bluuebunny/crossref_metadata_2025_split huggingface dataset:
New 915 MHz Low Power Generator for Materials Testing Utilizing an Evanescent Mode Cavity
Authors: Buffler Charles R. , Risman Per O. 
Published: April 2011

AbstractThe economy of utilizing 915 MHz vs. 2450 MHz microwave equipment has long been acknowledged for many industrial processes. A severe roadblock to advancing 915 MHz processing has been the lack of proper equipment to run test trials. At 2450 MHz low power equipment is readily available and inexpensive, even resorting to the use of the consumer microwave ovens. At 915 MHz, however, prototyping systems have only been available using very expensive 5 kW magnetrons. Experimenters have been forced to use 2450 MHz low power equipment to explore scale-up potential for high power 915 MHz systems. Because of wavelength and dielectric property differences, this procedure may give highly erroneous results, sometimes leading to the purchase of production equipment which does not work.This paper describes an inexpensive, low power, microwave system for prototype testing at 915 MHz. A 600 watt generator is coupled to a specially designed evanescent mode applicator/cavity for the trial testing prior to making a scale-up decision. A description of the generator and evanescent cavity design are presented.
Microwave Firing At 915 MHz - Efficiency and Implications
Authors: Evans N. G. , Hamlyn M. G. 
Published: April 2011

AbstractThe conversion efficiency of electrical to microwave power by magnetrons operating at 896 / 915 MHz is significantly greater than that of magnetrons operating at 2.45 GHz. The increased efficiency at this frequency improves the prospects of microwave firing being adopted as a commercially viable process but the change in frequency alters the microwave-material interactions that take place.This paper discusses the influence and implications of using 896 / 915 MHz for firing ceramics and compares dielectric property data at both frequencies. The results suggest that using the lower frequency will result in more efficient heating.
Microwave Skin Effect in Noncontact Photoconductivity Decay Measurements in Si Wafers
Authors: Ogita Y. , Takahashi S. 
Published: April 2011

AbstractA formula to calculate the photoconductivity decay curve influenced by the microwave distribution within a silicon wafer has been derived analytically. The difference of photoconductivity decay curves measured at 500 MHz and 10 GHz has been explained by the skin effect and by the comparing the experimental curves to those estimated by the analytical formula. The wafer resistivity and wafer thickness dependent photoconductivity decay curves calculated based on the skin effect have been demonstrated. The results have led to the conclusion that 10 GHz microwave probe scarcely influences on the photoconductivity decay for the silicon wafer with the resistivity >10 Ωcm and a wafer thickness <0.7 mm. For the wafer with a resistivity<10 Ωcm and a wafer thickness>0.7 mm, the photoconductivity decay curve is influenced by the skin effect at 10 GHz. However, the apparent lifetime (or effective lifetime) obtained from the gradient of the tail decay is out of the influence by the microwave skin effect.
Effect of Argon Ion Bombardment on the Stability of Narrow Cobalt Silicide/Polysilicon Structure
Authors: Maa Jer-Shen , Peng Chien-Hsiung 
Published: April 2011

AbstractThe stability of cobalt silicide formed on narrow polysilicon line degraded rapidly with shrinkage of linewidth as shown by the increase of sheet resistance after annealing. Stability was improved by adding a titanium interlayer under cobalt with or without a Ti or TiN cap layer. The stability was affected by silicide thickness and substrate doping. In best cases an increase of sheet resistance after annealing was still observed. Adding an Ar ion bombardment step improved the thermal stability drastically. This structure did not show any sheet resistance change after a 30 min annealing at 850°C, either with or without interlayer or cap layer.
Modeling of Extended Defects in Silicon
Authors: Law M. E. , Jones K. S. , Earles S. K. , Lilak A. D. , Xu J- W. 
Published: April 2011

AbstractTransient Enhanced Diffusion (TED) is one of the biggest modeling challenges present in predicting scaled technologies. Damage from implantation of dopant ions changes the diffusivities of the dopants and precipitates to form complex extended defects. Developing a quantitative model for the extended defect behavior during short time, low temperature anneals is a key to explaining TED. This paper reviews some of the modeling developments over the last several years, and discusses some of the challenges that remain to be addressed. Two examples of models compared to experimental work are presented and discussed.
The Effect of Temperature on Defect Production by Displacement Cascades in alpha;-IRON
Authors: Gao F. , Bacon D. J. , Flewitt P. E. J. , Lewis T. A. 
Published: April 2011

