bluuebunny/crossref_metadata_2025_split huggingface dataset:
Re-Examining the Bulge Test: Methods for Improving Accuracy and Reliability
Authors: Small Martha K. , Vlassak Joost J. , Nix William D. 
Published: March 2011

ABSTRACTSince its first application to thin films in the 1950's, the bulge test has had a prominent place in the field of thin film mechanical properties. The major appeal of the technique is that it is analogous to the familiar uniaxial tension test, which is commonly applied to bulk materials. At the same time, it avoids the sample tearing and alignment problems associated with micro-tensile tests. Unfortunately, bulge test results have been sometimes controversial and difficult to reproduce. In this paper we address possible causes for mese inconsistencies and describe a method by which the bulge test technique can be made to produce accurate and reliable results.
Mechanical Testing of Bonded Silicon on Insulator Wafers.
Authors: Farrepi S. N. , Roberds B. , Boettcher M. C. , Ismail M. S. , Bower R. W. , Desmond C. A. , Hunt C. E. 
Published: March 2011

ABSTRACTA series of mechanical tests have been conducted on bonded silicon to silicon (native oxide present only) and oxide to oxide wafers at several times and temperatures. Tensile tests have been designed to evaluate the strength of the bond. Tensile tests have been conducted over the full range of bond strengths ranging from the weak van der Waals forces to the full silicon bonds.
Mechanical Properties of Microsensor Materials: How to Deal with the Process Dependences?
Authors: Senturia Stephen D. 
Published: March 2011

ABSTRACTMicrosensors are measurement devices fabricated using planar integrated circuit technology together with enhancements generically called “micromachining”. It is well known that the thin-film materials used in microelectronics can have properties which differ from their bulk counterparts. In addition, thin-film materials exhibit residual stress, which is known to be strongly process dependent. The sensor designer must understand how the detailed process used to fabricate a particular device impacts the specific mechanical properties, hence, the expected mechanical device performance. This paper illustrates the problem of process-dependent material properties using examples of residual stress of several materials, and then presents an object-oriented material-property database which is being developed as part of a CAD system for microelectromechan-ical systems (MEMCAD).
The Anomalous Behavior of Silicon During Nanoindentation
Authors: Pharr G. M. 
Published: March 2011

ABSTRACTTwo separate phenomena occur during the low-load indentation of silicon which make its behavior distinctly different from that of most materials. First, silicon is one of only a very few materials whose hardness exceeds the pressure needed to transform it to a denser crystalline (or amorphous) form, and because of this, a reversible, pressure-induced phase transformation occurs during indentation. The transformation enhances the electrical conductivity of the material and creates a region around the indenter which flows like a soft metal. Second, silicon cracks when indented by a Berkovich or Vickers indenter at loads of less than 100 mN, i.e., loads typically used in nanoindentation experiments. These two phenomena, which account for a number of unusual features in the indentation load-displacement behavior, are documented and discussed.
Monitoring Time-Dependent Deformation in Small Volumes
Authors: Weihs T P , Pethica J B 
Published: March 2011

ABSTRACTTime-dependent deformation (TDD) in small volumes was monitored using an alternating (AC) force technique and a Nanoindenter. The AC technique provides a continuous measure of contact stiffness during an indentation. By holding the force constant and monitoring the stiffness, the applied pressure and an effective strain rate were measured. Reasonable strain rate sensitivities were obtained for permanent indentations involving significant plastic strains. Time-dependent recovery due to residual strain energy is also reported. For reversible, elastic indentations, TDD was seen when the applied force was held constant. The deformation is attributed to atomic diffusion.
Scanning Tunneling Microscopy of Nanoindentations
Authors: Castell Martin R. , Weihs Timothy P. 
Published: March 2011

ABSTRACTA scanning tunneling microscopy (STM) study of low load indentations into Si, GaAs and Au is presented. Compared with standard micrographs obtained through optical microscopy and scanning electron microscopy, the STM images show greatly improved resolution in and around the indentation. The effects of relaxation and pile-up may be observed through contour plots which show inward bowing of the indentation faces in Si.
Microhardness Characterization of 80/20 MOL % TiO2/SiO2 Sol-Gel Films
Authors: Melpolder S. M. , West A. W. , Bauer C. L. 
Published: March 2011

