bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Non-Equilibrium Molecular Dynamics Simulation Method for Rapid Solidification
Authors: Chokappa Dhanraj K. , Clancy Paulette 
Published: March 2011

ABSTRACTA new non-equilibrium Molecular Dynamics (NEMD) computer simulation method has been developed to study ultra-rapid melting and resolidification processes, e.g. laser annealing, ion implantation, etc. An atomic-level description of the material is combined with a new simulation technique to produce thermodynamic, structural and kinetic information as a function of time. Experimentally realistic values of the energy fluence, pulse duration and substrate temperature are used as input to the simulation. Rapid heat transfer simulating the action of the energy input is then set up allowing a complete prediction of the undercooling and associated kinetic properties. As such this new method offers the most realistic simulation model for rapid thermal processing to date.
Transient Structural Relaxation and Melting Temperature of Amorphous Silicon
Authors: Sinke W. C. , Warabisako T. , Miyao M. , Tokuyama T. , Roorda S. , Saris F. W. 
Published: March 2011

ABSTRACTThe structure of ion-implanted a-Si has been studied using Raman spectroscopy. It is shown that the average bond-angle distortion and the strain energy stored in the random network vary drastically upon annealing. Relaxation is enhanced in the case of heating by laser irradiation. The results imply that the apparent melting temperature of a-Si may vary from one experiment to another, depending on the heating rate and -method.
Amorphous Phase Formation During Ion Mixing of Ti/Si Bilayers at Elevated Temperature
Authors: Maex K. , Keersmaecker R. F. De , rossum M. Van , Weg W. F. Van Der 
Published: March 2011

ABSTRACTThe amorphous phaseformation in Ti-Si bilayers upon ion mixing at elevated temperatures and in Ti-Si multilayers upon thermal treatment was studied. In the case of ion mixing with 5×1015 cm−2 Xe atoms at temperatures around 240°C a 100nm thick amorphous Ti-Si alloy is formed with a very homogeneous Ti:Si=3 :4 composition. Thermal treatment of the Ti-Si multilayer structure at similar temperatures also yields amorphous silicide layers. The results are interpreted according to the evolution in a planar binary diffusion couple, where the Si and Ti concentrations in the reacted layer are dictated by thermodynamic and kinetic arguments.
Pulsed Laser Mixing of Metal Overlayers on Ceramics
Authors: Singh R. K. , Biunno N. , Narayan J. 
Published: March 2011

ABSTRACTPulsed laser mixing has been used as surface modification technique for the improvement in the mechanical properties of ceramics. Thin metallic layers of nickel were deposited on structural silicon nitride and were irradiated with Xenon Chloride (XeCl) laser pulses. The laser parameters were optimized to lead to the formation of mixed layers. The mixed interfacial layers were analyzed using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Rutherford Backscattering (RBS) techniques. Detailed heat flow calculations were performed to simulate the effects of intense laser irradiation on metal coated ceramic structures. The melt lifetimes and the interfacial temperatures obtained using these calculations, were applied to understand the laser mixing phenomena occuring in these layered structures. Thermodynamics of chemical reactions between the metal overlayers and the substrate were done to predict the formation of mixed interfacial layers during laser irradiation.
Activation Characteristics of Implanted Dopants in InAs, GaSb and GaP After Rapid Thermal Annealing
Authors: Neida A. R. Von , Short K. T. , Brown J. M. , Pearton S. J. 
Published: March 2011

ABSTRACTWe have studied in some detail the activation of implanted Si and Mg ions in InAs, GaSb and GaP after rapid thermal annealing. Even at doses of 1015 cm−2, the activation percentage of Mg is relatively high after optimum anneals -80% in GaP, 55% in GaSb and 45% in InAs. There is considerable outdiffusion of Mg in all three semiconductors for extended heat treatments. The amphoteric species Si shows good activation (60% for 1015 cm−2 dose) in InAs, a saturation electrically active concentration of ∼3 × 1013 cm−2 in GaP, and very low electrical activity in GaSb. The regrowth and damage removal characteristics in the three materials are similar to those of GaAs and InP.
Diffusion of Au in Amorphous Si During Ion-Beam Irradiation
Authors: Priolo F. , Poate J. M. , Jacobson D. C. , Linnros J. , Batstone J. L. , Campisano S. U. 
Published: March 2011

