bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Situ Measurement of Stresses in Thin Films
Authors: Abermann Reinhard 
Published: March 2011

ABSTRACTIn this paper the results of experiments are summarized in which the internal stress (i.e. force per unit width) of thin films was measured in situ under UHV conditions with a bending beam apparatus. It is demonstrated that characteristic types of stress vs. thickness curves can be correlated with different growth modes (i.e. columnar grain growth and island growth) caused by differences in the adatom mobility of the deposited material. With a selection of thin film systems it is then shown that stress measurements can be used to study the effect of gas incorporation, of gas diffusion from the substrate, of reaction with the substrate and of the substrate temperature on the growth and structure of a thin film. Finally it will be demonstrated that stress measurements can even be used to study gas adsorption on vapor deposited films.
Determination of the Mechanical Properties OP Integrated Circuit Packaging Materials using a Focused Acoustic Beam Technique
Authors: Zhang De , Crean Gabriel M. 
Published: March 2011

ABSTRACTA novel method for the measurement of the mechanical properties of integrated circuit interconnection and packaging materials using a conventional acoustic microscope lens, is presented in this paper. This technique allows the simultaneous generation and detection of longitudinal (LW) and shear (SH) acoustic waves in a material system based upon acoustic mode conversion principles at a water-solid interface. Experimental results obtained using a 50 MHz acoustic lens are presented for a range of ceramic materials and compared with published data. Acoustic ray propagation theory is employed to analyse the experimental results.
The Choice OP Optimal Microhardness Testing Conditions for Amorphous and Polycrystalline Films
Authors: Manika I. , Maniks J. 
Published: March 2011

ABSTRACTThe microhardness of polycrystalline and amorphous coatings on substrates of various hardness has been studied in a wide range of loads. The limits for indentation depth providing optimal conditions for microhardness testing have been found. Basing on the results of integral hardness testing of coated samples at comparatively high loads, a method has been proposed for the microhardness and thickness evaluation.
Observation of Glass Transition Temperatures in Polymeric Thin Films by Wafer Curvature Measurements
Authors: Townsend P. H. , Huber B. S. , Wang D. S. 
Published: March 2011

ABSTRACTWafer bending measurements have been used to study the glass transition temperature, Tg, of thin coatings of polystyrene and polycarbonate on Si wafers. The observed values of Tg agree with DSC and TMA measurements on bulk samples. The evolution of the substrate curvature has been used to examine the behavior of Tg in thin epoxy films and coatings derived from divinylsiloxane bisbenzocyclobutene, mixed stereo and positional isomers of 1, 3-bis(2-bicyclo[4.2.0]octa-1, 3, 5-trien-3-ylethenyl)-1, 1, 3, 3-tetramethyl disitoxane (CAS 117732–87–3). The dependence of the Tg of the epoxide coatings is studied as a function of the cross-linking. The evolution of the Tg in the benzocyclobutene coating is found to be a monotonie function of the level of conversion of the polymer network.
The Interactions Between Misfit Dislocations in InGaAs/GaAs Interfaces.
Authors: Kightley Philip , Goodhew Peter J , Beanland Richard 
Published: March 2011

ABSTRACTThe reactions between misfit dislocations arriving by glide at the interface between an In0.12Ga0.88As/GaAs multilayer and a GaAs substrate are analysed and reported. The glide forces for the (a/2)<110> dislocations are calculated as a function of vicinal tilt from (001) to (100). It is observed that the 4% changes in the magnitude of the force for a 2° vicinal angle are not sufficient to significantly alter the relative linear densities of the different types of dislocation.
Experimental Deformation Mechanics of Materials from their Near-Atomic-Resolution Defect Images
Authors: Choi H. C. , Schwartzman A. F. , Kim K.-S. 
Published: March 2011

ABSTRACTA novel approach to quantitative interpretation of high-resolution electron microscopy images of defects in materials has been developed. The emphasis of this paper is on the methodology, which has been named Computational Fourier Transform Moiré Analysis. The essential principle of this technique is to extract an accurate displacement field about a defect from its near-atomic-resolution picture using digital Fourier transformation procedures. From this data, the displacement gradient can be calculated which yields much information on the experimental deformation mechanics of the material under investigation. As a by-product, we produce the computational Moiré pattern without the need of an external perfect reference lattice image normally associated with the interference phenomena. This method is illustrated using a bounding Frank partial dislocation for a Frank loop of the vacancy type. Results are presented on its strain field, Burgers vector and dislocation core shape and dimensions. Further mention will be made on the types of J-integral calculations that can result from this experimental study.
Finite Element Simulation of Indentation Behavior of thin Films
Authors: Madsen D. T. , Giovinazzo R. J. , Ritter J. E. 
Published: March 2011

