bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrodeposited Gold: Real Time Stress And Structural Change At Room Temperature.
Authors: Acosta R. E. , Babich I. , Blauner P. , Wagner A. 
Published: March 2011

AbstractIn this work the stress and grain structure of electrodeposited gold films was determined as a function of time from deposition, with measurements being conducted in time intervals of minutes to days after deposition.A test structure that allows accurate and unambiguous measurement of out of plane distortion (OPD) was developed. Using this structure the time evolution of the stress of the films was followed using an interferometric microscope. Scanning ion microscopy was used to determine the time evolution of the grain structure of the samples. This technique, based on focused ion beam imaging, allows determination of grain structure of thin films without special sample preparation or restrictions in film thickness.The sign, magnitude, and stability of the stress at room temperature was found to be a function of the rate of deposition and the concentration of additive in the electrodeposition solution.For some of the films studied, grain growth from the hundreds of Angstroms to tens of microns was found to occur in a matter of minutes at room temperature.
Materials Issues In X-Ray Lithography
Authors: Dobisz E.A. , Peckerar M. C. , Chut W. , Rheet K. , Shirey L. S. , Marrian C. R. K. , Salvino R. E. , Foster K. , Kosokowski J. 
Published: March 2011

AbstractIn this paper, an outline of materials-related activities in the national X-Ray Lithography Program is given. The program is directed towards the development of sub-quarter micron design-rule x-ray lithography together with the ancillary technologies required to fabricate defect-free x-ray masks. Work done at the Naval Research Laboratory is highlighted and used for examples. Most materials related work occurs in conjunction in the x-ray mask fabrication pro. cess. Topics discussed include electron beam-matter interaction in the mask patterning process, membane fabrication, stress control in thin membranes, reactive-ion etching of absorber-layers, mask inspection and repair.
The Design And Performance Characteristics Of X-Ray Sensitive Resists
Authors: Novembre Anthony E. 
Published: March 2011

AbstractThe drive towards < 0.5 μm design rules in silicon device fabrication has led to the emergence of evaluating lithographic technologies based on the use of x-rays as the exposure source. X-rays (centered @ λ = 1.4 nm) emanating from a pulsed laser point source based system has been used for resist design purposes. Concurrent with the development of this exposure source has been the search for a resist which will provide high sensitivity ( ≤ 20 mJ/cm2) and resolution. The vast majority of resists in which the x-ray induced chemistry is amplified are viewed as the most promising class of materials to meet the high sensitivity requirement. Central to these so-called chemically amplified resists is the exposure induced generation of an acid catalyst. The acid during the subsequent post exposure bake (PEB) processing step removes a functionality in the resist resulting in film loss in the exposed regions and dissolution of those areas in the aqueous base developer. To date, the majority of such resists are multi-component which adds complexity to processing of these materials. Chemically amplified resists based on poly 4- t-butoxycarbonyloxystyrene and sulfur dioxide are shown to minimize this complexityThe novel insitu generation of the catalytic acidic species is presented, and the performance of these resists is improved through the use of model compounds based on arylmethyl sulfones.
Characterization of a Silicon Nitride Mask Membrane Process
Authors: Wells G.M. , Reilly M. , Nachman R. , Cerrina F. , Khakani M. A. El , Chaker M. 
Published: March 2011

AbstractA silicon nitride membrane growth process has been characterized. The films were grown by LPCVD on 100 mm diameter silicon substrates using ammonia and dichlorosilane as reactant gases. The films were grown using a range of gas ratios at three different temperatures. The film composition was determined by elastic recoil detection. The silicon-nitrogen absorption bands were characterized by FTIR spectroscopy. The photon transmission of the films was measured in the visible region from 350 – 850 nm, and in the x-ray region for photon energies from 1000 to 3000 eV. The film stresses were determined using the wafer bow technique. An increase in the silicon content of the films was observed for increased dichlorosilane gas flow and for increasing growth temperatures. The increased silicon content of the films is correlated to a decrease in the tensile stress and a decrease in the optical transmission of the films.
Evidence of Distortion in the Oxygen Environment around Praseodymium in Y1−xPrxBa2Cu3O7 from Praseodymium K-Edge XAFS
Authors: Booth Corwin H. , Bridges Frank , Cervantes Phillip , Boyce Jim , Claeson Tord 
Published: March 2011

