bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurements of Hydrogen Redistribution in Hot Electron Injection of Mos Capacitors
Authors: Marwick A. D. , Buchanan D. A. , Dimaria D. J. , Saunders Phil 
Published: March 2011

ABSTRACTRedistribution of hydrogen caused by hot electron injection has been studied in large Al-gate capacitors using internal photemission followed by hydrogen depth profiling with the 15 N nuclear reaction. A large peak of hydrogen (∼ 1015 at /cm2) at the Al/SiO2 interface due to a hydrated layer on the surface of the SiO2 was found to act as a source of hydrogen during the photoinjection. A small fraction of the hydrogen released from this peak was found to be re-trapped near the Si/;SiO2 interface if a field of >1 MV/cm was applied to the SiO2 during the injection. Up to 2 × 1014 atoms/cm2 of hydrogen were found to be trapped at this interface for injected fluences up to 5 C/cm2. These results are discussed in terms of current models of interface state generation involving hydrogen.
Densification and Crystallization of Amorphous SiO2 by Neutral Beam Bombardment
Authors: Mizutani Tatsumi 
Published: March 2011

ABSTRACTAmorphous SiO2 films formed by thermal oxidation of silicon have been bombarded by low-energy (350 — 400 eV) ion beam and neutral beam of inert atoms. The modified SiO2 layers have been characterized by Auger electron spectroscopy (AES), Rutherford backscattering spectroscopy (RBS) and reflection high energy electron diffraction (RHEED). It is shown that neutral beam bombardment does not cause preferential sputtering of oxygenfrom SiO2, whereas ion beam of the same energy causes significant preferential sputtering. For neutral bombardment, densification and crystallization of SiO2 have been observed. The formation of α-cristobalite and α-quartz from amorphous SiO2 has been observed for high dose bombardments (>1017neutrals/cm2). These densification and crystallization phenomena can be attributed to high temperature and high pressure local spot formation upon the incidence of energetic neutral atoms. For ion beam bombardments, these densification and crystallization phenomena have not been observed.
Low-Temperature Chemical-Vapor-Deposition of Silicon-Nitride from Tetra-Silane and Hydrogen Azide
Authors: Ishihara Ryoichi , Kanoh Hiroshi , Uchida Yasutaka , Sugiura Osamu , Matsumura Masakiyo 
Published: March 2011

ABSTRACTSilicon nitride films have been successfully deposited at a temperature as low as 300°C by chemical-vapor-deposition using tctra-silane (Si4 H10) and hydrogen azidc (HN3). Atomic ratio (N/Si) of the film deposited at 400°C was 1.47, i.e., the film was N-rich. Total hydrogen content was about 25atomic%. The breakdown-field strength was 6.5MV/cm at leakage-current density of 1μA/cm2, and the low-field resistivity was more than 1015 Ωcm. Similar electrical characteristics were obtained from films deposited at a temperature range between 300°C and 500°C. Amorphous silicon thin-film transistors equipped with this film as the gate dielectric showed good transfer characteristics.
Amorphous Silicon Thin Film Transistors Produced by Atmospheric Pressure CVD
Authors: Ann Byung Chul , Kim Jeong Hyun , Hong Chan Hee , Kim Woo Yeol , Kim Kwang Nam , Kang Hee Kyung , Jang Jin 
Published: March 2011

ABSTRACTWe have studied the preparation and device application of a-Si by atmospheric pressure CVD using disilane. The deposition rate of a-Si increases with the partial pressure of disilane and with the total pressure. The deposition rate of APCVD a-Si is, therefore, very high compared with LPCVD. The photosensitivity of APCVD a-Si is 104 at 100mW/cm2. We have made an inverse staggered type a-Si TFT using SiO2 as a gate insulator. The on/off current ratio and field effect mobility are 105 and 0.19cm2/Vs, respectively.
The Effects of Light and Electrical Stress on Asymmetric a-Si TFT
Authors: Oh C. H. , Chung I. J. , Kim W. Y. , Hwang J. R. , Lee S. K. , Kim Y. S. , Park J. S. , Han M. K. 
Published: March 2011