ABSTRACTKnoop hardness and nanoindentation studies were performed on single and multilayered 80/20 mol % TiO2/SiO2 films spin-coated onto [100] silicon wafers. The Knoop microhardness results indicated that a total sol-gel thickness (h) to indentation depth (h*) ratio of >2 was sufficient to obtain reliable thin film properties independent of substrate influence. Electron microscopy techniques were used to determine the sample's absolute film thickness, to examine the morphology of the indentations, and to determine the phase of the sol-gel thin films.
The Roles of Stress, Geometry and Orientation on Misfit Dislocations Kinetics and Energetics in Epitaxial Strained Layers.
Authors: Hull R. , Bean J. C. , Ross F. , Bahnck D. , Pencolas L. J. 
Published: March 2011

ABSTRACTThe geometries, microstructures, energetics and kinetics of misfit dislocations as functions of surface orientation and the magnitude of strain/stress are investigated experimentally and theoretically. Examples are drawn from (100), (110) and (111) surfaces and from the GexSi1–x/Si and InxGa1–x/GaAs systems. It is shown that the misfit dislocation geometries and microstructures at lattice mismatch stresses < - 1GPa may in general be predicted by operation of the minimum magnitude Burgers vector slipping on the widest spaced planes. At stresses of the order several GPa, however, new dislocation systems may become operative with either modified Burgers vectors or slip systems. Dissociation of totál misfit dislocations into partial dislocations is found to play a crucial role in strain relaxation, on surfaces other than (100) under compressive stress.
In Situ Deformation Studies of Fe/Al and Fe/Si Multi-Layered Films Prepared by Ion Beam Sputtering
Authors: Kubota K. , Naoe M. 
Published: March 2011

ABSTRACTIn situ deformation measurements of Fe/Al and Fe/Si multi-layered films on thin substrates were made by detecting the curvature of substrates during deposition. The deformation inside of Fe layers corresponding to the compressive and tensile stresses was detected for the Fe/Al and Fe/Si multi-layered films, respectively. For the Fe/Si multi-layered films, the internal stress in Fe layers became from tensile to compressive during deposition under bombardment of Ar Jons. These stresses in Fe layer were closely related to the soft magnetic properties of these multi-layered films. In situ deformation studies may be useful to make sure the effect of internal stress on the magnetic properties of these multi-layered films.
Yield Strength Enhancement in Multilayer Thin Films by Modulus Hardening
Authors: Krzanowski James E. 
Published: March 2011

ABSTRACTThe modulus hardening mechanism for yield strength enhancement in multilayer materials is theoretically investigated. The multilayer composition profile used in the analysis has a general trapezoidal shape with allowance for two different layer thicknesses and two interface widths. The image force method is used to determine effective stresses on dislocations in the multilayer structure. Analytical expressions are derived for the effective stresses in terms of the shear elastic moduli. Calculations are carried out for representative composition profile shapes. It is found that the dislocation experiences the maximum effective stress when it is in the interface between layers, and that the effective stress increases dramatically with decreasing interface width. However, the effective stress is not strongly affected by either the multilayer wavelength or the relative thickness of the layers.
Using Weibull Statistics to Analyze Ion Beam Enhanced Adhesion as Measured by the pull Test
Authors: Pawel J. E. , Lever W. E. , Downing D. J. , Mchargue C. J. , Romana L. J. , Wert J. J. 
Published: March 2011

ABSTRACTThe adhesion of iron films to single crystal Al2O3 substrates was investigated using a pull test. Chromium (300 keV) or nickel (340 keV) ions were implanted to a fluence of 1 × 1015 ions-cm-2 after film deposition. The adhesion test results were widely scattered due to a random distribution of interfacial flaw sizes controlling the failure nucleation. Because Weibull statistics were developed to describe the failure probability due to a population of flaw-initiated cracks, the Weibull distribution was chosen to analyze the data. Modifications in the adhesion strength due to the ion implantation were reflected in the failure distributions. It was found that the chromium ions improved the adhesion of the Fe/Al2O3 system while the implantation of nickel did not.
Tribological Propertees of Carbon thin Films Prepared by Plasma-Free Sputtering Method
Authors: Hirata T. , Naoe M. 
Published: March 2011