ABSTRACTIn constrast to other rare earths, replacement of Y with Pr in the high Tc superconductor YBa2Cu3O7 has a pronounced effect on Tc, with Tc going to zero at ≈ 55% Pr. We present Pr XAFS K-edge data for various concentrations of Pr in Y1−xPrxBa2Cu3O7. The Pr K-edge data show that the amplitude of the first Pr-O peak is greatly reduced when compared to the first Y-O peak in pure YBa2Cu3O7. In constrast, for the Y K-edge data in these alloys, there is little if any change in the oxygen environment, while the Cu K-edge data show at most a 10% reduction in the first Cu-0 peak. Fits to the Pr data suggest either that oxygen atoms in the CuO2 planes are missing or that some oxygen atoms about the Pr become highly disordered. Either result could help explain the reduction of Tc with increasing concentration of Pr.
X-Ray Topography
Authors: Dudley Michael 
Published: March 2011

ABSTRACTA review of the technique of White Beam Synchrotron X-ray Topography is presented along with some examples of its applications in materials science. Among the topics covered are: the characterization of growth defects in KTiOPO4, ZnTe, and SiC single crystals; studies of phase transitions in perovskite-like crystals; and studies of rapid thermal processing damage in semiconductors. Methodologies for analyzing dislocations, twins (rotational, mirror and inversion twins), precipitates and other crystallographic defects, will be reviewed.
Characterization of Defect Structures in SiC Single Crystals Using Synchrotron X-Ray Topography
Authors: Wang S. , Dudley M. , Carter C. , Asbury D. , Fazit C. 
Published: March 2011

ABSTRACTSynchrotron white beam X-ray topography has been used to characterize defect structures in 6H-SiC wafers grown on (0001) seeds. Two major types of defects are observed: super screw dislocations approximately perpendicular to the basal plane and dislocation networks lying in the basal plane. The super screw dislocations, which have open cores, are growth dislocations. These dislocations act as sources and/or sinks for the glide dislocation networks. Detailed analysis and discussion of dislocation generation phenomena and Burgers vectors will be presented.
Characterization of Cleaved GaAs(110) with a Scanning Photoemission Microscope Capable of Submicron Resolution
Authors: Ray-Chaudhuri A. K. , Ng W. , Liang S. , Singh S. , Solak H. , Cerrina F. 
Published: March 2011

ABSTRACTWe have utilized a scanning photoemission spectromicroscope with sub-micron spatial resolution to observe microscopic Fermi level pinning on the cleaved GaAs(110) surface. We present micrographs which identify pinning that is highly localized to the vicinity of a single linear cleavage step. This extends previous work utilizing scanning Kelvin probe and imaging photoelectron microscopy conducted at lower spatial resolution. A sub-monolayer coverage of In uniformly pins the surface, thus allowing us to observe only the image contrast mechanism resulting from topography. From this one can determine the spatial extent of defects near a cleavage step. Initial observations indicate that Fermi level pinning can extend from a cleavage step over the range of 2 μm. This indicates the additional presence of defects at the adjacent surfaces of the step.
Hard X-ray Sputtered-Sliced Phase Zone Plates
Authors: Bionta Richard M. , Skulina Kenneth M. 
Published: March 2011

ABSTRACTAl/Cu sputtered-sliced phase zone plates, designed to operate with a focal length of 0.18 m and 1.12 m at 8.05 keV, were tested at the Stanford Synchrotron Radiation Laboratory. The results of lens characterization and the implementation of a microscope are reported.
Real Time Structural Electrochemistry of Platinum Clusters using Dispersive XAFS
Authors: Allen P. G. , Conradson S. D. , Wilson M. S. , Gottesfeld S. , Raistrick I. D. 
Published: March 2011

ABSTRACTChemical reference tables state that the standard potential for the reaction of Pt with water, Pt + 2H2O → Pt(OH)2+ 2H++ 2e−, is 0.98 V, and electrochemical studies propose that this reaction may occur at potentials as low as 0.8 V [1–5]. Using dispersive x-ray absorption finestructure (XAFS) spectroscopy [6], we have directly probed the structural evolution of a Pt catalyst operating in-situ in a polymer electrolyte [7] fuel cell during cyclic voltammetry. The changes in the number of Pt and O nearest-neighbors and the Pt charge demonstrate a close correspondence with features in the voltammogram. Because dispersive XAFS is very sensitive to detecting structural changes, we have been able to detect the presence of chemisorbed oxygen at potentials of 0.6–0.9 V in the anodic sweep. Since double-layer charging is regarded as the only process in this region for bulk Pt [3–5], these results may reflect a limitation of previous (indirect) studies on Pt electrochemistry, or they may indicate that these clusters are different from their bulk metal counterparts. Exploiting the timeresolving capability of dispersive XAFS, we also monitored changes in the Pt charge and the number of O and Pt nearest-neighbors during the electrochemical oxidation and reduction of the Pt clusters in real-time. The results are inconsistent with those expected from the placeexchange mechanism [8–11] for the formation of the surface oxide on bulk Pt electrodes in aqueous solution;Our current model for understanding these behaviors is that, relative to bulk Pt, unusual types of surface sites play a major role in determining the reactivity of these clusters.
An overview of Analytical Electron Microscopy
Authors: Williams D. B. 
Published: March 2011