ABSTRACTThe asymmetric amorphous silicon thin film transistors are fabricated and exposed to various stress environments. A visible light illumination of 200,000 Ix and gate bias of 30 V are applied to both asymmetric and widely used symmetric a-Si TFT's. It is observed that the leakage current of asymmetric structure, where only one electrode is fully overlapped by gate electrode, is much less than that of symmetric one. The visible light illumination as well as gate bias stress do not degrade the leakage current of the asymmetric a-Si TFT's, while the leakage current in die symmetric TFT's are increased considerably due to the stress. Also, the degree of degradation in the threshold voltage, the field effect mobility and the subthreshold slope of asymmetric TFT's are relatively much less than that of conventional symmetric TFT's.
Compound Sidewall Spacer Technology for Submicron Mosfet
Authors: Roy P. K. , Kook T. , Kizilyalli I. C. , Nanda A. K. 
Published: March 2011

ABSTRACTThis work describes process development of various kinds of compound sidewall spacer in submicron CMOS technology to improve gate oxide (GOX) leakage characteristics. This is attained by minimizing the impact of gate-level defects (GLDs) caused by in-process particle incorporation. Transistor characteristics did not suffer from this new sidewall spacer process.
Crystallization Behavior in Precursor-Modified Sol-Gel Lead
Authors: Powders Titanate , Shie Wei-Heng , Lu Qing , Shih Wan Y. 
Published: March 2011

ABSTRACTThe molecular structure of precursors in sol-gel processing of PbTiO3 is modified via β-diketone substitution for the isopropyl groups of titanium isopropoxide. Crystallite size and crystallization behavior are studied using x-ray diffractometry and differential thermal analysis. The crystallite size decreases with increasing amount of β-diketone substitution. Whereas the weight percent of crystalline phase first decreases and then increases with increasing β-diketone substitution. Our results indicate that the β-diketone substitution reduces the size of the structural units in the gel network resulting in smaller crystallite size and more nucleation sites in the powders produced.
Dependence of the Growth of Al2O3 Films on the Growth Conditions in the ALE-Like Process
Authors: Fan Jia-Fa , Toyoda Koichi 
Published: March 2011

ABSTRACTEffects of the growth conditions on the growth and the quality of thin films of Al2O3 were investigated in the ALE-like process. It has been found that the growth rate remains nearly independent of the growth conditions when the pulse heights are 80–120 mTorr and 20–160 mTorr for H2O2 and TMA respectively, the pulse duration longer than 0.3 s, the base pressure below 1 mTorr, and the growth temperature higher than 150°C. Also, we found that the density, the chemical bonding strength, and the electrical properties improved markedly with raising the growth temperature although the growth rate remained nearly constant. In addition, area-selective growth and partly polycrystalline films were favorably obtained by using pulsed molecular beams of TMA and H2O2 in the growth.
On the Formation of Ultrathin Simox Structures by Low Energy Implantation
Authors: Namavar F. , Buchanan B. , Kalkhoran N. M. 
Published: March 2011

ABSTRACTSilicon-on-insulator (SOI) wafers made by standard energy (150–200 keV) Separation by IMplantation of Oxygen (SIMOX) processes have shown great promise for meeting the needs of radiation-hard microelectronics. However, if SIMOX material is to become a competitive substrate material for manufacturing commercial integrated circuits, the cost of the SIMOX wafers must be greatly reduced. The low energy SIMOX (LES) process accomplishes the needed reduction in cost by producing ultrathin layers which require much lower ion doses. These ultrathin layers are necessary for the next generation of commercial ultra high density CMOS integrated circuits, and must be of very high quality to be utilized for commercial applications. In this paper we discuss characterization of ultrathin LES structures.
GaAs Surface Stabilization by Vacuum Anneal with SiO
Authors: Gerardi G. J. , Rong F. C. , Poindexter E. H. , Harmatz M. , Shen H. , Warren W. L. 
Published: March 2011

