bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Grain Boundaries on Surface Diffusion Mediated-Planarization of Polycrystalline Cu Films
Authors: Brain R.A. , Gardner D.S. , Fraser D.B. , Atwater H.A. 
Published: April 2011

ABSTRACTIn situ, ultrahigh vacuum anneals were performed to induce Cu reflow at 500°C following deposition of Cu films and a Ta barrier layer on 1 μm wide by 1 μm deep trenches. Transmission electron micrograph cross-sections show profiles which suggest that grain boundaries and surface energy anisotropy significantly affect reflow. The extent of reflow is dependent on the structure of grain boundary-surface intersections, and the surface profile consists of regions of low curvature within grains and with sharp discontinuities in curvature at grain boundaries, a structure that inhibits surface diffusion. We present results showing how the surface diffusion mediated reflow varies with grain boundary groove angle and position, and compare these results with finite-element simulations that model surface diffusion-driven reflow.
Theoretical Investigation of Implanted Dopant Diffusion From a Silicide Layer to the Silicon Wafer for Ultra Shallow P-N Junction Formation
Authors: Sinder M. , Pelleg J. 
Published: April 2011

ABSTRACTIn this work a theoretical model is presented to analyze the technique recently suggested to form shallow p-n junction. According to this technique a silicide acts as a source of a dopant and it is followed by controlled diffusion anneal to accomplish the dopant penetration into a silicon wafer.In our analysis the dependence of the p-n junction depth on process parameters is discussed. The model considers two cases, namely, with and without dopant evaporation.Experimental data for B diffusion from CoSi2 acting as the source are used to evaluate our theoretical model. The agreement between theoretical and experimental results is satisfactory.
Modeling, Simulation and Control of Single Wafer Process in Cluster Tool Base on Ft-Ir In-Line Sensor
Authors: Liu Shaohua , Solomon Peter , Carpio R. , Fowler B. , Simmons D. , Wang J. , Wise R. , Imper G. , Riley N.B. , Moslehi M. , Ravindra N.M. 
Published: April 2011

ABSTRACTThis paper outlines our current approach to utilize infrared reflectance spectroscopy for thin film measurement in the semiconductor industry. The multi-layer thickness and doping concentration of IC wafers can be determined by a single angle, unpolarized infrared reflectance measurement performed using Fourier transform infrared spectrometer. A computer algorithm, which matches theoretical to measured infrared reflectance spectra, was successfully employed to determine multiple thin film properties.
Site Balance Models in Plasma Processing: A Comparison to Molecular Dynamics Simulations
Authors: Barone M.E. , Graves D.B. 
Published: April 2011

ABSTRACTMolecular dynamics (MD) simulations were conducted of Cl+ impact (at 10, 25 and 50 eV) of an initially bare silicon surface, leading to steady state coverage of Cl in a mixed chlorosilyl layer. Our main goal in this study was to compare the MD predictions to models of ion-assisted etching involving the concept of a site balance. For the case of 50 eV Cl+ etching silicon, the coverage vs. exposure results in the simulation could be reasonably well reproduced in a site balance model, but only if the correct parameters in the model were taken from the simulation. The results of the comparison suggest that MD simulations can be helpful in the development of physically sound phenomenological models of ion-assisted etching.
Hot-Carrier Effect in Submicron pMOSFETs
Authors: Saha S. , Yeh C. S. , Lindorfer Ph. , Luo J. , Nellore U. , Gadepally B. 
Published: April 2011

AbstractThis paper describes an application of process and device simulation programs in the study of substrate current generated by hot-carrier effect in submicron p-channel MOSFET devices. The impact ionization model for holes was calibrated for accurate simulation of substrate current in submicron devices, and an expression for the impact ionization rate of holes in silicon is obtained. The simulated substrate current for 0.57, 0.73 and 1.13 μm devices obtained by the optimized expression agrees very well with the measured data. The optimized impact ionization expression was also used to simulate the effect of p- Lightly Doped Drain impurity profile on substrate current, and the simulated peak substrate current and the corresponding maximum lateral channel electric field as a function of p- dose and length are presented.
Grain Boundary Migration and Grain Growth Induced by Electromigration in Copper and Aluminum Lines
Authors: Gladkikh A. , Glickman E. , Karpovsky M. , Lereah Y. , Palevski A. , Shubert J. 
Published: April 2011