AbstractMolecular dynamics (MD) simulations have been used to study the number and arrangement of defects produced by displacement cascades as functions of irradiation temperature, Tirr, in α-iron. The continuum treatment of heat conduction was used to adjust the temperature of the MD boundary atoms throughout the cascade process. This new hybrid model has been applied to cascades of either 2 or 5 keV at 100K, 400K, 600K and 900K. The number of Frenkel pairs decreases by about 20–30% as Tir increases from 100K to 900K, due to the increase in the lifetime of the thermal-spike phase. The same effect also brings about an increase in the proportion of selfinterstitial atoms that form clusters.
Transmission Electron Microscopy Study In-Situ of Radiation-Induced Defects in Copper at Elevated Temperatures
Authors: Daulton T. L. , Kirk M. A. , Rehn L. E. 
Published: April 2011

AbstractNeutrons and high-energy ions incident upon a solid can initiate a displacement collision cascade of lattice atoms resulting in localized regions within the solid containing a high concentration of interstitial and vacancy point defects. These point defects can collapse into various types of dislocation loops and stacking fault tetrahedra (SFT) large enough that their lattice strain fields are visible under diffraction-contrast imaging using a Transmission Electron Microscope (TEM). The basic mechanisms driving the collapse of point defects produced in collision cascades is investigated in situ with TEM for fcc-Cu irradiated with heavy (100 keV Kr) ions at elevated temperature. The isothermal stability of these clusters is also examined in situ.Areal defect yields were observed to decrease abruptly for temperatures greater than 300°C. This decrease in defect yield is attributed to a proportional decrease in the probability of collapse of point defects into clusters. The evolution of the defect density under isothermal conditions appears to be influenced by three different rate processes active in the decline of the total defect density. These rate constants can be attributed to differences in the stability of various types of defect clusters and to different loss mechanisms. Based upon observed stabilities, estimations for the average binding enthalpies of vacancies to SFT are calculated for copper.
High Resolution Transmission Electron Microscopy of Defect Clusters in Aluminum During Electron and Ion Irradiation at Room Temperature
Authors: Furuya Kazuo , Piao Min , Ishikawa Nobuhiro , Saito Tetsuya 
Published: April 2011

AbstractDefect clusters in Al during electron and ion irradiation have been investigated using highresolution transmission electron microscopy (HRTEM). An ION/HVEM system which consists of a high-voltage TEM and ion implanters was used for in-situ observation of damage evolution under 1000 keV electrons and 15 keV He+ irradiation at room temperature. HRTEM of Al in [110] orientation showed many planar defects along { 111 } planes during electron irradiation, while a high density of small polyhedron-shaped cavities (He-bubbles) was observed in addition to the planar defects after He+ irradiation. Multi-slice image simulation of various models of dislocation loops indicated the planar defect as an interstitial-type Frank loop.
Computer Simulation of the Migration Of Self-Interstitial Atoms in Alpha-Zirconium
Authors: Whiting B. J. , Bacon D. J. 
Published: April 2011

AbstractThe migration of single interstitials and small interstitial clusters in ox-zirconium at different temperatures has been analysed using a molecular dynamics model with a many-body interatomic potential. The migration exhibits a strong anisotropy. The defects are very mobile (with Em = 0. 01 eV) along <1120> directions in the basal plane, and this motion is dominant for the single interstitial at low temperature and the di- and tri-interstitials at all temperatures. Above about 500 K, the single interstitial exhibits 2-D and 3-D motion, but Em for non-basal motion is about 0.133 eV. These results point to important consequences for the behaviour of defects formed by displacement cascades in irradiated zirconium.
Mixing of Al Into Uranium Silicides Reactor Fuels
Authors: Ding Fu-Rong , Birtcher R. C. , Kestel B. J. , Baldo P. M. 
Published: April 2011

