bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photochromic-Induced Photorefractive Changes in Barium Titanate
Authors: Garrett M. H. , Chang J. Y. , Jenssen H. P. , Warde C. 
Published: March 2011

ABSTRACTPhotochromism in barium titanate was found to affect its deep and shallow trap properties. Argon ion laser illumination at 514.5 nm photo-induced semi-permanent (thermally reversible) changes in the visible absorption spectrum of barium titanate that were stable at room temperature. Increases in absorption at 514.5 nm, also the operating wavelength used to determine photorefractive properties, caused a decrease in the photorefractive response time but also a decrease in the sensitivity. When the photochromism was inactive the crystal shows light-induced absorption. With the photochromism saturated the crystal showed light-induced transparency. A model with two photoactive levels is used to characterize the photorefractive properties of this photochromic crystal.
The Effect of Copper Vacancies on the Optical Bowing of
Chalcopyrite Cu(In,Ga)Se2 Alloys
Authors: Albin D. S. , Carapella J. J. , Tuttle J. R. , Noufi R. 
Published: March 2011

ABSTRACTThe optical bowing behavior of polycrystalline thin film
Culn1-yGaySe2 alloys is dependent upon
the Cu stoichiometry. The variation in optical band gap, Eg, for
alloys in which Cu is near stoichiometric (25 at.%) is parabolic and follows
the relationship: Eg(y) = 1.011 + 0.421 y + 0.244 y2
(eV), where y is the alloy parameter, [at.% Ga] / [at.%Ga + at.%In].
Contrary to this, films with Cu-poor stoichiometries (∼19 at.% Cu) exhibit
little alloy bowing: Eg(y) = 1.01 + 0.733 y - 0.046 y2 (eV). The
increase in Eg with Cu deficiency appears to be the result of both a
structural effect associated with tetragonal lattice shrinkage, ΔV =
Vstoichiometric - VCu-poor (resulting from the
presence of Cu vacancies) and a chemical effect, possibly associated with a
counterbalance between p-d repulsion and anion displacement effects.
Preparation of Boron Nitride Films by Rf Reactive
Sputtering
Authors: Banerjee P. K. , Chaterjee B. , Kim J. S. , Mitra S. S. 
Published: March 2011

ABSTRACTBoron nitride films were deposited by rf reactive sputtering. The
composition of the film was determined by X-ray photo-electron
spectroscopy(XPS). Optical properties of boron nitride were studied by IR
spectroscopy. Resultant films showed optical characteristics similar to
those of hexagonal boron nitride. The ratio of boron to nitrogen was varied
from 3.11 to 1.45 by varying the amount of nitrogen. Resulting films have
refractive index in the range of 2.05 – 3.21.
Selectively Absorbing Properties of Sol Gel Dip Coated Indium
Tin Oxide Thin Films on A Glass Pane
Authors: Jung Hyung-Jin , Lee Hee-Hyung , Lee Dong-Heon , Lee Jeon-Kook 
Published: March 2011

ABSTRACTSelectively absorbing properties of indium tin oxide(ITO) thin film were
characterized in UV-VIS-NIR wavelength regions. Sodium diffusion from glass
pane had a bad influences on the properties of ITO layers. So
silica-zirconia barrier layers were formed by sol gel dip coating. ITO films
on buffer layered glass pane were formed by sol gel dip coating.
Transmittance and reflectivity dependence on the thickness of barrier layer
and ITO coating layers were studied by measuring sheet resistance and
UV-VIS-NIR spectroscopy.Transparency at 550 nm wavelegth and selective reflectivities were important
to apply to passive solar collectors. In single barrier layer and six-fold
ITO coated films, good selectivities were obtained. Homogeneity of indium
tin precursor coating solution was important. Atmosphere condition
(humidity, temperature), dip and drawing conditions were also additional
factors for uniformity of films.
Influence of Structure on the Soft X-Ray Optical Properties of Metallic Multilayers
Authors: Slaughter J. M. , Kearney Patrick A. , Falco Charles M. 
Published: March 2011

