bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amorphization Mechanisms in AlxGa1-xAs
Authors: Lagow B. W. , Turkot B. A. , Robertson I. M. , Rehn L. E. , Baldo P. M. , Roh S. D. , Forbes D. V. , Coleman J. J. 
Published: September 2012

AbstractBulk ion implantations of AlxGa1-xAs (x = 0.6 or 0.85) were performed at 77 K with 1.5 MeV Kr+, 1 MeV Ar+ or 1.5 MeV++ ions, and the resulting damage state examined by using Rutherford backscattering spectrometry-channeling at 77 K and 293 K and transmission electron microscopy at 300 K. Amorphization of a portion of the A1xGa1-x As layer occurred at 77 K only for the 1.5 MeV Kr+ implantation, although the dose required to cause amorphization was higher for the higher Al content alloy. TRIM calculations[10–11] show that with this implantation the density of high energy density cascades varies as a function of depth through the layer and that these are superimposed on a high, uniform density of defects. Comparison of the ion channeling spectra at 77 K and 293 K shows that recovery occurs over a portion of the layer in the Al0.6Ga0.4As but is not detected in the A10.85Ga0.15As layer. In both alloys, the room temperature microstructure consists of an amorphous and a crystalline region. The amorphous region extends from the deeper AlxGa1-xAs/GaAs interface into the layer, and is separated from the crystalline material by a crystalline region containing planar defects. The difference between the alloys is in the extent of this latter region, which decreases in width with increasing Al content. These results will be used to examine current models for amorphization in the AlxGa1-xAs system.
Fabrication of Multi-Level Buried Oxide Layers by Oxygen-Ion-Implantation into Si/Ge multilayers
Authors: Ogino Toshio , Kobayashi Yoshihiro , Prabhakaran Kuniyil , sumitomo Koji 
Published: September 2012

AbstractWe propose a novel technique based on preferential oxidation of Si in the Si/Ge system. Oxygen ions were implanted at 30 keV into Si/Ge multilayers while the substrate temperature was kept below 100°C. Significant oxygen concentration was then observed at the Si/Ge interfaces and at a thin Si layer embedded into the Ge layer. When the samples were then annealed above 400°c, the bonding state of the Si oxide approached that of SiO2. During this process, Ge atoms were expelled from the oxide layers. Transmission electron microscopy confirmed that silicon dioxide layers were formed. This new technique can be used to form semiconductor/insulator multilayered structures from Si/Ge multilayers.
Interaction of Cavities and Dislocations in Semiconductors
Authors: Follstaedt D. M. , Myers S. M. , Lee S. R. , Reno J. L. , Dawson R. L. , Han J. 
Published: September 2012

AbstractTransmission electron microscopy of He-implanted Si-Ge and InGaAs shows an attractive interaction between cavities and dislocations. Calculation indicates that cavities are attracted to dislocations through surrounding strain fields, and strong binding (100s of eV) occurs when a cavity intersects the core. In a strained SiGe/Si heterostructure, He implantation enhances relaxation rates, and cavities bound to misfit dislocations show evidence of increasing relaxation at equilibrium by lowering dislocation energies. The interaction is expected for all crystalline solids, and gives insight into voids in GaN/sapphire and bubbles in He-implanted metals.
Vacancy-Type Defects in Electron and Proton Irradiated II- VI Compounds
Authors: Brunner S. , Puff W. , Mascher P. , Balogh A. G. , Baumann H. 
Published: September 2012

AbstractIn this contribution, we present a study aimed at investigating the basic properties of radiation induced defects in ZnS and ZnO and the influence of the atmosphere on the annealing characteristics of the defects. Positron annihilation experiments (both lifetime and Dopplerbroadening measurements) were performed on both single- and polycrystalline samples, irradiated with 3 MeV protons or 1 MeV electrons. For ZnS it was found that both electron and proton irradiation caused significant changes in the positron annihilation characteristics. The annealing of proton irradiated ZnS in air leads to significant oxidation and eventual transformation into ZnO.
Ion Implantation and Annealing Effects in Silicon Carbide
Authors: Heera V. , Skorupa W. 
Published: September 2012

