bluuebunny/crossref_metadata_2025_split huggingface dataset:
Texture Analysis of Al and Cu Metallization Materials Using Orientation Imaging Microscopy
Authors: Carpenter D. T. , Alvis R. , Morales G. 
Published: April 2011

AbstractX-ray diffraction (XRD) is generally used to measure crystallographic texture, but complete analysis is rarely performed. Orientation imaging microscopy (OIM) gives similar data by electron diffraction and has potential for widespread use since it may be added to any scanning electron microscope. Analysis software has been developed to reduce QIM results into a form which may be compared directly to XRD results. OIM texture parameters measured from Al films showed good quantitative agreement with XRD parameters, however the texture in Cu films is more complex and difficult to compare. Although subject to certain limitations, OIM has several advantages over XRD including more efficient data collection, better sensitivity to minor texture components, and more flexible data analysis.
Effect of Mo Doping on Formation of Ti-Silicide Phases Studied by HRTEM
Authors: Gribelyuk M. A. , Samavedam S. B. , Kittl J. A. 
Published: April 2011

AbstractThe phase sequence of the RTP induced reaction at T=650°C has been studied. We found that pre-amorphization of poly-Si substrates does not change the reaction path. i.e. Ti5Si4, and C-49 TiSi2 phases were formed_ with the latter growing upon further anneal. In the Mo doped poly-Si/Ti system the C-54 TiSi2 phase has formed along with Ti5Si4 and two Mo silicide phases, MoSi2 and Mo5Si3; no C-49 TiSi2 was observed. We show that the reaction in the Mo doped system follows the template mechanism with MoSi2 and Mo5Si3 based phase acting as template phases for accelerated growth of C-54 TiSi2.
Tem Investigation of Titanium Silicide Thin Films
Authors: Myers A. F. , Steel E. B. , Struck L. M. , Liu H. I. , Burns J. A. 
Published: April 2011

AbstractTitanium silicide films grown on silicon were analyzed by transmission electron microscopy (TEM), electron diffraction, scanning transmission electron microscopy (STEM), and energy dispersive x-ray spectroscopy. The films were prepared by sequential rapid thermal annealing (RTA) at 675 °C and 850 °C of 16-nm-thick sputtered Ti on Si (001) wafers. In some cases, a 20-nm-thick TiN capping layer was deposited on the Ti film before the RTA procedure and was removed after annealing. TEM and STEM analyses showed that the silicide films were less than 0.1 μm thick; the capped film was more uniform, ranging in thickness from ∼ 25 – 45 nm, while the uncapped film ranged in thickness from ∼ 15 – 75 nm. Electron diffraction was used to determine that the capped film contained C54-TiSi2, C49-TiSi2, Ti5Si3, and possibly TiSi, and that the uncapped film contained C49-TiSi2, TiSi, Ti5Si3, unreacted Ti, and possibly C54-TiSi2.
The First Synchrotron Infrared Beamlines at the Advanced Light Source: Microscpectroscopy and Fast Timing
Authors: Martin Michael C. , McKinney Wayne R. 
Published: April 2011

ABSTRACTA set of new infrared (IR) beamlines on the 1.4 bending magnet port at the Advanced Light Source, LBNL, are described. Using a synchrotron as an IR source provides considerable brightness advantages, which manifests itself most beneficially when performing spectroscopy on a microscopic length scale. Beamline (BL) 1.4.3 is a dedicated microspectroscopy beamline, where the much smaller focused spot size using the synchrotron source is utilized. This enables an entirely new set of experiments to be performed where spectroscopy on a truly microscopic scale is now possible. BL 1.4.2 consists of a vacuum FTIR bench with a wide spectral range and step-scan capabilities. The fast timing is demonstrated by observing the synchrotron electron storage pattern at the ALS.
Preliminary Results from a New Spin Spectrometer
Authors: Tobina J. G. , Bedrossiana P. J. , Cumminsb T. R. , Waddillb G. D. , Mishrac S. , Larsond P. , Negrid R. , Millerd M. , Petersond E. , Boyd P. , Gunion R. 
Published: April 2011

ABSTRACTThe first preliminary results from a novel spectrometer for elementally-specific measurements of magnetic surfaces and ultrathin films are presented here. The key measurements are based upon spin-resolving and photon-dichroic photoelectron spectroscopy. True spinresolution is achieved by the use of a Mini-Mott detection scheme. The photon-dichroic measurements include the variant magnetic x-ray linear dichroism (MXLD). Both a multi-channel, energy dispersive collection scheme as well as the spin-detecting Mini-Mott apparatus are used in data collection. The [Spin Spectrometer] is based at the Spectromicroscopy Facility (Beamline7)at the Advanced Light Source.
Evidence for the Photoemission Nature of Gd 4f Resonant Photoemission
Authors: Mishra S. R. , Cummins T. R. , Gammon W. J. , Waddill G. D. , Van der-Laan G. , Goodman K. W. , Tobin J. G. 
Published: April 2011

