| 학회 | 한국재료학회 |
| 학술대회 | 2016년 가을 (11/16 ~ 11/18, 경주 현대호텔) |
| 권호 | 22권 2호 |
| 발표분야 | F. 광기능/디스플레이 재료 분과 |
| 제목 | Reduction of threading dislocations in GaN layer using partially crystallized cavity engineered sapphire substrate |
| 초록 | Recently, we have reported a new growth scheme of using a cavity engineered sapphire substrate (CES) in which cavity patterns were arrayed on a sapphire substrate [1]. Amorphous alumina layer was deposited on a photoresist patterned sapphire substrate and subsequent high temperature annealing resulted in the formation of a cavity array surrounded by a crystallized sapphire shell. During the growth of GaN layer on the CES, undesired GaN crystal was deposited on the cavity patterns, generating the additional threading dislocations. This is because the pattern was fully crystallized intosingle crystalline alpha phase from the sapphire substrate, by solid phase epitaxy (SPE) during the annealing. In this research, we investigated the growth of high quality GaN layer on a partially crystallized CES in which only the planar region between the patterns was crystallized by SPE. The morphological evolution of the GaN layers grown on the partially crystallized CES was investigated by scanning electron microscopy. It was observed that the parasitic GaN growth on top of the cavity patterns was suppressed and the GaN layer from the planar area was coalesced on top of the pattern without disturbance by the undesired GaN crystal. As a result, it was found that the threading dislocation density in the GaN layer grown on the partially crystallized CES was reduced by ~ 30 % compared to that on the fully crystallized CES. Details of the growth mechanism will be discussed in the presentation. [1] Jang et al., Journal of Crystal Growth, 430, 41–45 (2015) |
| 저자 | 장정환1, 이승민1, 최대한1, 임혜진1, 박용조2, 윤의준1 |
| 소속 | 1서울대, 2차세대융합기술(연) |
| 키워드 | LED; GaN; threading dislocation |