AbstractSiC is a promising semiconductor material for high-power/high-frequency and hightemperature electronic applications. For selective doping of SiC ion implantation is the only possible process. However, relatively little is known about ion implantation and annealing effects in SiC. Compared to ion implantation into Si there is a number of specific features which have to be considered for successful ion beam processing of SiC. A brief review is given on some aspects of ion implantation in and annealing of SiC. The ion implantation effects in SiC are discussed in direct comparison to Si. The following issues are addressed: ion ranges, radiation damage, amorphization, high temperature implantation, ion beim induced crystallization and surface erosion.
Effects of Ion Bombardment on Chemical Interactions at SiC Surface and AI/SiC Interfaces
Authors: Beck Heather L. , Lee Moon-H. , Ohuchi Fumio S. 
Published: September 2012

AbstractAn investigation into the SiC surface and its interaction with aluminum, in particular, focusing on the effect of ion bombardment and adsorption of oxygen, is described. Stoichiometric and carbon rich and SiC surfaces were produced and analyzed “in situ” by Auger electron spectroscopy and x-ray photoelectron spectroscopy. Cubic SiC shows preferential sputtering under Ar ion bombardment, leading to carbon rich surface, whereas high temperature annealing also causes carbon rich surface. Activity of these surfaces was compared with oxygen and aluminum adsorption. Stoichiometrically sputtered surface showed vastly increased oxygen affinity, whereas carbon-rich sputtered surfaces did not. Aluminum deposition caused significant Al-C interaction for the stoichometric ion-bombarded surface. Aluminum carbide was induced catalytically upon heating in the presence of oxygen. Carbon-rich surfaces had, however, no significant interactions with as-deposited Al due to strong surface C-C bonds.
Growth of Patterned SiC by Ion Modification and Annealing of C60 Films on Silicon
Authors: Moro L. , Paul A. , Lorents D. C. , Malhotra R. , Wu K. J. , Subramoney S. 
Published: September 2012

AbstractIrradiation of vapor-deposited C60 films with a KeV ion beam (Ar+ or Ga+) transforms the surface layer of C60 into a non-volatile carbon film. During the subsequent annealing at 900°C, the modified C60 layer confines the underlying C60 on the silicon surface, allowing the formation of SiC. With this method, patterned SiC structures on silicon with the high lateral resolution possible with ion beams are fabricated
Formation of a Buried Soft Layer in Sic for ”Compliant Substrate” by Ion Implantation
Authors: Lioubtchenko M. , Hunn J. , Suvkhanov A. , Parikh N. , Bray D. 
Published: September 2012

AbstractRadiation damage and its removal have been studied in ion implanted 6H-SiC by Rutherford backscattering/Channeling (RBS). We have implanted Ga and Ti at 800°C using doses of 1 × 1016 to 2× 1017 cm−2. The implanted samples have been subsequently annealed at 1050°C, and then at 1400°C for 30 sec to study the removal of damage produced during implantation. The energies of implanted species have been chosen to obtain 20 – 40 nmn projected ranges to form a buried metallic or graphitic layer. No significant damage removal has been observed after 1050°C anneal, however 1400°C annealing of 40 and 120 keV Ga implanted samples (fluence 2 × 1016 cm−2) resulted in significantly less damage as can be observed from RBS/Channeling data. In the case of Ti implanted samples annealing led to an appreciable increase in the channeled backscattering yield, which might be due to the formation of some new phase (e.g. TiSi or TiSi2 ) and may be related to distortions of the existing lattice.
Transient Enhanced Diffusion of Dopants in Preamorphised Si Layers
Authors: Claverie A. , Bonafos C. , Omri M. , Mauduit B. De , Assayag G. Ben , Martinez A. , Alquier D. , Mathiot D. 
Published: September 2012

AbstractTransient Enhanced Diffusion (TED) of dopants in Si is the consequence of the evolution, upon annealing, of a large supersaturation of Si self-interstitial atoms left after ion bombardment. In the case of amorphizing implants, this supersaturation is located just beneath the c/a interface and evolves through the nucleation and growth of End-Of-Range (EOR) defects.For this reason, we discuss here the relation between TED and EOR defects. Modelling of the behavior of these defects upon annealing allows one to understand why and how they affect dopant diffusion. This is possible through the development of the Ostwald ripening theory applied to extrinsic dislocation loops. This theory is shown to be readily able to quantitatively describe the evolution of the defect population (density, size) upon annealing and gives access to the variations of the mean supersaturation of Si self-interstitial atoms between the loops and responsible for TED. This initial supersaturation is, before annealing, at least 5 decades larger than the equilibrium value and exponentially decays with time upon annealing with activation energies that are the same than the ones observed for TED. It is shown that this time decay is precisely at the origin of the transient enhancement of boron diffusivity through the interstitial component of boron diffusion. Side experiments shed light on the effect of the proximity of a free surface on the thermal behavior of EOR defects and allow us to quantitatively describe the space and time evolutions of boron diffusivity upon annealing of preamorphised Si layers.
Effect of Argon Ion Bombardment on the Stability of Narrow Cobalt Silicide/Polysilicon Structure
Authors: Maa Jer-Shen , Peng Chien-Hsiung 
Published: September 2012