ABSTRACTAmorphous “Diamond-like” carbon films were deposited on plasma-free substrates at low temperature by the Facing Targets Sputtering (FTS) method. Tribological characteristics determined by tap, scratch and slide tests were much better than those for amorphous carbon films deposited by the conventional Magnetron Sputtering (MS) method. Consequently, these films deposited by the FTS method were surely useful for protective layers in rigid magnetic disk.
Microstructure and Tribological Properties OF Co-Cr thin Films Deposited by Facing Targets Sputtering and Magnetron Sputtering Methods
Authors: Kadokura Sadao , Naoe Masahiko 
Published: March 2011

ABSTRACTThe tribological properties and the slid surface profiles of Co-Cr thin films deposited by Facing Targets sputtering and Magnetron sputtering methods were investigated in regard to the durability of flexible disks. Co-Cr thin films with columnless microstructure and homogeneously packed particles were much tougher than ones with columnar microstructure for tribological test. The Co-Cr films deposited by conventional Magnetron sputtering method revealed typically columnar structure, while ones deposited by Facing Target sputtering method did columnless microstructure. This indicates probably homogeneous distribution of strong bonding forces between grain boundaries throughout the films, because no brittle fracture was observed even after the delamination between a plastic substrate and the CoOx/ Co-Cr / Ni-Fe triple layers took place by application of excess stresses. It was found that difference in morphology of Co-Cr thin film between Facing Target sputtering and conventional Magnetron sputtering methods was much significant.
Effeci of Stresses on Void Nucleation During Electromigration
Authors: Brotzen F. R. , Rosenmayer C. T. , Dunn C. F. , McPherson J. W. 
Published: March 2011

ABSTRACTBased on experimental findings obtained earlier by the authors [1], a model is devised in which the divergence of the vacancy flow created in the grain boundaries of Al-Si(1%) metallizations by high-density DC is attributed to temperature gradients and structural features. Void nuclei of critical size are created in areas of high vacancy concentration. These nuclei grow, fed by the electromigrational vacancy current. It is shown that stresses have only a negligible' effect on the vacancy diffusion but influence the nucleation process dramatically. Results expressed in terms of fraction of void area are calculated and then correlated with experimental results. Certain material parameters, whose values are not known, are derived from the experimental data. The physical significance of these parameters is discussed.
Thermal Stress Induced Void Formation in Narrow Passivated Cu Lines
Authors: Brown D. D. , Børgesen P. , Lilienfeld D. A. , Korhonen M. A. , Li C.-Y. 
Published: March 2011

ABSTRACT0.75–3 μm wide copper lines encased in a thin adhesion layer of Al or Cr were passivated at 300°C and annealed at 400°C. The passivation was then removed and the lines examined in a scanning electron microscope. The development of thermal stress induced voiding was found to depend primarily on aging conditions and adhesion.
Dielectric Loss in Li- and Na-Swept α-Quartz and the Effect of Irradiation
Authors: Toulouse J. , Nowick A.S. 
Published: March 2011

ABSTRACTAlkali ions, which compensate for substitional Al3+, play an important role in the frequency stability of α-quartz crystals. In this work, low temperature dielectricloss measurements (between 2.9 and 300 K) are carried out on crystals that have been “swept” so as to introduce either Li+ or Na+. High quality synthetic crystals as well as natural crystals are employed. The well known loss peaks due to Al-Na pairs are further explored and similar peaks due to Al-Li are sought after but not found. It is concluded that the Al-Li pair is oriented along the C2 -axis of the A104 distorted tetrahedron. After irradiation, large peaks are observed at very low temperatures both in Li+- and Na+-containing crystals. These peaks, which are distorted below ∼6 K due to the onset of quantum effects, may originate in alkali centers produced when alkali ions are liberated by the irradiation.
Order and Disorder in the Oxygen-Deficient Fluorite-Related Oxides
Authors: Eyring Leroy 
Published: March 2011

ABSTRACTThe fluorite-related oxides have many uses in applied materials science and they present an excellent subject for study in solid state science. They exhibit examples of nonstoichiometric phases of wide composition range and series of ordered intermediate phases. Some details of the ordering of oxygen vacancies in the nonstoichiometric fluorite-related phases of the rare earth oxides are presented, including imaging of the process at high resolution in the electron microscope. Other highresolution studies of the ordered intermediate phases have revealed the structural principles that relate members of the homologous series RnO2n−2 Other ordered structures not belonging to the series are also discussed and the whole related to the zirconia and hafnia systems stabilized by calcia and yttria.
The Influence of Cation Stoichiometry on the Electrical Conductivity and High-Temperature Stability of MgO.nAl203 Spinel
Authors: Sonder E. , Darken L. S. 
Published: March 2011

