Atomic Diffusion and Strain Measurement on Si Grating Structures by X-Ray Diffraction

1995 ◽  
Vol 380 ◽  
Author(s):  
So Tanaka ◽  
Christopher C. Umbach ◽  
Qun Shen ◽  
Jack M. Blakely

ABSTRACTWe have applied high resolution synchrotron X-ray diffraction to two-dimensional (2D) Si gratings with wavelengths of 300 and 400nm. We show that this method is very sensitive to both the geometry (grating wavelength, height, and angle of inclined sidewall) and the state of strain. Morphology changes produced by vacuum annealing can be detected so that the mass transport rates on Si surfaces can be measured. Strain measurements show that grating pillars covered with 1 lnm of thermal oxide were under tension (ε = 3.7 × 10−4). This strain was elastically relaxed by removing the oxide.

1949 ◽  
Vol 1 (3) ◽  
pp. 211-224
Author(s):  
G. B. Greenough

SummaryMany papers have been written on the measurement of strain by X-ray diffraction methods and on the interpretation of these strains in terms of stresses. Whereas, during the past few years, the experimental methods of determining the strains have. remained largely unchanged, research has shown that the older techniques for calculating stresses from strains are not always valid.In this paper an attempt is made to describe some of the principles of strain measurement by X-ray diffraction methods to those who are unfamiliar with the methods. The types of stress and strain systems which may exist in polycrystalline metals are then considered, particular attention being paid to the effect of the elastic and plastic anisotropy of the individual crystals. Some indication is given as to how the earlier methods of interpreting X-ray strain measurements should be modified, but no rigid routine method is proposed for use in a general case.


1995 ◽  
Vol 405 ◽  
Author(s):  
So Tanaka ◽  
Christopher C. Umbach ◽  
Qun Shen ◽  
Jack M. Blakely

AbstractThe strain induced by thermal oxidation in a cylindrical silicon (Si) structure has been studied by high resolution synchrotron x-ray diffraction. The strain in the structure studied is expected to display some of the features that exist in three-dimensional non-planar surfaces in electronic devices. The sample consisted of a 2-dimensional array, with period of 300nm, of approximately cylindrical pillars covered with a thin thermal oxide (thickness ∼6nm). These showed a tensile strain of 3.7×10-4 at room temperature. This strain can be relaxed elastically by chemical removal of the oxide. Process simulation indicates the importance of both the contribution due to interface stress during the oxide growth and stress due to differential thermal contraction during the cooldown. Significant differences exist between the strain in such cylindrical pillars and in a flat wafer.


1995 ◽  
Vol 403 ◽  
Author(s):  
T. Marieb ◽  
A. S. Mack ◽  
N. Cox ◽  
D. Gardner ◽  
X. C. Mu

AbstractPassivated Cu lines deposited by CVD, electroplating, and sputter-reflow were investigated using x-ray diffraction. Blanket films of the three types were measured for strain and texture post-deposition and after an anneal step to mimic the passivation temperature step. Texture in the CVD films was random, while the electroplated and sputtered films showed a strong {111} texture. Lines were then measured of each type. The measured strain was modeled using finite element calculations. While the strain in Cu was high compared to Al lines of similar geometry, no stress voiding was observed using high voltage scanning electron microscopy.


2008 ◽  
Vol 41 (6) ◽  
pp. 1076-1088 ◽  
Author(s):  
Guillaume Geandier ◽  
Pierre-Olivier Renault ◽  
Simon Teat ◽  
Eric Le Bourhis ◽  
Bruno Lamongie ◽  
...  

Performing a completein situmechanical property analysis of polycrystalline thin films using X-ray diffraction is time consuming with most standard diffraction beamlines at synchrotron facilities and not realistic with laboratory diffractometers. Two-dimensional detection is shown to enable relatively fast and reliable X-ray strain measurements duringin situtensile testing of gold films deposited on polyimide substrates. Advantages and drawbacks in the use of two-dimensional detectors for this type of analysis are discussed for two commonly used geometries: reflection and transmission.


