bluuebunny/crossref_metadata_2025_split huggingface dataset:
Current-Stress-Induced Interface States in p-Si Mos Diodes Detected by a.c. Conductance Measurement
Authors: Inoue Masao , Shirafuji Junji 
Published: April 2011

AbstractEffect of Fowler-Nordheim current stress on (100) p-Si metal/oxide/semiconductor diodes have been studied by means of a.c. conductance measurement. Growth of two distinct peaks are observed in the depletion and the inversion resions corresponding to the generation of two kinds of defects in the upper and lower halves of the bandgap. These defects show different behaviors against the current stress in the energy profiles of the density and the capture cross section. The degradation of the Si/SiO2 interface is discussed in relation to the defect creation.
Thermal Stability of Platinum Silicide in Deep Sub-Micron Lines
Authors: Xu Dan-Xia , Das Suhit R. , Erickson Lynden , Naem Abdalla 
Published: April 2011

AbstractThe properties of platinum silicide have been evaluated in the form of blanket films and confined lines with linewidth down to 0.15 μm. Pt films, ranging in thickness from 150Å to 1000Å, were prepared by sputter-deposition onto Si (100) blanket substrates or substrates patterned with windows of various sizes in SiO2. The samples were then annealed in a rapid thermal annealing system up to 550°C to form PtSi. The sheet resistance of silicide lines did not change significantly with linewidth. The thermal stability of the sheet resistance of PtSi was also measured for different linewidths and film thicknesses. The sheet resistance remained stable on annealing up to 850°C for a silicide film made of 250Å Pt and did not appear to be sensitive to the linewidth. The thickness dependence of the thermal stability of resistance was also evaluated.The stress of the silicide films was measured using a laser deflection system. The asdeposited metal films were under compressive stress, but the stress turned into tensile upon annealing when silicide started to form. After PtSi was formed, the stress remained stable with annealing temperature until approximately 900°C when the stress exhibited a sharp decrease. Unlike electrical conductance, however, the breakdown temperature for stress did not strongly depend on the film thickness.
A Comparative Study on Electromigration Failure Mechanism Between Near-Bamboo and Bamboo Al(Cu) Two-Level Structure
Authors: Wang P.-H. , Lee C. , jawarani D. , kawasaki H. , ho P. S. 
Published: April 2011

AbstractAs the interconnect line width reduces to the sub-micron range, the grain distribution of Al(Cu) alloy lines reaches a bamboo structure. Understanding of the electromigration resistance of near-bamboo and bamboo structures is essential to the sub-micron reliability issue. In this study, the mass transport and failure mechanism of 1 μm wide Al(1%Cu) two-level lines with near-bamboo and bamboo structures were investigated by a drift velocity technique [1]. Our results show that interfacial (A10X/A1 interface) diffusion coupled with grain boundary diffusion determines the failure mechanism of bamboo lines.
Reliability Aspects of Thin Dielectric Films Used in NVM ICs
Authors: Kotov Alexander E. 
Published: April 2011

AbstractThe behavior of small MOS structures with polycrystalline silicon gates subjected to stresses caused by electron injection was analyzed. A nature of degradation in MOS structures is more clearly and reliably extracted from the investigations of the microstructures with active areas less than 10 μm2. NVM cells with floating gate are convenient objects for such investigations. Due to the high current sensitivity and range of described novel techniques (10-17 - 10-7 A), small tunnel oxide area in memory cell (1-5 μm2) and temperature measurements (120 - 438 K) some new results in oxide degradation have been found.In this work the following chain of degradation processes during electron injection was experimentally detected: conversion from planar to local injection (area of localization~10-3 um2) => appearance of percolated path for low field leakage (it is defined by sufficient amount of generated deep level traps in dielectric Nt~ 1020 cm-3) => development of leakage channel into the breakdown region. TDDB method usually developed on large MOS structures with electrostatic energy more than critical value 107 eV is not able to distinguish this chain and correctly evaluate degradation. Taking into account a localization of electron injection, it was found that the charge to the leakage channel generation is about 104 -105 Cl/cm2 for cells without fabrication defects. A kinetics of localization is very sensitive to the tunnel oxidation process.Degradation stages of NVM cells, subjected to different electric stresses and anneals, have been investigated in wide current and temperature ranges. Polaron and Trap Model for the I-V leakage characteristics of degraded SiO2 films is presented.
Effect of Surface and Grain-Boundary Diffusion on Interconnect Reliability
Authors: Klinger L. M. , Glickman E. E. , Fradkov V. E. , Mullins W. W. , Bauer C. L. 
Published: April 2011

