Use of hydrogen etching to remove existing dislocations in GaN epitaxial layers

Yen Hsien Yeh, Chung Ming Chu, Yin Hao Wu, Ying Chia Hsu, Tzu Yi Yu, Wei-I Lee

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

In this paper, based on the anisotropic nature of hydrogen (H2) etching on GaN, we describe a new approach to the removal of threading dislocations in GaN layers. The top surfaces of c-plane (Ga-face) and a-plane GaNs are considered stable in H2; therefore, H2 etches only crystal imperfections such as dislocation and basal plane stacking fault (BSF) sites. We used H2 to etch undoped c-plane GaN, n-type c-plane GaN, a-plane GaN, and an InGaN/GaN multiple quantum well structure. Several examinations were performed, indicating deep cavities on the c-plane GaN samples after H2 etching; furthermore, gorge-like grooves were observed on the a-plane GaN samples. The deep cavities on the c-plane GaN were considered the etched dislocation sites, and the gorge-like grooves on the a-plane GaN were considered the etched BSF sites. Photoluminescence measurements were performed and the results indicated that the H2-etched samples demonstrate superior optoelectronic properties, probably because of the elimination of dislocations.

Original languageEnglish
Article number085002
JournalSemiconductor Science and Technology
Volume30
Issue number8
DOIs
StatePublished - 1 Aug 2015

Keywords

  • basal plane stacking fault
  • dislocation
  • hydrogen etching
  • semiconducting III-Vmaterial

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