ABSTRACTWe find a significant alteration of the surface properties of SI- GaAs as a result of a thermal treatment with SiO under vacuum. Low temperature photoluminescence measurements reveal a tenfold increase in emissions attributed to free or donor bound excitons and the exciton bound to a silicon acceptor. A paramagnetic center is also generated as a result of this treatment. The EPR signal has a g-value of 2.0017 and a linewidth of 0.1 mT. The enhanced photoluminescence and the EPR signal are both quenched by a short exposure to hydrogen plasma at room temperature. Chemical and spectroscopic evidence indicates that the resonance is due to a silicon related center near the GaAs surface. The surface stabilization is attributed to a reaction or incorporation of SiO with the arsenic depleted GaAs surface.
Photoionization and Photofragmentation of BxNy Clusters Produced by Photoablation of Boron Nitride Followed by Supersonic Expansion Cooling
Authors: Roland Paul A. , La Placa Sam J. , Wynne James J. 
Published: March 2011

ABSTRACTPhotoablation of isotopically pure boron metal and hexagonal boron nitride with a 532 nm laser, followed by supersonic expansion cooling, produces a variety of Bx, and BxNy, clusters, which are detected by photoionization of the neutral clusters with a 194 nm laser, followed by time-of-flight (TOF) mass spectrometry. Under certain experimental conditions, the mass spectrum derived from boron nitride shows resolved peaks corresponding to the clusters Bx+1Ny+. Under different experimental conditions, the mass spectrum shows an unresolved region corresponding to clusters ranging from atomic mass unit 100–1000 as well as resolved peaks, corresponding to Bx+ clusters for x = 2 − 100. These resolved peaks grow with increasing photoionization fluence, while the envelope of the unresolved region changes shape and grows with a diminished dependence on fluence. These data are interpreted as evidence that the unresolved clusters are being photofragmented as well as photoionizated by the 194 nm radiation, and the products of such photofragmentation are the aforementioned Bx+ clusters.
Excimer Laser Induced Mechanical and Electrical Nanostructures in Polymers
Authors: Phillips H. M. , Callahan D. L. , Le blanc S. P. , Ball Z. , Sauerbrey R. 
Published: March 2011

ABSTRACTPeriodic line structures with periods ranging from 166 nm to 950 nm have been produced in polyimide by direct ablation with a KrF (248 nm) laser using holographic techniques. Taking advantage of the large nonlinearity in the laser ablation process, linewidths ranging from 30 nm to several hundred nanometers could be obtained. These techniques were combined with the ability to induce electrical conductivity in polyimide to produce an array of 500 nm wide electrically conducting wires. The conductivity of these wires was similar to that found in macroscopic regions of laser induced conductivity.
Profiling of Hydrogen in Zirconium Surfaces by Laser Ablation with Resonance Ionization
Authors: Bickel G.A. , Mcrae G.A. , Green L.W. 
Published: March 2011

ABSTRACTElemental distributions in the bulk and metal oxide surface layers of zirconium alloys play key roles in the fracture toughness of the alloys. In particular, localized hydrogen build-up leads to hydride formation and delayed hydride cracking. Parts per million levels of H in Zr have been detected using the 1.06 μm or 355 nm output of a Nd:YAG laser for ablation followed by 2+1 resonance ionization detection of H and D. Analysis of the ablation plume has shown that it consists predominately of atomic species in thermal equilibrium between 2000 and 3600°C. Ablation of thin foils has shown that the ablation rate is on the order of mono-layers per shot and increases exponentially with increasing fluence. Laser ablation depth profiling results of H distributions in an anodically grown oxide film compare qualitatively with nuclear-reaction-analysis profiling of the same sample.
Selective Epitaxy as a Chemistry Free Route for Ybco Thin Film Patterning
Authors: Habermeier Hanns-Ulrich , Elkin Bentsian , Beddies Gunter , Leibold Bernd 
Published: March 2011

