bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Preanneal Heat Treatment on Oxygen Precipitation in Epitaxial Silicon
Authors: Wijaranakula W. , Burke P. , Forbes L. , Matlock J.H. 
Published: March 2011

AbstractSubstrate wafers used for fabrication of P/P+ epitaxial silicon wafers were preanneal heat treated at 650°C in nitrogen ambients prior to the epitaxial deposition process for various periods up to 300 minutes. Subsequently, epitaxial wafers were subjected to CMOS simulation heat treatments. Postepitaxial nucleation heat treatment at 750°C in nitrogen ambient was also done on some epitaxial wafers. The results shows that preanneal heat treatment can preserve precipitate nuclei from dissolution during the epitaxial deposition process and lead to a high bulk defect density. These results also indicate the effect of the thermal history and spatial location in the grown crystal on the bulk defect formation.
Algorithms for Use in Modeling Diffusions on Personal Computers
Authors: Chan Archie Y.C. 
Published: March 2011

AbstractThe capability of IBM PC to model the dopant redistribution of ion-implanted impurities in silicon was demonstrated and its performance compared with that of mainframe computers.TURBO PASCAL was found to be a preferable programming language due to its relatively high speed and good ability of graphics handling. The operation speed of PC was about 4 to 6 times slower than that of an IBM 3031/VM370/MVS mainframe system.
Electrical Properties of Polycrystalline-Silicon Thin Films for VLSI
Authors: Kamins T I 
Published: March 2011

AbstractThe electrical properties of polycrystalline silicon differ from those of single-crystal silicon because of the effect of grain boundaries. At low and moderate dopant concentrations, dopant segregation to and carrier trapping at grain boundaries reduces the conductivity of polysilicon markedly compared to that of similarly doped single-crystal silicon. Because the properties of moderately doped polysilicon are limited by grain boundaries, modifying the carrier traps at the grain boundaries by introducing hydrogen to saturate dangling bonds improves the conductivity of polysilicon and allows fabrication of moderate-quality transistors with their active regions in the polycrystalline films. Removing the grain boundaries by melting and recrystallization allows fabrication of high-quality transistors. When polysilicon is used as an interconnecting layer in integrated circuits, its limited conductivity can degrade circuit performance. At high dopant concentrations, the active carrier concentration is limited by the solid solubility of the dopant species in crystalline silicon. The current through oxide grown on polysilicon can be markedly higher than that on oxide of similar thickness grown on singlecrystal silicon because the rough surface of a polysilicon film enhances the local electric field in oxide thermally grown on it. Consequently, the structure must be controlled to obtain reproducible conduction through the oxide. The differences in the behavior of polysilicon and single-crystal silicon and the limited electrical conductivity in polysilicon are having a greater impact on integrated circuits as the feature size decreases and the number of devices on a chip increases in the VLSI era.
Effects of Rapid Thermal Processing on Thermal Oxides of Silicon
Authors: Lee S.K. , Shih D.K. , Kwong D.L. , Alvi N.S. , Wu N.R. , Lee H.S. 
Published: March 2011

AbstractThe effects of rapid thermal processing (RTP) on the electrical properties of thin gate oxides in MOS devices have been studied. MOS capacitors have been analyzed by capacitance-voltage (C-V), current-voltage (I-V), and constant current stress techniques. MOSFET degradation due to hot carrier injection has also been investigated. No significant RTP-induced degradation was detected in any category of the device properties considered here. An abnormal trapping behavior was observed on the wafer annealed at 1100°C for 5 seconds.
Excimer Laser-Induced Shallow Diffusion of Boron
Authors: Kato S. , Nagahori T. , Matsumoto S. , Fujioka T. 
Published: March 2011

AbstractThe very shallow junction of boron has been formed by the irradiation of ArF excimer laser on silicon substrate set in BF3 ambient. The sheet resistance decreases with the increase of the number of pulses and saturates above 150 pulses. It also decreases with increasing both gas pressure and laser energy density. The junction depth increases with increasing the number of pulses, ranging from about 400 Å to 2000 Å. It is confirmed from SIMS and four-point probe measurements that boron atoms diffused are electrically activated up to the concentration of about 1020cm−3.
Oxygen Precipitation Studies for N-Type and Epitaxial Silicon Substrates During Simulated Cmos Cycles by Synchrotron Section Topography
Authors: Tuomi T. , Hahn S. , Tilli M. , Wong C.-C. D. , Borland O. 
Published: March 2011

