bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laser Induced Metal Deposition on Semiconductor, Metallic and Polymeric Substrates From Electroplating Solutions
Authors: Zahavi J. , Tamir S. , Rotel M. , Campisi G.J. , Pehrsson P.E. , Halliwell M. 
Published: March 2011

ABSTRACTThis work is aimed at studying the feasibility of laser induced, high-speed, highly selective direct deposition of metals on substrates immersed in commercial electroplating solutions without masking procedures and external electric current.A Q-Switch Nd/YAG pulsed laser system and excimer UV pulsed laser systems operating respectively at wavelength of 532nm and at 193 and 248nm, were used in conjunction with commercial basic potassium gold cyanide and acidic gold tetrachloride solutions. The substrates were semiconductors (silicon, gallium arsenide and silicon carbide), metallic (platinum) and polymeric (polyimide).The morphology, structure, composition and properties of the gold deposits were examined by the SEM, TEM, X-ray, AES and ESCA techniques.Deposits were found to consist of elemental gold with thickness range from a few hundred angstroms to several micrometers, depending primarily on laser energy density and on the number of pulses. Deposition occurred wherever band gap energies (plus surface barrier) were smaller than the laser photon energy; none was observed in reverse situations, as in the cases of Si3N4 and fused SiO2.The deposits exhibited Schottky barrier contacts on silicon, silicon carbide and gallium arsenide.
Computer Simulation of Laser Induced Temperatures for the Laser Direct Writing technique
Authors: Tonneau Didier , Auvert Geoffroy 
Published: March 2011

ABSTRACTLaser induced temperatures in substrates irradiated with a scanning gaussian laser beam were calculated by the finite element method. A quartz substrate of a given thickness and covered with a one - micron - thick silicon coating was assumed to be either placed on a heat sink or thermally insulated. The maximum temperature in the center of the laser spot was found to be proportional to the laser power for a spot size larger than the silicon thickness. Furthermore at a given laser power, the temperature decreased with increasing laser spot diameter and the time to reach the equilibrium temperature increases with the spot radius for radii less than the substrate thickness. The laser induced temperature was found to be affected by laser - scan speeds for speed values above the heat diffusion rate.
Quartz Crystal Microbalance Determination of Laser Photochemical Deposition Rates: Mechanism of Laser Photochemical Deposition From the Group 6 Hexacarbonyls
Authors: Jackson Robert L. , Tyndall George W. 
Published: March 2011

ABSTRACTA quartz crystal microbalance has been used to measure the rates of focused uv laser-induced deposition from the Group 6 hexacarbonyls in real time. The experimental configuration employs acwuv laser beam focused onto the microbalance crystal surface at normal incidence to deposit material by decomposition of a metal complex vapor. Simple equations are given for determining absolute deposition rates in terms of the total mass deposited per unit time. Kinetic data obtained with this system have been used to study the mechanism of laser photodeposition from Cr(CO)e, Mo(CO)6, and W(CO)é induced by a frequency-doubled argon ion laser. The rate-determining deposition step involves condensation of products formed upon single-photon dissociation of the metal carbonyls in the gas phase. Additional observations indicate that the adsorbed photoproducts undergo further photo-initiated dissociation on the substrate surface.
Microstructure of Gold Films Grown by Ion Induced Deposition
Authors: Ro J.S. , Dubner A.D. , Thompson C.V. , Melngailis J. 
Published: March 2011

ABSTRACTA beam of ions incident on a substrate can cause adsorbed gas molecules to break up, resulting in material deposition. We have previously demonstrated deposition of gold from a gas of dimethyl gold hexafluoro acetylacetonate (C7H7F6O2Au) using both focused and broad ion beams. Here we investigate growth at various substrate temperatures and examine micro-structure using transmission electron microscopy. Films grown at room temperature were discontinuous even up to the thickness of 250μπι while films grown at higher substrate temperatures were continuous even at lower thicknesses. Deposition carried out on substrates at 100°C and 160°C using 70 kev Ar+ ions resulted in resistivities approaching the bulk value and a deposition yield of 60 to 75 atoms/ion. The relationship between growth conditions, micro-structure and resistivity will be discussed.
Superconductors With Structured Surfaces: Fields and Currents
Authors: Wu Z.C. , Jelski Daniel A. , George Thomas F. 
Published: March 2011

