Affiliation:
1. Key Laboratory of Nano-Devices and Application, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences (CAS), Suzhou 215123, People's Republic of China
2. School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei 230026, People's Republic of China
3. Guangdong Institute of Semiconductor Micro-Nano Manufacturing Technology, Foshan 528000, People's Republic of China
Abstract
We implemented invisibility criterion and black–white contrast orientation analysis into low-tilt electron channeling contrast imaging (ECCI) for dislocation-type discrimination in GaN and AlGaN layers grown on a Si(111) substrate. Our ECCI and x-ray diffraction (XRD) analysis attained consistent threading dislocation densities for GaN and AlGaN grown on Si, but demonstrated drastic discrepancy in the percentage of edge-type dislocations, potentially due to the lack of appropriate consideration of mixed-type [Formula: see text] dislocations in XRD. Further ECCI analysis of GaN/AlGaN heterointerface revealed mixed-type [Formula: see text] dislocation half-loops and dislocation bending due to compressive strain relaxation, validating that not all the dislocations originated from the mosaic or columnar structure. As a result, XRD analysis based on the mosaic block model does not give reliable edge-to-screw dislocation ratio. The observation of classic van der Merwe–Matthews-type dislocation half-loop nucleation and dislocation gliding could be associated with potential GaN/AlGaN optoelectronic device degradation issues.
Funder
Suzhou Institute of Nanotechnology, Chinese Academy of Sciences
National Key Research and Development Program of China
Special Project for Research and Development in Key areas of Guangdong Province
National Natural Science Foundation of China
Key Research Program of Frontier Science, Chinese Academy of Sciences
Bureau of International Cooperation, Chinese Academy of Sciences
Jiangsu Provincial Key Research and Development Program
Science and Technology Program of Suzhou
Jiangxi Provincial Department of Science and Technology
Subject
General Physics and Astronomy