ABSTRACTWe have measured the radiation-enhanced diffusion of Au in amorphous Si in the temperature range 77–700 K. Gold was implanted to depths of 500Å at concentrations of an atomic %. The samples were than amorphized to depths of -2μm using MeV Ar implants at liquid nitrogen temperature. Radiation-enhanced diffusion was induced by a 2.5 MeV Ar beam at doses of 2×1016−2×1017/cm2 and dose rates of 7×1012−7×1013/cm2sec. The diffusion coefficients show three well defined regions. At temperatures <400K diffusion is essentially athermal and due to ballistic mixing. At temperatures between 400K and 700K the diffusion, which is considerably enhanced over the usual thermal values, has an Arrhenius behavior with an activation energy of 0.37 eV. At higher temperatures thermal diffusion, with an activation energy of 1.42 eV, dominates.
Stokes/Anti-Stokes Raman Microprobe Analysis of Laser-Heated Silicon Microstructures on Silicon Dioxide
Authors: Pazionis Gregory D. , Tang Hua , Ge Lei , Herman Irving P. 
Published: March 2011

ABSTRACTTemperatures of laser-heated silicon microstructures on fused silica were determined by Stokes/anti-Stokes scattering using the 4880Å and 5145Å argon-ion laser lines, either separately or together to heat and probe the structure. Phonon shifts and broadening gave consistent measurements of temperature. Evaluation of temperatures from the ratio of Stokes/anti-Stokes intensities was shown to be sensitive to the details of scattering, collection, and detection.
Localized Laser-Assisted Deposition of Silicon,Silicon Nitride and Silicon Dioxide
Authors: Auvert Geoffrey , Pauleau Yves , Tonneau Didier 
Published: March 2011

ABSTRACTThe localized laser-induced deposition of an insulator for silicon-based microelectronics seems to be an unsolved problem. In order to understand the limiting mechanism in the deposition, the formation kinetics of silicon, silicon oxide and silicon nitride using various laser wavelengths and gas mixtures have been studied Depending upon wavelength and laser-induced temperature, various chemical reactions are involved. In the presence of ammonia, the growth rate of silicon nitride dots was found to be lower than the corresponding silicon deposition rate, indicating that deposition starts with silane decomposition followed by nitridation of silicon. By evaluating the influence of the wavelengths, the existence of a photolytic aided reaction is detected in the presence of 2.4 eV photons. In the presence of oxygen molecules and under most experimental conditions, no deposition occurs. The formation of volatile intermediate compounds can explain the difficulty of locally depositing silicon dioxide.
Adsorbed Tma on Dielectric Oxide Surfaces
Authors: Engelsberg A. C. , Chera J. J. , Korenowski G. M. 
Published: March 2011

ABSTRACTTrimethyl aluminum vapor is found to chemisorb on the surface of silicon dioxide and aluminum oxide via reaction with surface hydroxyl groupe. In addition to the chemisorbed layer, trimethyl aluminum also forms a weakly bound multilayer consisting of molecular dimers.
Distinguishing Laser Induced Thermal and Photochemical Surface Reactions by Photodeposit Morphology
Authors: Natzle Wesley C. 
Published: March 2011

ABSTRACTCr containing deposits were formed by focussing a chopped (2000Hz) 325nm CW He-Cd laser on the inner surface of the quartz window of a cell containing 110-150 mTorr of Cr(C0)6 precursor. The deposit thickness and the chemical identity of contaminants were determined by stylus profilometry and attenuated total reflectance IR spectrometry. In certain regimes of incident laser power density, deposits exhibit a dual morphology, with a narrow inner deposit up to several microns in thickness on top of a wider deposit less than 0.16 microns in thickness. Changes in the morphology with incident power density and changes in transmitted and reflected light during the deposition enables assignment to photothermal and photochemical mechanisms. A deposition rate for each mechanism and an optical attenuation coefficient for the photochemical deposit at 325nm were determined from the deposit thicknesses as a function of time.
Excimer Laser Photolysis of Organometallic Compounds Adsorbed on Substrates
Authors: Suzuki Hideyuki , Mori Koji , Kawasaki Masahiro , Sato Hiroyasu 
Published: March 2011

ABSTRACTExcimer laser photolysis at 248 nm of trimethylgal1ium (TMG) was studied by probing gallium atoms by laser induced fluorescence (LIF) technique. From the dependence of LIF intensity on the excitation wavelength, temperature and pressure, a thermally assisted photodissociation in the chemisorbed state was concluded.
Mass Spectrometric Study of Laser-Induced Chemical Vapor Deposition of Gold
Authors: Kodas Toivo T. , Comita Paul B. 
Published: March 2011