Author(s):  
K. H. Downing ◽  
S. G. Wolf ◽  
E. Nogales

Microtubules are involved in a host of critical cell activities, many of which involve transport of organelles through the cell. Different sets of microtubules appear to form during the cell cycle for different functions. Knowledge of the structure of tubulin will be necessary in order to understand the various functional mechanisms of microtubule assemble, disassembly, and interaction with other molecules, but tubulin has so far resisted crystallization for x-ray diffraction studies. Fortuitously, in the presence of zinc ions, tubulin also forms two-dimensional, crystalline sheets that are ideally suited for study by electron microscopy. We have refined procedures for forming the sheets and preparing them for EM, and have been able to obtain high-resolution structural data that sheds light on the formation and stabilization of microtubules, and even the interaction with a therapeutic drug.Tubulin sheets had been extensively studied in negative stain, demonstrating that the same protofilament structure was formed in the sheets and microtubules. For high resolution studies, we have found that the sheets embedded in either glucose or tannin diffract to around 3 Å.


2008 ◽  
Vol 73 (1) ◽  
pp. 24-31
Author(s):  
Dayu Wu ◽  
Genhua Wu ◽  
Wei Huang ◽  
Zhuqing Wang

The compound [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2 was obtained by the reaction of Cd(ClO4)2, bis(1-pyrazinylethylidene)hydrazine (L) and 4,4'-bipyridine in aqueous MeOH. Single-crystal X-ray diffraction has revealed its two-dimensional metal-organic framework. The 2-D layers superpose on each other, giving a channel structure. The square planar grids consist of two pairs of shared edges with Cd(II) ion and a 4,4'-bipyridine molecule each vertex and side, respectively. The square cavity has a dimension of 11.817 × 11.781 Å. Two guest molecules of bis(1-pyrazinylethylidene)hydrazine are clathrated in every hydrophobic host cavity, being further stabilized by π-π stacking and hydrogen bonding. The results suggest that the hydrazine molecules present in the network serve as structure-directing templates in the formation of crystal structures.


2009 ◽  
Vol 42 (2) ◽  
pp. 192-197 ◽  
Author(s):  
Thomas Gnäupel-Herold

A method is outlined that allows the determination of one-dimensional stress gradients at length scales greater than 0.2 mm. By using standard four-circle X-ray diffractometer equipment and simple aperture components, length resolutions down to 0.05 mm in one direction can be achieved through constant orientation of a narrow, line-shaped beam spot. Angle calculations are given for the adjustment of goniometer angles, and for the effective azimuth and tilt of the scattering vector for general angle settings in a four-circle goniometer. The latter is necessary for the computation of stresses from lattice strain measurements.


2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Runmei Ding ◽  
Zixin He ◽  
Meilin Wang ◽  
Danian Tian ◽  
Peipei Cen

AbstractBased on 2-(4-pyridyl)-terephthalate (H2pta) and oxalate ligands, two new lanthanide-containing coordination polymers (CPs), [Tb(pta)(C2O4)0.5(H2O)2)]·2H2O (1) and [Sm(pta)(C2O4)0.5(H2O)2)]·2H2O (2), have been synthesized under solvothermal conditions. The structures of both 1 and 2 have been determined by single-crystal X-ray diffraction. Infrared, elemental analysis, powder X-ray diffraction and thermogravimetric analysis data are also presented. The crystals of 1 and 2 exhibit isostructural layer-like networks, crystallizing in the triclinic space group P$‾{1}$. The layers are further stabilized and associated into 3D architectures through hydrogen bonding. Remarkably, the CPs 1 and 2 exhibit excellent water stability and remarkable thermostability with thermal decomposition temperatures of more than 420 °C.


Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1572
Author(s):  
Baku Nagendra ◽  
Paola Rizzo ◽  
Christophe Daniel ◽  
Lucia Baldino ◽  
Gaetano Guerra

Poly(ʟ-lactide) (PLLA) films, even of high thickness, exhibiting co-crystalline and crystalline α phases with their chain axes preferentially perpendicular to the film plane (c⊥ orientation) have been obtained. This c⊥ orientation, unprecedented for PLLA films, can be achieved by the crystallization of amorphous films as induced by low-temperature sorption of molecules being suitable as guests of PLLA co-crystalline forms, such as N,N-dimethylformamide, cyclopentanone or 1,3-dioxolane. This kind of orientation is shown and quantified by two-dimensional wide-angle X-ray diffraction (2D-WAXD) patterns, as taken with the X-ray beam parallel to the film plane (EDGE patterns), which present all the hk0 arcs centered on the meridian. PLLA α-form films, as obtained by low-temperature guest-induced crystallization, also exhibit high transparency, being not far from those of the starting amorphous films.


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