AbstractThe effect of surface and grain-boundary diffusion on interconnect reliability is addressed by extending the theory of thermal grooving to arbitrary grain-boundary flux. For a periodic array of grain boundaries, three regimes are identified: (1) equilibrium, (2) global steady state, and (3) local steady state. These regimes govern the stability of polycrystalline materials subjected to large electric (electromigration) or mechanical (stress voiding) fields, especially in thin films where grain size approximates film thickness.
The Detrimental Effect of a Passivation on the Electromigration Lifetime of Narrow Al-Si-Cu Lines
Authors: Witvrouw A. , Roussel Ph. , Deweerdt B. , Maex K. 
Published: April 2011

Abstract2 mm long, 0.8 μm wide and 0.8 μ thick Al-Si-Cu lines, passivated with a 1.14 μm thick PETEOS SiO2 were found to have a lower electromigration lifetime compared to identical unpassivated lines. The high tensile stress in the passivated lines is assumed to accelerate electromigration failure. This is confirmed by the very low activation energy for electromigration failure in the passivated lines and by the multiple events of recovery during and after electromigration testing, suggesting failure sites are slit voids.
Line Length Dependence of Small, Electromigration Induced Resistance Changes in Aluminum
Authors: Kraayeveld J.R. , Verbruggen A.H. , Willemsen A.W-J. , Radelaar S. 
Published: April 2011

AbstractTwo series of experiments were carried out to investigate the line length dependence of changes in the electrical resistance caused by passing a DC current through thin film Al conductors. First, the effect of adding side branches with a spacing of 5 μ m to 150 μ m long lines was studied. Experiments performed at T = 148 °C and at a DC current density of 0.5 MA/cm2 showed three effects due to adding the side branches: i) the magnitude of the resistance changes is reduced, ii) the resistance changes saturate on a time scale of one hour, and iii) the resistance changes fully recover after switching off the current. In the second series of experiments the current, temperature and line length dependence of resistance changes induced in short (3-100 μ m) lines between bonding pads were studied. For current densities smaller than a certain length dependent critical value the resistance saturates after applying the current and relaxes back to the original value after removing the current. The time to relax back, which is comparable to the time to reach saturation, is proportional to the sample length squared. This and the activation energy derived from the temperature dependence of the relaxation process suggest strongly that the observed time dependence of the resistance changes is determined by grain boundary diffusion (electromigration) along the whole length of the line.
A Simple Analysis of Average Mechanical Behavior and Strain Energy Density of Misoriented Grains in a Textured Film
Authors: Vinci R.P. , Weihs T.P. , Zielinski E.M. , Barbee T.W. , Bravman J.C. 
Published: April 2011

AbstractDifferences in strain energy density between grains of different orientation within a thin film may drive morphological changes such as abnormal grain growth, hillocking, and sunken grains. Models of these morphological changes generally assume that the behavior of each grain is the same as that of a blanket film of corresponding orientation. In order to investigate this assumption as it applies to the behavior of a (100)-oriented grain within a {111}-fiber textured copper film, simple continuum analytical and finite element models are applied to the case of a film on a rigid substrate subjected to temperature changes. The simple models indicate that the behavior of a misoriented grain does not simply duplicate that of a blanket film of the same orientation; the behavior of the surrounding grains must also be considered. The strain energy density difference between the grain and the surrounding film is less than that predicted by blanket film behavior. An elasticity equation is presented which describes the average stress-temperature behavior of widely dispersed misoriented grains within a textured film.
Recent Developments in Fuel Cell Materials
Authors: Appleby A. J. 
Published: April 2011

ABSTRACTChemical and physical requirements limit the choice of fuel cell electrolytes to strong aqueous acids and alkalis, (pyro)phosphoric acid, carbonate melts, and solid oxides (O= conductors, with rare H+ conductors). The choice of electrolytes and operating temperatures is therefore limited, controlling the choice of other materials (anode catalysts, cathode catalysts, current collectors, and construction materials), which are determined by the properties of the electrolyte, the temperature, the electrode potentials, the gas atmospheres, and thermodynamic and kinetic considerations. The families of state-of-the art and new materials for each class of electrolyte are reviewed. The area of greatest activity is the solid oxide fuel cell (500°C-1000°C). In a review of this length, the extensive list of new solid oxide developments can only be given by way of introduction.
Fabrication of a Polymer Battery based on Polypyrrole Electrodes and a Polymer Gel Electrolyte
Authors: Killian Jeffrey G. , Coffey B.M. , Poehler T.O. , Searson P.C. 
Published: April 2011