ABSTRACTA modulated surface temperature technique was used to study the surface chemical reactions occurring during the laser-assisted deposition of gold from dimethyl gold hexafluoroacetylacetonate. An argon ion laser was chopped and used to modulate the surface temperature on an area roughly 1 mm in diameter on an alumina substrate. Reactant and products of the photothermal reaction were sampled through an orifice located at the center of the deposit and were then introduced directly into a quadrupole mass filter. Since the reactant concentration at the surface decreased when the laser turned on while the product concentration at the surface increased when the laser turned on, modulating the surface reaction rate and employing phase-sensitive detection allowed the identification of reaction products.
Excimer Laser Induced Micron-Size Pattern Etching By Image Projection
Authors: Brannon James H. 
Published: March 2011

ABSTRACTPatterned fine-line features as small as 0.8 microns have been etched in polyimide, silicon, and copper by use of ablative and chemical techniques. KrF excimer laser pattern etching was accomplished by use of a Kohler-type projection system employing a Uv refracting microscope objective. Ablative etching of polyimide was accomplished in air, while silicon and copper were chemically etched using the vapor of chlorine or carbon tetrachloride.
Effects of Excimer Laser Irradiation on Mbe and Mo-Mbe Growth of (Al)Gaas On Gaas And (Ca,Sr)F2/Gaas Substrates
Authors: Donnelly V. M. , Tu C. W. , Beggy J. C. , McCrary V. R. , Harris T. D. , Lamont M. G. , Baiocchi F. A. , Farrow R. C. 
Published: March 2011

ABSTRACTWe report the growth of GaAs by laser-assisted molecular beam epitaxy, using As4 and either elemental Ga or triethylgallium (TEG) sources, and a 193 nm ArF excimer laser. Laser irradiation of (Al)GaAs has no effect on the growth rate or Ga-to-Al incorporation, when GaAs substrates and elemental group-III sources are used. When GaAs is grown from TEG, laser irradiation results in a selective-area film growth at temperatures below 450°C, where growth due to pyrolytic decomposition of TEG is very slow. The process is extremely efficient, with roughly unit probability for impinging TEG molecules sticking and being dissociated by laser radiation to form GaAs. From the strong dependence on laser fluence, the growth enhancement process appears to be pyrolytic in nature (due to rapid transient healing by the pulsed laser), and not photolytic. The cross section for photolysis must be at least ten times lower than the gas-phase value (9x10-18cm2). Using either Ga source, laser irradiation improves surface morphology and photoluminescence yields, compared to areas receiving less intense laser radiation.In growth of GaAs from elemental sources on (Ca, Sr)F2 lattice-matched to GaAs, laser irradiation inhibits growth due to laser-induced thermal desorption of adsorbed Ga atoms, which are relatively weakly bound to (Ca,Sr)F2 compared to GaAs surfaces.
Recent Progress in Excimer Laser Lithography
Authors: Higashikawa I. , Nonaka M. , Sato T. , Nakase M. , Ito S. , Horioka K. , Horiike Y. 
Published: March 2011

ABSTRACTA KrF excimer laser exposure method has been developed for laboratory use, which employs 10 to 1 achromatic projection lens of 0.37 NA and 5x5 mm field size , and a TTL alignment system using the double diffraction method, which was realized by the use,of the achromatic lens. Novolak type mid-UV resists, such as AZ-5214 and PR-1024, were best suited for use in 248 nm exposure, considering the sensitivity and etching resistance from a practical viewpoint, and an additional post exposure baking process also improved the resist profile. The dependences of the exposure characteristics on the energy density per pulse and pulse frequency of these resists were not observed in the region of the practical exposure conditions. An alignment precision of x±30-= 0.2 μm was achieved for the alignment mark consisting of poly Si pattern. Thus, a 0.3 μm line and space pattern was realized by using tri-level resist process and a 0.2 μm gate pattern was successfully fabricated on the coplanar pattern with a 0.4 μm step.
Reactions in Omcvd: Detection of Gas Phase Radicals In Gaas Deposition Under Single Gas-Surface Collision Conditions
Authors: Squire D.W. , Dulcey C.S. , Lin M.C. 
Published: March 2011

ABSTRACTLaser ionization mass spectrometry has been used to study the deposition of gallium from trimethylgallium with and without AsH3. The apparent Arrhenius activation energy for the production of gas-phase methyl radicals from trimethylgallium is measured to be 28 ± 2 kcal/mol in the presence of AsH3, about the same value as measured in the absence of AsH3. At a substrate temperature of 1150 K where gallium desorption is substantial, addition of AsH3 is found to increase methyl radical yield but drastically decrease gallium atom desorption. A mechanism is presented to describe the deposition of GaAs at low pressures under single gas-surface collision conditions.
Excimer Laser Irradiation Effect on Metalorganic Molecular Beam Deposition of Al and Alas : Prospects for Laser-Assisted Epitaxial Growth of Gaalas
Authors: Tokumitsu Eisuke , Yamada Takumi , Konagai Makoto , Takahashi Kiyoshi 
Published: March 2011

