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

作者：Kai Fu, Houqiang Fu, Xuguang Deng, Po-Yi Su, Hanxiao Liu, Kevin Hatch, Chi-Yin Cheng, D. C. Messina, Reza Vatan Meidanshahi, Prudhvi Peri, Chen Yang, Tsung-Han Yang, Jossue Montes, Jingan Zhou, Xin Qi, Stephen M. Goodnick, F. A. Ponce, David J. Smith, R. J. Nemanich, Yuji Zhao · 发表于：Applied Physics Letters · 年份：2021 · DOI：10.1063/5.0049473 · 被引用次数：32 · 研究领域：GaN-based semiconductor devices and materials、Ga2O3 and related materials、Semiconductor materials and devices

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.