH with metal oxide powders to form sufficient quantities of volatile reaction products for characterization by Infrared Spectroscopy (IR), Elemental Analysis (EA), Nuclear Magnetic Resonance (NMR), Mass Spectroscopy (MS), Thermogravimetric Analysis and Differential Thermal Analysis (DTA). PbO, ZnO and CuO powders reacted rapidly at 200 °C to form the corresponding metal β-diketonates and V2O5 reacted to give OV(hfac)2. A differential cold-wall reactor was to used to measure etch rates of CuOx films as a function of temperature and hfacH partial pressure. AES and XPS analysis of the laser ablation deposited CuOx film annealed in an O2 atmosphere revealed that the film was composed of CuO and Cu2O. Etch rates of up to a I l.βm/min at hfacH partial pressure of 1 Torr at 270 °C were obtained. Laser induced etching of the same CuOx film with hfacH showed evidence of copper oxide removal.
Removal of Surface Carbon Impurities from Ultra-Low Loss Fluoride Glasses
Authors: Sanghera J. S. , Pureza P. C. , Aggarwal I. D. 
Published: March 2011

ABSTRACTThis paper describes a novel route for removal of surface carbon from heavy-metal fluoride glasses melted in vitreous carbon crucibles. The technique utilizes dry etching with active fluorine produced in a NF3 plasma generated in a microwave cavity.
Amorphous Soft Magnetic Material Formation by Ion Mixing
Authors: Gerard P. , Suran G. , Blanchard B. , Devenyi J. , Dupuy M. , Martin P. 
Published: March 2011

ABSTRACTIon mixing of FeNi-Si multilayers is performed at the same dose of 3.1015 Xe+ cm−2 with either of the three energies 200, 300 or 400 keV. The irradiation is done at liquid nitrogen temperature (LNT) or at room temperature (RT). The mixed layers are characterized by reflection high energy electron diffraction (RHEED), transmission electron microscopy (TEM), Rutherford backscattering (RBS), secondary ion mass spectroscopy (SIMS) and ferromagnetic resonance (FMR). Films made at 400 keV are more reproducible and as homogeneous as the best amorphous films realized up to now, using sputtering techniques.
A New Hafnium-Beryllium System Prioduced by Ion Implantation and Annealing Techniques
Authors: Soares J.C. , Melo A.A. , DA Silva M.F. , Alves E.J. , Freitag K. , Vianden R. 
Published: March 2011

ABSTRACTLow and high dose hafnium imolanted beryllium samoles have been prepared at room temperature by ion implantation of beryllium commercial foils and single crystals. These samples have been studied before and after annealing with the time differential perturbed angular correlation method (TDPAC) and with Rutherford backscattering and channeling techniques. A new metastable system has been discovered in TDPAC-measurements in a low dose hafnium implanted beryllium foil annealed at 500°C. Channeling measurements show that the hafnium atoms after annealing, are in the regular tetrahedral sites but dislocated from the previous position occupied after implantation. The formation of this system is connected with the redistribution of oxygen in a thin layer under the surface. This effect does not take place precisely at the same temperature in foils and in single crystals.
Implantation Induced Filamentary Structures
Authors: Jaussaud C. , Maillot B. , Bruel M. 
Published: March 2011

ABSTRACTHeavy rare gases implantations have been performed in layered structures : Sb/In/Si bulk and Sb/Ga/Si bulk. Layer thicknesses lie in the range of 150 Å – 600 Å, ion doses in the range of 1014 cm−2 – 1016cm−2Ion implantation induces in such structures a change in the visual aspect from a metallic appearance to a dark black aspect. This modification corresponds to the creation of voids with, as a consequence, the expansion of the structure. This effect is so important that even for low and medium doses, the structure becomes filamentary. Expansions as high as 2,8 μm have been measured. SEM photographs illustrate this spectacular effect.Relations between expansion and implantation parameters are given. A comparison between this effect and those observed in bulk InSb, GaSb and Ge is presented.
Ion-Beam Processing of Ion-Implanted Si
Authors: Dietrich H.B. , Corazzi R.J. , Tseng W.F. 
Published: March 2011

