Inhomogeneous distribution of defect-related emission in Si-doped AlGaN epitaxial layers with different Al content and Si concentration

• 倉井, 聡

• Ushijima, Fumitaka

• Miyake, Hideto

• Hiramatsu, Kazumasa

• 山田, 陽一

Abstract

The spatial distribution of luminescence in Si-doped AlGaN epitaxial layers that differ in Al content and Si concentration has been studied by cathodoluminescence (CL) mapping in combination with scanning electron microscopy. The density of surface hillocks increased with decreasing Al content and with increasing Si concentration. The mechanisms giving rise to those hillocks are likely different. The hillocks induced surface roughening, and the compositional fluctuation and local donor-acceptor-pair (DAP) emission at hillock edges in AlGaN epitaxial layers were enhanced irrespective of the origin of the hillocks. The intensity of local DAP emission was related to Si concentration, as well as to hillock density. CL observation revealed that DAP emission areas were present inside the samples and were likely related to dislocations concentrated at hillock edges. Possible candidates for acceptors in the observed DAP emission that are closely related in terms of both Si concentration and hillock edges with large deformations are a VIII-SiIII complex and SiN, which are unfavorable in ordinary III-nitrides.

Journal

• Journal of applied physics

  Journal of applied physics 115 (5), 053509-, 2014

  American Institute of Physics

Keywords

• General Physics and Astronomy

Details

• CRID: 1050282812435974656
• NII Article ID: 120006364143
• DOI: 10.1063/1.4864020
• ISSN: 10897550
• ISSN: 00218979
• Web Site: https://petit.lib.yamaguchi-u.ac.jp/24679
• Web Site: https://pubs.aip.org/aip/jap/article-pdf/doi/10.1063/1.4864020/13712550/053509_1_online.pdf
• Text Lang: en
• Article Type: journal article
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