X-ray rocking curve imaging on large arrays of extremely tall SiGe microcrystals epitaxial on Si

2021 ◽  
Vol 54 (4) ◽  
Author(s):  
Mojmír Meduňa ◽  
Ondřej Caha ◽  
Emanuil Choumas ◽  
Franco Bressan ◽  
Hans von Känel
Keyword(s):  
Imaging Technique ◽  
Sample Surface ◽  
Real Space ◽  
Peak Position ◽  
Pixel Detector ◽  
Laboratory Equipment ◽  
Rocking Curve ◽  
X Ray ◽  
Local Lattice ◽  
The Individual

This work investigates layers of densely spaced SiGe microcrystals epitaxially formed on patterned Si and grown up to extreme heights of 40 and 100 µm using the rocking curve imaging technique with standard laboratory equipment and a 2D X-ray pixel detector. As the crystalline tilt varied both within the epitaxial SiGe layers and inside the individual microcrystals, it was possible to obtain real-space 2D maps of the local lattice bending and distortion across the complete SiGe surface. These X-ray maps, showing the variation of crystalline quality along the sample surface, were compared with optical and scanning electron microscopy images. Knowing the distribution of the X-ray diffraction peak intensity, peak position and peak width immediately yields the crystal lattice bending locally present in the samples as a result of the thermal processes arising during the growth. The results found here by a macroscopic-scale imaging technique reveal that the array of large microcrystals, which tend to fuse at a certain height, forms domains limited by cracks during cooling after the growth. The domains are characterized by uniform lattice bending and their boundaries are observed as higher distortion of the crystal structure. The effect of concave thermal lattice bending inside the microcrystal array is in excellent agreement with the results previously presented on a microscopic scale using scanning nanodiffraction.

Defect structure analysis of polycrystalline materials by computer-controlled double-crystal diffractometer with position-sensitive detector

1983 ◽  
Vol 16 (1) ◽  
pp. 89-95 ◽  
Author(s):  
R. Yazici ◽  
W. Mayo ◽  
T. Takemoto ◽  
S. Weissmann
Keyword(s):  
Position Sensitive Detector ◽  
Polycrystalline Materials ◽  
Sensitive Detector ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Local Lattice ◽  
Position Sensitive ◽  
The Individual ◽  
Double Crystal Diffractometer

The method represents an extension of a previously developed X-ray double-crystal diffractometer method when a film was used to record the crystallite reflections, each reflecting crystallite being regarded as the second crystal of a double-crystal diffractometer. By utilizing a position-sensitive detector (PSD) with interactive computer controls, the tedious and limiting task of data acquisition and analysis is greatly simplified. The specimen is irradiated with crystal-monochromated radiation and the numerous microscopic spots emanating from the reflecting crystallites are recorded separately by the position-sensitive detector and its associated multichannel analyzer at each increment of specimen rotation. An on-line minicomputer simultaneously collects these data and applies the necessary corrections. This process is then automatically repeated through the full rocking-curve range. The computer carries out the rocking-curve analysis of the individual crystallite reflections as well as that of the entire reflecting crystallite population. The instrument is provided with a specimen translation device which permits analysis of large sections of solid specimens. Thus, sites of local lattice defects induced either mechanically, chemically or by radiation can rapidly be established and quantitatively determined in terms of rocking-curve parameters as well as imaged by X-ray topography, by inserting a film in front of the PSD. The versatility and usefulness of the method is demonstrated by examples given from studies of fracture, fatigue and stress-corrosion cracking of commercial alloys.

Mosaicity and Wafer Bending in SiC Wafers as Measured by Double and Triple Crystal X-Ray Rocking Curve and Peak Position Maps

2007 ◽  
Vol 556-557 ◽  
pp. 213-218 ◽  
Author(s):  
K.W. Kirchner ◽  
Kenneth A. Jones ◽  
Michael A. Derenge ◽  
Michael Dudley ◽  
Adrian R. Powell
Keyword(s):  
Laser Light ◽  
Peak Position ◽  
Etch Pit Density ◽  
Normal Position ◽  
Rocking Curve ◽  
X Ray ◽  
Etch Pit ◽  
Density Map ◽  
Beam Transmission ◽  
Si Wafer

Double and triple crystal rocking curve and peak position maps are constructed for a 4HSiC wafer for the symmetric (0 0 0 8) reflection in the normal position, the same reflection for a sample rotated 90º, and an asymmetric (1 23 6) reflection for the wafer in the normal position. These measurements were corrected for the ‘wobble’ in the instrument by scanning a 4” (1 1 1) Si wafer and assuming that the Si wafer was perfect and attributing the variations in the measurements to instrumental error. The x-ray measurements are correlated with a cross polar image, etch pit density map, white beam transmission x-ray topograph, and a laser light scan.