AbstractSubstrates can undergo major temperature excursions during ion implantation if they are not well heat sunk. At power densities on the order of 50 watts per cm−2 radiatively cooled Si will melt in a matter of seconds. Such power densities can be maintained over a few sq. cms with many of the beams produced by even the moderate current machines currently used for doping Si and the III-V's. We have made use of this fact to study pulsed ion-beam annealing of implanted Si. Two types of studies have been carried out. In the first, 5–20 sec proton irradiations were done at power densities of 3–35 watts cm−2 to produce sample temperatures of 500 to 1100°C. 2×1016 cm−2 280 keV B, BF2 , As and P implants were annealed in this manner. Sheet resistances, ρs, versus power density curves were obtained for each ion and compared to psρs vs T data obtained for furnace annealed companion samples. In the second study the 2×1016cm−2 280 keV implants were carried out at progressively higher current densities so that the dopant beam itself raised the sample temperature to 500–1000°C. For each ion (other than B) it was possible to obtain power densities which resulted in self-annealing implants whose sheet resistances were as low as those obtained with the optimal furnace anneal. Details of the experiments, electrical and physical properties of the pulsed ion-beam annealed layers and device applications will be presented in this paper.
Lattice Site Location of Group VII Impurities in Silicon
Authors: Boerma D.O. , Smulders P.J.M. , Wierenga T.S. 
Published: March 2011

ABSTRACTChlorine- and iodine-implanted silicon have been investigated using the channeling/RBS technique after laser and oven annealing. Both annealing methods result in good epitaxial recrystallization of the implanted layer. A large near-substitutional I fraction exceeding 90% was found after oven annealing at 875°C. The near-substitutional fractions found after laser annealing for Cl and I, and after thermal annealing at 900°C for Cl are in the order of 50% only. The precise lattice site for these Cl and I fractions are determined by fitting the angular scans with simulated results. The results are interpreted in terms of vacancy association.
High Resolution Transmission Electron Microscopy Study of Se+ Implanted and Annealed GaAs
Authors: Sadana D.K. , Sands T. , Washburn J. 
Published: March 2011

ABSTRACTHigh resolution transmission electron microscopy (HRTEM) has been applied to the study of amorphization and recrystallization mechanisms in Se+ implanted (100) GaAs. An Se+ dose of 1 × 1014 cm−2 at 450 keV (projected range 1550Å) produced an amorphous band in the depth range 250 to 2150Å below the surface. Annealing at 400°C resulted in the epitaxial regrowth of the upper and lower transition region (0–250Å and 2150 – 2500Å, respectively). Regrowth of the amorphous layer was found to proceed by the nucleation and propagation of the dense network of stacking faults bundles. These bundles disappeared on higher ≥600°C) temperature annealing. Amorphization and recrystallization mechanisms in Se+ implanted GaAs are discussed in light of these HRTEM results.
Ion Implantation in Gallium Indium Arsenide
Authors: Anjum M. , Shahid M. A. , Gill S. S. , Sealy B. J. , Marsh J. H. 
Published: March 2011

ABSTRACTWe have studied the formation of heavily doped n-type layers in LPE GaInAs using ion implantation. 400 keV selenium ions have been implanted in dose ranges of 5 × 1013 to 1 × 1015 cm−2 at room temperature. For the high dose implants we have reproducibly achieved activities of 20–40% and sheet Hall mobilities of 700–1000 cm−2 V−1 s−1 and peak carrier concentrations of about 1019 cm−3. TEM and RBS results indicate that for long time anneals residual damage persists in the implanted layers, however, anneals at 800°C for 30 seconds perfectly recrystallize the implanted layers.
Microstructural Development of TiB2 Ion Implanted with 1 Mev Nickel
Authors: Sklad P. S. , Angelini P. , Lewis M. B. , Mchargue C. J. 
Published: March 2011