ABSTRACTNanoindentation experiments are now widely used to study the elastic and plastic properties of thin films. Simulation of these experiments has been performed using finite element analysis. Results show the large influence that pile-up or sink-in behavior have on hardness calculations. Results also show that a compliant substrate significantly affects the measured hardness of a stiffer coating. The measured hardness of a compliant coating is less effected by a stiffer substrate.
Microstructural Characterization of SiGe Heterolayers
Authors: David Theodore N. , Fejes Peter , Tomozane Mamoru , Liaw Ming 
Published: March 2011

ABSTRACTSiGe is of interest for use in heterojunction-bipolar transistors, infrared detectors and field-effect transistors. In this study, graded SiGe heterolayers grown on Si, and heterolayers grown on SIMOX by CVD, were characterized using TEM. The graded-heterolayers consisted of ten layers of Si1-xGex on substrate silicon. Misfit dislocations were present at interfaces in the bottom 4–5 layers of the heterostructure. This conforms with predictions from qualitative strain-energy considerations. The greatest density of misfit dislocations was present at the Si1-xGex interface between the bottom two layers of the heterostructure. Dislocations were observed to extend out of the interface and up into the heterolayer structure. The defects were found to interact with interfaces in the structure and finally cease extending upwards towards the surface of the wafer. In addition to graded heterolayers, SiGe heterolayers grown on SIMOX were also investigated. The structures consisted of epi-silicon grown on a Si/Si1-xGex superlattice which was in turn grown on a Si/SiO2 (SIMOX) structure. The behavior of defects in the layers was of interest. TEM characterization showed a large density of extended-defects present in the layers. Dislocations were observed to originate at the SIMOX oxide/Si interface, propagate up through the SiGe superlattice and into the epi-Si layer. Some dislocations were found to interact with the SiGe superlattice and cease propagating up towards the top of the wafer. SiGe superlattices with a higher concentration of Ge are more effective in reducing defect propagation towards the surface of the wafer.
Observations of the Solid Phase Epitaxial Regrowth for GaAs/Si
Authors: Kightley Philip , Goodhew Peter J , Augustus Peter D , Bradley Robert R 
Published: March 2011

ABSTRACTThe changes in defect structure caused by an anneal are studied by TEM for thin GaAs layers on Si. A low growth temperature of 450°C is always used for the first 300Å. When it is first deposited this layer contains considerable disorder which consists of planar defects, {112} epitaxy and an irregular distribution of dislocations. Annealing of the layer gives rise to a solid phase regrowth that consumes the misoriented and much of the twinned crystal and produces regular misfit dislocation arrays. Continued growth at high temperature can reduce the twin densities to below the detection limit of TEM. It is this solid phase transformation of this layer that allows good epitaxy to continue.
Structural Characterization of Multilayers Using X-ray Diffraction
Authors: Clemens B. M. , Bain J-A. , Payne A. P. , Hufnagel T. C. , Brennan S. M. 
Published: March 2011

ABSTRACTStructural deviations from ideal layering of bulk constituents can have dramatic effects on the properties of multilayered materials. We discuss three examples of the use of x-ray diffraction in non-standard geometries to examine these effects. In Mo/Ni multilayers, we use asymmetric diffraction and grazing incidence x-ray scattering (GIXS) to deduce the strain and intermixing. We find that coherency stresses between the BCC Mo and FCC Ni planes play a major role. In the Fe/Cr system, we use rocking curves and asymmetric scans about the small angle superlattice lines to investigate the nature and extent of layer roughness. We find that conformai roughness dominates our best samples, while non-conformal roughness increases with sputter deposition pressure. In the Gd/Co system, we use in-situ GIXS to investigate amorphization reaction during deposition. We find a strong diffusional asymmetry and rapid reaction during growth.
Effect of Structure on the Anomalous Mechanical Properties of Metallic Superlattices
Authors: Schuller Ivan K. , Fartash A. , Fullerton Eric E. , Grimsditcht M. 
Published: March 2011

