Papers by Keyword: X-Ray Microdiffraction

Abstract: In this article we focused to influence of current density on the structure parameters evaluated by microdiffraction experiment in transmission mode using synchrotron radiation. For this purpose the coatings of Ni-Co alloy were deposited on the Cu substrate using different current densities during the electrodeposition process. The results of the microdiffraction experiment showed the structure uniformity of the coatings along their thickness, as well as changes in the structure parameters depending on the used current density during the deposition process.

Abstract: We investigated local strain distribution in a cross-sectional area throughout the thickness of a thick aluminum nitride (AlN) film epitaxially grown on a trench-patterned AlN/α-Al₂O₃ template using X-ray microdiffraction measurements for AlN and Bragg reflections. The results show that the presence of voids caused by the trench pattern strongly influences on the distribution of the strain components in the and directions, which are perpendicular to the trench lines. Discrepancy between strain values obtained from the two Bragg reflections was shown to be the result of twisting of the crystal domains about the axis in the thick AlN film.

Abstract: Using X-ray microdiffraction (XRMD) and transmission electron microscopy (TEM) techniques, we have investigated the microscopic structure of Si(011)/Si(001) direct silicon bonding (DSB) substrates. XRMD was performed to measure the local lattice spacing and tilting in the samples before and after oxide out-diffusion annealing. Diffraction analyses for (022) lattice planes with two orthogonal in-plane directions of X-ray incidence revealed anisotropic domain textures in the Si(011) layer. Such anisotropy was also confirmed by TEM in the morphology at the Si(011)/Si(001) bonded interface. The anisotropic crystallinity is discussed on the basis of interfacial defect structures which are proper to the DSB substrate.

Abstract: The use of Si(011)/Si(001) direct silicon bonding (DSB) substrates is a key element of future complementary metal-oxide-semiconductor device technology. In the conventional bonding process, it is necessary to remove interfacial SiO2 to achieve direct atomic bonding. In this study, using X-ray microdiffraction and transmission electron microscopy, we investigate the structural changes caused by oxide out-diffusion annealing (ODA). It is revealed that crystallinity of the bonded Si(011) layer is degraded after low temperature ODA and gradually recovered with an increase in the ODA temperature and annealing time, which is well correlated with the interfacial SiO₂/Si morphology. Characteristic domain textures depending on the ODA temperature are also detected.

Abstract: Electron backscatter diffraction (EBSD) techniques have been used to measure the dislocation density tensor for various materials. Orientation data are typically obtained over a planar array of measurement positions and the minimum dislocation content required to produce the observed lattice curvature is calculated as the geometrically necessary (or excess) dislocation density. The present work shows a comparison of measurements in two-dimensions and three-dimensions using a dual beam instrument (focused ion beam, electron beam) to obtain the data. The two-dimensional estimate is obviously lower than that obtained from three-dimensional data since the 2D analysis necessarily assumes that the third dimension has no curvature in the lattice. Effects of the free-surface on EBSD measurements are discussed in conjunction with comparisons against X-ray microdiffraction experiments and a discrete dislocation dynamics model. It is observed that the EBSD measurements are sensitive to free-surface effects that may yield dislocation density observations that are not consistent with that of the bulk material.

Abstract: This time, we would like to report our recent study on Pb(ZrTi)O3(PZT)-based ferroelectrics, currently one of interesting topics in condensed matter science. In this study, a new method, called synchrotron X-ray microdiffraction (XRMD) in situ, was introduced to examine the electric field-induced structural modulation of the epitaxially grown tetragonal PZT thin film. To evaluate the d-spacing (d001) from the measured intensity contour in the two theta-chi space, the peak position in each diffraction profile was determined by applying the two-dimensional Lorentzian fitting. By tracing the change of d-spacing as a function of the applied electric field and by examining the Landau free energy function for P4mm symmetry, we were able to estimate the two important parameters that characterize the field-induced structural modulation. Further theoretical analysis shows that the compressive epitaxial in-plane stress dominantly contributes to the elongation of the c-axis lattice constant in the c-axis oriented epitaxial PZT film.

Abstract: Crystalline precipitates in a bulk-metallic-glass (BMG) braze were investigated with an intense x-ray microbeam. The precipitates were found in the Pd40Cu30P20Ni10 BMG braze matrix after joining crystalline Ti-6Al-7Nb. However, the role (if any) played by the precipitates in improving the mechanical bond of the BMG/crystalline joint is unknown. X-ray microdiffraction and microfluorescence measurements from small sample volumes were made with an ~ 0.5 x 0.5 μm2 beam. Spatially-resolved Laue diffraction and x-ray fluorescence measurements were made on several second-phase crystals within the BMG matrix. Although precipitate crystals with the observed compositions were anticipated to be predominantly hexagonal, one of the crystals was found to be cubic or tetragonal. The instrumentation includes capabilities for 3D depth-resolved measurements of crystal structure and for fluorescence analysis of elemental composition. Depth profiling gave information about the grain distribution and morphology in the BMG matrix.