AbstractSynchrotron section topography is applied to the study of silicon wafers pulled out froma simulated advanced CMOS twin-tub process. Substrates are heavily doped with antimony and phosphorus. For comparison also high-resistivity samples are studied. Prior to epi deposition of arsenic doped layers some wafers are subjected to a three-step intrinsic gettering cycle.Section topographs show that in the lightly doped samples a denuded zone is formed by the CMOS process itself in contrast with the heavily doped ones in which the intrinsic gettering is needed.
Infrared and Ion Beam Analysis of SIxN1−x Alloys Grown by Ion Beam Assisted Deposition
Authors: Donovan E.P. , Brighton D.R. , Vechten D. Van , Hubler G.K. 
Published: March 2011

AbstractThin films of amorphous SixNl-x alloys were produced by nitrogen ion beam assisted deposition of electron beam evaporated silicon. Infrared reflection spectra were measured in the range 600 to 10000 cm−1. Fringes were observed due to interference between light multiply-reflected from the front surface and film-substrate (single crystal silicon) interface. Similar measurements were performed on films crystallized by post-deposition furnace anneals. Analyses of the reflection spectra were used to obtain refractive index profiles. Profiles were correlated with nitrogen content as measured by Rutherford BackscatterLng Spectometry (RBS) and Auger Electron Spectroscopy (AES). Film adhesion, density, and purity were found to be improved for depositions assisted by nitrogen ion beams (1000 to 25,000 eV) relative to unassisted evaporation, and the index of refraction decreases monotonically with increasing nitrogen content.
Performance and Reliability of thin Gate Dielectrics for VLSI: Materials and Processing Perspective
Authors: Singh R. 
Published: March 2011

AbstractCurrent trends are in the direction of submicron MOSFETs employing gate dielectrics in the thickness range of about 30 - 100A°. The performance and reliability of submicron MOSFETs can be improved by using high dielectric constant gate dielectric material. A new concept involving 2 or more dielectric material is proposed in this paper. In- situ rapid isothermal processing is proposed for the fabrication of thin gate dielectrics.
Lateral Extension of Dislocations in Nmos Ic.
Authors: Tseng W. F. , Wilkins B. R. , Mccarthy D. 
Published: March 2011

AbstractDislocations extending through channel regions of NMOSFETs with submicron gate lengths have been observed. Additionally, arrays of dislocations in the field regions of IC's have also been observed and found to be generating from the corners of the first n+ region during subsequent high temperature process.
Dolts of Polysilicon for Solar Cell Applications
Authors: Mclarty P.K. , Huang Y.I. , Ioannou D. E. , Johnson S.M. 
Published: March 2011

AbstractDLTS was applied to p—type polycrystalline silicon, grown by a casting technique to form ingots with a nominal doping level of ∼1016 acceptors/cmg. Both Schottky diodes and n+p mesa structures were used for the measurements. Very complex DLTS spectra were obtained from diodes that contained electrically active grain boundaries, whereas no traps were detected in areas that did not contain electrically active grain boundaries. Several electron and hole traps were resolved.
Characterization of the Sol-Gel Transition of Alumina Sols Prepared from Aluminum Alcoxides via 27Al NMR
Authors: Olson William L. , Bauer Lorenz J. 
Published: March 2011

ABSTRACT27Al NMRsp ectra were obtained on a series of alumina sols prepared by the hydrolysis of aluminum sec-butoxide. Subtle but distinct differences were observed in the solution 27Al NMR spectra of sols which varied in appearance from being very milky to completely transparent. No changes were observed in the 27Al spectra of sols which had been aged. The adddition of sufficient quantities of acid or base to gel the sol precipitated dramatic changes in the Al spectra. Aluminum-27 NMR was found to be a highly useful tool for probing the sol-gel transformation of this system.
Raman Spectra of Rings in Silicate Materials
Authors: Tallant D. R. , Bunker B. C. , Brinker C. J. , Balfe C. A. 
Published: March 2011

