TY - CHAP TI - MICROSTRUCTURAL EVOLUTION AND SUBSTRATE SELECTIVITY IN PECVD MU-C-SI T2 - Microcrystalline Semiconductors : Materials Science & Devices PY - 1993/// VL - 283 SP - 495-500 PB - SE - UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:A1993BY10P00077&KeyUID=WOS:A1993BY10P00077 ER - TY - JOUR TI - FEMTOSECOND SPECTROSCOPIC STUDY OF ULTRAFAST CARRIER RELAXATION IN HYDROGENATED AMORPHOUS-SILICON A-SI-H AU - ESSER, A AU - HEESEL, H AU - KURZ, H AU - WANG, C AU - PARSONS, GN AU - LUCOVSKY, G T2 - Journal of Applied Physics AB - We present a study of spectral- and time-resolved reflectivity and transmission measurements on hydrogenated amorphous silicon (a-Si:H) with 50 fs time resolution. Electron-hole pairs are photoexcited into the extended states of a-Si:H by an ultrashort pump pulse at ℏω=2 eV. The temporal evolution of the photoinduced optical response is studied for a broad range of excitation densities from 1018 up to 1020 cm−3, and on a timescale of up to 200 ps. The temporal evolution of the optical response is discussed in terms of recombination and trapping mechanisms for carriers in the extended states of a-Si:H. DA - 1993/// PY - 1993/// DO - 10.1063/1.353263 VL - 73 IS - 3 SP - 1235-1239 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:A1993KK92100034&KeyUID=WOS:A1993KK92100034 ER - TY - JOUR TI - TRANSPORT-PROPERTIES OF OPTICALLY GENERATED FREE-CARRIERS IN HYDROGENATED AMORPHOUS-SILICON IN THE FEMTOSECOND TIME REGIME AU - ESSER, A AU - HEESEL, H AU - KURZ, H AU - WANG, C AU - PARSONS, GN AU - LUCOVSKY, G T2 - Physical Review B AB - We present spectral- and time-resolved reflectivity and transmission measurements on hydrogenated amorphous silicon, a-Si:H, with 50 fs time resolution. Electron-hole pairs are photoexcited into the extended states of a-Si:H by an ultrashort pump pulse at a photon energy of 2 eV. The optical response of photogenerated carriers is studied on an ultrashort time scale, \ensuremath{\Delta}t\ensuremath{\sim}100 fs, after the excitation process where recombination and trapping can be neglected. The spectral dependence of the optical response is analyzed in terms of a hopping model for the transport of the photogenerated carriers in the extended states of a-Si:H. DA - 1993/// PY - 1993/// DO - 10.1103/PhysRevB.47.3593 VL - 47 IS - 7 SP - 3593-3597 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:A1993KP08600014&KeyUID=WOS:A1993KP08600014 ER - TY - CONF TI - Structure and properties of grain boundaries in high-Tc superconductors AU - Jagannadham, K T2 - Superconductivity and its applications A2 - Narayan, J. C2 - 1993/// C3 - AIP Conference Proceedings CY - Buffalo, New York DA - 1993/// PY - 1992/// VL - 273 SP - 37–49 ER - TY - JOUR TI - Evaluation of physical and electrical properties of CoSi2 thin films on (100)Si grown by pulsed laser deposition AU - Tiwari, P. AU - Singh, R. AU - Narayan, J. T2 - Philosophical Magazine B AB - Abstract Laser physical vapour deposition (LPVD) has been used to deposit thin CoSi2 films on (100) silicon at different substrate temperatures ranging from room temperature to 600°C. Silicide films were deposited by ablating a solid target of CoSi2 in vacuum with a pulsed KrF excimer laser. Particulate-free silicide thin films were characterized by X-ray diffraction, Rutherford backscattering, and analytical and high-resolution transmission electron microscopy. We have found that films deposited at 200°C and below are amorphous; films deposited at 400°C are polycrystalline; and films deposited at 600°C are (001) textured. Resistivity of these films has been measured as a function of temperature. This plot for CoSi2 exemplifies a typical resistivity behaviour for metallic compounds. The room temperature resistivity has been found to be about 15μΩ cm with a residual resistivity of about 4 μΩ cm for these films. A theoretically based Bloch-Gruneisen model has been applied to analyse the nature of such a plot. These results suggest that LPVD technique could be used for the