Trenched epitaxial lateral overgrowth of fast coalesced a-plane GaN with low dislocation density

Te Chung Wang, Tien Chang Lu, Tsung Shine Ko, Hao Chung Kuo, Min Yu, Sing Chung Wang, Chang Cheng Chuo, Zheng Hong Lee, Hou Guang Chen

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Abstract

The crystal quality of a -plane GaN films was improved by using epitaxial lateral overgrowth on trenched a -plane GaN buffer layers. Not only the threading dislocation density but also the difference of anisotropic in-plane strain between orthogonal crystal axes can be mitigated by using trenched epitaxial lateral overgrowth (TELOG). The low threading dislocation density investigated by the cross-sectional transmission electron microscopy was estimated to be 3× 107 cm-2 on the N-face GaN wing. On the other hand, the Ga-face GaN wing with a faster lateral overgrowth rate could be influenced by the thin GaN layer grown on the bottom of the trenches, resulting in higher dislocation density generated. As a result, the authors concluded that a narrower stripped GaN seeds and deeper stripped trenches etched into the surface of sapphire could derive a better quality a -plane GaN film. Finally, they demonstrated the fast coalescence process of TELOG GaN films below 10 μm thick.

Original languageEnglish
Article number251109
JournalApplied Physics Letters
Volume89
Issue number25
DOIs
Publication statusPublished - 2006 Dec 1

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All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

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