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

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Veröffentlicht in:Applied physics letters 2021-05, Vol.118 (22)
Hauptverfasser: Fu, Kai, Fu, Houqiang, Deng, Xuguang, Su, Po-Yi, Liu, Hanxiao, Hatch, Kevin, Cheng, Chi-Yin, Messina, Daniel, Meidanshahi, Reza Vatan, Peri, Prudhvi, Yang, Chen, Yang, Tsung-Han, Montes, Jossue, Zhou, Jingan, Qi, Xin, Goodnick, Stephen M., Ponce, Fernando A., Smith, David J., Nemanich, Robert, Zhao, Yuji
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Sprache:eng
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Zusammenfassung: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.
ISSN:0003-6951
1077-3118
DOI:10.1063/5.0049473