ABSTRACTThe constructive interference between direct and indirect channels above the absorption threshold of a core level leads to a massive increase in the emission cross section leading to a phenomenon called “resonant photoemission”. Using novel magnetic linear dichroism in angular distribution photoelectron spectroscopy experiment we have tried to understand the nature of the resonant photoemission process in Gd metal. The presence of dichroism in Gd 4f photoemission intensity at a photon energy corresponding to resonant photoemission clearly demonstrates the photoemission-like nature of the resonant photoemission process.
Esca Microscopy on Elettra: Chemical Characterization of Surfaces and Interfaces With Sub-Micron Spatial Resolution
Authors: Kiskinova m. , Casalis L. , Gregoratti L. , Gunther S. , Marsi M. 
Published: April 2011

ABSTRACTThe chemical sensitivity, spatial resolution and data acquisition rates achieved with the scanning photoelectron microscope built at ELETTRA, a third-generation synchrotron facility in Italy has made it an indispensable tool for surface analysis of laterally heterogeneous materials. The information on the composition and evolution of coexisting phases, mass transport and other surface processes occurring on a microscopic scale can be obtained by combining elemental and chemical mapping with core and valence level photoelectron spectromicroscopy with spatial resolution better than 0.15 μm and energy resolution better than 0.5 eV. Selected recent results will be presented to illustrate the capabilities and some of the possible applications of synchrotron radiation spectromicroscopy for characterization of complex spatially heterogeneous materials and studies of dynamic processes related to the interface chemical structure.
State-of-the-Art X-Ray Photoelectron Spectroscopy (XPS): Conventional and Synchrotron X-Ray Sources for Micro-XPS
Authors: Principe E. L. , Odom R. W. , Johnson A. L. , Ackermann G. D. , Hussain Z. , Padmore H. 
Published: April 2011

ABSTRACTThis paper presents preliminary data on analyses of selected materials using two state-ofthe- art XPS systems: the Physical Electronics Inc. (PHI, Eden Prairie, MN) Quantum 2000 instrument and the microXPS beamline (7.3.2.1) at the Advanced Light Source (ALS). This research compares and contrasts relevant performance characteristics of the two systems including elemental and chemical state detection sensitivity, imaging capabilities including lateral resolution and useful image fields, role of X-ray dose damage to surface, analysis speed as well as analytical throughput.
Update On Synchrotron Radiation TXRF: New Results
Authors: Brennan S. , Pianetta P. , Ghosh S. , Takaura N. , Wiemer C. , Fischer-Colbrie A. , Laderman S. , Shimazaki A. , Waldhauer A. , Zaitz M. A. 
Published: April 2011

ABSTRACTSynchrotron-based total-reflection x-ray fluorescence(SR-TXRF) has been developed as a leading technique for measuring wafer cleanliness. It holds advantages over other techniques in that it is non-destructive and allows mapping of the surface. The highest sensitivity observed thus far is 3x108 atoms/cm 2 (- 3fg) for 1000 second count time. Several applications of SR-TXRF are presented which take advantage of the energy tunability of the synchrotron source or the mapping capability.
High-Resolution X-Ray Photoemission Electron Microscopy at the Advanced Light Source
Authors: Stammler Thomas , Anders Simone , Padmore Howard A. , Stöhr Joachim , Scheinfein Michael , Ade Harald 
Published: April 2011

ABSTRACTX-ray Photoemission Electron Microscopy (X-PEEM) is a full-field imaging technique where the sample is illuminated by an x-ray beam and the photoemitted electrons are imaged on a screen by means of an electron optics. It therefore combines two well-established materials analysis techniques - photoemission electron microscopy (PEEM) and x-ray spectroscopy such as near edge x-ray absorption fine structure (NEXAFS) spectroscopy. This combination opens a wide field of new applications in materials research and has proven to be a powerful tool to investigate simultaneously topological, elemental, chemical state, and magnetic properties of surfaces, thin films, and multilayers at high spatial resolution. A new X-PEEM installed at the bend magnet beamline 7.3.1.1 at the Advanced Light Source (ALS) is designed for a spatial resolution of 20 nm and is currently under commissioning. An overview of the ongoing experimental program using X-PEEM in the field of materials research at the ALS is given by elemental and chemical bonding contrast imaging of hard disk coatings and sliders, field emission studies on diamond films as possible candidates for field-emission flat-panel displays, and the study of dewetting and decomposition phenomena of thin polymer blends and bilayers.
Anomalous X-Ray Scattering Studies of Short-, Intermediate- and Extended-Range Order in Glasses
Authors: Price David L. , Saboungi Marie-Louise , Armand Pascale , Cox David E. 
Published: April 2011