ABSTRACTThis paper discusses the behavior of currents and fields along a structured superconductor. First the effect of surface structure on supercurrents is investigated. Then the effect of structure on the critical nucleation field is discussed in two cases, one with the magnetic field parallel to the ripples and the other with the field parallel to the grating wavenumber. In the first case, it is found that the critical field is reduced as a function of grating height, whereas in the latter case it is increased. Finally, the relevance of this work for laser-induced chemistry above a superconducting surface is discussed. The Ginzburg-Landau model is used throughout.
Photo-Assisted Molecular Layer Epitaxy
Authors: Nishizava Jun-Ichi , KurabayashI Toru 
Published: March 2011

ABSTRACTPhotoexcitation effects of GaAs vapor phase epitaxy have been studied. The growth rate is enhanced by irradiating the substrate zone with an exciier laser irradiation at 2 4 9 n m wavelength, however, the growth rate is reduced by irradiating the source Ga zone with a 249 or 222m exciier laser at températures below 650*C. Because of sharp wavelength dependence and from the result of the theoretical estimations, these effects have been concluded to be caused not by a therma1 -induced reaction but, rather, by photoinduced reactions.Influence of photoexcitation of the film grown by molecular layer epitaxy has been also studied. Photoirradiation could be independently undertaken at different crystal growth steps, e.g. the irradiation duration could be synchronized with the time duration of each gases supply and exhaust. By this method “synchronized irradiation”, the quality of the epitaxial film and the surface morphology of epitaxial films grown by molecular layer epitaxy were improved.
Photolytic Deposition of Insb Films
Authors: Zuhoski S. P. , Killeen K. P. , Biefeld R. M. 
Published: March 2011

ABSTRACTFilms of InSb were deposited on GaAs <100> substrates at room temperature by excimer laser photolysis at 193 or 248 m of a mixture of trimethylindium (TMIn) and trimethylantimony (TMSb) in a hydrogen carrier medium. These films were compared to thermally grown MOCVD InSb films by optical microscopy and x-ray analysis and found to be stoichiometric polycrystalline, InSb. In situ UV absorption spectroscopy has been used for the first time on an MOCVD system to monitor and control the partial pressures of the metalorganic reactants during deposition. This latter diagnostic was found to be critically important since parasitic reactions cause depletion of TMIn during transport from the source bubbler to the growth chamber.
Excimer Laser-Assisted Movpe of Cdte on Gaas (100): Crystal Growth and Mechanisms
Authors: Zinck J.J. , Brewer P.D. , Jensen J.E. , Olson G.L. , Tutt L.W. 
Published: March 2011

ABSTRACTExcimer laser-assisted MOVPE has been used to deposit thin films of CdTe (111) on GaAs (100) substrates. Auger spectroscopy indicates that the films are stoichiometric and that carbon and oxygen contamination are below the levels of detectability. Good crystalline quality of the layers is confirmed by x-ray diffractometry. Growth rates up to 2 /μm/hr have been recorded in real time using time-resolved reflectivity. The CdTe growth rate is found to have a linear dependence on reactant partial pressure and laser average power, but was independent of substrate temperature in the range of 150° C to 300* C. Laser-induced fluorescence spectroscopy has been used to determine that photolysis of diethyltellurium at 248 nm is a one photon process which produces ground state Te atoms. The flux of reactive species to the substrate surface has been probed by mass spectrometry. Evidence for the generation of monoethyltelluride, either by recombination or direct photolysis, is presented.
Growth of Highly Oriented CdsXSe1.X Thin Films By Uv Laser Evaporation Deposition
Authors: Kwok H.S. , Mattocks P. , Shaw D.T. , Shi L. , Wang X.W. , Witanachchi S. , Ying Q.Y. , Zheng J.P. 
Published: March 2011

ABSTRACTCdSxSe1−x thin films have been grown by uv laser-evaporation deposition in a clean vacuum environment. The films have their c-axis perpendicular to the surface, and are optically smooth and homogeneous. These high quality films should be useful in nonlinear integrated optics applications.
Epitaxial Growth of Thin Ge Films on [001] Gaas by Laser Photochemical Vapor Deposition from GeH4
Authors: Tavitian V. , Kiely C. J. , Eden J. G. 
Published: March 2011

ABSTRACTEpitaxial Ge films have been grown on [001] GaAs for substrate temperatures (Ts) as low as 285°C by photodissociating GeH4 at 193 nm in parallel geometry. For a laser fluence of ~15 mJ - cm-2, the film growth rate varies from 0.6 to ~5 nm - min-1, depending upon Ts and gas pressure. Plan and cross-sectional TEM studies of the Ge/GaAs bicrystal demonstrate that the 400–700 A thick Ge films are single crystal and epitaxial with the substrate. The present limitation on epitaxial film thickness appears to be imposed by reduced adatom mobility at the temperatures investigated.
Low Temperature Oxide and Nitride Film Depositions by Simultaneous Use of Ionized Cluster Beam Source and Microwave Ion Source
Authors: Takagi Toshinori , Takaoka Gikan H. , Ishikawa Junzo 
Published: March 2011

