Reverse Leakage Analysis for As-Grown and Regrown Vertical GaN-on-GaN Schottky Barrier Diodes

Kai Fu, Jingan Zhou, Xuguang Deng, Xin Qi, David J. Smith, Stephen M. Goodnick, Yuji Zhao, Houqiang Fu, Xuanqi Huang, Tsung Han Yang, Chi Yin Cheng, Prudhvi Ram Peri, Hong Chen, Jossue Montes, Chen Yang

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Vertical GaN-on-GaN Schottky barrier diodes based on as-grown and regrown samples were fabricated to investigate the effects of the etch-then-regrow process on device performance. The surface roughness increased slightly after dry etching and decreased after regrowth. According to X-ray diffraction results, the etch-then-regrow process caused a slight increase of defect density due to increased edge dislocations. Schottky parameters extracted from forward current-voltage curves, such as turn-on voltages of 0.74 V and 0.72 V, ideality factors of 1.07 and 1.10, and barrier heights of 1.07 eV and 1.05 eV, were obtained for diodes based on the regrown and as-grown samples, respectively. The breakdown voltage of the regrown sample was much lower than the as-grown sample. The regrowth interface can be regarded as a n-doping GaN layer due to the high interface charge density after the etch-then-regrown process. This equivalent {n} -doping GaN layer reduced the effective thickness of the UID-GaN under the Schottky contact thus causing lower breakdown voltage for the regrown sample. Poole-Frenkel emission and trap-assisted tunneling processes were responsible for the leakage of both as-grown and regrown samples according to the temperature dependence of the reverse currents.

Original languageEnglish (US)
Article number8949530
Pages (from-to)74-83
Number of pages10
JournalIEEE Journal of the Electron Devices Society
Volume8
DOIs
StatePublished - 2020

Keywords

  • GaN-on-GaN
  • Schottky barrier diodes
  • interface
  • leakage
  • regrow

ASJC Scopus subject areas

  • Biotechnology
  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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