ABSTRACTRaman spectroscopic studies on gel-derived silicates have confirmed that narrow bands near 607 cm-1 and 492 cm-1, first observed in the Raman spectrum of fused silica, are associated with three- and four-fold siloxane rings. Using these results, we have identified three- and four-fold siloxane rings in other high-surface-area silica materials, including leached glasses and Cab-OSil. This Raman spectroscopic evidence not only shows that small siloxane rings are a common characteristic of a number of silica materials but also suggests that they form preferentially at silica surfaces. This paper reviews the Raman spectroscopic evidence that led to the identification of the vibrational frequencies of the small siloxane rings and presents the results of Raman experiments on high-surface-area silica materials in which the concentration of small siloxane rings is enhanced compared to fused silica.
Chemical Route to Aluminosilicate Gels, Glasses and Ceramics
Authors: Pouxviel J. C. , Boilot J. P. , Dauger A. , Huber L. 
Published: March 2011

ABSTRACTChemically ultra-homogeneous gels have been prepared, in the SiO2-Al2O3 system, using new metal-organic precursors with Al-O-Si linkages. By thermal treatment at 900°C, transparent monolithic gels lead to aluminosilicate glasses and above 1000°C, to optically transparent glass-ceramics (for instance by homogeneous crystallization of mullite in an amorphous silica matrix).
Precursors to Boron-Nitrogen Macromolecules and Ceramics
Authors: Narula C. K. , Paine R. T. , Schaeffer R. 
Published: March 2011

ABSTRACTBoron nitride has been prepared in the past from classical high temperature reactions and more recently by CVD methods. Few attempts have been made to prepare this important material from pyrolyses of preceramic oligomers or polymers. In the present study oligomerization reactions of substituted borazenes with silyamine crosslinking groups have been found to provide useful gel materials which upon pyrolysis form boron nitrogen materials. Selected aspects of this chemistry and some characterization of the materials is presented.
Structure and Properties of Ceramic Fibers Prepared From Polymeric Precursors [1]
Authors: Lipowitz J. , Freeman H. A. , Goldberg H. A. , Chen R. T. , Prack E. R. 
Published: March 2011

ABSTRACTCeramics can be prepared by pyrolysis of organosilicon polymers. Advantages of this method of ceramics preparation are; the ability to prepare shapes difficult to achieve by other methods such as fibers and films; the ability to achieve high purity because reagents used to prepare the polymer can be purified by well established chemical methods; processing at lower temperature than conventional methods [2].
Solution Chemistry of Silicate and Borate Materials
Authors: Bunker B. C. 
Published: March 2011

ABSTRACTReactions which create and destroy Si-O-Si, Si-O-B, and B-O-B bonds occur in leached layers on borosilicate glasses during glass dissolution. Solid state NMR, Raman, and TEM techniques have been used to determine the distribution of species formed in leached layers as a function of solution pH and the mechanisms of glass-water reactions. The chemical principles which govern the reactivity of silicate and borate bonds in leached layers appear to be similar to those which govern the formation of silicate and borate gels via sol-gel techniques.
Molecular Mimicry of Structure and Electron Density Distributions in Minerals
Authors: Gibbs G. V. , Boisen M. B. 
Published: March 2011

ABSTRACTMolecular orbital calculations on hydroxyacid molecules with first- and secondrow X-cations (X = Li through N and Na through S) yield bond lengths and angles that mimic those of chemically similar minerals. These bond lengths are used to find a formula giving bond length as a function of a bond-strength parameter that reproduces XO bond lengths in crystals with main-group X-cations from all six rows of the periodic table within 0.05Å on average. The molecular orbital calculations also provide insights into reaction energies, physical properties of crystals such as electron density distributions, and data not amenable to direct measurement. They also provide a basis from which computational models for mineral structures may be constructed.
Drying Behavior of Sol-Gel Derived A12O3 and Al2O3-Sic Composites
Authors: Krabill R. H. , Clark D. E. 
Published: March 2011

ABSTRACTGel drying is a critical step in the sol-gel synthesis of Al2O3 and Al2O3-SiC composites. Problems exist during the drying stage that affect the monolithic properties of the sintered products. Classical drying theory was applied to the drying behavior of Al2O3 and Al2O3-SiC composites in an effort to optimize the drying process and understand the controlling mechanisms.
Sol-Gel Coatings on Carbon/Carbon Composites.
Authors: Sim S. M. , Krabill R. H. , Dalzell W. J. , Chu P-Y. , Clark D. E. 
Published: March 2011

ABSTRACTThe need for structural materials that can withstand severe environments up to 4000°F has promulgated the investigation of sol-gel derived ceramic and composite coatings on carbon/carbon composite materials. Alumina and zirconia sols have been deposited via thermophoresis on carbon/carbon substrates.
The Effect Of Hydrolysis Conditions On The Characteristics Of PbTiO3 Gels And Thin Films
Authors: Budd K. D. , Dey S. K. , Payne D. A. 
Published: March 2011

