Journal of the Korean Crystal Growth and Crystal Technology (한국결정성장학회지)

The Korea Association of Crystal Growth (한국결정성장학회)
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Surface morphology variation during wet etching of GaN epilayer grown by HVPE

HVPE법으로 성장시킨 GaN 단결정의 wet etching에 의한 표면 변화

  • Oh, Dong Keun (Division of Materials Science and Engineering, Hanyang University) ;
  • Choi, Bong Geun (Division of Materials Science and Engineering, Hanyang University) ;
  • Bang, Sin-Yeong (Division of Materials Science and Engineering, Hanyang University) ;
  • Kang, Suk Hyun (Division of Materials Science and Engineering, Hanyang University) ;
  • Kim, So Yeon (Division of Materials Science and Engineering, Hanyang University) ;
  • Kim, Sae Am (Division of Materials Science and Engineering, Hanyang University) ;
  • Lee, Seong Kuk (UNIMO Photron) ;
  • Chung, Jin Hyun (UNIMO Photron) ;
  • Kim, Kyoung Hun (Korea Institute of Ceramic Engineering and Technology) ;
  • Shim, Kwang Bo (Division of Materials Science and Engineering, Hanyang University)
  • Received : 2012.09.14
  • Accepted : 2012.10.05
  • Published : 2012.12.31
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Abstract

In this paper, we investigated characteristics of etching induced surface morphology variation by wet etching of GaN epilayer were grown on sapphire (0001) substrate by hydride vapor phase epitaxy (HVPE). As a results of scanning electron microscope (SEM) observation, three types of hexagonal etch pits (Edge, Screw, Mixed) were formed by the GaN epilayer thickness variations. A lot of etch pits, attributed to screw and mixed type TD, were observed at thinner epilayer, leading to high etch pit density. On the other hand, the thickness of GaN epilayer increased with the number of etch pits corresponding to edge and mixed dislocations, which are the majority of TDs are observed.

본 연구에서는 HVPE법으로 사파이어 기판(0001) 위에 성장시킨 GaN epilayer의 etching에 따른 표면변화 특성을 조사하였다. 주사전자 현미경(SEM) 관찰 결과, 3가지 형태를 갖는 육각형 모양의 etch pit(edge, screw, mixed) 들이 GaN epilayer의 두께 변화에 따라서 형성되었다. 이러한 관통전위들은(TDs) epilayer의 두께가 얇고, etch pit density가 높을수록 screw and mixed type TDs이 많이 관찰되었고, 두께가 증가할수록 etch pit density가 낮아지면서 edge and mixed type TDs들이 주로 존재하는 것을 관찰 할 수 있었다.

Keywords

References

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