ABSTRACTAnalytical electron microscopy techniques comprising imaging, chemical analysis and microdiffraction are described together with details of the instrumentation required. Using the analytical electron microscope (AEM), the materials scientist can gain combined chemical and crystallographic information with a spatial resolution and sensitivity not available in other imaging instruments. Examples of the application of the AEM to determine solute distribution and crystal structure data are given.
Effects of Microstructure and Chemical Composition on Ebic Contrast in Hem Solar Cell Silicon
Authors: Sullivan T.D. 
Published: March 2011

ABSTRACTEBIC images of an HEM solar cell display extensive spatial innomogenieties in the production of short-circuit current. TEM imaging reveals a variety of morphologies having dimensions on the order of 10 Um embedded in the material.Correlation of a region with high current collection to one or these distinct morphological regions suggests that segregation or B is responsible for the EBIC contrast.
Structure of Thermally-Induced Microdefects in Czochralski Silicon
Authors: Ponce F. A. , Hahn S. 
Published: March 2011

ABSTRACTThe process of oxygen precipitation in Czochralski silicon materials has been studied using high resolution transmission electron microscopy. The resulting structure depends strongly on the thermal history of the material. The initial stages of precipitation involve the formation of clusters exhibiting strain fields which are coherent and isotropic at intermediate temperatures (∼7000°C). Incoherent defects are formed when the interstitial oxygen precipitates into substitutional sites in the silicon lattice. For long-time anneals, the quasi-equilibrium defect structure ranges from needle-like coesite (450–600°C), silica platelets (600–1000°C) to polyhedral silica precipitates (900–1200°C).
Computer Interfaced Electron Microscope
Authors: Kokubo Y. , Moriguchi S. , Hosoi J. , Watanabe E. , Nash J. 
Published: March 2011

ABSTRACTSome applications of the computer for the electron microscope, in three major areas - 1) control of the microscope,2) image processing, and 3) structure Analysis - are discussed in the present paper.
Stem Microanalysis of Hazed Polycrystalline Silicon Layers
Authors: Carpenter G.J.C. , Houghton D.C. 
Published: March 2011

ABSTRACTThe LPCVD of polysilicon on oxidized silicon wafers sometimes results in defective material having a “hazed” appearance. Examination of this material by SEM has revealed surface nodules which correlate on a one-to-one basis with anomalously large silicon grains, observed by transmission microscopy. Darkfield microscopy has shown that this abnormal grain growth initiated during deposition. X-ray EDS analysis of isolated poly-Si nodules revealed the presence of metallic impurities.
Misfit Dislocations in the Interface between the Metallic and Insulating Phases in Cr Doped V203
Authors: Otsuka Nobuo , Sato Hiroshi 
Published: March 2011

ABSTRACTThe formation of misfit dislocations in the interface between the metallic and insulating phases which occur in 1.2% Cr doped V203 near room temperature was confirmed by TEM. Orientations of Burgers vectors of misfit dislocations were determined by the weak beam technique. The Burger vectors were parallel to principal axes in the basal plane (<100>) and inclined somewhat to interfaces. The Burgers vectors of misfit dislocations are, however, close enough to the direction of the maximum misfit in the interface. Only one or two misfit dislocations appear in an interface regardless of the thickness of specimens, and these were always located near the surface.
Applications of High Resolution Electron Microscopy in Ceramics Research
Authors: Van Tendeloo G. 
Published: March 2011

ABSTRACTHigh resolution microscopy of ceramics has its specific problems due to the difficulties in preparing thin foils. Most of these Problems however can be overcome and recent years a lot of effort has been concentrated on electron microscopy of ceramics because of their high technological importance. Some results on important ceramics such as SiC, Mg-Si-O, ZrO2 -ZrN and Si-Al-O-N obtained by high resolution microscopy will be briefly discussed here.
Calcium Site Occupancy in BaTiO3
Authors: Chan H. M. , Harmer M. P. , Lal M. , Smyth D. M. 
Published: March 2011