deposition of stoichiometric low resistivity silicide thin films using lower thermal budgets. The correlation between microstructure and electrical properties of these films is discussed. DA - 1993/9// PY - 1993/9// DO - 10.1080/13642819308215296 VL - 68 IS - 3 SP - 413-420 J2 - Philosophical Magazine B LA - en OP - SN - 1364-2812 1463-6417 UR - http://dx.doi.org/10.1080/13642819308215296 DB - Crossref ER - TY - JOUR TI - Deformation twinning in high-hydrogen-solubility refractory alloy crystals AU - Jagannadham, K. AU - Armstrong, R.W. AU - Hirth, J.P. T2 - Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties AB - Abstract Abstract Deformation twinning was studied in single crystals of three high-hydrogen-solubility refractory alloys; Ta-10 at.% Nb, Nb-10 at.% Mo, and Nb-10 at.% V. The hydrogen concentration was maintained close to 150 p.p.m. by weight. Four different crystal orientations were tested in uniaxial tension and compression; in each case, at four different temperatures: 77K, 142K, 195K and 300K. Trace analyses of the deformation markings were carried out on pairs of perpendicular surfaces to determine the crystallographic nature of slip, twinning, cleavage and hydride precipitates. The sense of the deformation twin shear strains conforms with their occurrence under tensile or compressive stresses for the different crystal orientations. The activation energy for the nucleation of twins is determined by means of dislocation modelling of the twin lamella. It is shown that a stress concentration, either from planar dislocation arrays formed during microslip or from a cleavage crack tip, enables the activation energy to be overcome. Different twin morphologies in two temperature ranges, at 77K and from 142K to 195K, are described. Particular electron microscopy observations of the dislocation substructures associated with twinned regions in the Nb-10 at.% V alloy are presented. DA - 1993/// PY - 1993/// DO - 10.1080/01418619308221213 VL - 68 IS - 2 SP - 419-451 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-21144472884&partnerID=MN8TOARS ER - TY - CONF TI - Laser processing, characterization, and modeling of epitaxial Si/TiN/Si (100) heterostructures AU - Chowdhury, Rina AU - Chen, X. AU - Jagannadham, K. AU - Narayan, J. C2 - 1993/// C3 - Materials Research Society Symposium Proceedings DA - 1993/// VL - 285 SP - 501-506 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0027313965&partnerID=MN8TOARS ER - TY - CONF TI - Epitaxial growth of TiN on GaAs(100) by pulsed laser deposition AU - Zheleva, Tsvetanka S. AU - Jagannadham, K. AU - Kumar, A. AU - Narayan, J. C2 - 1993/// C3 - Materials Research Society Symposium Proceedings DA - 1993/// VL - 285 SP - 343-348 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0027268780&partnerID=MN8TOARS ER - TY - CONF TI - Epitaxial growth in large lattice mismatch systems: characteristics of domain epitaxy AU - Zheleva, Tsvetanka S. AU - Jagannadham, K. AU - Narayan, J. C2 - 1993/// C3 - Materials Research Society Symposium Proceedings DA - 1993/// VL - 280 SP - 393-398 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0027884438&partnerID=MN8TOARS ER - TY - JOUR TI - ON THE APPLICATION OF THE STATISTICAL STRENGTH MODEL OF FIBER-REINFORCED COMPOSITES AU - ZHU, YT AU - ZONG, GS T2 - JOURNAL OF COMPOSITE MATERIALS DA - 1993/// PY - 1993/// VL - 27 IS - 9 SP - 944-959 ER - TY - JOUR TI - CHEMISTRY OF ELECTRON-DOPED LN2-XCEXCUO4 SUPERCONDUCTORS AU - MANTHIRAM, A AU - ZHU, YT T2 - JOURNAL OF ELECTRONIC MATERIALS DA - 1993/// PY - 1993/// VL - 22 IS - 10 SP - 1195-1198 ER - TY - JOUR TI - Minimal-data approaches for determining outer-layer dielectric responses of films from kinetic reflectometric and ellipsometric measurements AU - Aspnes, D. E. T2 - Journal of the Optical Society of America A AB - For stratified samples where material is being uniformly deposited or removed at a known rate, I show that the dielectric function ∊o of the outermost region is determinable exactly and analytically at