ABSTRACTAluminum oxide (A12O3), nitride(A1N) and silicon nitride(SiN) films were prepared at a low substrate temperature of 100°C. Film resistivity was higher than 5x1013 Ω-cm and the breakdown voltage was greater than 3x10° V/cm. The films deposited on sapphire and silicon substrates were very flat, and were chemically and thermally stable. The A1-O, A1-N and Si-N bonds could be formed effectively by using both ionized clusters and reactive gas ions, and transparent and good quality films were obtained. Through these results, the simultaneous use of an ionized cluster beam (ICB) system and a microwave ion source was found to have a high potential for preparing oxide and nitride films at a low substrate temperature.
Synthesis of Epitaxial Silicon Carbide Films by Laser CVD
Authors: Nakamatsu Hirohide , Hirata Kazuhiko , Kawai Shichio 
Published: March 2011

ABSTRACTArF exciraer laser CVD was performed to give epitaxial SiC films on the sapphire or (α-A12O3 (0001) substrate. The rate of film growth was limited by the diffusion of the supplied gases. Small amounts of the gas supply failed to produce the SiC deposition and etched the substrate. The UV light irradiation of the substrate was necessary for the photo-excitation to grow the adherent epitaxial films. Filtered UV light from a D2 lamp revealed that the light with the wavelength shorter than about 310nm was effective for the epitaxial growth. It was found to be essential to excite intermediate products or by-products in the absorbed layer on the substrate. The epitaxial SiC films on the αA12O3 gave blue photoluminescence which may be ascribed to the superstructure of 3C-type SiC crystals.
Control of Solid-Excitation-Based Photochemical Dry Etching of Semiconductors by Ion-Bombardment-Induced Damage
Authors: Ashby C.I.H. , Myers D. R. 
Published: March 2011

ABSTRACTCarrier-driven photochemcial dry etching of semiconductors can be selectively suppressed by ion-implantation-induced defects. The magnitude of this suppression depends on the semiconductor impurity doping concentration, the ion fluence, and the photo-excitation wavelength.
Laser Direct Writing of Aluminum
Authors: Cacouris T. , Scelsi G. , Scarmozzino R. , Osgood R.M. , Krchnavek R.R. 
Published: March 2011

ABSTRACTWe report, for the first time, laser direct writing of high conductivity aluminum interconnects from dimethylaluminum hydride (DMALH). These lines were deposited from a metallorganic gas with a focused deep-UV laser beam and were directly connected to aluminum test structures. Electrical measurements and Auger electron spectroscopy were used to characterize the laser deposited films.
Elastic-Recoil-Detection Measurement of Instabilities in Proton-Exchanged Lithium Niobate
Authors: Arnold G. W. , Carnera A. , Mazzi G. , Mazzoldi P. 
Published: March 2011

ABSTRACTThe H and Li profiles in proton-exchanged (PE) LiNbO3, have been measured using elastic recoil detection (ERD). Profiles were determined as a function of crystal orientation, time after PE, annealing temperature, MgO-doping, and added Li-benzoate to the benzoic acid proton source. The proton-exchange process produces Hx Li1−x NbO3 structures where x stabilizes near values of x=0.5 or x=0.7-0.75 depending on specific conditions. The ERD measurements represent the first direct and simultaneous measurements of H- and Li-concentrations in PE LiNbO3 and their variation with process parameters.
Low Resistivity Contact Formation for Lsi Interconnection With Short-Pulse-Laser Induced Mo Cvd
Authors: Uesugi F. , Morishige Y. , Shinzawa T. , Kishida S. , Hirata M. , Yamada H. , Matsumoto K. 
Published: March 2011

ABSTRACTThe contact characteristics between Al interconnections in LSI's and direct written Mo lines has been substantially improved by adopting, for the first time, short-pulse-laser induced Mo CVD. The linewidth stability upon Al interconnections has also been improved. Transient, localized heating with short laser pulses effectively overcomes the heat dissipation through Al interconnections which degraded contact characteristics and prevented fine drawing near the Al interconnection. This new scheme can appreciably widen the applicable device field of direct writing circuit restructuring.
Direct Writing of Carbon Interconnections
Authors: Lyons Alan M. , Wilkins C. W. , Mendenhall F. T. 
Published: March 2011