ABSTRACTThe mechanical properties of metallic superlattices have been shown to exhibit anomalous properties. Several of the elastic constants are found to exhibit anomalies which are correlated with structural anomalies in lattice mismatched systems which do not form solid solutions. Lattice matched systems which form solid solutions in their thermodynamics phase diagram, show much smaller elastic anomalies and no structural anomalies. Anomalous plastic behavior, on the other hand, seems to be present in both types of superlattices, indicating that the plastic behavior is possibly defect induced. Detailed quantitative structural measurements combined with comprehensive mechanical properties hold the promise of determining the physical origins of the anomalous properties of metallic superlattices.
Atomistic Simulation of the Nanoindentation of Diamond and Graphite Surfaces
Authors: Harrison J. A. , Colton R. J. , White C. T. , Brenner D. W. 
Published: March 2011

ABSTRACTMolecular dynamics simulations which make use of a many-body analytic potential function have been used to study the nanometer-scale indentation of diamond and graphite. We find that the simulation correctly reproduces experimentally determined trends in load versus penetration data. As a result, trends in mechanical properties, e.g. Young's modulus, are also reproduced.
Small Scale Yielding at a Crack Normal to the Interface Between an Elastic and a Yielding Material
Authors: He Ming Y. , McMeeking R. M. , Zhang Ning T. 
Published: March 2011

ABSTRACTBy using the elastic singular field as a prescribed loading condition, small scale yielding solutions are obtained for a crack normal to the interface between a brittle and a ductile material. Results for both a crack in the brittle material and one in the ductile material are obtained by finite element analysis. The crack tip fields obtained by the finite element analysis are compared with the asymptotic solutions. It is found that near the tip the stress fields approach the asymptotic solutions. If the crack is in the brittle material, the high triaxial stresses are developed near the interface ahead of the crack tip.
Tribology and Abrasive Wear of Mo Lecularly Doped Polycarbonate Coatings
Authors: Murti D. K. , Odell P. G. , Mizes H. A. 
Published: March 2011

ABSTRACTMolecularly doped polymers are widely used in copiers and printers. During the imaging process, toner particles and the cleaning blade wear the photoconductor drum as it rotates. This paper quantizes the abrasive wear of molecularly doped polycarbonate coatings. No clear correlation is found between the wear rate and measured mechanical properties. The surface topography is dominated by a series of parallel grooves with a spacing of approximately 0.1 pm.
A saw Sensor Study of the Relative Adhesion and Surface Properties of Polyimide Films
Authors: Galipeau D. W. , Feger C. , Veteldmo J. F. 
Published: March 2011

ABSTRACTA surface acoustic wave (SAW) sensor is used to study the relative humidity response of polyimide films where interfacial and surface properties are varied. The relationship between these responses and the relative adhesion strength of these films is of particular interest since it could have application as a nondestructive, quantitative measure of adhesion strength. The results show clear differences in the SAW humidity response for cured and uncured films. There are also significant differences in the SAW humidity response for films applied with and without adhesion promoter. In addition the humidity response has proven to be particularly sensitive to the surface treatment of the polyimide film. These results suggest applications of the SAW sensor as a cure indicator, an in-situ sensor for the monitoring of film surface properties in process control applications and as an adhesion sensor.
Diamond-Like Carbon Coating—It'S Application for Polymeric Substrates
Authors: Kimock Fred M. , Hsieh Alex J. , Dehmer Peter G. , Yip Pearl W. 
Published: March 2011

ABSTRACTWe report on a recently commercialized Diamond-Like Carbon (DLC) coating that has been deposited on polycarbonate at near room temperature, via a unique ion beam system. Aspects of high speed impact behavior, chemical resistance, abrasion resistance, and thermal stability of the coating are examined. Results of scanning electron microscopy studies indicate that adhesion of the DLC coating is very good; no delamination of the coating was found on ballistically tested specimens. The well-bonded DLC coating did not cause the impact performance of polycarbonate to become brittle. Chemical exposure test results show that the DLC coating is capable of protecting polycarbonate from chemical attack by aggressive organic liquids. These ion beam deposited DLC coatings have considerable potential as protective coatings for optical systems.
Electromigration Damage by Current Induced Coalescence of Thermal Stress Voids
Authors: Børgesen P. , Korhonen M. A. , Sullivan T. D. , Brown D. D. , Li C.-Y. 
Published: March 2011