ABSTRACTTheelectrical conductivityof MgO:nAl2O3spinelhas been measured for 1 < n < 3.6 for temperatures between 500 and 1400°C. The results for nonstoichiometric spinel are significantly different from those of stoichiometric material. Spinel with n up to 2 was found to be stable at temperatures above 1000°C, whereas, MgO:3.6Al2O3exhibited multiple indications of instability and disproportionation.
Cathodoluminescence from Therimochemically reduced MgO Crystals
Authors: Ballesteros C. , Piqueras J. , Llopis J. , Gonzalez R. 
Published: March 2011

ABSTRACTCathodoluminescence of thermochemically reduced MgO crystals has been studied in the scanning electron microscope. Two peaks at around 3.0eV (410nm) and 2.4eV (520nm) have been detected. The intensity evolution of these two peaks with temperature and electron beam irradiation has been recorded. The results are analyzed on the basis of emission from anion vacancies (F and F+ centers)
Permeability of Filter Pressed Monosized SiO2
Authors: Danforth S.C. , Velazquez M. 
Published: March 2011

ABSTRACTThe feasibility of slip casting monosized ceramic powders has been investigated using colloidal (spherical) SiO2particles. Pertinent aspects of powder syntheses, particle characteristics, and slip preparation are discussed. Processing variables affecting thepermeabilityof the cast compact to fluid flow are discussed in relation to forming cast bodies with near ideal (ordered) particle packing.
Sinterability of Agglomerated Powders
Authors: Lange F.F. 
Published: March 2011

ABSTRACTPowdered compacts that do not have periodic, particulate arrangements exhibit nonperiodic density variations and are, by definition, agglomerated. The void phase in the compact can be separated into pores. The pore coordination number distribution and the critical coordinated number (Rc) governs the volume fraction of pores that can spontaneously disappear by diffusion, and therefore, the compact's sinterability. The pore coordination number distribution is favorably influenced by increasing the compact's initial density and decreasing the size of the multiple particle packing unit (for example, agglomerate size). During heating the pore coordination number distribution is unfavorably shifted by local sintering, which is produced by the spontaneous disappearance of pores with favorable coordination numbers (R < Rc). Local densification produces a dense, polycrystalline skefetal network. Grain growth during densification, supported by dense regions, favorably alters the coordination number of pores within the skeletal network and improves sinterability. The configuration and microstructure of the dense, skeletal network will control its compliance to deformation by either effective or applied (hot pressing) compressive stresses. Deformation of the dense, skeletal network will improve the coordination number distribution and thus sinterability. From this thinking, one concludes that the ideal situation requires either a periodic particle arrangement (which requires monodispersed powders), or lacking this arrangement, alterations in surface chemistry (or structure) such that Rc → ∞.
Hydrothermal Preparation and Sintering of Fine Ceramic Powders
Authors: Sōmiya Shigeyuki 
Published: March 2011

ABSTRACTHydrothermal preparation is one of the methods to make fine ceramic powders. There are: (1) hydrothermal oxidation, (2) hydrothermal precipitation, (3) hydrothermal synthesis, (4) hydrothermal decomposition, (5) hydrothermal crystallization, etc. Starting materials for hydrothermal oxidation is mainly metal. Reaction between metal and high temperature-high pressure solution occurs to form oxide. Therefore, starting materials for very fine powders are: (1) metal powders or chips, (2) gel, solutions, etc., (3) oxides and solutions, (4) solids, and (5) hydrous material. This paper describes hydrothermal crystallization and oxidation. Fine powders of ZrO2, Al2O3, HfO2, and Al2O3-ZrO2 are described.Sintered bodies are also able to get under hydrothermal conditions with reactions. Hydrothermal reaction sintered bodies of iron oxides, Cr2O3, ZrO2 and HfO2 were obtained under 100 MPa above 1000°C with 1–5 μm grains.
Short-Circuit Diffusion Processes in Oxidation Films
Authors: Hughes A.E. , Atkinson A. , Chadwick A.T. 
Published: March 2011