ABSTRACTMeasurements of the equilibrium electrical conductivity of Ca-doped BaTiO3indicate a highly acceptor-doped behavior when y > 1 in the general formula (Ba1−xCaxO)yTiO2. It has been suggested that when there is an excess of alkaline earth oxides, some Ca++occupies Ti-sites, where it acts as a doubly charged acceptor, CaTi''. This possibility has been checked with a recently developed technique for determining the crystallographic site occupancy of impurity atoms. Known as ALCHEMI (Atom Location Using Channeling-Enhanced Microanalysis), the technique relies on the dependence of the characteristic X-ray emission on the incident electron beam direction. A significant channeling effect was observed for slightly positive and negative excitations of the [100] reflection. The results indicate that for the composition (Ba0,85Ca0.15O)1.02TiO2.00, a substantial fraction of the total calcium (> 20%) occupies Ti sites.
Determination of the Specific Site Occupation of Rare Earth Additions in Y17Sm06,Lu07Fe5O12Thin Films by the Orientation Dependence of Characteristic x-Ray Emissions
Authors: Krishnan Kannan M. , Rez Peter , Mishra Raja , Thomas Gareth 
Published: March 2011

ABSTRACTThe orientation dependence of characteristic x-ray emissions have been used to determine specific site occupations of Rare Earth additions in epitaxially grown films of Y1.7Sm0.6Lu0.7Fe12.A.theoretical formulation based on the assumption of highly localiszed inner shell excitations was used not only to oredict specific site sensitive orientations, but also to refine experimentally observed data employing a constrained least squares analysis to give probabilities for the occupation of the RE additions in the different crystallographic sites. Thus, it has been shown that in this compound the preference for the RE additions is a predominantly octahedral occupation with a probability ≳95%. Some of theassumptions and limitations of the technique have also been discussed.
Progress Toward Viable Epitaxial Oxide Ferroelectric Waveguide Heterostructures on Gaas
Authors: Fork D. K. , Kingston J. J. , Anderson G. B. , Tarsa E. J. , Speck J. S. 
Published: March 2011

AbstractDiscoveries within the last two years have created possibilities for the fabrication of epitaxial oxide heterostructures on GaAs substrates. In particular, magnesium oxide, MgO, may have broad applications, including its use as a cladding layer in optical waveguides. This report expands upon earlier work by revealing additional epitaxial structures involving lithium niobate which have been grown. There are now five known variants of Z-lithium niobate on GaAs: direct Z-cut growth on GaAs (111)A or B, Z-cut growth on MgO (111)/GaAs (111)A or B, and Z-cut growth on MgO (111)/GaAs (001). Broad in-plane misalignment (about 15°) characterizes the latter structure, whereas the former posses a textural width of 3° to 5° in the plane. All structures contain internal boundaries resulting from 180° rotations about the Zaxis. A critical issue for any ferroelectric heterostructure is its integrity in the presence of thermally induced tensile strain. Approaches to the mitigation of thin fim fracture are discussed and a novel approach to strain relief via ridge waveguide fabrication is reported.
Chemical Vapor Deposition of Epmtaxial BaTiO3 Films for Frequency Doubling Devices
Authors: Van Buskirk Peter C. , Stauf Gregory T. , Gardiner Robin , Kirlin Peter S. , Bihari B. , Kumar J. 
Published: March 2011

AbstractFerroelectric materials such as BaTiO3 are notable for their nonlinear optical and electrical properties. Optical frequency doubling in thin films integrated with compact semiconductor laser pumped solid state lasers is an attractive candidate for high efficiency generation of blue light. Chemical vapor deposition (CVD) using a single liquid source has been used to grow BaTiO3 films on MgO. X-ray diffraction in the pole figure configuration indicates the films to be epitaxial, and rocking curves had FWHM ≈ 0.7°. An optical scatterometer (λ = 633 nm.) has been used to identify deposition conditions that result in the lowest scatter losses. This paper describes these results as well as waveguide designs to enhance the second harmonic generation efficiency in epitaxial BaTiO3 films on MgO.
Reactive ion Etching of PbZrxTi1−xO3 and Ruo2 Tein Films
Authors: Vijay Dilip P. , Desu Seshu B. , Pan Wei 
Published: March 2011