ABSTRACTAccording to a new electromigration model, small thermal stress induced voids remain trapped at grain and phase boundaries, growing under an electric current. When they reach a ‘threshold’ size, migration and coalescence leads to rapid line failure. Predictions are compared to experimental results for Al, Al(0.6%Si), and Al(1.6%Cu) lines.
Defect-Characterization in Implanted Locos + Trench-Isolated Structures
Authors: David Theodore N. , Vasquez Barbara , Fejes Peter 
Published: March 2011

ABSTRACTAs device dimensions decrease in silicon integrated-circuits, conventional LOCOS (local-oxidation of silicon) isolation becomes inadequate to meet dimensional demands. Variations on LOCOS are therefore being explored for further miniaturization of devices. One such variation involves poly-buffered LOCOS + trench-isolation (PBLT). In this study, PBLT structures were characterized using TEM. Wright-etched cross-section SEM micrographs showed etch-pits associated with a combination of high-dose (> 5E14 cm-2) phosphorous implants and PBLT isolation. TEM characterization showed that dislocations were formed in the structures for a combination of high-dose (1E15 cm-2) phosphorous implants (followed by an anneal) and PBLT isolation. Structures exposed to lower-dose (1E14 cm-2) implants showed no defects and neither did 1E15 implanted structures prior to annealing. The results are modelled in terms of the stress configurations present in the structures, and in terms of dislocation-sources resulting from implantation-related dislocation-loops. The dislocation-sources operate in the presence of stresses associated with the isolation-trenches. Glide-loops form, which then grow in response to stresses in the structures and dislocations result on glide planes.
Electromigration Behavior of Aluminum Films Deposited by Partially Ionized Beam.
Authors: Kononenko O. V. , Fionova L. K. , Matveev V. N. 
Published: March 2011

ABSTRACTAluminum films deposited by partially»ionized beam were stressed by a current density of 2×106 A/cm2 at a temperature of 300°C. The films prepared at the acceleration voltage of 5 kV lived over 200 hours.
Characteristics of Palladium Thin Films Deposited by the Ionized Cluster Beam Technique
Authors: Huffman Maria , Kalkur T. S. , Kammerdiner L. , Kwor R. , Levenson L. L. , Reeder M. 
Published: March 2011

ABSTRACTAn ionized cluster beam (ICB) source was used to deposit Pd onto oxidized silicon substrates. The ICB source was operated in both the neutral mode (no ionization and no acceleration) and in the ICB mode with ionization and acceleration voltages at 3 kV and 6 k.V. Also, substrate temperatures were varied between 100°C and 400°C. The Pd film thicknesses were generally between 1, 200Å and 1, 800Å, with one film thickness about 500Å. The films were examined by transmission electron microscopy (TEM), transmission electron diffraction (TED), and x-ray diffraction (XRD). Grain size measurements by TEM and XRD showed that ionization and acceleration of Pd resulted in a slight increase in grain size compared to films deposited without ionization or acceleration at any substrate temperature. However, the grain size increased significantly as the substrate temperature rose. XRD showed that all ICB deposited Pd films have significant (111) texturing as determined by comparison to XRD data for Pd powder. For Pd films deposited at 400°C, almost all grains were oriented with the (111) planes parallel to the substrate surface. The electrical conductivity of all Pd films was comparable to that of bulk Pd.
Crystallite Dimensions and Strain in Poly-Si and Ti-Silicide Thin Films Measured with Grazing Incidence X-Ray Diffraction
Authors: Leiberich A. , Roy P. K. 
Published: March 2011