any given wavelength from the value and the thickness derivative of the complex reflectances for p-polarized, s-polarized, or normally incident light without any knowledge of the underlying structure. This minimal-data approach greatly simplifies analysis compared with the standard procedure, in which dielectric functions are determined sequentially from a combination of new data and previously established sample parameters. It is also robust, eliminating cumulative error and error propagation that can cause conventional analysis to fail. An interferometric method for acquiring complex-reflectance data is proposed, although to achieve the necessary level of accuracy with present technology would be a formidable challenge. For ellipsometric measurements these technical obstacles do not exist, but an equivalent exact solution is not possible. However, I develop a common-pseudosubstrate approximation (CPA) that in applications to semiconductor crystal growth is accurate to better than 0.1%. The minimal-data approach also provides new insights about how sample parameters are determined from measured optical functions. For example, to determine deposition rates one needs to establish the second derivative (curvature) as well, which places additional constraints on measurement accuracy and/or the amount of data required. Also, the small-term expansion of the ellipsometrically determined pseudodielectric function 〈∊〉, originally derived as a thin-film limit of the three-phase model, is shown to be more generally valid. This result provides a theoretical basis for the direct analysis of several phenomena, including interface mixing, from 〈∊〉 data obtained during epitaxial growth. Using the CPA, I derive expressions that allow one to assess whether the performance of a given ellipsometer is adequate for growth control. Finally, the influence of selvage layers on determined values of ∊0 is briefly discussed. DA - 1993/5/1/ PY - 1993/5/1/ DO - 10.1364/josaa.10.000974 VL - 10 IS - 5 SP - 974 J2 - J. Opt. Soc. Am. A LA - en OP - SN - 1084-7529 1520-8532 UR - http://dx.doi.org/10.1364/josaa.10.000974 DB - Crossref ER - TY - JOUR TI - Effect of the chemical nature of transition‐metal substrates on chemical‐vapor deposition of diamond AU - Chen, X. AU - Narayan, J. T2 - Journal of Applied Physics DA - 1993/9/15/ PY - 1993/9/15/ VL - 74 IS - 6 SP - 4168–4173 ER - TY - JOUR TI - Transport processes of optically generated free carriers in amorphous silicon, a-Si:H in the femtosecond time regime AU - Esser, A. Heesel AU - H., Kurz AU - H., Wang AU - C., Parsons AU - G.N., AU - Lucovsky, G. T2 - Physical Review DA - 1993/// PY - 1993/// VL - B IS - 47 SP - 3593 ER - TY - JOUR TI - Optical-detection of photoconductivity in hydrogenated amorphous silicon, a-Si:H, in the subpicosecond time-domain AU - Kurz H., Esser A. AU - Heesel H., Lucovsky G. AU - Wang C., AU - G., Parsons T2 - Journal of Non-crystalline Solids DA - 1993/// PY - 1993/// VL - 166 SP - 575-578 ER - TY - JOUR TI - Femtosecond spectroscopic study of ultrafast carrier relaxation in hydrogenated amorphous silicon a-Si:H AU - Esser, A. Heesel AU - H., Kurz AU - H., Wang AU - C., Parsons AU - G.N., AU - Lucovsky, G. T2 - Journal of Applied Physics DA - 1993/// PY - 1993/// VL - 73 SP - 1235 ER - TY - JOUR TI - ENGINEERING CATALYST SURFACES WITH METAL-CARBONYL CLUSTERS AU - LAMB, HH T2 - CATALYSIS TODAY AB - This article reviews recent progress in the application of metal carbonyl clusters to preparation of supported catalysts and suggests opportunities for future research. Catalysis by surface-bound metal carbonyl clusters and catalysis by structurally simple supported metals derived by decarbonylation of surface-bound clusters have been achieved. A catalytic cycle for ethene hydrogenation by triosmium clusters on silica has been proposed, and molecular metal clusters have been stabilized on basic metal oxides under conditions of CO hydrogenation catalysis. In these examples, molecular metal clusters are the only