AbstractThe changes of microstructure in Al and Cu thin film lines due to electromigration have been studied using transmission electron microscopy. Grain boundary migration, inclination and dislocation activity were found to be critically involved in the electromigration induced hillock formation that can be described as three dimensional grain growth.
The Effects of Deposition temperature on the Growth of Copper films produced by low pressure metal-organic chemical vapour deposition
Authors: Yoon S.S. , Kang S.W. , Chun S.S. 
Published: April 2011

AbstractCopper was deposited onto TiN by low pressure metal-organic chemical vapour deposition, using hfacCu(I)TMVS and argon carrier gas. The effects of the deposition temperature on the growth of copper films were investigated by observing the surface morphology and the cross sectional morphology of copper films. At the initial stage of growth, copper films tended to have the island-like growth mode, irrespective of the deposition temperatures. It was also observed that the aspect ratio(=height to width) of the islands gradually increased as the deposition temperature increased. The poorer movability of the copper atoms at the higher deposition temperature was evaluated on the basis of hindering effect by the following copper deposits.
The Effects of Test Condition, Microstructure and Linewidth on Electromigration Void Morphology
Authors: Bauguess S. , Dreyer M. L. , Tucker M. , Theodore D. , Lee C. T. , Edwards S. 
Published: April 2011

AbstractIn this paper, experimental results for electromigration void morphology and failure time distribution are presented as a function of test condition, grain size distribution and conductor linewidth. Unpassivated Al-Cu(1.5%)-Si(1.5%) conductors with linewidths in the range lum ≤W ≤l0μm were subjected to accelerated temperature stresses of T=150° C and 250°C and current stresses in the range j= 0.5-4X106 A-cm-2, for each temperature stress. Unlike previous reports, erosion-like voids dominated at all current densities and temperatures for both W/D50≤1 and W/D50 > 1. The void distribution within a line was strongly dependent on test conditions and linewidth. The critical current density was extracted from electromigration lifetimes measured as a function of current density. The results show that the linewidth dependence of electromigration lifetimes depend strongly on the Blech relation.
Quantitative Measurement of Interface Fracture Energy in Multi-Layer Thin Film Structures
Authors: Ma Qing , Fujimoto Harry , Flinn Paul , Jain Vivek , Adibi-Rizi Farshid , Moghadam Farhad , Dauskardt Reinhold H. 
Published: April 2011

AbstractInterfacial debonding of multi-layer thin film systems can severely affect the reliability of devices. To quantitatively evaluate the interface adhesion strength, a sandwich structure four-point bending technique was developed. In the sandwich structure samples, the thin film structure of interest was diffusion bonded between two silicon substrates. A fourpoint bending method was applied to propagate a crack along the interface of interest. Two thin film systems with nominally the same structure, but processed under different conditions, were measured for their SiO2/TiN interface fracture energies. Results showed that the interface fracture energy of one system was about 50% larger than that of the other system. Cross-section TEM observations revealed that the stronger interface was also significantly rougher.
Ionic Modeling of Lithium Manganese Spinel Materials for Use in Rechargeable Batteries
Authors: Cygan Randall T. , Westrich Henry R. , Doughty Daniel H. 
Published: April 2011

ABSTRACTIn order to understand and evaluate materials for use in lithium ion rechargeable battery electrodes, we have modeled the crystal structures of various manganese oxide and lithium manganese oxide compounds. We have modeled the MnO2 polymorphs and several spinels with intermediate compositions based on the amount of lithium inserted into the tetrahedral site. Three-dimensional representations of the structures provide a basis for identifying site occupancies, coordinations, manganese valence, order-disorder, and potentially new dopants for enhanced cathode behavior. X-ray diffraction simulations of the crystal structures provide good agreement with observed patterns for synthesized samples. Ionic modeling of these materials consists of an energy minimization approach using Coulombic, repulsive, and van der Waals interactions. Modeling using electronic polarizabilities (shell model) allows a systematic analysis of changes in lattice energy, cell volume, and the relative stability of doped structures using ions such as aluminum, titanium, nickel, and cobalt.
Charge Transport Properties of a Partially Reduced V2O5 Xerogel Intercalated with a Polymer Electrolyte
Authors: Albritton Thomas Joyce , Kloster Grant M. , Shriver D. , Kannewurf C. R. 
Published: April 2011