ABSTRACTTwo different routes for micropatterning of YBCO thin films by selective epitaxy are presented; both methods are based on the intermixing of YBCO with silicon at the growth temperature for ( 001 ) as well as ( hk0 ) YBCO thin film epitaxy. One method ( I ) uses a pre-patterned yttria stabilized zirconia [ YSZ ] thin film epitaxially grown on a silicon single crystal giving rise to the epitaxy of c-axis oriented YBCO on YSZ whereas intermixing yields a nonsuperconducting Si-Y-Ba--Cu-O phase elsewhere. The other method (II ) uses SrTiO3 substrates suitable for ( 103 ) as well as ( 110 ) YBCO epitaxy coated with a pre-patterned amorphous silicon layer prior to YBCO deposition. Both techniques are chemistry free routes for YBCO thin film patterningand pave the way for superconductor/semiconductor hybride device fabrication ( route I ) as well as basic investigations of the anisotropic electronic and optical properties of YBCO ( route II ).
Controlling of Microstructure Generation by Direct Holographic Etching of Semiconductor Substrates
Authors: Toyoda K. , Kumagai H. , Ezaki M. , Obara M. 
Published: March 2011

ABSTRACTControlling of microstructure generation was investigated in laser etching of n-GaAs. For single-beam etching and holographic etching with high ratios of average spacing of holographic grating to average spacing of microstructures (Λh/Λr), ripple structures were fabricated. Especially in p-polarization, spatial fluctuation was greater than that in s-polarization. This might occur because phase distortion inherent in the laser beam cannot be eliminated by the p-polarization beam irradiation. For holographic etching with small Λh/Λr ratios, ripple structures were changed into grating structures because these grating structures might be generated in phase with holographic gratings.
Laser Induced Damage Threshold Measurements at the Microscopic Level
Authors: Zwan Allen D. , Miller David R. 
Published: March 2011

ABSTRACTWe have (tudied the laser damage threshold to silver films (500Å - 1000Å) grown on single crystal silicon <100>, in a newly developed laser damage UHV system at pressures of 10−1 torr. A 1.06μm Nd:Glass laser is used to damage the mirror surfaces in 1-on-1 pulse studies. In-situ damage characterization includes Auger, reflectivity of the primary beam, diffuse scattering of a helium-neon laser, and mass spectrometry detection of desorbed surface species. External characterization includes optical microscopy and SEM. All in-situ damage probes are well correlated and baseline damage occurs at fluences near 3.4 MW/cm2. Time-of-flight to the mass spectrometer shows ejected particles with energies in the 5 to 10 eV range indicating a plasma damage mechanism. Prior to typical thermally induced damage the external microscopy shows well defined precursor morphology changes which appear as feather-like microstructure at the submicron level.
Hyperthermal CI Atom Beam Produced by Laser Vaporization of Cryogenic ICI Films
Authors: Weaver Gabriela C. , Campos Francis X. , Leone Stephen R. 
Published: March 2011

ABSTRACTA source of energetic, neutral Cl atoms is produced by laser vaporization of cryogenic ICI films using either the 532 nm or 266 nm output of a pulsed Nd:YAG laser. The pulsed Cl mean kinetic energy can be tuned from 0.4 eV to 3.4 eV by varying the laser repetition rate or the rate of deposition of the ICl film. Also present in the beam are ICI, I, I2, and Cl2 The heavier species all have lower velocities than the Cl atoms, and this difference in velocities can be accentuated by vaporizing thinner films. Using a mechanical velocity chopper, the fastest part of the beam can be selected, which consists of > 90% Cl atoms. Results suggest that the vaporization process involves a directed mass flow in which the heavier molecules are propelled to higher velocities by the faster Cl atom flux. The atom source may be used for selective etching studies.
Excimer Laser Induced Deposition of Bisrcacuo Htsc Thin Films and Buffer Layers -Depth Profiling by SNMS
Authors: Lqrenz M. , Hochmuth H. , Börner H. , Unger K. 
Published: March 2011

