Observation of partial relaxation mechanisms via anisotropic strain relief on epitaxial islands using semiconductor nanomembranes
| Autor: | Barbara L. T. Rosa, Angelo Malachias, Luciana Dornellas Pinto, L. A. B. Marçal, Rodrigo R. de Andrade, Wagner N. Rodrigues, Patricia L. Souza, Ricardo Nunes, Mauricio P. Pires |
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| Rok vydání: | 2017 |
| Předmět: |
Diffraction
Materials science Bioengineering 02 engineering and technology 010402 general chemistry Epitaxy 01 natural sciences law.invention Condensed Matter::Materials Science law Lattice (order) General Materials Science Electrical and Electronic Engineering Anisotropy Condensed matter physics business.industry Mechanical Engineering General Chemistry 021001 nanoscience & nanotechnology Anisotropic strain Synchrotron 0104 chemical sciences Semiconductor Mechanics of Materials Transmission electron microscopy 0210 nano-technology business |
| Zdroj: | Nanotechnology. 28:305702 |
| ISSN: | 1361-6528 0957-4484 |
| DOI: | 10.1088/1361-6528/aa78e7 |
| Popis: | In this work we attempt to directly observe anisotropic partial relaxation of epitaxial InAs islands using transmission electron microscopy (TEM) and synchrotron x-ray diffraction on a 15 nm thick InAs:GaAs nanomembrane. We show that under such conditions TEM provides improved real-space statistics, allowing the observation of partial relaxation processes that were not previously detected by other techniques or by usual TEM cross section images. Besides the fully coherent and fully relaxed islands that are known to exist above previously established critical thickness, we prove the existence of partially relaxed islands, where incomplete 60° half-loop misfit dislocations lead to a lattice relaxation along one of the 〈110〉 directions, keeping a strained lattice in the perpendicular direction. Although individual defects cannot be directly observed, their implications to the resulting island registry are identified and discussed within the frame of half-loops propagations. |
| Databáze: | OpenAIRE |
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