bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of the Effect of Rapid Thermal Annealing on the Structural and Electrical Properties of Heteroepitaxial CaF2 /CoSi2 /Si(111) Structures
Authors: Phillips Julia M. , Hensel J. C. , Joy D. C. , Augustyniak W. M. 
Published: March 2011

AbstractWe have used electron channeling and scanning electron microscopy to study the crystallinity and morphology of epitaxial CaF2 layers on CoSi2 /Si(111) substrates before and after a rapid thermal anneal. The channeling patterns from the layers after a rapid thermal anneal are nearly indistinguishable from patterns from bulk crystals, indicating high crystalline quality. The annealing procedure also improves the film morphology substantially. We have studied the effect of the rapid thermal anneal on the electrical resistivity of the underlying CoSi2 layer. The room temperature resistivity is unaffected by the anneal, but the low temperature behavior of the resistivity indicates a high degree of diffuse surface scattering, in contrast to as-grown films.
Epitaxial Growth of Near Noble Silicides on (111)Si by Rapid Thermal Annealing
Authors: Cheng H. C. , Wu I. C. , Chen L. J. 
Published: March 2011

AbstractThe epitaxial growth of near noble silicides, including CoSi2, NiSi2, FeSi2, Pd2 Si, and PtSi on (111)Si, by rapid thermal annealing was studied by transmission electron microscopy. Single-crystalline CoSi2 was formed on (111)Si in the solid phase epitaxy regime by a non-ultra-high vacuum method. The effect on gas ambient was found to be of critical importance on the growth of single-crystal CoSi2 on (111)Si. The best NiSi2, FeSi2, Pd2 Si, and PtSi epitaxy grown on (111)Si by rapid thermal annealing were found to be of comparable quality to those grown by conventional furnace annealing.
Titanium-Silicon Interactions During Ion Beam Irradiation
Authors: Tracy Bryan M. , Shukla Rama K. , Davies Paul W. 
Published: March 2011

AbstractAs* ion beam irradiation of thin titanium (∼300Å) films deposited on silicon substrates at sufficiently high dose and energy has been shown to induce an athermal thin film reaction (as evidenced by insenstivity of the reaction to irradiation current) leading to the formation of a homogeneous titanium subsilicide phase with an extremely smooth interface to the underlying silicon. RBS indicates a stoichiometry of Ti3Si4 for this silicide phase. Subsequent rapid thermal annealing (RTA) of this silicide results in the incorporation of additional silicon leading ultimately to the formation of the stable C-54 TiSi2 phase. Silicided junctions fabricated using a ion beam irradiation show improved sheet resistance uniformity and leakage characteristics when compared with those fabricated using the conventional RTA salicide process.
Comparative Studies of Thin-Film Ti-Si and Ti-SiO2 Rapid Thermal Reactions Using the RIP/TEM Technique
Authors: Natan Menachem 
Published: March 2011

AbstractOne requirement of self-aligned microelectronics metallization processes is selectivity of reactions, e.g., a deposited, thin metal film must react with Si to form a silicide, yet avoid reaction with SiO2 Rapid thermal processing (RTP) techniques may enhance selectivity by utiliz-ing differences in competing reaction kinetics. In this paper, we apply the RTP/transmission electron microscopy (RTP/TEM) technique to determine processing temperature (T)/time (t) “win-dows” for selective sulicide formation in Ti-Si vs Ti-SiO2 reactions. Free-lying Si/Ti/Si and SiO2/Ti/SiO2 films deposited on electron microscope grids were RTP'd in pairs and immediately examined by TEM. The products of the interfacial reactions, their sequence of appearance, and the T/t conditions for silicide nucleation and growth in each system are described.
Rapid Thermal Annealing of Sputtered Ti-Ni-Si Films
Authors: Setton M. , Horache E. H. , Spiegel J. Van Der , Santiago J. J. , Fischer J. E. , Siegal M. 
Published: March 2011

AbstractA ternary compound results from the fast radiative processing of Ni/Ti bilayers on Si<100> substrates. In the Ti-Ni-Si system, Ni is the dominant moving specie at low temperatures while Si starts to diffuse at 575°C. For bilayers with Ti in excess, the final product,above 750°C, is a mixture of ternary compound and TiSi2 whereas excess Ni leads to a layer of NiSi between the substrate and the ternary layer, at tempera-tures below 700° C.
Ultra-Thin p+ Layers in GaAs
Authors: Short K. T. , Chakrabarti U. K. , Pearton S. J. 
Published: March 2011