ABSTRACTAn Analytical Electron Microscopy (AEM) investigation of polycrystalline TiB2 implanted with 1 MeV Ni+ to 1 × 1021 ions/m2 has shown that the implanted region remained crystalline and showed no evidence of precipitation. A region containing tangled dislocations extended from the implanted surface to ∼500 nm. Between ∼500 and 750 nm, the microstructure was more complicated and could be indicative of a high density of 5 to 10 nm diam defects. The maximum nickel concentration determined by energy dispersive spectroscopy (EDS) occurred at ∼450 nm, slightly deeper than the calculated depth of 390 nm. Observations after in situ annealing revealed cavities and nickel-rich precipitates. Radiation damage models are invoked to explain the microstructures observed.
Chemical and Physical Interactions in Covalent Polymers Implanted with Transition Metals
Authors: Pehrsson Pehr E. , Weber D. C. , Koons N. , Campana J .E. , Rose S.L. 
Published: March 2011

ABSTRACTMultiple analytical techniques including FABMS, XPS/Auger, magnetic susceptibility,and conductivity are used to probe the effects of transition-metal implantation on the structural and physical properties of covalent polymers and HOPG. Post-implantation chemistry and solid-state interactions between the implanted atoms and the polymer are investigated.
Surface Modification by Ion Beam Enhanced Deposition
Authors: Kant R. A. , Sartwell B. D. 
Published: March 2011

ABSTRACTCopper films given multiple sequences of Ta implantation and Cu depositions were analyzed using electron microscopy, backscattering, and Auger spectroscopy. Ta retention is 92% following direct implantation, and 100% retention was achieved for the same Ta dose if sputtered Cu is replaced during implantation. Lateral migration of Ta and microroughness were observed for all cases studied. Evidence for TaC formation is presented.
H Implantation Improves Superconductivity in Non-Transition Metals
Authors: Ochmann F. , Stritzker B. 
Published: March 2011

ABSTRACTThe superconducting transition temperature, Tc, of a series of non-transition metals was improved by implantation of H and D into these metals kept below 10 K. In all cases the increase of Tc was considerably larger for H and D implantation with respect of He implantation causing only radiation effects. It could be shown that the enhancement of Tc depends on the electron-phonon coupling constant of the host metal, suggesting that mainly phonon effects dominate the improvement of Tc.
Retention of Ions Implanted at Non-Normal Incidence
Authors: Grabowski K.S. , Hartley N.E.W. , Gossett C. R. , Manning I. 
Published: March 2011

ABSTRACTFuture applications of ion implantation require a knowledge of how the retention of implanted ions varies with angle of ion incidence. In this work the retention of 150-keV Ar,Ti,Cr,and Ta ions in AISI-M50 and 52100 bearing steels was measured for incidence angles up to 60° off normal. Fluences between 3×1015 and 3×1017/cm2 were used, typically on 3/8” diameter cylindrical samples. Retention was measured for Ar, Ti, and Cr by ion induced x-ray emission and for Ta by backscattering of He ions. Range and sputtering parameters needed for model calculations were experimentally determined from Ta-implanted thin Fe film samples. Generally, at the low-fluence limit a near-cos θ dependence obtained while at the high-fluence limit a (cos θ)8/3 dependence applied where θ is the angle between the sample normal and the beam direction.
The Reduction of Wear and Wear Variability Under Lubricated Sliding by Ion Implantation
Authors: Au J.J. , Sioshansi P. 
Published: March 2011

ABSTRACTBlock-on-ring wear tests were performed on Ti-implanted AISI 52100 steel sliding against three commercial alloys: CDA 673 brass, AISI 4140 low alloy steel, and AISI 0–6 tool steel. A turbine oil, meeting MIL-L 23699 specifications, was used as the lubricant. The 52100 wear rings were ion implanted to a fluence of 2 × 1017 Ti/cm2 at 55 KeV or 125 KeV. Comparison with non-treated 52100 wear rings indicated that ion implantation reduced the amount of wear and wear variability. It is hypothesized that reduced adhesion and improved lubricant film formation due to the presence of the implanted layer was responsible for the reduction in wear and wear variability.