X-ray rocking curve imaging on large arrays of extremely tall SiGe microcrystals epitaxial on Si
| Autor: | Emanuil Choumas, Mojmír Meduňa, Ondřej Caha, Franco Bressan, Hans von Känel |
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| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Diffraction Materials science Physics::Instrumentation and Detectors Scanning electron microscope business.industry Lattice (group) 02 engineering and technology Crystal structure Bending 021001 nanoscience & nanotechnology Epitaxy 01 natural sciences General Biochemistry Genetics and Molecular Biology Optics Distortion 0103 physical sciences X-ray crystallography 0210 nano-technology business |
| Zdroj: | Journal of Applied Crystallography. 54:1071-1080 |
| ISSN: | 1600-5767 |
| DOI: | 10.1107/s1600576721004969 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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