Effects of buffer leakage current on breakdown characteristics in AlGaN/GaN HEMTs with a high-k passivation layer

Hideyuki Hanawa, Yoshiki Satoh, Kazushige Horio

Research output: Contribution to journalArticle

5 Citations (Scopus)


A two-dimensional analysis of off-state breakdown characteristics in AlGaN/GaN HEMTs is performed by considering a deep donor and a deep acceptor in a buffer layer, with the relative permittivity of passivation layer ε<inf>r</inf> as a parameter. The analysis is made with and without impact ionization of carriers to study how the buffer leakage current affects the breakdown performance. It is shown that when ε<inf>r</inf> is low, the breakdown voltage is determined by the impact ionization of carriers, and when ε<inf>r</inf> becomes high, it is determined by the buffer leakage current. This buffer leakage current decreases as ε<inf>r</inf> increases because the electric field at the drain edge of the gate is weakened, and hence the breakdown voltage increases as ε<inf>r</inf> increases. It is also shown that when the gate voltage is more negative, the breakdown voltage in the high ε<inf>r</inf> region becomes higher because the buffer leakage current becomes smaller.

Original languageEnglish
Pages (from-to)96-99
Number of pages4
JournalMicroelectronic Engineering
Publication statusPublished - 2015 Nov 1



  • Breakdown voltage
  • Buffer leakage current
  • GaN HEMT
  • High-k passivation layer

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Surfaces, Coatings and Films
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics

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