Effects of V/III ratio on a -plane GaN epilayers with an InGaN interlayer

• Published in: Chinese physics B 2014-02, Vol.23 (2), p.26801-1-026801-5
• Main Authors: Wang, Jian-Xia, Wang, Lian-Shan, Yang, Shao-Yan, Li, Hui-Jie, Zhao, Gui-Juan, Zhang, Heng, Wei, Hong-Yuan, Jiao, Chun-Mei, Zhu, Qin-Sheng, Wang, Zhan-Guo
• Format: Article
• Language: English
• Subjects: Crystal structure; Density; Gallium nitrides; Indium gallium nitrides; Interlayers; Morphology; Stacking faults; Strain
• ISSN: 1674-1056; 1741-4199
• DOI: 10.1088/1674-1056/23/2/026801

The effects of V/III growth flux ratio on a-plane GaN films grown on r-plane sapphire substrates with an InGaN interlayer are investigated. The surface morphology, crystalline quality, strain states, and density of basal stacking faults were found to depend heavily upon the V/III ratio. With decreasing V/III ratio, the surface morphology and crystal quality first improved and then deteriorated, and the density of the basal-plane stacking faults also first decreased and then increased. The optimal V/III ratio growth condition for the best surface morphology and crystalline quality and the smallest basal-plane stacking fault density of a-GaN films are found. We also found that the formation of basal-plane stacking faults is an effective way to release strain.