AbstractMultilayer thin film structures for reflecting soft x-rays are now being fabricated in a number of laboratories. However, understanding of. the optical properties of these structures is presently limited by lack of knowledge of the microstructure of the layers, as well as of the details of the interfaces. In this paper we present results from our studies of multilayers grown by molecular beam epitaxy (MBE), characterized in situ by reflection high energy electron diffraction (RHEED), low energy electron diffraction (LEED), Auger, and x-ray photoelectron spectroscopy (XPS), and characterized ex situ by scanning tunneling microscopy (STM), transmission electron microscopy (TEM), x-ray diffraction, and Rutherford back scattering (RBS). In the case of Mo/Si multilayers, we observe the formation of an amorphous interfacial silicide, which can have a positive effect on the performance of these evaporated multilayer mirrors. We observe a contraction in the period of these multilayers as the deposition temperature is raised from 50 °C to 250 °C, corresponding to an increase in the thickness of the interfacial silicide. This contraction indicates that the silicide is more dense than the average atomic density of its components. We also discuss Ag/B and Pd/B multilayers, which have very similar theoretical performance. However, due to differences in the multilayer structures formed, the actual performance of multilayers made from these materials is radically different. The structural differences originate from different growth modes for Ag and Pd on B.
Interfacial Mixing in Epitaxial Co/Pt Superlattices: a Source of Magnetocrystalline Anisotropy
Authors: Farrow R. F. C. , Hermsmeier B. D. , Lee C. H. , Marks R. F. , Marinero E. E. , Lin C. J. , Chien C. J. , Hagstrom S. B. 
Published: March 2011

AbstractWe report the results of photoelectron forward scattering studies of Co-Pt interfaces during the growth of epitaxial superlattices by MBE. These studies reveal that the interfaces are not atomically abrupt but exhibit limited interdiffusion. The dependence of magnetic anisotropy on growth axis and the strong 2-fold in-plane anisotropy for [110] oriented superlattices suggests that magnetocrystalline anisotropy is a major factor in determining the anisotropy in Co/Pt superlatticcs. The possibility that this anisotropy may arise from a combination of structural defects and local ordering is discussed.
The Effect of Grain Boundaries and Substrate Interactions with Hydrogen on the CVD Growth of Device-Quality Copper.
Authors: Kaloyeros A. E. , Dettelbacher C. , Eisenbraun E. T. , Lanford W. A. , Li H. , Olowolafe J. F. , Murarka S. , Pintchovski F. , Shy Y. -T. , Toscano P. J. 
Published: March 2011

AbstractThe effects of grain boundaries and substrate interactions with hydrogen on the CVD growth of device-quality copper were investigated by high-resolution x-ray photoelectron spectroscopy (HRXPS), Auger electron spectroscopy (AES), four-point resistivity probe, x-ray diffraction (XRD), and hydrogen profiling techniques. The films were deposited at 200° C in a stainless-steel cold-wall-type CVD reactor in an atmosphere of pure H2 from various β-diketonate precursors, including bis(6,6,7,7,8,8,8-heptafluoro-2,2- dimethyl-3,5-octanediono)copper(II), Cu(fod)2, and bis(2,2,6,6-tetramethyl- 3,5-heptanedionato)copper(II), Cu(tmhd)2. The results of these studies showed that films grown on in-situ plasma-cleaned metallic substrates were uniform, continuous, adherent, and highly pure. Films with grain size larger than 500Å exhibited very low resistivity, as low as 1.7 μΩcm. Preliminary investigations of the mechanisms of selective copper CVD showed that selectivity is independent of precursor chemistry and is a function of the nature and degree of substrate interactions with hydrogen.
The Real-Space Multiple-Scattering Theory and the Electronic Structure of Grain Boundaries.
Authors: Sowa Erik C. , Gonis A. , Zhang X. -G. 
Published: March 2011

AbstractWe describe the recently developed real-space multiple-scattering theory (RSMST), which is designed for performing first-principles electronic-structure calculations of extended defects, such as surfaces and interfaces including atomic relaxations and with or without impurities, without using artificial periodic boundary conditions. We present the results of non-charge-selfconsistent RSMST calculations of the local electronic densities of states at twist and tilt grain boundaries in fcc Cu and bcc Nb, and report on progress towards the implementation of charge self-consistency and total-energy capabilities.
Determination of Energy Minima for Dissimilar Metal Interfaces
Authors: Shewmon Paul , Dregia Suliman 
Published: March 2011

AbstractRelative orientations which correspond to minimum energy can be found by particle rotation methods, both for particles on free surface and particles inside a solid. For common fcc metals (Ni,Ag,Cu,Ag) the minimum energy orientations predicted by Embedded Atom Method calculations correspond well with experimental observations. Epitaxial studies of growth on (001)Cu and (111)Cu show the observed orientation relationships of vapor deposited Ag and Au are consistent with EAM calculations and the limited particle rotation experiments available.
Tem Characterization of Grain Boundaries in Mazed Bicrystal Films of Aluminum
Authors: Dai-Men U. , Westmacott K. H. 
Published: March 2011