ABSTRACTSecondary Neutrals Mass Spectrometry SNMS was used to investigate interdiffusion processes in laser deposited BiSrCaCuO HTSC thin films on various substrate materials. The in-situ deposition of epitaxial Bi2Sr2Ca1Cu2O8+x films requires a substrate temperature just below the decomposition temperature of the 2212 -phase of BiSrCaCuO. This high substrate temperature of about 850°C seems to be the reason for interdiffusion processes of BiSrCaCuO films and MgO(100), YSZ(100) and Si(100) with YSZ or SrTiO3 buffer layers as substrate materials. Therefore, Tc(R=0) of BiSrCaCuO films on silicon with buffer layer is not higher than 70 K at present. SNMS depth profiling gives a more detailed insight into interdiffusion phenomena than other analytical techniques.
Biaxially-Textured YBa2Cu3O7–x Thin Film Growth on Polycrystalline and Amorphous Substrates Using Ion Assisted Laser Deposition of Yttria-Stabilized Zirconia Intermediate Layers
Authors: Reade R. P. , Berdahl P. , Russo R. E. , Garrison S. M. 
Published: March 2011

ABSTRACTThe growth of (001)-textured, biaxially-aligned yttria-stabilized zirconia (YSZ) intermediate layers on amorphous or randomly-oriented polycrystalline substrates is desirable for subsequent YBa2Cu3O7–x (YBCO) c-axis thin film growth. Laser deposition of YSZ on polycrystalline metal substrates (Haynes Alloy #230) in 1.0 millitorr oxygen at 70°C produces partial (001) texture but no alignment of in-plane axes. Highly-textured biaxially-aligned layers are obtained by using an ion beam to assist growth. Similar layers are obtained on amorphous silica and polycrystalline alumina substrates. The effects of ion-beam parameters including incident angle, source gas, and beam voltage and current are presented. Highly c-axis-oriented, biaxiallyaligned YBCO thin films have been deposited in situ on these YSZ layers, with Tc(R=0) ∼ 92K and Jc(77K) = 6 × 105 A/cm2. Angular magnetoresistance data shows a dip in resistance with magnetic field normal to the film, in contrast to films grown epitaxially on single crystal substrates, which have maximum resistance with field normal.
Preparation and Growth of Pb2Sr2Y0.5Ca0.5Cu3O8+δ Thin Film Superconductors
Authors: Naqvi S.H.H. , Vickers M. , Tarling S. , Barnes P. , Boyd I.W. 
Published: March 2011

ABSTRACTThe lead based superconductor Pb2Sr2Y0.5Ca0.5Cu3O8+δ is a most complex material. If any oxygen is present in the PbO-CuOδ-PbO sandwich layer (i.e. if δ>0) the superconductivity deteriorates. This is also a most difficult material to grow not only because of the large number of cation stoichiometries which have to be precisely balanced but also because of the tendency for multiple phases to form. Pulsed laser deposition (PLD) has been applied to prepare thin films of the 2213-phase on MgO (100) single crystal substrates at low temperature (300°C) in low oxidizing atmospheres. A basic set of ex-situ growth conditions has been determined which produce for the first time good quality films of this material as characterized by DC resistivity using the Van der Pauw method, as well as EDX and XRD. The layers are reasonably c-axis oriented and display a superconducting onset transition temperature of 79K and zero resistance at 65K after subsequent annealing in a nitrogen ambient.
Growth of (110) Oriented YBa2Cu3O7−δ Films by Laser Ablation
Authors: Chen Neng Y. , Rietveld G. , Lander L.W. , Matijasevic V.C. , Hadley P. , Mooij J.E. 
Published: March 2011