AbstractSEM observations have shown that irradiation induced interaction of the aluminum cladding with uranium silicide reactor fuels strongly affects both fission gas and fuel swelling behaviors during fuel burn-up. We have used ion beam mixing, by 1.5 MeV Kr, to study this phenomena. RBS and the 27 A1( p, γ) 28 Si resonance nuclear reaction to was used to measure radiation induced mixing of Al into U3Si and U3Si2 after irradiation at 300γ;C.Initially U mixes into the Al layer and Al mixes into the U3 Si. At a low doses, the Al layer is converted into Ual4 type compound while near the interface the phase U(Al93 Si. 07 )3 grows. Under irradiation, Al diffuses out of the Ual4 surface layer, and the lower density ternary, which is stable under irradiation, is the final product. Al mixing into U3 Si2 is slower than in U3 Si, but after high dose irradiation the Al concentration extends much father into the bulk. In both systems Al mixing and diffusion is controlled by phase formation and growth. The Al mixing rates into the two alloys are similar to that of Al into pure uranium where similar aluminide phases are formed.
Modeling Amorphization of Tetrahedral Structures Using Local Approaches
Authors: Jesurum C. Esther , Pulimt Vinay , Berger Bonnie , Hobbst Linn W. 
Published: April 2011

AbstractMany crystalline ceramics can be topologically disordered (amorphized) by disordering radiation events involving high-energy collision cascades or (in some cases) successive single-atom displacements. We are interested in both the potential for disorder and the possible aperiodic structures adopted following the disordering event. The potential for disordering is related to connectivity, and among those structures of interest are tetrahedral networks (such as SiO2, SiC and Si3N4) comprising corner-shared tetrahedral units whose connectivities are easily evaluated. In order to study the response of these networks to radiation, we have chosen to model their assembly according to the (simple) local rules that each corner obeys in connecting to another tetrahedron; in this way we easily erect large computer models of any crystalline polymorphic form. Amorphous structures can be similarly grown by application of altered rules. We have adopted a simple model of irradiation in which all bonds in the neighborhood of a designated tetrahedron are destroyed, and we reform the bonds in this region according to a set of (possibly different) local rules appropriate to the environmental conditions. When a tetrahedron approaches the boundary of this neighborhood, it undergoes an optimization step in which a spring is inserted between two corners of compatible tetrahedra when they are within a certain distance of one another; component forces are then applied that act to minimize the distance between these corners and minimize the deviation from the rules. The resulting structure is then analyzed for the complete adjacency matrix, irreducible ring statistics, and bond angle distributions.
Electron-Irradiation-Induced Crystallization of Amorphous Orthophosphates
Authors: Meldrum A. , Boatner L. A. , Ewing R. C. 
Published: April 2011

AbstractAmorphous LaPO4, EuPO4, GdPO4, ScPO4, LuPO4, and fluorapatite [Ca5(PO4)3F] were irradiated by the electron beam in a transmission electron microscope. Irradiations were performed over a range of temperatures from −150 to 300 °C, electron energies from 80 to 200 keV, and current densities from 0.3 to 16 A/cm2. In all cases, the materials crystallized to form a randomly oriented polycrystalline assemblage. Crystallization is driven dominantly by inelastic processes, although ballistic collisions with the target nuclei can become important at energies higher than 175 keV, particularly in apatite. Using a high current density, crystallization is so fast that continuous lines of crystallites can be “drawn” on the amorphous matrix.
Atomic Sites of Isolated 111In Atoms After Low Energy Deposition on Stepped Cu(100) Surfaces
Authors: Laurens C.R. , Roşu M.F , Pleiter F. , Niesen L. 
Published: April 2011

AbstractWe deposited low-energy 111 atoms on a vicinal Cu(100) surface at 82K, and measured the atomic sites by means of the perturbed angular correlations technique (PAC). The sites of the as-deposited In atoms were determined for deposition energies ranging from 5 to 100 eV. The results are coinpared to Molecular Dynamics simulations of the deposition process.
Simulation of Surface Diffusion Using Embedded Atom Potentials in FCC Metals
Authors: Takano Jun-Ichiro , Doyama Masao , Kogure Yoshiaki 
Published: April 2011

AbstractThe binding energies of gold, silver and copper adatoms and their clusters to each (111) surface have been calculated. The binding energy EN of an N-adatom cluster can be roughly written as EN=3NE1+mE2, where 3E1, is the binding energy of a single adatom to the (111) surface and m is the number of bonds within the cluster and E2 is the binding energy of the bond within the cluster. It was found that E1=0.95eV, E2=0.42–0.49eV for gold, E1=0.62eV, E2=0.38-0.44eV for silver and E1=0.81eV, E2=0.43–0.49eV for copper (by use of a newly determined N-body embedded atom potential). The activation energies of motion of these adatom clusters on each (111) surfaces have been calculated by use of a newly determined N-body embedded atom potential and molecular dynamics method.
The Structure of Antigen-Antibody Layers Adsorbed on Silica Surfaces: a Scanning Angle Reflectometry Study
Authors: Mann E. K. , Heinrich L. , Voegel J. C. , Schaaf P. 
Published: April 2011