scholarly journals Large-surface-area diamond (111) crystal plates for applications in high-heat-load wavefront-preserving X-ray crystal optics

2016 ◽  
Vol 23 (5) ◽  
pp. 1118-1123 ◽  
Author(s):  
Stanislav Stoupin ◽  
Sergey Antipov ◽  
James E. Butler ◽  
Alexander V. Kolyadin ◽  
Andrey Katrusha
Keyword(s):  
Surface Area ◽  
Heat Load ◽  
Crystal Surface ◽  
High Heat ◽  
Peak Position ◽  
Large Surface Area ◽  
Crystal Optics ◽  
Rocking Curve ◽  
X Ray ◽  
High Heat Load

Fabrication and results of high-resolution X-ray topography characterization of diamond single-crystal plates with large surface area (10 mm × 10 mm) and (111) crystal surface orientation for applications in high-heat-load X-ray crystal optics are reported. The plates were fabricated by laser-cutting of the (111) facets of diamond crystals grown using high-pressure high-temperature methods. The intrinsic crystal quality of a selected 3 mm × 7 mm crystal region of one of the studied samples was found to be suitable for applications in wavefront-preserving high-heat-load crystal optics. Wavefront characterization was performed using sequential X-ray diffraction topography in the pseudo plane wave configuration and data analysis using rocking-curve topography. The variations of the rocking-curve width and peak position measured with a spatial resolution of 13 µm × 13 µm over the selected region were found to be less than 1 µrad.

scholarly journals InSegtCone: Interactive Segmentation of crystalline Cones in compound eyes

2020 ◽  
Author(s):  
Pierre Baptiste Thomas Tichit ◽  
Tunhe Zhou ◽  
Hans Martin Kjer ◽  
Vedrana Andersen Dahl ◽  
Anders Bjorholm Dahl ◽  
...  
Keyword(s):  
High Throughput ◽  
Imaging Technique ◽  
Compound Eyes ◽  
Interactive Segmentation ◽  
X Ray ◽  
Micro Tomography ◽  
The Individual ◽  
3D Anatomy ◽  
High Throughput Imaging ◽  
Computing Method

Understanding the diversity of eyes is crucial to unravel how different animals use vision to interact with their respective environments. To date, comparative studies of eye anatomy are scarce because they often involve time-consuming or inefficient methods. X-ray micro-tomography is a promising high-throughput imaging technique that enables to reconstruct the 3D anatomy of eyes, but powerful tools are needed to perform fast conversions of anatomical reconstructions into functional eye models. We developed a computing method named InSegtCone to automatically segment the crystalline cones in the apposition compound eyes of arthropods. Here, we describe the full auto-segmentation process, showcase its application to three different insect compound eyes and evaluate its performance. The auto-segmentation could successfully label the full individual shapes of 60%-80% of the crystalline cones, and is about as accurate and 250 times faster than manual labelling of the individual cones. We believe that InSegtCone can be an important tool for peer scientists to enable extensive comparisons of the diversity of eyes and vision in arthropods.

Dislocation contrast on X-ray topographs under weak diffraction conditions

2021 ◽  
Vol 54 (4) ◽  
Author(s):  
Hongyu Peng ◽  
Tuerxun Ailihumaer ◽  
Yafei Liu ◽  
Balaji Raghotharmachar ◽  
Xianrong Huang ◽  
...  
Keyword(s):  
Ray Tracing ◽  
Grazing Incidence ◽  
Local Lattice Distortion ◽  
Rocking Curve ◽  
Distinctive Features ◽  
X Ray ◽  
Orientation Contrast ◽  
Weak Beam ◽  
Local Lattice ◽  
Contrast Analysis

The contrast of dislocations in 4H-SiC crystals shows distinctive features on grazing-incidence X-ray topographs for diffraction at different positions on the operative rocking curve. Ray-tracing simulations have previously been successfully applied to describe the dislocation contrast at the peak of a rocking curve.The present work shows that the dislocation images observed under weak diffraction conditions can also be simulated using the ray-tracing method. These simulations indicate that the contrast of the dislocations is dominated by orientation contrast. Analysis of the effective misorientation reveals that the dislocation contrast in weak-beam topography is more sensitive to the local lattice distortion, consequently enabling information to be obtained on the dislocation sense which cannot be obtained from the peak.