ABSTRACTThe electronic conductivity and redox behavior of conjugated polymers make them suitable for charge storage applications. We present preliminary results for an all polymer system consisting of a p-doped polypyrrole cathode and pseudo n-doped polypyrrole/polystyrenesulfonate anode. Using a thin film construction technique, electrodes were assembled into cells using a polymer gel electrolyte based on polyacrylonitrile, which has a high room temperature conductivity. Charge capacities of 13 mAh g−1 based on the mass of the electroactive polymer in the cathode have been obtained for over 100 cycles.
The Role of Sei in Lithium and Lithium Ion Batteries
Authors: Peled E. , Golodnttsky D. , Ardel G. , Menachem C. , Bar Tow D. , Eshkenazy V. 
Published: April 2011

ABSTRACTThis paper presents and discusses fundamental processes taking place at the lithium and LixC6 electrode/electrolyte interphases and models for these interphases. We deal with both nonaqueous and polymer (dry and gel) electrolytes, graphitized and nongraphitized carbonaceous materials as anodes for Li-ion batteries. Each electrode/electrolyte combination has its own unique features and problems but there are some general phenomena common to all of them. Issues to be reviewed include SEI composition, morphology and formation reactions, graphite surface modifications including chemical bonded SEI and micro channels formation, electrode degradation processes, lithium deposition-dissolution and intercalation-deintercalation mechanisms, rate-determining steps (RDS), electrolyte and electrode parameters and conditions affecting the above mentioned processes. Technologyrelated issues are emphasized.
Sn-Substituted LaNi5 Alloys For Metal Hydride Electrodes
Authors: Wasz Margot L. , Schwarz Ricardo B. , Srinivasan Supramaniam , Sridhar Kumar M. P. 
Published: April 2011

ABSTRACTOur research examines the efficacy of tin additions to LaNi5 in improving the hydrogen storage capacity of the material during charging/discharging. Alloys were prepared using high energy ball milling (mechanical alloying), a technique superior to arc casting for alloying elements with a wide disparity in melting points. Characterization by x-ray diffraction and Rietveld analysis shows that tin preferentially occupies the Ni(3g) sites in the LaNi5 structure, and the unit cell volume increases linearly with tin content to the maximum tin solubility of 7.33 atomic percent (LaNi4.56Sn0.44). We found that powders prepared by mechanical alloying and not exposed to air require no activation to induce hydrogen absorption. The hydrogen storage capacity in the gas and electrochemical phase was measured as a function of tin content. We found that with increasing tin, the plateau pressure decreases logarithmically, whereas the hydrogen storage capacity decreases linearly.
The Effect of Ru on Unsupported Pt-Ru Alloys for Methanol Electro-Oxidation at Different Temperatures
Authors: Chu Deryn , Walker Charles , Gilman Sol 
Published: April 2011

ABSTRACTUnsupported different atomic ratios of platinum-ruthenium bulk alloys were prepared. The alloys were characterized by cyclic voltammetry, X-ray diffraction and energy dispersive X-ray spectroscopy. These alloys were also tested as anodes for methanol electro-oxidation in sulfuric acid over a range of temperatures. Ruthenium is inactive for methanol electro-oxidation at 25 °C, but becomes active at higher temperatures. When a comparison is made on the basis of “true” (hydrogen adsorption) surface area, a 30 atomic percent Ru electrocatalyst provides the highest activity for methanol electro-oxidation as measured at either 0.4 or 0.5V vs. RHE at both 25 and 60 °C.
Carbonaceous Materials Containing Silicon as Anodes for Lithium-Ion Cells
Authors: Wilsons A.M. , Dahn J.R. , Xue J.S. , Gao Y. , Feng X.H. 
Published: April 2011