AbstractScanning Angle Reflectometry (SAR) is used to investigate the structure of protein layers deposited sequentially, first the antigen and then the antibody, on a silica surface. The reflectivity curves are analyzed by means of the optical invariants, a general description valid in the thin film limit which permits the determination of three and only three structural parameters for a dielectric layer, independent of any model of the layer. The three parameters can be related to the first two moments of the mass density in the layer, or to an average film thickness and density. In addition, a new invariant is constructed which directly yields information about the distribution of mass in the layer, and thus goes beyond the usual uniform layer model.
Processing Temperature Dependence on Surface Morphology and Microstructure of Gold Films
Authors: He L. , Siewenie J. , Shi Z. Q. 
Published: April 2011

AbstractMicrostructure properties, and surface morphology of gold films processed at different temperature were investigated by transmission electron microscopy (TEM) and atomic force microscope (AFM). The film thickness was chosen less than several hundreds angstrong. Previous electrical measurement found that the low temperature (LT=77K) film showed several orders lower resistance compared to the film obtained at room temperature with very thin (about 100Å) thickness. This indicated potential application of these LT films on electronic and optoelectronic devices. TEM study found that the LT films showed much smaller density of grain boundaries than that of the room temperature (RT=300K) samples. In AFM observation, for film thickness of 100Å, LT film showed smoother, and continuous surface while the RT film consisted of discrete islands. When the thickness was increased to 200Å, the LT film showed much larger-sized grains compare to that of the RT film. For LT deposition, 2-dimensional larger-sized grains were first formed at low temperature deposition which later extended to be 3-dimension. The low grain boundary density of the LT film is consistent with its lower resistivity observation.
Studies of Interface and Surface Structures of BaTiO3 Thin Films Grown on SrTiO3 (001) Substrates by Mbe
Authors: Shigetani Hisashi , Kobayashi Kazuyoshi , Fujimoto Masayuki , Sugimura Wataru , Matsui Yoshio , Tanaka Junzo 
Published: April 2011

AbstractWe studied a lattice distortion and relaxation of BaTiO3(BT) thin films grown on SrTiO3 (001) substrates(ST) by a molecular beam epitaxy method using an oxygen radical source RT were prepared by alternately deposition of BaO and TiO2 layers, and the structure of the thin films was evaluated by X-ray diffraction, reflection high energy electron diffraction, transmission electron microscopy, atomic force microscopy, coaxial impact collision ion scattering spectroscopy and X-ray photoelectron spectroscopy The lattice constants of the films varied with distance from the interface of BT and ST It was found that lattice distortion and relaxation of BT On the other hand, the surface analysis indicated that adsorbed oxygen was enriched on the BaO-terminated surface in comparison with the TiO2-terminated surface Then we proposed new mechanism of BT thin film growth with adsorbed oxygen.
Microelectronic Film Thickness Determination Using a Laserbased Ultrasonic Technique
Authors: Logan R. , Maznev A. A. , Nelson K. A. , Rogers J. A. , Fuchs M. , Banetv M. 
Published: April 2011

AbstractA non-contact and non-destructive laser-based acoustic technique called impulsive stimulated thermal scattering (ISTS) is used to measure thicknesses of films in single-layer and multilayer assemblies such as W/Si, Ti/Si, and Ti/SiO2/Si structures. Thicknesses are determined to within a few percent accuracy with a laboratory version of the measurement apparatus, using conventional large-frame lasers and optics, and in a commercial prototype using compact diode-pumped and diode lasers and optics which all fit onto a 1-ft × 2-ft breadboard. ISTS and conventional measurements (profilometry, SEM, and 4-point resistance) are made on the same samples and the results are found to compare favorably.
Structure of Kcn Monolayer Films Vapor-Deposited onto Cleaved KBr(001) by Helium Atom Diffraction
Authors: Safron S. A. , Baker J. R. , Lit J. A. , Akhadov E. A. , Trelenberg T. W. , Skofronick J. G. 
Published: April 2011