AbstractThe structure and faceting behavior of near-90° <110> tilt grain boundaries in thin films of aluminum with a unique mazed bicrystal geometry is characterized by conventional, highresolution and high-voltage electron microscopy. In this microstructure the absence of triple junctions allows grain boundaries to facet in optimum orientation (inclination) during annealing. The degree of anisotropy of the boundaries is expressed in the form of a rose plot. Small local deviations in misorientation are shown to be necessary to accommodate optimum boundary segments. The crystallographic symmetry inherent in this microstructure is apparent and utilizedthroughout the analysis.
A Preliminary Characterization of the Defect Structure of the Zeta Phase in the Interfacial Region of Fe-Zn Couples
Authors: Giannuzzi Lucille A. , Howell Paul R. , Pickering Howard W. , Bitler William R. 
Published: March 2011

AbstractA preliminary investigation of the defect structure of the monoclinic zeta phase, within the interfacial region of Fe-Zn couples, has been performed using cross-section transmission electron microscopy (TEM). Twin boundaries and dislocations have been unambiguously identified, however, examples of defects which, as of yet are unknown, are also presented. The monoclinic zeta phase was found to twin by a rotation of 180° about the normal to the (110) plane.
Surface Wave Velocity of Silver/Chromium and Gold/Chromium Superlattices
Authors: Kaneko Takeo , Ogu Shinzo , Kyuno Kentaro , Inoue Yasushi , Yamamoto Ryoichi , Yoshihara Akira 
Published: March 2011

AbstractRayleigh surface wave velocities in Ag/Cr and Au/Cr metallic superlattices have been measured by Brillouin scattering spectroscopy. These metallic superlattices were prepared by the metal-MBE method. X-ray diffraction measurements indicated that the structures of Ag/Cr and Au/Cr superlattices were almost the same. In the Au/Cr superlattices a maximum in a plot of surface wave velocities as a function of the bilayer thickness was observed. On the contrary, a distinct dip was shown in Ag/Cr systems. This anomalous behavior of the sound velocity could not be attributed to the expansion and the contraction of the lattices. Differences in atomic scale structure in the interface seem to play a major role in these systems.
Interfacial Energy Reduction Analysis in Fibrous Structures
Authors: Sandlin A. C. , Schaefer R. J. 
Published: March 2011

AbstractThe morphology of directionally solidified CuAl-Pb monotectic alloys has been studied. The structure consisted of a hexagonal array of Pb rods in a Cu-based matrix. In addition, elongated grain boundaries in the Cu-based matrix with lens-shaped Pb fibers on the boundary and a “denuded zone”, depleted of Pb rods, were observed. Existence of these boundaries is shown to reduce the overall surface energy of the system leading to the formation of the elongated grain boundaries.
Reconstructions and Morphological Instabilities of FCC (110)Surfaces
Authors: Sun J. , Rottman Craig 
Published: March 2011

AbstractWe compare the ground state energy of the following structures of fcc (110) surfaces: the (1×1) flat surface, the (n×1) reconstruction (2 ≤ n < ∞), and the (∞ × 1) structure where the surface is faceted into macroscopic (111) surfaces. We map out the phase diagram using a lattice model with pair and triplet interactions. We argue that it is unlikely that any realist pair potential will give a reconstructed ground state. We also doubt that including, in addition, three body interactions will stabilize the reconstructed structure for interatomic interactions derived from the embedded atom method.
Concentration-Dependent Surface-State Shifts: Au on Cu(001)
Authors: Hansen J. C. , Wagner M. K. , Tobin J. G. 
Published: March 2011

AbstractHigh-resolution angle-resolved photoemission has been used to investigate the behavior of the Cu(001) surface state as a function of Au coverage and substrate temperature. Binding-energy shifts of this state are dependent on the concentration of Au atoms substituted into the top surface layer of the Cu(001) substrate. The results demonstrate the use of surfacelocalized Tamm states as a specific probe of the chemical environment in the surface plane.
Low Energy Electron Diffraction During Pulsed Laser Annealing: A Time Resolved Surface Structural Study
Authors: Becker R. S. , Higashi G. S. , Golovchenko J. A. 
Published: March 2011

ABSTRACTNanosecond structural changes in a crystal lattice during pulsed laser annealing have been measured using time-resolved Low Energy Electron Diffraction (LEED). LEED is both structure and surface (∼ 10Å) sensitive. Lattice temperatures can be extracted from Debye-Waller like extinction coefficients. Combining these with nanosecond time resolution provides a surface probe for short-time dynamical processes. The technique is used to observe the time evolution of a Ge(l11) surface during pulsed laser annealing. The results demonstrate rapid formation of a liquid layer and subsequent surface recrystallization and cooling.
Optical Properties of Laser Induced Heavily Doped Silicon Layers
Authors: Slaoui A. , Fogarassy E. , Siffert P. , Morhange J.F. , Balkanski M. 
Published: March 2011