ABSTRACTGraphite and pregraphitic carbons capable of reversibly reacting with lithium ions are hosts commonly used in Li-ion cells. As a continuation of previous work, we have used chemical vapour deposition of benzene and silicon-containing precursors to prepare carbons containing nanodispersed silicon. The silicon resides within the unorganized regions in the pregraphitic carbons. These materials reversibly react with lithium in electrochemical cells and the reversible specific capacity has been known to increase from -300 mAhg−1, in the absence of silicon, to near 500 mAhg−1 as silicon is added. We also report on Si-O-C materials which have been shown to reversibly react with Li in electrochemical cells with reversible specific capacities as high as 770mAhg−1. These materials have been made by thermal pyrolysis of siloxane polymers and epoxy-silane composites prepared from hardened mixtures of epoxy novolac resin and epoxy-functional silane. These materials all show promise for use as anode materials in advanced rechargeable lithium batteries.
Electrochemical Behavior of Carbon Aerogels Derived From Different Precursors
Authors: Pekala R.W. , Alviso C.T. , Nielsen J.K. , Tran T.D. , Reynolds G.A.M. , Dresselhaus M.S. 
Published: April 2011

ABSTRACTThe ability to tailor the structure and properties of porous carbons has led to their increased use as electrodes in energy storage devices. Our research focuses on the synthesis and characterization of carbon aerogels for use in electrochemical double layer capacitors. Carbon aerogels are formed from the sol-gel polymerization of (1) resorcinol-formaldehyde or (2) phenolic-furfural, followed by supercritical drying from carbon dioxide, and subsequent pyrolysis in an inert atmosphere. These materials can be produced as monoliths, composites, thin films, powders, or microspheres. In all cases, the aerogels have an open-cell structure with an ultrafine pore size (<100 nm), high surface area (400-1100 m2/g), and a solid matrix composed of interconnected particles, fibers, or platelets with characteristic dimensions of 10 nm. This paper examines the effects of the carbon precursor and processing conditions on electrochemical performance in aqueous and organic electrolytes.
Transient Behavior of Ultracapacitors and Supercapacitors
Authors: Huggins Robert A. 
Published: April 2011

ABSTRACTSeveral different mechanisms can be used to provide short term high power pulses from electrochemical systems. Their fundamental characteristics and applicability to the different types of transient output requirements will be discussed. When significant amounts of energy must be delivered, the most favorable materials operate by means of insertion reactions. The methods that can be employed to quantitatively evaluate the critical materials parameters will be described. Spreadsheet techniques are especially useful for modelling the transient transport behavior of components containing such materials under various boundary conditions. LaPlace transform methods can then be used to convert information about the parameters of individual components into the dynamic response of the total system.
Ionic Conductivity in Laco1-XMgX03-δ: A Potential Cathode Material for Solid Oxide Fuel Cells
Authors: Yu Anbin , Haile Sossina M. 
Published: April 2011

ABSTRACTA serious concern with present designs of solid oxide fuel cells is the requirement that “triple-point junctions” exist, sites at which the cathode, electrolyte and oxidizing gas are in simultaneous contact. Only at these junctions can the cathode catalyze the reduction of oxygen into 0= ions and initiate their subsequent transport through the electrolyte. Enhanced ionic conductivity in the cathode material may increase the surface area over which reduction can take place and relax the triple-point constraint. To this end, we have examined the electrical and structural properties of LaCo1-xMgx03-δ materials under various atmospheres. Oxygen ion transport in this and related ABO3 perovskites takes place via oxygen vacancy migration. We have opted to investigate the effect of Mg doping on the transition metal site in an effort to maintain a significant oxygen vacancy concentration in oxidizing atmospheres (as would be encountered during fuel cell operation) and to isolate the effects of A- and B-site doping.
A Basic Thin Film Study of Spinel Limn204As a Possible Cathode Material for Lithium Secondary Cells
Authors: Miura Takashi , Kishi Tomiya 
Published: April 2011

ABSTRACTIn a series of fundamental studies on the cathode active materials for a lithium secondary cell using geometrically well-defined sample electrodes, thin films of spinel LiMn204on a platinum plate were investigated in this work in an LiCl04/propylene carbonate solution. These pyrolytically prepared films exihibit reversible extraction/insertion behavior for lithium under galvanostatic charge/discharge cycling between 4.3-3.5 V. The chemical diffusion coefficient of lithium in LixMn204determined by the galvanostatic intermittent titration technique (GITT) was in the order of 10−7-10−10cm2- s−1within a spinel single-phase region of 0.6<x<1.0 and increased with increasingx.
Gas Diffusion-Type Oxygen Electrode Using Perovskite-Type Oxides for Metal-Air Batteries
Authors: Hyodo Takeo , Miura Norio , Yamazoe Noboru 
Published: April 2011