ABSTRACTTriisobutylaluminum (TIBA) was used as an aluminum source for metalorganic molecular beam epitaxy (MOMBE). The optical absorption coefficient for TIBA was found to be larger than both tri ethyl aluminum and triethylgallium. TIBA was introduced into a laser-induced MOMBE system and selective deposition of Al and AlAs was carried out. Al metal was deposited on the area where the ArF excimer laser was irradiated and no deposition was observed without the excimer laser irradiation at a substrate temperature of 350 C. Furthermore, a laser large enhancement of the growth rate of AlAs was observed at 350 C.
Photo-Cvd Silicon Nitride for Gaas Mesfet Passivation
Authors: Padmanabhan R. , Miller B. J. , Tam G. 
Published: March 2011

ABSTRACTSilicon nitride films were deposited using a photochemical vapor deposition method. The defect density in these films was under 100/cm2 and the film adhesion was in excess of 104 psi. No lift-off was observed at power densities of up to 10 A/cm2 at applied voltages of up to 100. The film stress was compressive and under 5x103 psi. Total mobile ion concentration in the films did not exceed 109/cm2. Device analysis was carried out using Motorola dual gate MESFETs. Device degradation was evaluated in terms of surface potential sensitive parameters like source-drain current and resistance, by making comparisons in these parameters before and after passivation. Some degradation (up to 17 %) occurred in some of these parameters subsequent to device passivation. These results are comparable to or better than those encountered in most other low temperature films (like plasma enhanced CVD and polyimide films). The observed device properties are explained in terms of the film composition and the applicability of photo-CVD nitride films for MESFET passivation is discussed.
Laser-Assisted Liquid-Phase Etching of Copper Conductors and its Application to Advanced Integrated Circuit Interconnect
Authors: Miracky Robert F. , Doss Kantesh 
Published: March 2011

ABSTRACTWe have demonstrated a method f or the selective-area, laser-assisted liquid-phase etching of 6-μm thick copper conductors, by focusing the 488-μm line of an argon ion laser onto the surface of samples immersed in a dilute solution containing sulfuric acid and hydrogen peroxide. Average etch rates of up to 5.0 μm/s have been achieved, in the process of completely severing 14-μm wide copper lines, with little attendant damage to the underlying layer of polyimide. Two etchant formulations were identified which exhibited large etch rates at elevated temperatures and low enough background etch rates (approximately 1 μm/hr at 0 °C) to be useful in practical applications.
Laser Chemical Etching of Metals in Neutral Salt Solutions
Authors: Datta M. , Romankiw L. T. , Vigliotti D. R. , von Gutfeld R. J. 
Published: March 2011

ABSTRACTWe report the first results of experiments using a focused argon ion laser to locally induce chemical etching of steel and stainless steel in neutral salt solutions for maskless patterning. The solutions include sodium chloride, sodium nitrate and potassium sulfate. Vertical etch rates up to 4 microns/s are observed.
Control of Etching of LiNbO3, by Implant Damage Profile Tailoring
Authors: Brannon P. J. , Ashby C. I. H. , Arnold G. W. 
Published: March 2011

ABSTRACTDamage-profile tailoring using multi-energy ion implants can produce smooth side walls and deeper etched features with ion-bombardment-enhanced wet etching of LiNb03 than is possible with a single-energy implant. High ion fluences can produce buried microcracks which may contribute to propagation losses commonly observed in ion-implanted waveguides.
Laser-Initiated Aluminothermic Reaction Applied to Preparing Mo-Si Film on Silicon Substrates
Authors: Ding Li , Xuebiao Lu , Zhengzhuo Zhou , Mingxin Qiu , Chenglu Lin 
Published: March 2011

ABSTRACTMo-Si films on silicon substrates has been prepared by the CO2 laser-initiated aluminothermic reaction. The features of these films have been characterized by RBS, AES, etc. The formation mechanism is discussed.
Rapid Thermal Annealing of Fib-Implanted Ga Shallow Impurity Profiles
Authors: Lin C-M. , Steckl A.J. , Chow T.P. 
Published: March 2011

