The impact of interfacial Si contamination on GaN-on-GaN regrowth for high power vertical devices

Kai Fu, Houqiang Fu, Xuguang Deng, Po Yi Su, Hanxiao Liu, Kevin Hatch, Chi Yin Cheng, Daniel Messina, Reza Vatan Meidanshahi, Prudhvi Peri, Chen Yang, Tsung Han Yang, Jossue Montes, Jingan Zhou, Xin Qi, Stephen M. Goodnick, Fernando A. Ponce, David J. Smith, Robert Nemanich, Yuji Zhao

Research output: Contribution to journalArticlepeer-review

Abstract

The development of gallium nitride (GaN) power devices requires a reliable selective-area doping process, which is difficult to achieve because of ongoing challenges associated with the required etch-then-regrow process. The presence of silicon (Si) impurities of unclear physical origin at the GaN regrowth interface has proven to be a major bottleneck. This paper investigates the origin of Si contamination at the epitaxial GaN-on-GaN interface and demonstrates an approach that markedly reduces its impact on device performance. An optimized dry-etching approach combined with UV-ozone and chemical etching is shown to greatly reduce the Si concentration levels at the regrowth interface, and a significant improvement in a reverse leakage current in vertical GaN-based p-n diodes is achieved.

Original languageEnglish (US)
Article number222104
JournalApplied Physics Letters
Volume118
Issue number22
DOIs
StatePublished - May 31 2021
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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