ABSTRACTWe present the formalism of anomalous x-ray scattering as applied to partial structure analysis of disordered materials, and give an example of how the technique has been applied, together with that of neutron diffraction, to investigate short-, intermediate- and extended-range order in vitreous germania and rubidium germanate.
X-Ray Absorption Fine Structure (Xafs) Studies Of Cobalt Silicide Thin Films
Authors: Naftel S. J. , Coulthard I , Hu Y. , Sham T. K. , Zinke-Allmang M. 
Published: April 2011

ABSTRACTCobalt silicide thin films, prepared on Si(100) wafers, have been studied by X-ray absorption near edge structures (XANES) at the Si K-, L2,3 and Co K-edges utilizing both total electron (TEY) and fluorescence yield (FLY) detection as well as extended X-ray absorption fine structure (EXAFS) at the Co K-edge. Samples made using DC sputter deposition on clean Si surfaces and MBE were studied along with a bulk CoSi2 sample. XANES and EXAFS provide information about the electronic structure and morphology of the films. It was found that the films studied have essentially the same structure as bulk CoSi2. Both the spectroscopy and materials characterization aspects of XAFS (X-ray absorption fine structures) are discussed.
Interfacial Electronic Charge Transfer and Density of States in Short Period Cu/Cr Multilayers
Authors: Bello A. F. , Buuren T. Van , Klepeis J. E. , Barbee T. W. 
Published: April 2011

ABSTRACTNanometer period metallic multilayers are ideal structures to investigate electronic phenomena at interfaces between metal films since interfacial atoms comprise a large atomic fraction of the samples. The multilayers studied were fabricated by magnetron sputtering and consist of bilayers from 1.9 nm to 3.3 nm. X-ray diffraction, cross-section TEM and plan-view TEM show the Cu layers to have a BCC structure Cu in contrast to its equilibrium FCC structure. The electronic structure of the Cu and the Cr layers in several samples of thin Cu/Cr multilayers were studied using x-ray absorption spectroscopy (XAS). Total electron yield was measured and used to study the white lines at the Cu L2 and L3 absorption edges. The white lines at the Cu absorption edges are strongly related to the unoccupied d-orbitals and are used to calculate the amount of charge transfer between the Cr and Cu atoms in interfaces. Analysis of the Cu white lines show a charge transfer of 0.026 electrons/interfacial Cu atom to the interfacial Cr atoms. In the Cu XAS spectra we also observe a van Hove singularity between the L2 and L3 absorption edges as expected from the structural analysis. The absorption spectra are compared to partial density of states obtained from a full-potential linear muffin-tin orbital calculation. The calculations confirm the presence of charge transfer and indicate that it is localized to the first two interfacial layers in both Cu and Cr.
Synchrotron X-ray Absorption Spectroscopy Studies of Pt/Si Systems
Authors: Coulthard I. , Naftel S. J. , Shama T. K. 
Published: April 2011

ABSTRACTPlatinum was deposited onto porous silicon by a reductive deposition technique utilizing the inherent reducing power of porous silicon. The resulting deposits were studied by X-ray Absorption Near Edge Structure (XANES) at the Si-K, Pt-M3, 2, and Pt-L 3 ,2 edges. Samples of varying deposition concentrations were studied and were compared with untreated porous silicon and platinum silicides to determine the nature of the deposits and their effect upon the porous silicon substrate itself.
Exafs characterisation of amorphous GaAs
Authors: Ridgway M. C. , Glover C. J. , Foran G. J. , Yu K. M. 
Published: April 2011

ABSTRACTThe structural parameters of stoichiometric, amorphous GaAs have been determined with extended x-ray absorption fine structure (EXAFS) measurements performed in transmission mode at 10K. Amorphous GaAs samples were fabricated with a combination of epitaxial growth, ion implantation and selective chemical etching. Relative to a crystalline sample, the nearest-neighbor bond length and Debye-Waller factor both increased for amorphous material. In contrast, the coordination numbers about both Ga and As atoms in the amorphous phase decreased to ˜3.85 atoms from the crystalline value of four. All structural parameters were independent of implantation conditions and as a consequence, were considered representative of intrinsic, amorphous GaAs as opposed to an implantation-induced extrinsic structure.
Real time In Situ X-Ray Topographic Observation of Deformation of Single Crystals and Thin Films
Authors: Zhao Z. B. , Hershberger J. , Chiaramonti A. , Rek Z. U. , Bilello J. C. 
Published: April 2011