AbstractThe formation of shallow (0.05–0.2 μm) p+ layers in GaAs by pulse diffusion of Zn from a doped oxide source, thermal diffusion of Cd by vapor transport, or by low energy implantation of Cd, Mg, Be, Zn or Hg ions was investigated by electrochemical capacitance-voltage profiling, Secondary Ion Mass Spectrometry, Rutherford backscattering and Hall measurements. Hole densities in excess of 1019 cm−3 are obtainable by either Zn diffusion or acceptor implantation, though the high temperature cycle must be kept to ≤3 sec at (≤1000°C to prevent excessive redistribution of the acceptor dopants. Pulse diffusion at temperature °C leads to shallow regions with atomic concentrations above 1019 cm−3, but electrically active concentrations orders of magnitude less. These results are explained in terms of the unavailability of a sufficient density of vacancies at low temperatures.
The Transition Between Amorphous Regrowth and Explosive Crystallization
Authors: Bruines J. J. P. , Hal R. P. M. van , Koek B. H. , Viegers M. P. A. , Boots H. M. J. 
Published: March 2011

AbstractThe transition between amorphous regrowth and explosive crystallization of a 220nm thick amorphous Si layer on a crystalline Si substrate has been studied using time-resolved reflectivity, transmission electron microscopy, and Rutherford backscattering spectroscopy. Upon irradiation by 7.5ns FWHM pulses from a frequency-doubled Nd:YAG laser, interferences in the reflectivity indicate growth of amorphous Si from the surface. The observation of a narrow Cu peak, buried below the surface, points towards solidification from both the rear and the front. Transmission electron microscopy studies revealed the occurrence of small patches of polycrystalline Si. The relative amount of this polycrystalline Si is increased by longer laser pulses, higher substrate temperatures, and thicker amorphous Si layers. The results are discussed in terms of the temperature distribution and the time available for the nucleation of polycrystalline Si at the liquid-solid interface.
Photon-Induced Adhesion and Chemical Changes in Aluminium Films on Silicon.
Authors: Kellock Andrew J. , Liesegang J. , Nyberg G. L. , Williams J. S. 
Published: March 2011

AbstractIn the present study, thin layers of Al (<500 Å), deposited on Si under varying vacuum and substrate-cleaning conditions, have been irradiated with various wavelength photons. The films and interfacial oxide layers have been analysed with Rutherford backscattering and channeling (RBS-C), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) techniques both before and after irradiation. Results indicate that substantial oxygen uptake, indiffusion and interface reaction can take place in some thin Al films during photon irradiation at room temperature. Such photon-induced chemical changes correlate with an increase in film adhesion.
Deposition of a-Si Films Using Silane Molecular Beams Excited by Heated Wire and ArF Laser
Authors: Hanabusa M. , Tsuboi T. , Sato T. , Furuno S. , Iguchi S. , Inoue T. 
Published: March 2011

AbstractAmorphous silicon films were deposited by using silane molecular beams excited either by ArF laser beams or heated tungsten wires. Reaction mechanisms are discussed on the basis of the dependence of deposition rates on substrate temperature and, in the case of the heated-wire method, on wire temperature.
Optically-Induced, Room-Temperature Oxidation of Gallium Arsenide
Authors: Yu Chien-Fan , Schmidt Michael T. , Podlesnik Dragan V. , Osgood Richard M. 
Published: March 2011

AbstractRoom-temperature, optically-induced oxidation of the gallium arsenide surface has been studied with laser radiation of different wavelengths. It was found that deep-ultraviolet light is much more effective in enhancing oxidation than near-ultraviolet or visible light. The growth rate of the oxide was also found to be drastically increased by the presence of chemisorbed water molecules on the surface.
Photoenhanced Deposition of Silicon Oxide Thin Films Using an Internal Nitrogen Discharge Lamp
Authors: Robertson Paul A. , Milne W. I. 
Published: March 2011

AbstractThis paper describes the optical and electrical properties of silicon oxide thin films produced using a novel photoenhanced deposition technique. Since there is no damage to the growing film surface from energetic ions, this process has the potential to produce better semiconductor/insulator interfaces than those grown using conventional RF glow discharge techniques. The deposition system is comprised of a windowless nitrogen discharge lamp contained within the reaction vessel. This unified approach allows the low wavelength UV light from the lamp to couple directly into the reaction gases without attenuation by a window material or the need for mercury sensitisation. Thin films of silicon oxide have been deposited onto single crystal silicon wafer substrates from a nitrous oxide/monosilane reaction gas mixture. The deposition rate and physical properties of films produced in this way are comparable to those of high quality insulator films deposited by plasma enhanced CVD techniques. The results of electrical tests indicate that this material could be used as a low temperature deposited insulator for thin film devices.
Laser-Induced Formation of Thin TiO2 Films from TiC14 and Oxygen an a Silicon Surface.
Authors: Kawai Tomoji , Choda Takahiro , Kawai Shichio 
Published: March 2011