ABSTRACTSol-gel processing represents a promising method of fabrication for thin films of electronic ceramics which are useful in a number of packaging and device applications. In this study, the influence of acid and base catalysts on the structure of PbTiO3 gels and films (0.1–1.0 μm) was investigated, for the purpose of inducing and identifying gel structures which were the most suitable as precursors for thin dielectric layer. Continuous, crack-free films, with dielectric strengths in excess of 106 V/cm were developed. Basic solutions gelled rapidly, phase separated, and were probably more crosslinked than acidic gels. Acidic gels seemed more capable of polymeric rearrangement during drying, yielding denser amorphous structures with microcrystalline regions. High-field dielectric constants (1 MV/m ac) in the range K=30–40 and K=160–170, were determined for amorphous and crystalline films, respectively.
Chemistry And Applications Of Inorganic-Organic Polymers (Organically Modified Silicates)
Authors: Schmidt H. , Seiferling B. 
Published: March 2011

ABSTRACTThe combination of inorganic polymeric networks with organic components leads to inorganic-organic polymers. A convenient method for the introduction of organic radials into an inorganic backbone is the use of organosubstituted silico esters in a polycondensation process. This leads to≡Si-O-Si≡ network containing materials, so-called organically modified silicates (ORMOSILs). For the synthesis of the inorganic backbone, in opposition to the high temperature preparation of non-metallic inorganic materials like ceramics, “soft chemistry” methods have to be applied in order to preserve organic groupings to be incorporated. Therefore, the sol-gel process is a suitable technique [1–5]. A review over basic synthesis principles and chemical methods, their effect on special material properties and the application potential will be given.
Crystallization and Melting of Amorphous Silicon on a Microsecond Time Scale
Authors: Olson G. L. , Roth J. A. , Nygren E. , Pogany A. P. , Williams J. S. 
Published: March 2011

AbstractMeasurements of the competition beween solid phase epitaxy, solid phase random nucleation, and melting in amorphous Si on a microsecond time scale are reported. We find that the behavior of amorphous Si under microsecond pulsed dye laser irradiation depends strongly on film thickness and temperature. In “thin” (≲1000 Å) films solid phase epitaxy is observed at temperatures up to and exceeding 1300°C with random nucleation dominating at T>1330° C; however, melting of amorphous Si does not occur. In contrast, in “thick” (2600 Å) amorphous films melting is observed at T˜1190°C. These results are discussed with respect to measurements obtained previously in the nanosecond time regime using Q-switched laser heating and in the 0.1–1 millisecond regime using “chopped beam” cw laser heating.
Faster Quenching by Silicon Pulsed Laser Annealing Under Water
Authors: Polman A. , Roorda S. , Ogale S. B. , Saris F. W. 
Published: March 2011

AbstractA novel method of pulsed laser processing of ion-implanted silicon is presented, in which samples are irradiated in water ambient. The water layer in contact with the silicon during irradiationh as a considerable influence on melting and solidificationd ynamics. Still, perfect epitaxy of a thin amorphous layer can be obtained using this method.For epitaxy to occur on a sample irradiated under water, 40 % more absorbed energy is necessary than for a sample irradiated in air. This indicates the occurrence of a considerable heat-flow from the silicon into the water layer during the laser pulse. From impurity redistribution after irradiation it is found that by processing a sample under water liquid-phase diffusion is reduced. Diffusion theory arguments indicate that this can be due to a reduction in total melt duration by about afactor 2–3. This can be due to faster cooling of the liquid silicon layer after the laser pulse whereas the melt-in time might be influenced as well. As a consequence, shallower impurity profiles can be obtained in crystalline silicon. No oxygen incorporation is detected and the surface morphology is not disturbed using this new process.
Crystallization of Silicon on Electro-Optic Plzt by a Laser Beam Modulated in Shape and Intensity Profile
Authors: Lin T. H. , Burgener M. L. , Esener S. C. , Lee S. H. 
Published: March 2011