ABSTRACTAn experimental apparatus, which is capable of performing real time in situ X-ray topographic observation of deformation process via synchrotron white beam topography, has been developed. This device enables both tensile data (load-displacement) and topographic images to be recorded simultaneously. It has been utilized to study the deformation behaviors of crystals of Mo and W.These specimens have been subject to mechanical cycling with increasing load, and their deformation processes have been observed in real time and in situ via x-ray topography. This leads to the observation of several phenomena, which would have been difficult to reveal by other experimental techniques. They include stress concentration, microyielding, reversible variation of contrasts and stress relaxation. In addition, the deformation behaviors of small angle grain boundaries have also been examined. Furthermore, the specimens can be heated through a heating device attached to the tensile stage, which allows high temperature topography to be performed in real time. The technique has been applied to the Ta films on Si (100) substrates. With increasing temperature, the topographic observations have revealed that the Ta films yield, fracture and then proceed to delaminate from their substrates.
Rapid Prototype Fabrication of Smooth Microreactor Channel Systems in PMMA by VUV Laser Ablation at 157 NM for Applications in Genome Analysis and Biotechnology
Authors: Lapczyna Markus , Stuke Michael 
Published: April 2011

AbstractA rapid prototyping method for the fabrication of microstructures in polymer substrates has been developed, using a combination of laser direct-write patterning of silicon membrane contact masks and vacuum-ultraviolet (VUV) pulsed laser ablation. The process allows the flexible and rapid prototyping of microreactors and microchannel systems with submicrometer resolution. Thanks to the high photon energy of the VUV (7.9 eV) irradiation, PMMA and also other polymers can be ablated without leaving behind carbonated and/or fluorescent surfaces. Fluences of ≅ 100 mJ/cm2 lead to etch rates of ≅ 140 nm/pulse and result in very smooth surfaces with a roughness in the nanometer range on a micrometer lateral scale. The structured substrates are sealed with a PMMA foil by means of a newly developed low temperature technique without adhesives.
Heat Flow Modelling of the Laser Drilling Process as Applied to Unidirectional Carbon Fibre Composites
Authors: Cheng C.F. , Tsui Y.C. , Clyne T.W. 
Published: April 2011

AbstractLaser drilling has been carried out with a pulsed Nd:YAG laser. The laser has been applied to the drilling of APC-2 (PEEK-61%C fibre), with specimens up to 1 mm in thickness and using both moving and stationary beams. Hole shapes and heat-affected zone (HAZ) microstructures were studied using SEM, optical microscopy of polished sections and optical interferometric surface profilometry. Two prominent microstructural features were noted in the HAZ of the composite. These were (a) swelling of the ends of the carbon fibres (from about 8 microns to about 12 microns in diameter) and (b) an extensive zone around the hole in which the matrix had clearly undergone melting and some flow. The fibre swelling was such that neighbouring fibres were brought into close contact. The degree of swelling was found to remain constant as the laser pulse energy was increased, although the morphology of the fibre ends became more wrinkled and porous. The phenomenon is thought to be caused by internal gas pressure generation and distortion of the turbostratic structure within the fibre.A heat flow model has been developed to simulate the drilling process, based on an explicit finite difference formulation and a Cartesian (3-D) mesh. The post-iterative heat accumulation method was used to simulate the effect of latent heat absorption. The explicit approach was found superior to implicit schemes, which tend to exhibit poor stability when handling the phase change algorithm in regions of extremely high thermal gradient. The total solution time was kept within reasonable limits by using a graded mesh, which was fine only in the regions close to the beam axis. Comparisons between predicted and observed hole dimensions showed good agreement over a range of conditions, including variations in beam energy and beam motion. This suggests that effects omitted from the model, such as melt ejection, were not playing a significant role.
Switching Kinetics of Pulsed Laser Deposited Epitaxial PZT Films
Authors: Yamazato M. , Grishin A. M. , Yamagata Y. , Ikegami T. , Ebihara K. 
Published: April 2011

