Improved Crystal Quality and Surface Morphology of Nonpolar a-plane GaN Grown on r-plane Sapphire Substrates
Improved Crystal Quality and Surface Morphology of Nonpolar a-plane GaN Grown on r-plane Sapphire Substrates
- 주제(키워드) Nonpolar , GaN , MOCVD , Crystallinity , Surface morphology
- 발행기관 한국물리학회
- 발행년도 2011
- 총서유형 Journal
- UCI G704-000411.2011.58.41.012
- KCI ID ART001545044
- 본문언어 영어
초록/요약
In this paper, we report on the improved crystal quality and surface morphology of nonpolar a-plane ([11-20]) GaN layers grown on r-plane ([1-102]) sapphire substrates by using a metal-organic chemical vapor deposition. Both the reactor pressure and the V/III ratio were modulated using twosteps during the growth in order to optimize the growth conditions for the fully coalesced GaN layers with smooth surfaces. As a result, a root-mean-square roughness of 0.678 nm was observed with atomic-force microscopy for the nonpolar a-plane GaN, and the full-widths at half-maximum values of the omega-rocking curve were 432 and 648 arcsec from the c- and the m-direction parallel scans, respectively. The low-temperature photoluminescence spectra were also investigated to identify the origin of the improvement in the crystallinity.
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