ABSTRACTThe goal of this paper is to investigate optical properties of heavily doped silicon, performed by laser annealing of implanted layers.The optical properties were investigated by using U.V. and visible light (between 200 and 500 nm)reflectance and Raman spectrometry measurements. The experimental observations have been correlated with the contribution of the supersaturated solid solution of arsenic in the silicon lattice. Furthermore,the absorption coefficent of these layers has been deduced from ellipsometry measurements.
CW Laser Annealed Small-Geometry NMOS Transistors
Authors: Naem A.A. , Boothroyd A.R. , Calder I.D. 
Published: March 2011

ABSTRACTSmall geometry NMOS transistors were fabricated using junctions implanted with 1016; Asplus;/cm2; @ 180 keV and annealed through 1067 Å of SiO 2; with a cw argon laser. Phosphosilicate glass densification was the only other high temperature step. Channel lengths were varied from 1.3 to 50 μ. and channel widths from 1 to 50,μ. Physical characterization of these devices revealed a junction depth of 3000 Å with negligible lateral diffusion. The smallest transistor had approximately a square channel with WxL = 1×l.3μ2;. IDS;−VDS; characteristics of this device were similar to those of large geometry devices due to counteracting short and narrow channel effects. The threshold voltage was 0.61±0.013 V across an entire wafer, while there was no punch-through for VDS;<13 V and no avalanche breakdown for VDS; < 14 V. The junctions showed a forward-biased ideality factor of 1.17, and the contact resistance in an 8 × 8 μ2; area was 1.5Ω to the source/drain regions and 0.5Ω to laser-recrystallized polysilicon interconnects. It is concluded that cw laser annealing can be used to fabricate small-geometry devices with excellent performance and without any deleterious effects.
Some Results Concerning the Residual Stresses Distribution in Laser Treated Samples
Authors: Chabrol C. , Coquerelle G. , Gerbet D. , Nicolas G. , Vannes A. 
Published: March 2011

ABSTRACTResidual stress introduced in middle carbon steels by a solid-solid transformation following a laser heating are studied by two methods : a destructive one which consists in taking away layers of material, the other one, a non destructive method, based on the ferromagnetic noise analysis. The first method gives an average value of the stresses existing in the machined layers, the second one gives informations on localized variations.
Lattice Temperature of GaAs and Si During Nanosecond Laser Annealing
Authors: Pospieszczyk A. , Abdel Harith M. , Stritzker B. 
Published: March 2011

ABSTRACTSingle crystals of GaAs (100) and Si (110) were laser annealed with a 20 ns ruby laser pulse. Both the velocity distribution and the density variation of evaporated Ga or As and Si atoms were determined by a time-of-flight measurement. In addition time-resolved measurements were made of the reflectivity of the surface during the laser annealing. The data consistently show that the molten phase occurs at energy densities of ≳ 0.35 J cm–2 for GaAs and ≳O.8 J cm for Si.
Taser Induced Bulk Defects in Single Crystal Silicon Below the Melting/Vaporization Thresholds
Authors: Parker Donald L. 
Published: March 2011

ABSTRACTHighly focused Q-switched Nd:VDG fundamental (1.05 micron wavelength IR) and second harmonic (0.53 micron wavelencth green) laser pulses have been shonm to produce bulk defects in single crystal silicon at peak power densities below the vaporization threshold for the IR and below the melting threshold for the green. The defects decrease the encess rinoritv carrier lifetime as measured by junction leakage, junction step recovery, the MOS CV method, bioolar transistor current qain, and pn junction photocurrent. Green pulses have no effect on the thermal oxide dielectric strength or pn junction breakdown voltage at power densities up to the melting threshold. IR pulses begin to lower the junction breakdown voltage below the vaporization threshold and oxide dielectric strength is drastically lowered at or slightly below this threshold. The defect density decreases exponentially into the crystal with effective ranges of 0.7 micron and 1.7 microns for the green and IR respectively. IR absorption is very nonlinear near the vaporization peak power density threshold. The defects are a point type; are unchanged by a subsequent 400°C anneal; and are completely removed by an 800°C anneal. The results suggest some detrimental effects of laser processing of silicon intergrated circuits as well as some new potential applications.
Device Applications of Rapid Thermal Processing
Authors: Gibbons J. F. , Dobkin D. M. , Greiner M. E. , Hoyt J. L. , Opyd W. G. 
Published: March 2011