AbstractWe have fabricated epitaxial PbZr0.52Ti0.48O3 (PZT, 40~1200 nm)/YBa2Cu3O7-x (YBCO, 400 nm) film ferroelectric/superconductor heterostructures on the single-crystal neodymium doped yttrium monoaluminate [YAlO3+1%Nd2O3] and MgO substrates by KrF pulsed laser deposition technique. The dielectric constant of 950 and loss tangent δ of 0.04 have been found to be frequency independent in the range 100 Hz to 100 kHz while electric resistivity ρ (150 kV/cm) is of 6×1011 Ω·cm, remnant polarization and coercive field are 32 μC/cm2 and 43 kV/cm, respectively. Fast ferroelectric switching kinetics with characteristic switching time around 50 ns has been observed. Universal electric field and temperature dependencies of switching time as well as film thickness dependence of coercive electric field have been observed and correspond to ferroelectric needle-like domain switching.
A New p-Type Conductive Oxide with Wide Band GAP, SrCu2O2
Authors: Kudo A. , Yanagi H. , Hosono H. , Kawazoe H. 
Published: April 2011

AbstractSrCu2O2 thin films were prepared onto SiO2 glass substrates by pulsed laser deposition. The film deposited in O2 atmosphere of 7×10-4 Pa at 573 K showed high optical transmission in visible and near infrared regions. The optical band gap of the film was estimated to be -3.3 eV. The dc electrical conductivity of the film was 3.8 × 10-3 Scm-1. Potassium was used for substitutional hole-doping. The dc electrical conductivity of the K-doped film at 300 K increased to 4.8 × 10-2 Scm-1. Positive sign of Seebeck and Hall coefficients demonstrated p-type conduction of the K-doped film. Hole concentration and mobility at 300 K were 6.1 × 1017 cm-3 and 0.46 cm2V-1s-1, respectively.
Growth of High Quality Single Crystal ZnO Films on Sapphire by Pulsed Laser Ablation
Authors: Sharma A.K. , Dovidenko K. , Oktyabrsky S. , Moxey D.E. , Muth J.F. , Kolbas R.M. , Narayan J. 
Published: April 2011

AbstractThe structural and optical characterizations of single crystal zinc oxide films on sapphire have been performed. The ZnO films were deposited by pulsed laser deposition in an oxygen environment. These films were annealed in oxygen for further improvement in the oxygen stoichiometry. Both as-deposited and oxygen annealed films were high quality single crystal as characterized by X-ray diffraction and transmission electron microscopy. The defect density, comprised mainly of dislocations and stacking faults, was low as compared to high quality films of III-nitrides deposited on sapphire. Under these growth conditions, the ZnO films grow two dimensionally on sapphire as opposed to GaN which grows three dimensionally. The band edge photoluminescence was found to be dominant, and an order of magnitude higher in the annealed films. Transmission measurements and the electrical resistivity of the annealed films also show the films were of high quality after annealing. It is envisaged that these improvements in the quality of the ZnO films occur as a result of reduction of oxygen vacancies and the density of point defects.
Tem Characterization of ZnO and AIN/ZnO Thin Films Grown on Sapphire
Authors: Dovidenko K. , Oktyabrsky S. , Sharma A. K. , Narayan J. 
Published: April 2011

AbstractThin (~ 250 nm) films of ZnO grown by pulsed laser deposition on basal plane of sapphire were studied by transmission electron microscopy (TEM). Plan-view TEM study proved the films to be single crystal with the following epitaxial relationship with the substrate: (0001)znO || (0001)sap with the 30 30° in-plane rotation - [0110]ZnO || [1210]sap. Dislocations lying mostly in basal plane of ZnO and aligned along both <:1010> and <1120> directions having b=1/3[1120] were found. ZnO films were found to have layered growth morphology contrary to columnar morphology of III-nitrides. Consequently, the threading dislocation density in ZnO films (opposing to the AIN and GaN) drops very fast with the thickness: down to 107cm-2 at ~ 250 nm. The effect of post-annealing (which caused significant improvement in electrical and optical properties) on the microstructure of ZnO films was also studied. Contrary to the atomically sharp and clean interface in the as-deposited films, the post-annealed ZnO/sapphire interface contained reacted layer of 30 - 60 A thickness. The structure of the interlayer was determined to be ZnAl2O4 (spinel). The formation of this single crystal spinel layer did not cause deterioration of the ZnO film structure or properties. We have also explored the possibilities of using ZnO as a buffer for III-nitride growth. The epitaxial AIN films were grown on top of the ZnO layer by pulsed laser deposition. Thin (20 -60 A) interfacial reaction layer (also spinel ZnAm2O4) was observed between AIN and ZnO. Formation of this interlayer is studied in conjunction with the AIN epitaxy and the characteristics of defects and interfaces.