AbstractA uniform thin TiO2 film with the rutile structure which is usually made at higher than 700°C, can be formed at room temperature by the laser irradiation of adsorbed TiCl4 followed by oxidation and repeated cycles of this procedure on a silicon(100) single crystal surface. The laser irradiation to gaseous mixture of TiCl4 and oxygen from the direction parallel or perpendicular to the substrate, on the other hand, leads to the formation of a TiO2 film consisting of amorphous fine particles. The mechanism of the film formation is briefly discussed.
Oxidation and Nitridation by Pulsed Laser Irradiation of Solids Immersed in Liquids
Authors: Roorda S. , Polman A. , Ogale S. B. , Saris F. W. 
Published: March 2011

AbstractNitridation and oxidation of titanium is achieved by pulsed laser irradiation of Ti immersed in liquid ammonia or water. Rutherford Backscattering Spectrometry shows that large amounts of nitrogen and oxygen can be incorporated in the metal surface to a depth of several 1000 Å. X-ray diffraction shows evidence of compound formation. Scanning Electron Microscopy reveals that initial surface texture is smoothed, and that stress induced cracks and holes may appear. Irradiation of Fe and Si immersed in various liquids shows that modification depends on which combination of solid and liquid is used. Influence of processing parameters such as laser-energy density and number of laser pulses on compound formation has been investigated. The process is viewed as a reactive solute incorporation in the laser melted surface layer, followed by compound formation.
Ion Bombarment Effect on the Growth of Microcrystalline Germanium
Authors: Drevillon B. , Godet C. , Antoine A. M. 
Published: March 2011

AbstractThe influence of surface mobility on the growth of Ge films is studied as a function of preparation conditions. The positive ion bombardment during film deposition on chromium substrates is analyzed using an electrostatic analyzer. The dielectric functions of the films are measured over the range 1.7–4.5 eV using in-situ spectroscopic phase modulated ellipsometry (SPME). The spectra of microcrystalline germanium (μc-Ge) present a shoulder near 4.2 eV which corresponds to the E2. optical transition observed in single crystal germanium. For substrate temperatures greater than 150°C, a transition from a-Ge:H to μc-Ge appears when the ion kinetic energy exceeds a threshold energy Eth, around 120 eV. Eth decreases as a function of substrate temperature. The Eth value is found to be higher than the threshold value corresponding to the opposite transition, giving evidence of a substrate memory effect on the growth of μc-Ge. Kinetic ellipsometry measurements of the early stage of the μc-Ge deposition on chromium are accurately, modelled by microcrystalline nucleation at a 50 Å level. After 200 Å thickness, μc-Ge grows with an overlayer. The description of μc-Ge as a mixture of c-Ge, a-Ge:H and voids is discussed.
Surface Processes in Laser-Induced Etching of Silicon Studied by X-Ray Photoelectron Spectroscopy
Authors: Hirose Masataka , Ogura Tsuyoshi 
Published: March 2011

AbstractA silicon surface exposed to NF3 gas was irradiated with an ArF excimer laser beam. The reaction products on the surface and their chemical bonding features were studied by in-situ x-ray photoelectron spectroscopy at each step of the photochemical etching. It was found that SiFX (1≤X≤4) units and molecular fluorine exist in the reacting surface region. The surface Si-Si bonds attacked with fluorine are progressively fluorinated and the final surface products are mainly SiF4 and SiF3. A possible mechanism of fluorine etching is discussed on the basis of a valence electron transfer (VET) model.
Etching of SiO2 with CO2 and CO2 + Ar+ Lasers
Authors: Pan D. , Dai B. T. , Agrawalla B. S. , Imen K. , Allen S. D. 
Published: March 2011