ABSTRACTThe present study describes the measurement of microcrystalline grain dimensions and crystallite strain for polycrystalline silicon (poly-Si) and titanium suicide, using grazing incidence X-ray diffraction (GIXRD). A variety of poly-Si sample configurations were synthesized by different low pressure chemical vapor deposition (LPCVD) processing techniques. Selected samples were subsequently processed by phosphorous diffusion doping and reaction with thin titanium layers. Characterization with GIXRD reveals differing crystallite grain dimensions, ranging from =80Å to =900Å. Crystal strain was measured in direction perpendicular to (111) lattice planes. Phosphorous diffusion doping is shown to remove this (111) strain, in addition to increasing crystallite grain dimensions. The GIXRD characterization, which measures a specific fraction of the sample crystal texture, indicates that deposition rate modulated poly-Si LPCVD reduces (111) microscopic strain in poly-Si films two-fold, compared to conventional poly-Si deposition. The crystallite dimensions of conventional poly-Si, are found to peak approximately in direction perpendicular to (110) planes. The same trend is observable for deposition rate modulated poly-Si, where grain dimensions, measured in [110] direction, are reduced by =30%. Larger crystallite dimensions were measured in direction perpendicular to (110) planes, for both cubic poly-Si and orthorhombic Ti-silicide layers, suggesting the presence of preferred crystallite growth directions, resulting in anisotropie crystallite grain dimensions.
The Effect of Deposition Temperature on the Microstructure of Lpcvd Polysilicon Films
Authors: Hangas J. , Liu D. R. , Oei D. G. , McCarthy S. L. , Peters C. 
Published: March 2011

ABSTRACTThe microstructure, of unannealed and annealed polysilicon films was studied using TEM and XRD. The LPCVD films were grown at 600°C and 620°C with 320 mTorr of silane, and at 580°C with 220 mTorr of silane. The substrates were [001] Si with a thin oxide film. The stress state of the films changed from compressive at 580°C and 620°C, to tensile in a narrow region around 600°C. The same materials were annealed at 1100°C. The unannealed films vary from partially amorphous at 580°C, where the slowest growth rate was observed, to randomly oriented and equiaxed at 600°C, to columnar and highly oriented at 620°C. The grains in the 620°C material have a high stacking fault and polytype density, and it was proposed that these occurred on growth, and not from dislocation motion. The grain size increased from 40–250run to 100–300 nm in the 600°C samples when annealed at 1100°C, and the density of twins and stacking faults was reduced. The hexagonal phase was observed only in unannealed materials in SAED and as broad “wings” at the base of the llld.c (diamond cubic) peak in XRD. Within the limits of SAED, no change in lattice parameter of the hexagonal phase was observed.
Metal Colloids in Oxides*
Authors: Narayan J. , Chen Y. , Moon R. M. 
Published: March 2011

ABSTRACTA method, based upon subtractive coloration or high-temperature reduction, was developed to produce metal precipitates or colloids in oxides. The structure, symmetry, morphology and composition of precipitates were analyzed by analytical electron microscopy and neutron scattering technioues. In the MgO:Ni system, the colloids were coherent nickel precipitates having a fcc structure (a0 = 3.52 Å), and occasionally a bcc structure (a0 = 2.88 Å). The coherent precipitates were analyzed to have either <100>m,∣∣ <111>p or <l00>m ∣∣<100>p matrix-precipitate orientation relationship depending upon the high-temperature reduction treatment. The optical absorption spectra of these materials were characterized by broad optical bands centered near 2.2 and 5.0 eV. By changing the size distribution of the precipitates, it was possible to obtain optical spectra of these materials suited for solar selective absorber applications. The dislocations and sub-boundaries provided nucleation sites for the formation of precipitates, and decreased the temperature of reduction. By providing sources of dislocations, the precipitates enhance the ductility and inhibit the propagation of cracks.
Special Grain Boundaries in Alumina
Authors: Morrissey K. J. , Carter C. B. 
Published: March 2011

ABSTRACTA particular type of grain morphology observed in commercial polycrystalline compacts of α-alumina is discussed along with special features which have been found to be associated with this morphology. The particular feature of interest is the occurrence of grains which are referred to in this paper as being lath-like in appearance. The important features of these lath-like grains include the occurrence of faceted grain boundaries which are often associated with pores and the special geometric relationships between the grains and the surrounding matrix.
Cathodoluminescence Emission from Crystalline Linbo3
Authors: Llopis J. , Ballesteros C. , Gonzalez R. , Chen Y. 
Published: March 2011

ABSTRACTCathodoluminescence (CL) emission from as-grown and indented LiNbO3 single crystals has been studied. The spectrum is strongly affected by deformation of the surface region. Three emission bands at about 410, 525 and 580nm have been observed. Irradiation with the electron microscope beam at very high current intensities causes a severe damage on the irradiated area. This effect can also be observed on the indented areas where the indentation pyramid can not be recognized after prolonged irradiation.