ABSTRACTSeveral attempts have been made by different groups to grow (110) YBa2Cu3O7−δ thin films on (110) substrates. In most of the cases, both (103) and (110) orientations of YBa2Cu3O7−δ have been found in the film. The substrate temperature during deposition is one of the major factors that determines the crystal orientation of the YBa2Cu3O7−δ. In our experiment, effort is made to examine the influence of the initial substrate temperature from 595 °C to 660 °C on the relative amount of (110) and (103) oriented grains. The orientations are determined by x-ray analysis with a Weissenberg camera. The amount of (103) oriented YBa2Cu3O7−δ is reduced systematically with decreasing substrate temperature. At the lowest deposition temperatures we find only (110) oriented growth.
Laser Ablation Deposited YBa2Cu3Ox, Thin Films on YSZ/Si(100)
Authors: Sánchez F. , Varela M. , Queralt X. , Aguiar R. , Morenza J.L. 
Published: March 2011

ABSTRACTSuperconducting YBa2Cu3Ox (YBCO) thin films have been deposited on Si(100) substrates with yttria-stabilized zirconia (YSZ) buffer layers by laser ablation. Buffers have been obtained by laser ablation as well. The films have been characterized by scanning electron microscopy, x-ray diffractometry, secondary ion mass spectrometry, and four-contact electrical resistivity measurements. Secondary ion mass spectrometry results indicate very low interdiffusion between Si, YSZ and YBCO. The best YBCO films are textured with c axis perpendicular to the substrate and their resistance shows a normal state metallic behavior with zero resistance at temperatures higher than 80 K. The properties of YBCO films have been related with the substrate temperature and oxygen partial pressure during deposition.
Photodesorption Dynamics in Threshold-Fluence UV Laser Induced Surface-Decomposition of Bi2Sr2CaCu2O8
Authors: Wiedeman Lawrence , Helvajian Henry 
Published: March 2011

ABSTRACTIn this article, we review experimental measurements taken in our laboratory for the low-fluence UV pulsed laser photodecomposition of the perovskite ceramic Bi2Sr2CaCu2O8. We present the measured photoejected product kinetic energy (KE) distributions, including that for the ion and the neutral, the atomic and polyatomic species. For the specific case of the neutral species desorption, we present new experimental results that elucidate the change in the photophysical desorption process as a function of the incident laser fluence. The results show the transition from the electronic-induced desorption to thermal evaporation as the laser fluence is increased. The KE distribution data suggests that for low-fluence laser excitation, the primary photodesorption process is two-hole localization at a binding site followed by coulomb repulsion. A fraction of the escaping ions acquire the full coulomb KE (e2/ro; ro internuclear distance). The neutral species acquire a partial fraction of the available KE (i.e., the KE gained prior to the neutralization). The appearance of polyatomic species desorption is explained via the spectator-stripping model.
Titanium Oxynitride Thin Film Deposition by Pulsed Laser Ablation of Titanium Targets in Nitrogen
Authors: Craciun V. , Craciun D. , Amirhaghi S. , Vickers M. , Tarling S. , Barnes P. , Boyd I. W. 
Published: March 2011

ABSTRACTReactive pulsed laser deposition of titanium targets in a nitrogen atmosphere has been used to deposit thin titanium oxynitride films on Si substrates. The gold coloured layers exhibited a smooth, featureless surface and good chemical resistance in HF-HNO3 mixtures. The films had a high oxygen content which was responsible for relatively high electrical resistivity, measured to be 200–600 μΩ cm. This new method can easily be applied to the growth of other important nitrides such as ZrN, WN, HfN or the deposition of multilayer structures such as TiN/Ti on a variety of substrates.