AbstractDry etching of fused SiO2 in the presence of several etchants using CO2 and CO2 + Ar+ lasers yields controlled, rapid removal rates of 10 Ao – 500 μm/sec and smooth, high quality surfaces. Etching occurs mainly by thermal ablation of SiO2 due to strong CO2 laser absorption. The addition of the Ar+ laser, which is absorbed by Br2 etchant to yield Br atoms, increases the etch rate as a result of a combination of photochemical and gas-phase heating effects.
Ultrafast Aqueous Etching of Gallium Arsenide
Authors: Willner A. E. , Podlesnik D. V. , Gilgen H. , Osgood R. M. 
Published: March 2011

AbstractVery rapid room-temperature photochemical etching of n-type GaAs was achieved in aqueous hydrofluoric acid in conjunction with ultraviolet laser illumination. The etch rates of ˜500 μm/min represent an order of magnitude increase in etch rates over previously reported results for solutions that contained no hydrofluoric acid. Furthermore, incorporation of nitric acid into the hydrofluoric acid solution resulted in smooth etched surfaces thus allowing deep, waveguiding etching. This rapid process was used to etch deep, large-area structures in GaAs samples.
Excimer Laser Applications: Polymer Etching and Metal Deposition
Authors: Ritz Michael , Srinivasan V. , Babu S. V. , Patel Ramesh C. 
Published: March 2011

AbstractExcimer laser induced ablative decomposition of polyimide and poly(methylmethacrylate) at high fluences (> 1 J/cm2) is discussed. It is shown that 0.4 μm sized features can be imaged in polyimide using ArF laser pulses. Preliminary results from experiments in which copper particles (<1 μm in size) have been deposited by exposing thin films of a copper formate and glycerol paste to KrF laser radiation are presented.
The Influence of Doping on the Etching of Si(111)
Authors: Winters Harold F. , Haarer D. 
Published: March 2011

AbstractIt has been recognized for some time that the doping level in silicon influences etch rate in plasma environments[1–8]. We have now been able to reproduce and investigate these doping effects in a modulated-beam, mass spectrometer system described previously [9] using XeF2 as the etchant gas. The phenomena which have been observed in plasma reactors containing fluorine atoms are also observed in our experiments. The data has led to a model which explains the major trends.
Constant Final-State Photoemission Study of Silicon Fluoride Reaction Layer Created During Etching: Morphology of the Reaction Layer
Authors: Yarmoff J. A. , McFeely F. R. 
Published: March 2011

AbstractSoft x-ray core-level photoemission was used to study the reaction layer formed on a Si(111) surface during steady-state etching by XeF2. These surfaces show shifted Si 2p core levels which correspond to particular silicon fluoride species residing in the reaction layer. Spectra were collected in constant final state (CFS) mode for electron kinetic energies ranging from 2 eV to 90 eV. The use of CFS mode allowed the electron escape length to remain constant during individual spectra. The electron escape length for the reaction layer as a function of kinetic energy was then determined by monitoring the intensity of the bulk silicon signal. Thus, by analyzing the proportions of each silicon fluoride species observed in the individual CFS spectra as a function of the electron escape depth in the reaction layer, the distribution of the silicon fluoride species in the layer was obtained. The distribution determined placed SiF at the interface between the reaction layer and the bulk silicon, and the remaining species, SiF2, SiF3 and SiF4, successively layered on top. This observation leads to a model for the structure of the reaction layer.
Surface Temperature Rise Induced by a Focused Laser Beam. Application to Laser-Induced Chemical Vapor Deposition
Authors: Kodas Toivo T. , Baum Thomas H. , Comita Paul B. 
Published: March 2011

AbstractSurface temperatures of a laser-heated structure consisting of intersecting gold and nickel lines on an Si substrate with an SiO2 surface layer were determined experimentally and theoretically. Temperatures were measured with micron-sized thin-film thermocouples formed from intersecting gold and nickel lines. Temperature profiles were calculated using a finite difference method which took into account the optical and physical properties of the thermocouple metal lines, the silicon dioxide layer and the silicon substrate. For a 0.2 μm SiO2 layer, maximum surface temperatures were much higher with the metal lines than without because of the lower reflectivity of the gold relative to the silicon and the limited ability of the thin metal lines to conduct heat away from the irradiated region. Calculated maximum temperatures on the metal lines depended strongly on the thicknesses of the insulating SiO2 layer and the metal lines. Application of these results to the dynamics of laser-induced chemical vapor deposition is discussed.
Excited-Atom Production by Electron Bombardment of Alkali-Halides
Authors: Walkup R. E. , Avouris Ph. , Ghosh A. P. 
Published: March 2011