AbstractThe stability of cobalt silicide formed on narrow polysilicon line degraded rapidly with shrinkage of linewidth as shown by the increase of sheet resistance after annealing. Stability was improved by adding a titanium interlayer under cobalt with or without a Ti or TiN cap layer. The stability was affected by silicide thickness and substrate doping. In best cases an increase of sheet resistance after annealing was still observed. Adding an Ar ion bombardment step improved the thermal stability drastically. This structure did not show any sheet resistance change after a 30 min annealing at 850°C, either with or without interlayer or cap layer.
Plasma Ion Implantation for Flat Panel Displays
Authors: Chan Chung , Qin Shu , Zhou Yuanzhong , Liu Wei , Wu Shuichi , Vai Mankuan Michael , Bursuc Ionel , Shao Jiqun , Denholm Stuart 
Published: September 2012

AbstractDevelopment of ion doping and hydrogenation equipment using plasma ion implantation (PII) is being studied. It is shown that low energy, high throughput operation could eliminate problems associated with etching, charging, cooling, and contamination. The applications of a new plasma source and neural network implementation optimization are also reported.
N-Type Doping by Plasma Ion Implantation Using a PH3 SDS System
Authors: Qin Shu , Zhou Yuanzhong , Warner Keith , Chan Chung , Shao Jiqun , Denholm Stuart 
Published: September 2012

AbstractPH3 SDS (safe delivery system) gas was used for the first time in P11 doping experiments to fabricate n+p junctions and NMOS devices. Two gas recipes (PH3 diluted in H2 and He) were investigated. Under lower pressure, a minimum etching effect was observed. A 4x1015/cm2 phosphorus dose and a 22 Ω/□ sheet resistance were achieved in 4 seconds. Very low contamination level was involved. An anomalous tail of P profile in Si substrate was observed using SIMS measurements.
Investigations of Plasma Immersion Ion Implantation Hydrogenation for Poly-Si Tfts Using an Inductively Coupled Plasma Source
Authors: Zhou Yuanzhong , Qin Shu , Chan Chung 
Published: September 2012

AbstractA plasma immersion ion implantation (PIII) hydrogenation process using an inductively-coupled plasma (ICP) source is implemented for defect passivation in polycrystalline silicon (poly-Si) thin film transistors (TFT's). Device parameter improvement saturates in 4 minutes, which is considerably shorter than for other reported hydrogenation methods. Stress test indicates that the devices hydrogenated by this novel technique have much better long-term reliability. The hydrogenation effects on two types of trap states are analyzed the current-voltage characteristics of the devices. The densities of deep states and tail states are significantly reduced after short time hydrogenation.
Growth of Low-Temperature Polycrystalline Si Film by Direct Negative Si Ion Beams
Authors: Sohn M. H. , Kim D. , Ahn Y. O. , Kim S. I. 
Published: September 2012

AbstractPolycrystalline Si (Poly-Si) films were successfully grown at temperature less than 500 °C by using a direct Si ion beam deposition technique. In this process, the ion beam energy of Si- is directly coupled to the formation of the films. High substrate temperature (>600 °C), normally required for conventional CVD techniques, has been a major barrier for the Poly-Si Thin Film Transistor Liquid Crystal Display (TFT LCD) which uses a glass substrate. Thus, the ability to produce Poly-Si film below the glass transition temperature and to control the grain size will make this direct Si- ion beam deposition process a potential alternative technique for future TFT LCD. The grain size dependence on the ion beam energy and substrate temperature was investigated using a Transmission Electron Microscope (TEM). The grain size could be controlled from 0.1 μm to 1 μm at ion beam energies from 10 to 50 eV with a substrate temperature less than 500 °C. The resistivity of the as-deposited film was of the order of 100 Ωcm due to in-situ doping effect.
Growth of Ge1-xCx Alloys on Si by Combined Low-Energy Ion Beam and Molecular Beam Epitaxy Method
Authors: Shibata H. , Kimura S. , Fons P. , Yamada A. , Makita Y. , Obara A. , Kobayashi N. , Takahashi H. , Katsumata H. , Tanabe J. , Uekusa S. 
Published: September 2012