ABSTRACTRecently, there has been considerable interest in advanced materials and processing techniques for practical applications. V2O5 xerogels have generated much attention because they are layered materials that undergo reversible redox intercalation with lithium. The sol-gel process has been used to intercalate V2O5 xerogels with the polymer electrolyte, oxymethylene linked poly(ethylene oxide) - lithium triflate [(a-PEO)n(LiCF3SO3)]. The resulting nanocomposite is a mixed ionic-electronic conductor in which the ionic charge carriers in the polymer electrolyte are in intimate contact with the electronic charge carriers in the V205 xerogel. Variable-temperature electronic conductivity and thermoelectric power measurements have been performed to examine the charge transport properties.
Design and Testing Criteria for Bipolar Plate Materials for Pem Fuel Cell Applications
Authors: Borup R. L. , Vanderborgh N. E. 
Published: April 2011

ABSTRACTBipolar plates for proton exchange membrane (PEM) fuel cells are currently under development. These plates separate individual cells of the fuel cell stack, and thus must be sufficiently strong to support clamping forces, be electrically conducting, be fitted with flow channels for stack thermal control, be of a low permeability material to separate safely hydrogen and oxygen feed streams, be corrosion resistant, and be fitted with distribution channels to transfer the feed streams over the plate surface. To date, bipolar plate costs dominate stack costs, and therefore future materials need to meet strict cost targets.A first step in the bipolar plate development program is an assessment of design constraints. Such constraints have been estimated and evaluated and are discussed here. Conclusions point to promising advanced materials, such as conductive, corrosion resistant coatings on metal substrates, as candidates for mass production of fuel cell bipolar plates. Possible candidate materials are identified, and testing procedures developed to determine suitability of various materials.
Development of Aluminosilicate Polyelectrolytes for Solid-State Battery Applications
Authors: Rawsky Glenn C. , Henretta Kevin J. , Lowrey Robert , Shrtver Duward F. , Vaynman Semyon 
Published: April 2011

ABSTRACTWe have synthesized and characterized a range of novel polyelectrolytes containing weakly basic aluminosilicate anions in the polymer backbone in order to achieve t+ = 1 and high ionic mobility. Room-temperature conductivity is observed to increase in the series: [NaAl(OEOMe)2 ((OE)xO)2/2]n < [NaAl(OR)2(OSiMe2(CH2)3(OE)xO(CH2)3SiMe2O)2/2]n < [NaAl(OSiR3)(OSiMe2(CH2)3(OE)xO (CH2)3SiMe2O)3/2]n. This trend is ascribed to reduced ion pairing due to decreasing anion basicity, and lowered Tg resulting from increasing siloxy character. The addition of cryptand [2.2.2] increases conductivities by 1 -1.5 orders of magnitude. A maximum room-temperature conductivity is observed at a ratio of ≈10 etheric oxygens/cation. Related lithium polymer electrolytes were evaluated in mechanically joined solid state Li |PE |[LixMn2O4-C-PE] cells.
Materials for a New Generation of Vehicles
Authors: Grobstein Toni 
Published: April 2011

ABSTRACTThe Partnership for a New Generation of Vehicles (PNGV) is a national initiative with three goals: First, to significantly improve national competitiveness in manufacturing; second, to implement commercially viable innovations from ongoing research on conventional vehicles, and third, to develop a vehicle to achieve up to three times the fuel efficiency of today's comparable vehicle (ie, the 1994 Chrysler Concorde, Ford Taurus, and Chevrolet Lumina). Note this vehicle will have the equivalent customer purchase price of today's vehicles adjusted for economics, while meeting the customers' needs for quality, performance, and utility. Eight federal agencies are currently contributing to these goals, as well as the three principal US automobile manufacturers, numerous automotive component suppliers, research laboratories, and universities.Materials research and development is a significant effort within PNGV. The goals in this area include development of lightweight, recyclable materials for structural applications, high strength, long-life, high temperature materials for engine components, improved materials for alternative propulsion and energy storage systems, and cost-effective process technologies and component fabrication methods. Application of advanced materials to automobiles will involve consideration of diverse factors, including weight savings, affordability, recyclability, crashworthiness, repairability, and manufacturability.
Improving the Electrochemical Performance of Carbon Filaments by Solvent Cleansing
Authors: Shui Xiaoping , Frysz Christine A. , Chung D. D. L. 
Published: April 2011