AbstractWe present experimental results which suggest a new mechanism for the production of excited atoms and ions by electron bombardment of alkali-halides. Doppler shift measurements show that the electronically excited atoms have a thermal velocity distribution in equilibrium with the surface temperature. Measurements of the absolute yield of excited atoms, the distribution of population among the excited states, and the dependence of yield on incident electron current support a model in which excited atoms are produced by gas-phase collisions between desorbed ground-state atoms and secondary electrons. Similarly, gas-phase ionization of ground-state neutrals by secondary electrons accounts for a substantial portion of the positive ions produced by electron bombardment of alkali-halides.
Laser Microfabrication Technology and its Application to High Speed Interconnect of Gate Arrays
Authors: Bernhardt Anthony F. , McWilliams Bruce M. , Mitlitsky Fred , Whitehead John C. 
Published: March 2011

AbstractNickel and doped polysilicon lines can be written at speeds exceeding 1000 microns/sec using laser direct-write deposition. We explore the roles of gas pressure, composition, and laser power in determining writing speed and line morphology. The use of a surface layer of amorphous silicon provides optical absorption, thermal and electrical insulation which help to maintain high, relatively stable, surface temperature.Laser direct-write deposition is used to interconnect CMOS gate arrays by means of computer controlled laser pantography. Complex circuits, such as an array of five 16-stage shift registers and one 16-stage counter have been successfully fabricated and tested.
Nucleation and Growth of Silicon Microstructures by Direct-Laser Writing
Authors: Kotecki David E. , Herman Irving P. 
Published: March 2011

AbstractThis paper reports on a study of the nucleation phase of thin film growth during pyrolytic deposition by direct-laser writing. A Monte Carlo computer simulation is used to model the initial surface dynamics occurring during the deposition of silicon from silane (SiH4) on strongly binding substrates such as silicon, and on weakly binding substrates such as silicon dioxide (SiO2) and silicon nitride (Si3N4). Results show that for high peak temperatures (≥ 1200 K) and weakly binding substrates, the most probable location for the initiation of thin film growth is radialy displaced from the center of the locally laser-heated region of the surface. At low peak temperatures, thin film nucleation is found to begin at the center of the locally laser-heated surface for all substrates.
Plasma Stimulated Growth of InP from TEL and PH3
Authors: Reinecke H. , Grafahrend F. , Brauers A. , Lüth H. , Balk P. 
Published: March 2011

AbstractThis study describes the application of a dc-plasma to stimulate growth of InP in a MOCVD system using In(C2 H5)3 and PH3. Precracking of PH3 enables a substantial reduction of the growth temperature to well below 500 K. In addition, at temperatures where InP is commonly deposited (∼870 K) a significant lowering of the V/III input ratio is possible. The fact that InP is relatively insensitive to low energy ion bombardement permits deposition in a canal ray configuration.
Plasma Deposition of Tungsten
Authors: Greenberg K. E. 
Published: March 2011

AbstractTungsten films were plasma-deposited using an abnormal glow discharge through a mixture of tungsten hexafluoride, hydrogen, and argon. The films adhered well to silicon, silicon dioxide, gallium arsenide, and aluminum substrates placed directly on the discharge cathode. Typical deposition rates were on the order of 160 Angstroms/minute with as-deposited film resistivities of 40 to 70 microohm-cm. The tungsten was analysed using a number of techniques including X-ray diffraction, scanning electron microscopy, and Auger spectroscopy, Low-resistivity (<10 microohm-cm) films that adhered well to silicon-dioxide were obtained with a two-step process utilizing plasma deposition and conventional chemical vapor deposition.
An Investigation into the Growth of Lead Titanate by MOCVD Using a Pyrolytic and a Sputter Assisted Plasma Process
Authors: Brierley Crofton J. , Considine Laurence , Sethi Rajinder S. , Whatmore Roger W. 
Published: March 2011

AbstractThe thin film growth of PbTiO3 by MOCVD has been investigated using both a pyrolytic process and a sputter assisted plasma deposition process. In the first process, lead tertiary butoxide and titanium iso-propoxide are introduced to a low pressure reactor simultaneously to deposit thin films containing lead and titanium onto a hot substrate (400–500 °C). In the alternative process lead is sputtered from a magnetron target in the presence of titanium isopropoxide vapour. Thin films containing lead and titanium are deposited onto a substrate which need not be heated. X-ray and EDAX analysis indicate the presence of Ti02 and elemental lead in the as grown layers. Oxygen annealing of ihese layers at 900° and 1100°C leads to the formation of polycrystalline PbTiO3 and where the substrate is silicon, a PbO/SiO2 glass phase.