Upsampling speckle patterns for coherent X-ray diffraction imaging

2013 ◽  
Vol 46 (2) ◽  
pp. 319-323 ◽  
Author(s):  
Y. Chushkin ◽  
F. Zontone
Keyword(s):  
Diffraction Pattern ◽  
Imaging Technique ◽  
Real Space ◽  
Field Of View ◽  
Combination Method ◽  
Pixel Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Imaging ◽  
Diffraction Patterns

Coherent X-ray diffraction imaging is a lensless imaging technique where an iterative phase-retrieval algorithm is applied to the speckle pattern, the far-field diffraction pattern produced by an isolated object. To ensure convergence to a unique solution, the diffraction pattern must be oversampled by a factor of two or more. Since the resolution in real space depends on the maximum wave vector where the intensity is detected,i.e.on the detector field of view, there is a practical limitation on oversampling in reciprocal space and resolution in real space that is ultimately determined by the number of pixels. This work shows that it is possible to reduce the effective pixel size and maintain the detector field of view by applying a linear combination method to shifted diffraction patterns. The feasibility of the method is demonstrated by reconstructing the images of test objects from diffraction patterns oversampled in each dimension by factors of 1.3 and 1.8 only. The described approach can be applied to any diffraction or imaging technique where the resolution is compromised by a large pixel size.

Distribution and Burgers vectors of dislocations in semiconductor wafers investigated by rocking-curve imaging

2005 ◽  
Vol 38 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Daniel Lübbert ◽  
Claudio Ferrari ◽  
Petr Mikulík ◽  
Petra Pernot ◽  
Lukas Helfen ◽  
...  
Keyword(s):  
Large Scale ◽  
Random Distribution ◽  
High Spatial Resolution ◽  
Sample Surface ◽  
X Ray Diffraction ◽  
Semiconductor Wafer ◽  
Rocking Curve ◽  
X Ray ◽  
Dislocation Densities ◽  
Distribution Of Dislocations

The method called `rocking-curve imaging' (RCI) has recently been developed to visualize lattice imperfections in large crystals such as semiconductor wafers with high spatial resolution. The method is based on a combination of X-ray rocking-curve analysis and digital X-ray diffraction topography. In this article, an extension of the method is proposed by which dislocation densities in large-scale samples (semiconductor wafer crystals) can be quantified and their variation across the sample surface determined in an instrumentally simple way. Results from a nearly dislocation-free S-doped InP crystal and a semi-insulating GaAs are presented; both display a clearly non-random distribution of dislocations.

Rocking-Curve Peak Shift in Thin Heterojunction Single Layers

1989 ◽  
Vol 145 ◽  
Author(s):  
C.R. Wie ◽  
Y-W. Choi ◽  
H.M. Kim ◽  
J.F. Chen ◽  
T. Vreeland ◽  
...  
Keyword(s):  
Thin Layer ◽  
Thick Layer ◽  
Diffraction Theory ◽  
Peak Shift ◽  
Peak Position ◽  
Thin Layers ◽  
Simple Method ◽  
Rocking Curve ◽  
X Ray ◽  
Layer Peak

AbstractA simple method for determining layer composition and mismatch of semiconductor hetero-epitaxial samples is by measuring the separation of peaks in x-ray rocking curve (XRC). This method fails if the peak separation is affected by other factors. For a small layer thickness, the layer peak position is affected by the x-ray amplitudes of the substrate or other thicker layers through the interference and overlap effects. In this case, a diffraction theory fitting process is necessary for a correct determination of layer parameters. We have used dynamical and kinematical x-ray diffraction theories to calculate the layer peak position as a function of its thickness for various layer/substrate combinations. These two theories yield substantially different results, indicating that the kinematical diffraction theory analysis is no longer valid for these thin layers. When a thick layer is present along with the thin layer, the thick layer is more influential than the substrate to the thin layer peak position, making the dynamical theory fitting necessary even from higher thickness.

Resolution of X-Ray Rocking Curve Measurements Made with Finite Counting Statistics

2015 ◽  
Vol 24 (03n04) ◽  
pp. 1550007 ◽  
Author(s):  
Tedi Kujofsa ◽  
John E. Ayers
Keyword(s):  
Peak Position ◽  
Bragg Angle ◽  
Full Width ◽  
Half Maximum ◽  
Peak Width ◽  
Effective Number ◽  
Rocking Curve ◽  
X Ray ◽  
Experimental Resolution ◽  
Counting Statistics

We have analyzed the strain resolution of x-ray rocking curve profiles from measurements of the peak position and peak width made with finite counting statistics. In this work, we have considered x-ray rocking curves which may be Gaussian or Lorentzian in character and have analyzed the influence of the effective number of counts, full-width-at-half-maximum (FWHM) and the Bragg angle on the resolution. Often experimental resolution values are estimated on the order of 10−5 whereas this work predicts more sensitive values (10−9) with smaller FWHM and larger effective counts and Bragg angles.

Mosaicity and Wafer Bending in SiC Wafers as Measured by Double and Triple Crystal X-Ray Rocking Curve and Peak Position Maps

2007 ◽  
pp. 213-218
Author(s):  
K.W. Kirchner ◽  
Kenneth A. Jones ◽  
Michael A. Derenge ◽  
Michael Dudley ◽  
Adrian R. Powell
Keyword(s):  
Peak Position ◽  
Rocking Curve ◽  
X Ray
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