AbstractA combined ion beam and molecular beam epitaxy (CIBMBE) method was applied for the deposition of a Ge1-xCx alloy on Si(100) using a low-energy ( 50 – 100 eV ) C+ ion beam and a Ge molecular beam. Metastable Ge1-xCx solid solutions were formed up to x = 0.047, and the CIBMBE method was shown to have a very high potential to grow metastable Ge1-x,Cx alloys. It was also revealed that the sticking coefficient of C+ ions into Ge was ∼28% for Ei, = 100 eV and ∼18% for Ei = 50 eV. Structural characterization suggests that the deposited films are single crystals grown epitaxially on the substrate with twins on {111} planes. Characterization of lattice dynamics using Raman spectroscopy suggested that the deposited layers have a small amount of ion irradiation damage.
Combined Ion-Beam and Laser-Beam Synthesis of Silver Oxide Nanoclusters in Soda-Lime Glass
Authors: Haglund R. F. , Osborne D. H. , Gonella F. , Mazzoldi P. , Battaglin G. 
Published: September 2012

AbstractIon beam deposition offers a number of interesting possibilities for creating nonlinear materials for photonic devices such as waveguides. Ion beams have been used by a number of groups to create metal and semiconductor nanocrystallites in silica and other glassy substrates in a geometry suitable for shallow channel waveguides. In this paper, we describe the use of He ion beams to initiate nucleation of Ag nanocrystallites in ion-exchanged soda-lime glass. The nanocrystallites are remarkably uniform in size, and exhibit substantial third-order optical nonlinearity. The combination of ion exchange and ion implantation has an advantage over conventional implantation techniques because it produces guiding layers deep enough (several microns) to form practical channel waveguides. In addition, we have shown that it is possible, by means of subsequent laser irradiation, to further alter the properties of the nonlinear composite material. In this particular case, irradiation by visible or infrared laser beams following ion implantation induces oxidation of the silver nanocrystallites, as documented by Auger analysis of the composite material. Furthermore, the third-order nonlinearity of the composite material changes sign, changing a self-focusing nonlinearity into one which is self-defocusing. These experiments suggest a number of possibilities for combining ion- and laser-beam irradiation to create laterally structured waveguide materials as well as nonlinear channel waveguides.
High Current Implantation of Negative Copper Ions into Silica Glasses
Authors: Kishimoto N. , Gritsyna V. T. , Kono K. , Amekura H. , Saito T. 
Published: September 2012

AbstractHigh- current implantation of Cu- ions into silica glasses has been demonstrated using mAclass negative ion beams at 60 keV. Negative ion implantation has an advantage to alleviate specimen charging for insulating substrates and has attained high dose rates, up to 260 μA/cm2. Spherical Cu colloids form in the silica glasses without additional thermal annealing. Optical absorption and reflection of the implanted specimens vary with the current density, even at a fixed dose level. A beam- induced surface plasma may affect the high current implantation.
Optical and Structural Characterization of Zinc Implanted Silica Under Various Thermal Treatments
Authors: Mu R. , Chen Jinli , Gu Z. Y. , Ueda A. , Tung Y. -S. , Henderson D. O. , White C. W. , Zhu Jane G. , Budai John D. , Zuhr R. A. 
Published: September 2012

AbstractZinc ion implanted silica with controlled thermal annealing has been investigated. Low temperature optical measurements indicate the presence of Zn clusters in the as-implanted silica. Optical spectra of the annealed sample under a reducing environment suggest Zn cluster and Zn metal colloid formation. The absorption peak at ∼5.3 eV may be due to the surface plasma absorption of Zn metal colloids in silica. The oxidized samples (10 and 6 x 1016 ions/cm2) show an absorption peak at ∼4.3 and ∼4.8 eV, respectively and imply ZnO quantum dot formation. The blueshift in exciton absorption can be attributed to the quantum confinement effects.
Quantum-Sized Silicon Precipitates in Silicon-Implanted and Pulse-Annealed Silicon Dioxide Films: Photoluminescence and Structural Transformations
Authors: Tyschenko I. E. , Kachurin G. A. , Zhuravlev K. S. , Pazdnikov N. A. , Volodin V. A. , Gutakovsky A. K. , Leier A. F. , Fröb H. , Leo K. , Böime T. , Rebohle L. , Yankov R. A. , Skorupa W. 
Published: September 2012

