| Autor: |
Wang, Huan Huan, Wu, Fang Zhen, Byrapa, Sha Yan, Yang, Yu, Raghothamachar, Balaji, Dudley, Michael, Chung, Gil, Zhang, Jie, Thomas, Bernd, Sanchez, Edward K., Mueller, Stephan G., Hansen, Darren M., Loboda, Mark J. |
| Zdroj: |
Materials Science Forum; February 2014, Vol. 778 Issue: 1 p332-337, 6p |
| Abstrakt: |
Nomarski optical microscopic, KOH etching and synchrotron topographic studies are presented of faint needle-like surface morphological features in 4H-SiC homoepitaxial layers. Grazing incidence synchrotron white beam x-ray topographs show V shaped features which transmission topographs reveal to enclose 1/4[0001] Frank-type stacking faults. Some of these V-shaped features have a tail associated with them and are referred to as Y-shaped defects. Geometric analysis of the size and shape of the V-shaped faults indicates that they are fully contained within the epilayer and appear to be nucleated at the substrate/epilayer interface. Detailed analysis shows that the positions of the V-shaped stacking faults match with the positions of c-axis threading dislocations with Burgers vectors of c or c+a in the substrate and thus appear to result from the deflection of these dislocations onto the basal plane during epilayer growth. Similarly, the Y-shaped defects match well with the substrate surface intersections of c-axis threading dislocations with Burgers vectors of c or c+a in the substrate which were deflected onto the basal plane during substrate growth. Based on the observed morphology of these defect configurations we propose a model for their formation mechanism. |
| Databáze: |
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