organometallic surface species detected by in situ spectroscopy. Surface-bound metal carbonyl clusters have been used to prepare well-defined catalytic entities, ensembles of supported mononuclear complexes and supported metal atom clusters, which retain the nuclearity of the precursor. The latter are structurally simple supported metals which provide an opportunity to explore structure sensitivity in catalysis by nano-scale metal clusters. Of technological importance, metal carbonyl clusters and mononuclear organometallics are being used to engineer multi-layer catalysts with advanced architectures and novel catalytic properties. DA - 1993/10/22/ PY - 1993/10/22/ DO - 10.1016/0920-5861(93)80100-f VL - 18 IS - 1 SP - 3-19 SN - 0920-5861 ER - TY - BOOK TI - Diamond films and coatings development, properties, and applications AU - Robert F. Davis, DA - 1993/// PY - 1993/// PB - Park Ridge, NJ: Noyes Pub. ER - TY - PAT TI - High temperature rectifying contact AU - Humphreys, T. P. AU - Nemanich, R. J. AU - Das, K. C2 - 1993/// DA - 1993/// PY - 1993/// ER - TY - PAT TI - Method for synthesis and processing of continuous monocrystalline diamond thin films AU - Narayan, J. C2 - 1993/// DA - 1993/// PY - 1993/// ER - TY - PAT TI - Dislocation density reduction in gallium arsenide on silicon heterostructures AU - Narayan, J. AU - Fan, J. C. C2 - 1993/// DA - 1993/// PY - 1993/// ER - TY - PAT TI - Method for determining interface properties of semiconductor materials by photoreflectance AU - Pollack, F. H. AU - Shen, H. E. AU - Lucovsky, G. C2 - 1993/// DA - 1993/// PY - 1993/// ER - TY - JOUR TI - Textured growth of diamond on silicon via insitu carburization and bias-enhanced nucleation AU - Wolter, S. D. AU - Stoner, B. R. AU - Glass, J. T. AU - Ellis, P. J. AU - Buhaenko, D. S. AU - Jenkins, C. E. AU - Southworth, P. T2 - Applied Physics Letters DA - 1993/// PY - 1993/// VL - 62 IS - 11 SP - 1215-1217 ER - TY - JOUR TI - CENTER FOR ADVANCED ELECTRONIC MATERIALS PROCESSING AU - MASNARI, NA AU - HAUSER, , JR AU - LUCOVSKY, G AU - MAHER, DM AU - MARKUNAS, RJ AU - OZTURK, MC AU - WORTMAN, JJ T2 - PROCEEDINGS OF THE IEEE AB - Microelectronics manufacturing technology is rapidly moving toward integrated circuits with submicron minimum feature sizes. This is being driven by the development of devices and circuits with reduced device lateral dimensions, increased density per chip, thinner material layers, increased use of the vertical dimension (three-dimensional circuits), low volume/fast tumaround design (ASIC's), increased use of heterojunctions, mixed material technologies, and quantum-based device structures. These trends require precise control of thin layers processed on wafers and a need for lower temperature processing or a lower overall thermal budget DA - 1993/1// PY - 1993/1// DO - 10.1109/JPROC.1993.752025 VL - 81 IS - 1 SP - 42-59 SN - 0018-9219 ER - TY - JOUR TI - TAYLOR,G.I., REVISITED - THE CONE OF UNEXTENDED DIRECTIONS IN DOUBLE SLIP AU - HAVNER, KS T2 - INTERNATIONAL JOURNAL OF PLASTICITY AB - Recently developed general equations for the cone of unextended directions in arbitrary d double slip in f.c.c. crystals, in each of uniaxial tension and compression, are applied to the interpretation of finite deformation measurements from the classic series of papers (1923–27) by G. I. Taylor on cubic metal crystals. Measurements of comparable completeness are not found readilu elsewhere in the literature. From the equations and the experimental data (including lattice positions from X-ray diffraction analysis), the respective amounts of finite double slip are calculated for several cases from comparisons of theoretical and experimentally determined cones in stereographic projection. Apparent misconceptions in the literature about the subsequent deformations of Taylor's crystals after the loading axis reached a crystallographic symmetry line are addressed. DA - 1993/// PY - 1993/// DO - 10.1016/0749-6419(93)90027-N VL - 9 IS - 2 SP - 159-179 SN - 0749-6419 ER -