ABSTRACTThe in situ formation of conductive carbon lines in polymeric substrates was demonstrated by “writing” with CO2 and Nd:YAG lasers. The formation of conductive carbon lines on polymer substrates proceeds through a series of steps including; absorption of light, initiation of decomposition reactions, and thermal propagation of the pyrolysis. The effect of material composition, power density, energy density, and wavelength on the electrical resistance and morphology of the carbon lines was investigated.
Above a critical laser energy density (= 400 J/cm2) sufficient light is absorbed by the substrate such that initiation of the pyrolysis reactions occurs. The decomposed polymer strongly absorbs the incident radiation and the thermal propagation of the reactions forms shiny, conductive, carbon lines. The dimensions of these lines are dependent on the energy density impinging on the polymer and are independent of the wavelengths investigated. If too high a power density is employed (∼ 104 Watts/cm2), an ablated track is formed down the center of the carbon line. This results in the relative insensitivity of the linear resistance with increasing power above 104 Watts/cm2.
Periodic Structure Formation During Laser Direct-Writing of Palladium Acetate Films: An Optically Regulated Mechanism
Authors: Baufay L. , Gross M. E. 
Published: March 2011

ABSTRACTLaser direct-writing of micron-size metallic features from Pd acetate film precursors is achieved using a scanned cw Ar+ laser. Marked periodic structure is observed in these features under a wide range of exposure conditions. A model based on laser reflectivity and transmittance measurements has been developed to describe the formation of the periodic structure. The model takes into account a complex relationship between optical absorption, laser-induced heating and reaction rate. The decomposition of Pd acetate to metal is endothermic and, therefore, this system differs fundamentally from the “explosive” crystallisation of amorphous semiconductors.
Study of the Carrier Concentration Effect on Si Enhanced AlGaAs/GaAs Superlattice Mixing
Authors: Mei Ping , Venkatesan T. , Schwarz S. A. , Stoffel N. G. , Harbison J. P. , Florez L. A. 
Published: March 2011

ABSTRACTWe have investigated the carrier concentration effect on AlGaAs/GaAs superlattice mixing enhanced by Si doping. The Al0.01Ga0.99As/GaAs superlattice sample with various Si-doping concentrations was grown by molecular beam epitaxy (MBE). Secondary ion mass spectrometry (SIMS) and carrier concentration profiling were used to characterize the Al diffusion and the free-carrier concentration profiles. The Al diffusion coefficients at 800 C show a high power dependence on the free carrier concentration which is not consistent with a Ga vacancy diffusion mechanism. A possible explanation can be provided by a mechanism based on a Si pair diffusion model.
Atmospheric Pressure OMCVD Growth of GaAs Using Triethylarsenic and Alkylgallium Organometallic Precursors
Authors: Speckman Donna M. , Wendt Jerry P. 
Published: March 2011

ABSTRACTTriethylarsenic was successfully used as a substitute for arsine in the atmospheric pressure OMCVD growth of GaAs epilayers. N-type GaAs films were produced at V/III ratios of 14–45 and growth temperatures of 560–590°C. The highest quality epilayers obtained were grown at temperatures of 560–570°C and V/Ill ratios of 23–27, with the best films exhibiting net carrier concentrations and 77K mobilities of ∼1015 cm−3 and ∼14,000cm2/V-s, respectively. All of the films grown using Et3As were found to be contaminated with carbon, which appears to result from an inherent decomposition mechanism of the Et3As reagent.
Band-Edge Luminescence of MOCVD GaAs Grown Directly on Silicon
Authors: Lamont M. G. , Harris T. D. , Sauer R. , Lum R. M. , Klingert J. K. 
Published: March 2011

ABSTRACTWe report a detailed study using photoluminescence and photoluminescence excitation of MOCVD GaAs grown directly on Si substrates. Temperature variation and selective excitation allow reliable assignment of spectral features. This assignment permits measurements of strain and strain uniformity, identification of impurities, and assessment of general materials quality. In 2–5μm thick layers similar spectra are observed with little variation from substrate character. Most samples show one of the two split valence band features plus defect recombination, always including carbon. Strain uniformity varies widely and correlates with substrate thickness. The range of spectra observed from a variety of samples, and guidelines for interpretation of nonresonantly excited spectra will be discussed.
Modifications in the Course of Reaction Between Co and GaAs Due To The Presence of a Ge Film
Authors: Genut M. , Eizenberg M. 
Published: March 2011