ABSTRACTIn order to develop an air cathode of metal-air batteries, oxygen reduction behavior of gas diffusion-type carbon electrodes loaded with perovskite-type oxides, Lai-xA'xFe03(A'=Ca, Sr, Ba, 0<x<1.0), was examined in 8 M KOH at 60 °C. Among the oxide catalysts tested, La0.5Sr0.5Fe03(specific surface area : 21.5 m2.g−1) gave the highest electrode performance. On the basis of electrode reaction kinetics, H2O2decomposition rates, and temperature programed desorption of oxygen, it was concluded that such a performance was attributable to the active sites of the oxide for the direct 4-electron reduction of oxygen. Moreover, the electrode using Lao.5Sro.5FeO3was found to be rather stable in a short-term operation for 90 h at 300 mA-cm−2.
In sito Ion Beam Analysis of Radiation Damage Kinetics in MgTiO3 Single Crystals at 170-470 K
Authors: Yu Ning , Mitchell Jeremy N. , Sickafus Kurt E. , Nastasi Michael 
Published: April 2011

AbstractRadiation damage kinetics in synthetic MgTiO3 (geikielite) single crystals have been studied using the in situ ion beam facility at Los Alamos National Laboratory. The geikielite samples were irradiated at temperatures of 170, 300, and 470 K with 400 keV xenon ions and the radiation damage was sequentially measured with Rutherford backscattering using a 2 MeV He ion beam along a channeling direction. Threshold doses of 1 and 5×1015 Xe/cm2 were determined for the crystalline-to-amorphous transformation induced by Xe ion irradiation at 170 and 300 K, respectively. However, geikielite retained its crystallinity up to a dose of 2.5x1016 Xe/cm2 at the irradiation temperature of 470 K. This study has shown that MgTiO3, which has a corundum derivative structure, is another radiation resistant material that has the potential for use in radiation environments.
Effect of Cascade Remnants on Freely Migrating Defects in Cu -1 % Au Alloys
Authors: Iwase A. , Rehn L. E. , Baldo P. M. , Funk L. 
Published: April 2011

AbstractThe effects of cascade remnants on Freely Migrating Defects (FMD) were studied by measuring Radiation-Induced Segregation (RIS) in Cu-l%Au at 400°C during simultaneous irradiation with 1.5-MeV He and (400-800)-keV heavy ions (Ne, Ar or Cu). The large RIS observed during 1.5-MeV He-only irradiation was dramatically suppressed under simultaneous heavy ion irradiation. For Cu simultaneous irradiation, the suppression disappeared immediately after the Cu irradiation ceased, while for simultaneous inert gas (Ne or Ar) irradiation, the suppression persisted after the ion beam was turned off. These results demonstrate that the displacement cascades created by heavy ions introduce additional annihilation sites, which reduce the steady-state FMD concentrations. As the cascade remnants produced by Cu ions are thermally unstable at 400°C, the RIS suppression occurs only during simultaneous irradiation. On the other hand, the inert gas atoms which accumulate in the specimen apparently stabilize the cascade remnants, allowing the suppression to persist.
Effects of ion beam irradiation on the crystallization of Copper films
Authors: Hishita Shunichi , Oyoshi Keiji , Suehara Shigeru , Aizawa Takashi 
Published: April 2011

AbstractRadiation effects of 2 MeV Ar+ ions on the crystallization of copper films were investigated with or without oxygen adsorption. Metal copper films of 1-5 nm thickness deposited on SrTiO3 (100) at 300K. by evaporation consisted of fine crystals with random orientation. The crystals were grown without epitaxial relationship to the substrate by ion irradiation. The epitaxial growth of copper crystals was achieved by the combined use of oxygen adsorption and ion irradiation. The epitaxial relationship between the film and the substrate was determined Cu (100) // SrTiO3( 100) and Cu [001] // SrTiO3 [001].
Ion Induced Damage and their Annealing in LiTaO3 Single Crystal
Authors: Zhang Z , Rusakova I.A. , Chu W.K. 
Published: April 2011

AbstractLiTaO3 single crystals have been implanted with 100 keV oxygen ions at room temperature with doses of 1×1014 /cm2,6xl014/cm2,1.2x1015/cm2, 6xl015/cm2, and 2xl016/cm2. Annealing temperatures ranged from 550 °C to 1075 °C. RBS-channeling and TEM were used for characterization. For partially damaged samples, complete recovery of the crystalline structure was achieved after annealing at 550 °C, which is below the Curie temperature. For totally amorphized samples, thermal annealing induced multidomain growth. These domains extend beyond the original amorphous/crystal interface deep into bulk (1 – 1.5 μm ).