AbstractPLZT, a ferroelectric material with a high quadratic electro-optic coefficient, is combined with silicon technology via chemical vapor deposition to enable the realization of Si/PLZT spatial light modulators. Laser crystallization is required to produce device quality silicon deposited on PLZT. The critical issues in the laser crystallization are (i) achieving crystallization in the absence of a good seed, and (ii) preventing damage to the PLZT. To prevent PLZT damage during the laser heating, a 3.5 μm silicon dioxide layer is used as a thermal buffer between the silicon and the PLZT and the effective scanning time is shortened to 100 μs. A double humped cw argon ion laser with a shaped beam is used to achieve successful crystallization with good surface smoothness and large grain size. This technology and devices fabricated on these samples will be discussed.
Melting Point Measurements for Quasicrystalline Phases
Authors: Knapp J. A. , Follstaedt D. M. 
Published: March 2011

AbstractMelting transitions of metastable quasicrystalline phases of Al-Mn have been observed using rapid electron-beam heating of fine-grained icosahedral surface layers. The congruent melting-point for icosahedral Al80 Mn20 was directly measured to be 910±20°C. Heating to higher temperatures shows another transition which is inferred to correspond to the liquidus of the decagonal phase at 965±20°C for 20 at.% Mn. The microstructure and formation kinetics of the decagonal phase are discussed, and its electron diffraction is described.
Time-Resolved Picosecond Reflectivity Study of Laser-Excited Layered Compounds
Authors: Huang C. Y. , Malvezzi A. M. , Bloembergen N. , Di Salvo F.J. 
Published: March 2011

AbstractWe have employed the pump-and-probe technique to perform picosecond time resolved measurements of the reflectivity changes in two archetypal layered compounds, IT-TiS2 and lT-TiSe2 probed at 1.064 μm after pumping by 20 ps, .532 μm laser pulses. At the threshold fluence, ∼ 40 mJ/cm2, the reflectivity drops sharply, marking the occurrence of a phase transformation on the surface of the sample. Above threshold, the reflectivity reaches a value as low as ∼0.1 at high fluences, strongly suggesting that, like in graphite, the high temperature phase is not metallic.
Damage Production in B-Sic During Ion Implantation
Authors: Withrow S. P. , More K. , Edmond John A. , Kong H. S. , Maziasz P. J. , Davis R. F. 
Published: March 2011

AbstractDamage in single crystal ß-SiC(100) as a result of ion bombardment has been studied using Rutherford backscattering (RBS) and cross-section transmission electron microscopy (X-TEM). Samples were implanted with 123 keV 27Al at liquid nitrogen temperature. RBS spectra for He channeling in the (110) axis at 45° were obtained as a function of implantation dose to determine damage accumulation. X-TEM was used to characterize damage structure for selected doses. The surface of the SiC becomes amorphous for doses greater than 1 x 1015 /cm 2. At lower doses, significant uniaxial lattice strain along the (100) direction is suggested by comparison of RBS channeling spectra obtained for several high index axes. High resolution TEM on a sample implanted at 4 x 1014 /cm2 shows no damage structure in the surface region; lattice damage in a broad layer centered roughly at the depth of highest energy deposition is characterized by small amorphous pockets in a crystalline matrix. Qualitatively similar backscattering results were obtained for other elements implanted at room and liquid nitrogen temperature.
The Effect of Damage Density Profile on Moving specles in Ion-Induced Reactions
Authors: Tao K. , Hewett C. A. , Lau S. S. , Buchal Ch. , Poker D. B. 
Published: March 2011

AbstractWe present evidence in this study that the moving species under ion mixing conditions are affected by the implantation damage distribution in the sample. This observation holds for metal-semiconductor, metal-metal and semiconductorsemiconductor systems. The direction of thermal annealing and atomic transport appears to play a role in ion-mixing as well. When these two factors are in the same direction, only one dominant moving species is observed. When these two factors are in opposite directions, both constituents can contribute to the atomic transport in ion mixing.
Temperature Dependence of Ion Mixing Of Markers in Zr
Authors: Kim S. -J. , Nicolet M. -A. , Averback R. S. 
Published: March 2011

AbstractIon mixing of thin markers in Zr was investigated by irradiating with 660 keV Kr++ ions at temperatures between 300 to 423 K. Very thin films of vacuum evaporated Ti, Cr, Fe, Co, Ni, Cu+ Hf, W, and Au served as markers. The samples were analyzed by 2 MeV He backscattering spectrometry. The marker elements that are likely to dissolve interstitially in Zr have higher mixing efficiencies at elevated irradiation temperature than the markers that are likely to dissolve substitutionally. The results are explained by radiation-enhanced diffusion theory.