AbstractIn this work, we have identified a suitable etch gas (CCI2,F2 ) for Reactive Ion Etching (RIE) of PZT thin films on RuO2 electrodes. The etch rate and anisotropy have been studied as a function of etching conditions. The effect of gas pressure, RF power and O2 concentration on the etch rate have been determined. It was found that ion bombardment effects are primarily responsible for the etching of both PZT and RuO2 thin films. Etch rates of the order of 20-30 nm/min were obtained for PZT thin films under low gas pressure and high RF power conditions. The etch residues and the relative etch rates of the components of the PZT solid solution were determined using XPS. The results show that the etching of PbO is the limiting factor in the etch process. For RuO2 thin films, etch rates of the order of 8-10 nm/min were obtained when O2 was added to the etch gas.
Epitaxial Ferroelectric Heterostructures of Isotropic Metallc Oxide (SrRuO3) and Pb(Zr0.52Ti0.48)O3
Authors: Eom C. B. , Van Dover R.B. , Phillips Julia M. , Fleming R.M. , Cava R.J. , Marshall J.H. , Werder D.J. , Chen C.H. , Fork D.K 
Published: March 2011

AbstractWe have fabricated epitaxial ferroelectric heterostructures of isotropic metallic oxide (SrRuO3) and ferroelectric thin films [SrRuO3/Pb(Zr0.52Ti0.48)O3 /SrRuO3] on (100) SrTiO3 and YSZ buffer layered Si substrates by 90° off-axis sputtering. These heterostructures have high crystalline quality and coherent interfaces as revealed by X-ray diffraction, Rutherford backscattering spectroscopy and cross-sectional transmission electron microscopy. The ferroelectric layers exhibit superior fatigue characteristics over 1010 cycles with large remnant polarization.
Impact of Backend Processing on Integrated Ferroelectric Capacitor Characteristics
Authors: Maniar P.D. , Moazzami R. , Jones R.E. , Campbell A.C. , Mogab C.J. 
Published: March 2011

AbstractIntegration of a ferroelectric capacitor module in a standard CMOS process subjects the ferroelectric to various ambients during backend processing, some of which can render the ferroelectric essentially non-operational for NVRAM applications. Post-crystallization processing of sol-gel deposited integrated ferroelectric PZT capacitors in the presence of hydrogen-containing, reducing ambients is observed to degrade the nonvolatile polarization. Low-pressure hydrogen anneals at temperatures as low as 200°C substantially degrade the nonvolatile polarization while the DRAM polarization remains roughly constant. Leakage current drops by one order of magnitude and fatigue is accelerated. A ferroelectric capacitor module can be integrated with minimal degradation with careful modifications in the backend processing.
Textured Pb(Zr0.54Ti0.46)O3 Thin Films with YBa2Cu3O7-δ and Yttria-Stabilized Zirconia Buffer Layers on (001)Si
Authors: Zheleva Tsvetanka , Tiwari P. , Narayan J. 
Published: March 2011

AbstractCharacteristics of textured Pb(Zr0.54Ti0.46)O3 (PZT) thin films on (001)Si with YBa2Cu3O7-δ (YBCO) and yttria-stabilized zirconia (YSZ) buffer layers have been studied using X-ray diffraction and high resolution electron microscopy techniques. Excimer KrF laser has been used for deposition of PZT, YBCO and YSZ thin films. The YBCO layer was utilized to provide a seed for PZT growth, while YSZ layer acted as a seed and a buffer layer for the growth of YBCO on (001)Si. High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction were used to determine the texture and the nature of defects, interfaces and grain boundaries. Predominant orientation relationships were found to be [001]PZT//[001]YBCO; [001]YBCO//[001]YSZ; and [001]YSZ//[001]Si.
Organometallic Chemical Vapor Deposition of Lead Zirconate-Titanate Thin Films
Authors: Keuser M. De , Veldhoven P.J. Van , Dorman G.J.M. 
Published: March 2011

AbstractIn this paper the growth of PbZrxTi1-xO3 on 10 cm platinized silicon wafers using the precursors cursors tetra-ethyl-lead, titanium-tetra-isopropoxide, or titanium-tetra-tertiarybutoxide and zirconium-tetra-tertiarybutoxide will be discussed in some detail. The composition of the films as a function of growth parameters will be treated and the accompanying change in the ferroelectric properties will be discussed. For device manufacturing, the PbZrxTi1-xO3 films are subjected to a number of processing steps. Some results for partially processed wafers will be presented. Also, preliminary results of depositions on 15 cm wafers will be given.