ABSTRACTModifications in the course of reaction between Co thin films and single crystal GaAs substrate due to the addition of a Ge film either on top or below the metal layer have been studied. The microstructure and phase formation for the systems: Co/GaAs, Co/Ge/GaAs, and Ge/Co/GaAs have been studied by Auger electron spectroscopy, transmission electron microscopy and X-ray diffraction.
Ultrathin Single Crystal CoSi2 Layers on Si(111) and Si(100)
Authors: Tung R. T. , Batstone J. L. , Yalisove S. M. 
Published: March 2011

ABSTRACTThe growth of ultrathin epitaxial CoSi2 layers on Si by molecular beam epitaxy has been studied. This paper briefly outlines recent progress in the growth on Si(111) substrates. New results on the growth of epitaxial CoSi2 on Si(100) are also presented.
The Electronic Properties of Silicon-Silicide Epitaxial Interfaces
Authors: Ossicini Stefano , Bisi O. 
Published: March 2011

ABSTRACTThe selfconsistent electronic properties of the epitaxial Si(111)-NiSi2 interface are computed for the experimentally observed type-A and type-B growth orientations. The densities of states projected on the various sites provide a detailed analysis of the siliconsilicide interface electronic states. The measured Schottky barrier heights may be interpreted by assuming that deviations from epitaxy must be taken into account.
High Resolution Transmission Electron Microscopy Investigation of the Defect Structure in CdMnTe Layers Grown on GaAs by MOCVD
Authors: Mazur J. H. , Grodzinski P. , Nouhi A. , Stirn R. J. 
Published: March 2011

ABSTRACTElectron diffraction and high resolution electron microscopy were used for analysis of Cd1−xMnxTe films grown on (100)2°[011] GaAs substrates by metal organic chemical vapor deposition (MOCVD) at 420°C (x=O.3) and 450°C (x=0.5). It has been found that these two conditions produce dramatically different microstructures. Two orientation relationships of the epilayers with respect to the substrate were observed. It is suggested that this phenomenon may be related to GaAs substrate surface morphology.
In-Situ Rapid Thermal Annealing of Heterostructures Grown by Molecular Beam Epitaxy
Authors: Cerullo M. , Phillips Julia M. , Anzlowar M. , Pfeiffer L. , Batstone J. L. , Galiano M. 
Published: March 2011

ABSTRACTA new in-situ rapid thermal annealing (RTA) apparatus which can be used to anneal entire wafers in an ultra high vacuum environment has been designed to be used in conjunction with the epitaxial growth of heterostructures. Drastic improvement in the crystallinity of CaF2/Si(100) can be achieved with RTA, and our results suggest that RTA can be used as an on-line processing technique for novel epitaxial structures.
Strain Adjustment in Si/Sige Superlattices
Authors: Kasper E. , Herzog H.-J. , Jorke H. , Abstreiter G. 
Published: March 2011

ABSTRACTThe performance of future microelectronic circuits will be strongly enhanced by the monolithic integration of superlattice devices with convenventional integrated circuits ontop of a silicon substrate. With this material concept the mismatch between the superlattice materials and the silicon substrate has to be accommodated. SiGe/Si is a model system for the study of mismatch effects because of similar chemistry and well pronounced strain effects.Growth of SiGe/Si strained layer superlattices (SLS) by molecular beam epitaxy is reported. Adjustment of strain within the superlattice influences strongly the stability and band ordering of the SLS. SiGe/Si superlattices with strain symmetrization exhibit good thermodynamic stability and band ordering of type II. The concept of strain symmetrization by a thin homogeneous buffer layer is explained. Design rules for a virtual substrate consisting of the actual substrate with the thin buffer layer on it are given.
Strained Layer Semiconductor Films: Structure and Stability
Authors: Feldman L. C. , Bevk J. , Davidson B. A. , Gossmann H.-J. , Ourmazd A. , Pearsall T. P. , Zinke-Allmang M. 
Published: March 2011

ABSTRACTStrained layer epitaxy is a process for the formation of new materials with a strain and composition modulation in the one to one hundred monolayer range. Two aspects of strained epitaxial growth are discussed in this paper. We first consider the clustering process, a basic limitation in strained layer epitaxy. A second experiment examines the strain in few monolayer epitaxial films of Ge embedded in Si(100). We show that the strain in these monolayer films is comparable to that expected from bulk elastic constants and discuss the new properties of these films.