Structural and optical properties of epitaxially laterally overgrown a-plane GaN epilayer on SiO2 stripe patterned r-plane sapphire

• Published in: Electronic materials letters Vol. 9; no. 5; pp. 587 - 592
• Main Authors: Lee, Yong Seok, Kim, Hun, Seo, Tae Hoon, Park, Ah Hyun, Lee, Seul Be, Chung, Sang Jo, Choi, Chel-Jong, Suh, Eun-Kyung
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.09.2013; 대한금속·재료학회
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Coalescing; Condensed Matter Physics; Materials Science; Nanotechnology; Nanotechnology and Microengineering; Optical and Electronic Materials; 전자/정보통신공학; plane; GaN; MOCVD
• ISSN: 1738-8090; 2093-6788
• DOI: 10.1007/s13391-013-3065-7

We have studied the structural anisotropic characteristics of epitaxially laterally overgrown (ELOG) a -plane GaN epilayer on r -plane sapphire substrate with two different SiO 2 -stripe orientations using metal organic chemical vapor deposition. The SiO 2 stipe patterns were made along [0001] and crystographilic orientations of GaN which correspond to and directions of r -plane sapphire, respectively. The ELOG a -plane GaN on [0001]-stripe orientation reveals symmetric morphology in the extent of lateral overgrowth compared to that grown on -oriented stripe. Threading dislocation and basal stacking fault densities in wing region were ∼8 × 10 7 cm −2 and ∼5.2 × 10 4 cm −1 , respectively. Raman measurement of the fully coalesced a-plane GaN indicated a compressive strain of about 0.39 Gpa in the window region.