AbstractStrong blue, red and near-infrared photoluminescence has been observed from Si+-implanted and pulse-annealed SiO2 layers. Raman scattering and high-resolution electron microscopy analyses have revealed a correlation between the structure of the Si inclusions in the SiO2 matrix and the photoluminescence. Structural transformations in the Si-rich SiO2 layers during pulse and furnace annealing have been discussed in terms of the changes in the light emission observed experimentally. Small Si clusters, non-crystalline inclusions and nanocrystals are believed to be the light sources. The blue, red and near-infrared photoluminescence is associated with small complexes of excess Si atoms, non-crystalline Si nanoinclusions and quantum-confined Si nanocrystals, respectively.
Er-Doped Amorphous and Crystalline Al2O3 and La2O3 Films Grown with Low Energy Ions From an Ecr Plasma
Authors: Barbour J. C. , Potter B. G. , Follstaedt D. M. , Knapp J. A. , Sinclair M. B. 
Published: September 2012

AbstractThe effects of low energy ions from a biased electron cyclotron resonance plasma during growth of Al2O3 and La2O3 are used to modify the density and crystalline quality of these oxide films. The type of phase formed for Al2O3 is varied with the ion-assisted growth from amorphous to crystalline γA12O3. The photoluminescence (PL) properties of different Er-doped Al- and La-oxide phases are examined, and through comparison of the PL spectra, the local environment of Er in these oxide materials is discussed.
Ion Beam Damage of Polymer Surfaces: Insights from Molecular-Dynamics Simulation
Authors: Brenner D. W , Shenderova O. , Parker C. B. 
Published: September 2012

AbstractMolecular-dynamics simulations are used to model the bombardment of crystalline polyethylene by carbon and rare-gas atoms with kinetic energies between 20 eV and 80 eV. The simulations predict substantial near-surface damage, including radical formation via loss of hydrogen from the chains, insertion of carbon into the polymer backbone, and chain crosslinking. For the rare gas atoms, the observed chemical dynamics are dependent on the mass of bombarding species, with the ratio of broken carbon-hydrogen to carbon-carbon bonds decreasing with increasing mass. The total number of bonds broken, however, is a linear function of kinetic energy with the lighter species having a higher slope and lower threshold energy for inducing damage.
Effects of MeV Ion Beam on Polymers
Authors: Evelyn A. L. , Ila D. , Zimmerman R. L. , Bhat K. , Poker D. B. , Hensley D. K. 
Published: September 2012

AbstractThe electronic (εe) and nuclear (εa) stopping effects produced by 3.5 MeV and 5.0 MeV ion bombardment in polyvinylidine chloride (PVDC), polyethylene (PE) and polyethylene sulfide were studied and compared. To separate these effects we chose two bombardment energies and a thin film polymer stacking technique developed in house. The resulting stacked layered system consisting of each polymer was bombarded with 3.5 MeV and 5.0 MeV alpha particles. The layered system was selected such that the first few layers experience most of the effects of the electronic energy deposited and the last layer receives the effects of the nuclear stopping. The electrical conductance and the changes in the chemical structure were measured by direct resistivity measurements, Raman microprobe analysis, RBS, and FTIR. The post-irradiation characterization resolved the effects of the stopping powers on the polymer films.
Ion Beam Injected Point Defects in Crystalline Silicon: Migration, Interaction and Trapping Phenomena
Authors: Priolo F. , Privitera V. , Coffa S. , Libertino S. 
Published: September 2012

AbstractOur recent work on the room temperature migration and trapping phenomena of ion beam generated point defects in crystalline Si is reviewed. It is shown that a small fraction (∼ 10−6) of the defects generated at the surface by a shallow implant is injected into the bulk. These defects undergo a long range trap-limited diffusion and interact with both impurities, dopants and preexisting defects along their path. In particular, these interactions result in dopant deactivation and/or partial annihilation of pre-existing vacancy-type defect markers. It is found that in highly pure, epitaxial Si layers, these effects extend to several microns from the surface, demonstrating a long range migration of point defects at room temperature. By a detailed analysis of the experimental evidences we have identified the Si self-interstitials as the major responsible for the observed phenomena. This allowed us to give a lower limit of 6×10−11-cm2/s for the room temperature diffusion coefficient of the Si self-interstitials. Room temperature trap-limited migration of vacancies is also detected as a broadening in the divacancy profile of as implanted samples. In this case the room temperature diffusion coefficient of vacancies has been found to be ≥3 × 10−12 cm 2/s. These data are presented and their implications discussed.