ABSTRACTFound inherent in the submicron-diameter vapor-grown carbon filament fabrication process was a tarry residue, which comprised polyaromatic hydrocarbons. Cyclic voltammetry conducted using carbon working electrodes and an iron cyanide electrolyte showed that the residue harmed the electrochemical performance. Removal of the residue from the filaments using a solvent resulted in increases in the electron transfer rate (to values as high as 0.2 cm/s) and reversibility of the iron cyanide redox species, increase in the packing density and decrease in the filament-filament contact electrical resistivity.
Pulsed Laser Deposition of Transition Metal Oxides for Secondary Batteries
Authors: Striebel Kathryn A. , Deng C. Z. , Cairns E. J. 
Published: April 2011

ABSTRACTPulsed laser deposition has been used to prepare thin films of several complex metal oxides of significance in secondary batteries from a single stoichiometric target with a substrate temperature of 600°C in the presence of 200 mtorr O2. Films of the candidate bifunctional air electrocatalysts, for metal air batteries, Lao.6Cao.4CoO3, Lao.6Sr0.4CoO3, Lao.6Cao.4MnO3 and Lao.6Sro.4MnO3 were prepared on glassy carbon substrates. Glassy carbon was found to either erode during the ablation process (with the cobaltates) or cause film cracking after deposition because of its extremely low coefficient of thermal expansion.. The use of stainless steel substrates yielded 0.3μm-thick dense films of Lao.6Cao.4CoO3 and Lao.6Cao.4MnO3 which were suitable for electrochemical measurements in concentrated alkaline electrolytes. LiMn2O4 and LiCoO2 films were prepared at thickness' of 0.3μm and 1 5μm The 0.3μm-thick films delivered 176 mC/cm2-μm and 323 mC/cm2-μm for LiMn2O4 and LiCoO2, respectively, in 1M LiClO4/PC.
Search for Ion Induced Mixing in Ceramic-Ceramic Systems
Authors: Padmanabhan K.R. 
Published: April 2011

AbstractThin sputtered ceramic films deposited on ceramic substrates were subjected to either Kr+ or Xe+ ion bombardment for ion beam mixing studies in ceramic-ceramic systems. The amount of mixing if any was evaluated from Rutherford backscattering and Auger electron spectroscopy. In some instances ceramic films were deposited on epitaxial films or single crystal substrates for ion channeling analysis. No significant mixing was observed in any of the systems with ZrC. However, analysis of the interface in Si3N4/ SiC system indicates appreciable mixing and ion beam induced damage to the substrate. The mixing appears to be dose dependent for heavier ions.
Modification of the Structure-Phase State of Coatings by Ion Implantation Techniques
Authors: Korotaev A.D. , Tyumentsev A.N. , Pinzhin Yu.P. , Safarov A.F. , Bugaev S.P. , Shchanin P.M. , Koval N.N. , Vizir A.V. 
Published: April 2011

AbstractTransmission electron microscopy was used to study the effect of nitrogen-ion irradiation on the microstructure of ion-plasma TiN coating deposited on a substrate of austenitic stainless steel. The principal peculiarities of the changes in the fine structure at the substrate-coating interface and in the bulk of the coatings having a thickness of several micrometers have been revealed for the conditions of ion-beam-assisted deposition and plasma-assisted deposition. Possible mechanisms for the effect of ion irradiation on the microstructure of the substrate-coating composition are discussed.
Effects of High Energy Ion Irradiation on Crystallization of Amorphous Germanium Films Deposited on Calcium Fluoride Substrates
Authors: Nakao Setsuo , Saitoh Kazuo , Ikeyama Masami , Niwa Hiroaki , Tanemura Seita , Miyagawa Yoshiko , Miyagawa Soji 
Published: April 2011

AbstractAmorphous (a-) Ge films were deposited on air-cleaved CaF2 (111) substrates at different deposition temperatures (Td). The films were irradiated with 0.9 MeV Ge or Si ions at low ion current intensity (1c) l00nA/cm2. Their structural changes were studied by Rutherford backscattering spectrometry (RBS) -channeling technique and thin film x-ray diffraction (XRD) measurement. It was found that the films were epitaxially crystallized by Ge and Si ion irradiation although they included randomly oriented grains. Ge ion irradiation was more effective for the crystallization than Si ion irradiation. However, the amount of the randomly oriented grains was slightly higher when using Ge ions. On the other hand, ion irradiation to the films prepared at high Td also exhibited higher incidence of randomly oriented grains.
Molecular Dynamics Studies of the Ion Beam Induced Crystallization in Silicon
Authors: Marques L.A. , Caturla M.-J. , Huang H. , Díaz De La Rubia T. 
Published: April 2011