ABSTRACTIn this paper, we present the results of a study to fabricate shallow p+ n junction using Ga FIB implantation in conjunction with rapid thermal annealing (RTA). A focused 75 KeV ion beam with BO mA/cm2 current density and 0.5 μm beam diameter was used to implant Ga into (100) Si substrates at the doses from 1E13 to 5E15/cm2. The annealing temperature is from 600 °C to 1000 °C for various times, 10–30 sec. Secondary ion mass spectrometry (SIMS) and spreading resistance profiling (SRP) were used to measure the implanted Ga atomic and carrier concentration depth profiles. As compared to the conventional broad beam (BB) implantation, the FIB implanted impurity concentration depth profile has a longer tail and thus a deeper p+n junction. The damage generated by the high dose rate implantation is possibly responsible for this phenomenon. The results of SRP measurements of the FIB as-implanted samples show no Scif-anneal ing occured during implantations. p+n diodes fabricated using FIB exhibit good junction properties: ideality factor of 1.1, reverse–bias leakage current of below 5 nA/cm2 at -IV, and breakdown voltage of about 35 V.
Laser-Induced Metal Deposition on Silicon Membranes for X-Ray Lithography
Authors: Petzold H.-C. , Putzar R. , Weigmann U. , Wilke I. 
Published: March 2011

ABSTRACTThe repair of clear defects on X-ray masks (2 urn Si membranes) requires the localized deposition of metal films with high aspect ratios and high X-ray opacity. Laser-induced heavy metal deposition from organometal-lic gas atmospheres has been investigated with respect to these requirements. An experimental comparison of pyrolytic (W) and photolytic (esp. W, Sn) depositions on thin Si membranes was performed to find out which of these two mechanisms is more favourable for X-ray mask repair. Using a simple model, the laser-induced temperature distribution in the membrane was calculated which strongly affects pyrolytic deposition. Although photolytic deposition tends to yield X-ray opacities below corresponding bulk values, this process turned out to be more suitable due to its better spatial resolution in this case of Si membranes used as substrates.
Direct Writing of Copper Lines From Copper Formate Film
Authors: Gupta Arunava , Jagannathan Rangarajan 
Published: March 2011

ABSTRACTThe focused output from an argon ion laser (514 nm) has been used for direct writing of copper by photothermal decomposition of copper formate film on quartz and silicon substrates. The low decomposition temperature of the metallo-organic (∼200°C) allows deposition of fairlys thick copper lines at writing speeds as high as 10 mm/sec. The processing can be done in air since the rapid decomposition and cooling under scanning condition results in minimal oxidation of the deposited copper. The temperature distribution produced during laser writing on silicon substrate has been calculated to help explain some of the observed results.
Scanning Tunneing Microscope Study of Cadmiun Telluride
Authors: Kim H. S. , Zheng Y. C. , Bryant P. J. 
Published: March 2011

ABSTRACTLayered samples of cadmium telluride grown epitaxially on gallium arsenide substrates have been investigated by means of scanning tunneling microscopy (STM). The surface geometric and electronic structures are both of interest. Techniques were developed to remove the native oxide by etching, or to create a fresh surface by cleaving, and to protect them from oxidation by employing mineral or paraffin oil media. STM studies were conducted within the protective medium. These techniques were adapted and tested for both etched and cleaved samples of Si, CdTe and HgTe. The currentvoltage characteristics of the CdTe surface were investigated during dynamic changes of the tunnel current and barrier height while the probe-to-sample separation (gap) was static. Recorded values are shown for current versus bias for several constant gap values. A range of bias values has been employed to test a possible solution for the problem of interference between the contributions from geometric and electronic structure factors.
II–VI / III–V Heterostructures
Authors: Kolodziejski L. A. , Gunshor R. L. , Otsuka N. , Nurmikko A. V. 
Published: March 2011

ABSTRACTThe integration of several optoelectronic device functions onto a common substrate material is an area which is currently being actively pursued. In an effort to achieve this objective, experiments are under way to examine the epitaxial growth and material properties of a variety of both II–VI and III–V compounds grown on a substrate where the II–VI/III–V heterostructure can be utilized. This paper describes some recent developments involving the molecular beam epitaxial (MBE) growth and characterization of two important II–VI/III–V heterostructures: ZnSe/GaAs and InSb/CdTe;. a comparison is made between epitaxial layer/substrate interfaces and epilayer/epilayer interfaces for both heterostructures. The ZnSe/GaAs heterointerface, having a 0.25% lattice constant mismatch, has potential for use in passivation of GaAs devices. The InSb/CdTe heterointerface possesses an even closer lattice match, ∼0.05% (comparable to the (Al,Ga)As/GaAs material system), and is motivated by possible device applications provided by InSb/CdTe quantum wells.