Numerical analysis of breakdown voltage enhancement in AlGaN/GaN HEMTs with a high-k passivation layer

Hideyuki Hanawa, Hiraku Onodera, Atsushi Nakajima, Kazushige Horio

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41 Citations (Scopus)


2-D analysis of breakdown characteristics in AlGaN/GaN high electron mobility transistors (HEMTs) is performed by considering a deep donor and a deep acceptor in a buffer layer. The dependence of the OFF-state breakdown voltage on the relative permittivity of the passivation layer r and the thickness of the passivation layer d are studied. It is shown that as r increases, the OFF-state breakdown voltage increases. This is because the electric field at the drain edge of the gate is weakened as r increases. This occurs because in the insulator the applied voltage tends to drop uniformly in general, and hence when the insulator is attached to the semiconductor, the voltage drop along the semiconductor becomes smoother at the drain edge of the gate if the r of the insulator is higher. It is also shown that the OFF-state breakdown voltage increases as d increases because the electric field at the drain edge of the gate is weakened as d increases. It is concluded that AlGaN/GaN HEMTs with a high-k and thick passivation layer should have high breakdown voltages.

Original languageEnglish
Article number6712055
Pages (from-to)769-775
Number of pages7
JournalIEEE Transactions on Electron Devices
Issue number3
Publication statusPublished - 2014 Mar



  • 2-D analysis
  • GaN high electron mobility transistor (HEMT)
  • breakdown voltage
  • high-k passivation layer

ASJC Scopus subject areas

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

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