AbstractWe have studied the ion bombardment induced amorphous-to-crystal transition in silicon using molecular dynamics techniques. The growth of small crystal seeds embedded in the amorphous phase has been monitored for several temperatures in order to get information on the effect of the thermal temperature increase introduced by the incoming ion. The role of ion-induced defects on the growth has been also studied.
Study of Diamond Nucleation on Silicon Using Direct Negative Carbon Ion Beam Source
Authors: Ko Y.W. , Ahn Y.O. , Sohn M.H. , Park Y. , Kim S.I. 
Published: April 2011

AbstractThe initial nucleation stages of sp3 bonded amorphous diamond on silicon substrates have been investigated. The energy of the incident carbon ions/atoms is understood as a key parameter for the vapor phase formation of amorphous diamond like carbon coatings. SKION's solid state carbon ion source is used for this study. The ion source is UHV compatible and capable of producing a controlled energy ion beam in the energy range of 5-300 eV. In the initial stage of the deposition, carbon is found to be deposited as a silicon carbide up to a thickness of about 180Á at room temperature. Silicon is diffused to the surface and forms SiC. As the energy of the ion beam increases, the formation of silicon carbide becomes apparent. Further carbon ion bombardment then leads to the formation of an sp3 bonded amorphous diamond film. Post-annealing above 900°C leads to the formation of crystalline silicon resulting in a Si-rich SiC surface due to silicon out-diffusion.
Loss Measurements of Stoichiometric Ti and O Implanted LiNbO3 Waveguides
Authors: Williams E. K. , Ila D. , Sarkisov S. , Venkateswarlu P. , Poker D. B. 
Published: April 2011

AbstractPlanar waveguides created by the implantation at 500°C of 2.5 x 1017 Ti ions/cm2 and 7.5 x 1017 O ions/cm2 have been characterized for loss by the scattered light technique. Preliminary results indicate losses of less than 2.5 dB/cm.
A Molecular Dynamics Simulation Study of Defect Production in Vanadium
Authors: Morishita K. , Diaz De La Rubia T. 
Published: April 2011

AbstractWe performed molecular dynamics simulations to investigate the process of defect production in pure vanadium. The interaction of atoms was described by the EAM interatomic potential modified at short range to merge smoothly with the universal potential for description of the high energy recoils in cascades. The melting point of this EAM model of vanadium was found to be consistent with the experimental melting temperature. The threshold energies of displacement events in the model system are also consistent with experimental minimum threshold in vanadium, and its average was found to be 44 eV. We evaluated the efficiencies of defect production in the displacement events initiated by recoils with kinetic energy up to 5 keV, and found that the probability of cluster formation is smaller than that of simulated events in fee metals reported in the literature.
Optical Properties of Multi-Component Antimony-Silver Nanoclusters Formed in Silica by Sequential Ion Implantation
Authors: Zuhr R.A. , Magruder R.H. , Anderson T.S. 
Published: April 2011

AbstractThe linear and nonlinear optical properties of nanometer dimension metal colloids embedded in a dielectric depend explicitly on the electronic structure of the metal nanoclusters. The ability to control the electronic structure of the nanoclusters may make it possible to tailor the optical properties for enhanced performance. By sequential implantation of different metal ion species multi-component nanoclusters can be formed with significantly different optical properties than single element metal nanoclusters. We report the formation of multi-component Sb/Ag nanoclusters in silica by sequential implantation of Sb and Ag. Samples were implanted with relative ratios of Sb to Ag of 1:1 and 3:1. A second set of samples was made by single element implantations of Ag and Sb at the same energies and doses used to make the sequentially implanted samples. All samples were characterized using RBS and both linear and nonlinear optical measurements. The presence of both ions significantly modifies the optical properties of the composites compared to the single element nanocluster glass composites. In the sequentially implanted samples the optical density is lower, and the strong surface plasmon resonance absorption observed in the Ag implanted samples is not present. At the same time the nonlinear response of the these samples is larger than for the samples implanted with Sb alone, suggesting that the addition of Ag can increase the nonlinear response of the Sb particles formed. The results are consistent with the formation of multi-component Sb/Ag colloids.