ABSTRACTThe potential of rapid thermal processing for applications in silicon integrated circuit technology, silicon microwave bipolar technology and GaAs FET technology is explored.In addition, two novel applications for GaAs processing are described.
Soi by CVD: An Overview of Material Aspects and Implications of Device Properties
Authors: Jastrzebski L. , Kokkas A. G. 
Published: March 2011

ABSTRACTTwo CVD techniques producing monocrystalline SOI films, silicon-on sapphire (SOS) and Epitaxial Lateral Overgrowth (ELO), are described and the nature of the crystallographic defects in the films is discussed. The geometrical structure of SOI devices, device properties, dynamic characteristics, capacitance, and radiation hardness are then examined with emphasis on evaluating the potential of SOI technologies in future applications.
Grain Boundary Confinement in Soi Films Using Patterned Ar Coatings and Seeded Oscillatory Growth
Authors: Drowley C.I. , Zorabedian P. , Kamins T.I. 
Published: March 2011

ABSTRACTRegular arrays of grain-boundary-free silicon strips several hundred microns long have been produced in a silicon-on-insulator (SOI) structure by using a patterned anti-reflection (AR) coating in combination with seeded oscillatory growth techniques. The AR coating pattern consists of a series of parallel stripes (typically 10 μm wide, separated by 10 μm spaces) starting from a seeding window. A laser beam (typically a 50 μm × 250 μm elliptical beam) is scanned perpendicular to the stripes, with the long axis of the beam parallel to the scan direction. The beam is stepped 1–2 μm between successive scans to advance the single crystal along the direction of the AR stripes. Grain boundaries are confined to the region under the AR stripes. Stereographic analysis of KOH etch pits formed in the single crystal strips has shown that the orientation of the stripes gradually rotates from (001)[110] to (013)[331] as the crystal propagates away from the seed. MOS transistors formed in the single-crystal strips have mobilities comparable to devices formed in bulk films. These mobilities are approximately 20% higher than those found in devices formed in large-grain recrystallized polysilicon films.
The Role of Oxygen in Zone-Melting Recrystallization of Silicon-On-Insulator Films
Authors: Fan John C. C. , Tsaur B-Y. , Chen C. K. , Dick J. R. , Kazmerski L. L. 
Published: March 2011

ABSTRACTUsing secondary-ion mass spectroscopy, we have found that oxygen is strongly concentrated at the sub-boundaries in zone-melting-recrystallized silicon-on-insulator films prepared by the graphite-strip-heater technique. This observation suggests that the formation of sub-boundaries during recrystallization may be caused by constitutional supercooling resulting from the presence of oxygen that is dissolved into the molten Si zone from the adjacent SiO2 layers. Since all zone-melting-recrystallized films to date have been bordered by SiO2 layers, regardless of the heating techniques employed, the sub-boundaries almost always present in these films may well have dissolved oxygen as their common origin.
Characteristics of Short-Channel Mosfet's in Laser Crystallized Si-on-Insulator
Authors: Ng K. K. , Celler G. K. , Povilonis E. I. , Trimble L. E. , Sze S. M. 
Published: March 2011

ABSTRACTData are reported on short-channel MOSFET's fabricated in laser crystallized silicon-on-insulator (SOI) structures. In this experiment, special effort was made to minimize enhanced diffusion of dopants from the source and drain regions along grain boundaries. Instead of the standard anneal used for the implant activation, rapid thermal annealing and low temperature furnace annealing were used. These modified processes yielded functional MOSFET's with channel lengths as short as 1.5 μm, and ring oscillators of 2.0 μm. A speed of 115 ps per stage was obtained in these ring oscillators which is not only the fastest ever reported on any SOI structure, but also a factor of 2 faster than that from the same circuits in bulk Si. The results demonstrate quantitatively the speed improvement of SOI over bulk material due to reduced parasitic capacitance.
Thick Films for Dielectric Isolation by Lateral Epitaxy from the Melt
Authors: Celler G. K. , Trimble L. E. 
Published: March 2011

ABSTRACTDielectric Isolation (DI) technology has been available for almost twenty years. It was first developed for low capacitance, high speed circuits, and was later adapted to radiation hardened devices and for high voltage isolation. We describe a new method of forming DI structures that simplifies wafer fabrication, reduces the density of process induced defects, and may lead to a more flexible device design. Our process is based on recrystallization from the melt of thick Si films deposited over oxidized Si wafers, with a regular array of seeding windows opened in the isolation oxide. The recrystallized films are free of grain boundaries and subboundaries.