ABSTRACTThe rate ofoxidation of metalsat high temperatures is usually controlled by the transport of metal ions or oxygen through the growing film of oxide on the surface. Since many technologically useful alloys (eg steels, nickelbased alloys) are based on the 3d transition metals, the transport properties of the oxides of these elements are of particular interest. In the temperature range 500–1000°C, where these alloys are used, the important transport paths in the oxide are not those that involve diffusion in the bulk crystal lattice, but other “short-circuit” paths. Basic experiments on the oxidation of nickel and direct tracer measurements of diffusion coefficients show that rain boundaries are the most important short-circuit paths under protective oxidation conditions. Similar conclusions can be drawn for other metals including chromium. The methods used in this work have been extended to study the way in which a surface treatment withCeO2reduces the oxidation rate of nickel, apparently by inhibiting the outward transport of metal ions along grain boundaries. Segregation of cerium ions to grain boundaries increases the diffusion coefficient of nickel; the inhibition is caused instead by particulates of CeO2in the middle region of the scale.
Planar Waveguides Formation Process in Linbo3 by Ti IN-Diffusion and H-Li Ion Exchange: A Structural Study
Authors: CANALI C. , CARNERA A. , CELOTTI G. , DELLA MEA G. , MAZZOLDI P. 
Published: March 2011

ABSTRACTThe interactions and compounds formed between Ti and LiNbO3, occurring before the true Ti in-diffusion process for optical wa veguides production,have been studied by using different analysis techniques.The relationship between lattice modifications and H concentration profile in proton exchanged LiNbO3 waveguides are also reported.
Cation Distribution in Transition Metal Oxide Spinels: Thermodynamic and Kinetic Considerations
Authors: Dorris S. E. , Erickson D. S. , Mason T. O. 
Published: March 2011

ABSTRACTThe point defect reaction which governs the magnetic and electrical properties of transition metal oxide spinels is the distribution of cations between tetrahedral and octahedral sublattices. Two types of redistribution occur -- ionic and electronic. The thermodynamics and kinetics of these processes can be studied via the electrical properties, thermoelectric coefficient and conductivity.
Aspects of the Reliability of Ceramics
Authors: Evans A. G. 
Published: March 2011

ABSTRACTFailure processes in brittle solids have been described. Particular emphasis has been placed upon a distinction of the various flaw populations that dictate failure and their relation with the dominant manufacturing (or environmental) variables. Micromechanics models of failure from the more significant flaws, and considerations of their relative roles in the failure process, have been cursorily presented. The fracture toughness, its significance in failure, and its dependence upon microstructure, have been examined, in conjunction with considerations of crack shielding and enhanced toughness. Finally, the role of statistical processes has been outlined, within the context of the important flaw populations.
Growth and Characterization of Ternary and Quaternary Compounds of Iny (AlxGa1−x)1-yAs on (100) InP
Authors: Tseng W. F. , Comas J. , Steiner B. , Metze G. , Cornfeld A. , Klein P. B. , Gaskill D. K. , Xia W. , Lau S. S. 
Published: March 2011

ABSTRACTThe acquisition of RHEED oscillation information on (100) GaAs substrates is described for use in the growth of “lattice-matched] Iny (AlxGa1−x)1-Y As layers on (100) InP substrates with 0.52 < y < 0.53 and 0.00 < x < 1.00. The observed frequency of the RHEED oscillations on GaAs is the same as on InP, however, the measured lattice parameters of the grown layers are less than that of InP. The x-ray diffraction images show that the misfit dislocations perpendicular to the primary flats of 2” round (100) InP wafers are denser than the parallel ones. Photoluminescence (at 10K) and photoreflectance (at 300K) measurements on a composite layer structure of x=0, 0.2, 0.4, 0.6, 0.8 and 1 clearly show six distinct peaks with narrow FWHMs of less than 20 meV. The measured bandgaps increase linearly with the Al content.
Non-Destructive Measurements of III-V Semiconductor Device Structure by a Hard X-ray Microprobe
Authors: Uchida F. , Shigeta J. , SUZUKI Y. 
Published: March 2011

ABSTRACTA non-destructive characterization technique featuring a hard X-ray Microprobe is demonstrated for lll-V semiconductor device structures. A GaAs FET with a 2 μm gate length is measured as a model sample of a thin film structure. X-ray scanning microscopic images of the FET are obtained by diffracted X-ray and fluorescence X-ray detection. Diffracted X-ray detection measures the difference in gate material and source or drain material as a gray level difference on the image due to the X-ray absorption ratio. Ni Ka fluorescence detection, on the other hand, provides imaging of 500 Å thick Ni layers, which are contained only in the source and drain metals, through non-destructive observation.