AbstractAngular distribution measurements of the helium atom scattering intensity from monolayer films of KCN/KBr(001) for several azimuths over a temperature range of approximately 40–200 K reveal that above ˜95 K the KCN monolayer forms a (1×1) overlayer structure with respect to the KBr substrate. (The lattice spacing of bulk KCN in the rocksalt-structure phase differs from that of KBr by only ˜ 1%.) Below this temperature the overlayer appears to be (2×1), and “missing” diffraction spots in the <110> high symmetry direction suggest the existence of a glide plane. The inferred structure for this low temperature phase consists of K+ ions fixed in their rocksaltstructure positions relative to the substrate and the CN− ions oriented so that their dipoles are aligned antiferroelectrically within the new unit cell.
Surface Structure Determination of C(2×2) N2/Ni(100) and Low and Intermediate Coverages of Co/Cu(111) by Angle-Resolved Photoemission Fine Structure (Arpefs) Using Synchrotron Radiation
Authors: Moler E. J. , Huff W. R. A. , Kellar S. A. , Hussain Z. , Chen Y. F. , Shirley D. A. 
Published: April 2011

AbstractWe have determined the adsorption site and interlayer spacings of c(2×2) N2/Ni(100),(√3 × √3)R30° and (1.5 × 1.5)R18° CO adsorbed on Cu(111), using ARPEFS and a full Multiple-Scattering, Spherical Wave (MSSW) calculation program. The nitrogen molecule stands upright at an atop site, with a N-Ni bond length of 2.25(1) Å, a N-N bond length of 1.10(7) Å, and a first layer Ni-Ni spacing of 1.76(4) Å. The C-Cu bond length is 1.91 (1) Å in the (√3 × √3)R30° phase and 1.91(2) Å in the (1.5 × 1.5)R18° phase. The first layer Cu-Cu spacing is 2.07(3) Å in the (√3 × √3)R30° phase. The first layer Cu-Cu spacing in the (1.5 × 1.5)R18° phase is 2.01(4) Å, a contraction of 3 % from the clean metal value of 2.07 Å.
Development of Si(100) Surface Roughness at the Initial Stage of Etching in F2 and XeF2 Gases - Ellipsometric Study
Authors: Aliev V.S. , Kruchinin V.N. 
Published: April 2011

AbstractThe development of the roughness of the Si (100) surface has been investigated at the initial stage of etching in the molecular flow of F2 and XeF2 gases. It was discovered that roughness grew during etching in XeF2 gas and decreased during etching in F2 gas, that is, F2 gas polishes Si surface unlike XeF2. This difference was explained with the help of ellipsometric study of the kinetics of adsorption layer formation.
Impact of Chemical and Epitaxial Treatment on Surface Defects on Silicon Wafers
Authors: Schmolke R. , Gräf D. , Suhren M. , Kirchner R. , Piontek H. , Wagner P. 
Published: April 2011

AbstractDefects on polished as well as hot SC1 treated silicon wafers were investigated with an Atomic Force Microscope (AFM) and Surface Scanning Inspection Systems (SSIS). Measurement with two SSIS of different type allows to identify most of the surface defects as non particulate scatterers. AFM of these defects reveals tiny pits or groups of pits. An almost linear relation is found between the geometrical lateral defect dimension and their average size in units of LSE (Latex Sphere Equivalent; an effective measure for the scattering cross section) as reported by one of the SSIS for the defects on wafers treated with hot SC1. Growth rates of about 40 nmLSE/h are observed for the defects during subsequent treatments of wafers with hot SC1. The LSE-size distribution of as-grown defects with a peak at about 105 and 110 nmLSE is obtained for two types of wafer by modeling the defect evolution during hot SC1 treatment. The number of surface flaws ≥ 0.12 μmLSE on a substrate is reduced by two orders of magnitude for epitaxial layers as thin as 1.5 μm.
Comparison Of Gettering Ability between I/I Defects And Si Substrate
Authors: Horikawa Mitsuhiro , Kitano Tomohisa 
Published: April 2011

AbstractA Si wafer is contaminated with 1.5 × 1013 Fe/cm3 and the Fe gettering ability of low dose I/I defects is compared with that of a Si substrate with/without a poly-silicon back seal. Polysilicon has higher gettering ability than I/I defects and prevents Fe from gettering at these defects. When there is no poly-silicon and temperature is as low as 700°C, however, I/I defects act as gettering sites for Fe, even if the dose is as low as 2 × 1013 cm−2. Fe gettering by I/I defects leads to a decrease in minority carrier diffusion length. DLTS measurement reveals that Fe getters at I/I defects in the interstitial atom state.