Analysis of Reduction in Lag Phenomena and Current Collapse in Field-Plate AlGaN/GaN HEMTs with High Acceptor Density in a Buffer Layer

Yasunori Saito, Ryuhei Tsurumaki, Naohiro Noda, Kazushige Horio

Research output: Contribution to journalArticle

4 Citations (Scopus)


We make a two-dimensional transient analysis of field-plate AlGaN/GaN HEMTs with a semi-insulating buffer layer, where only a deep acceptor above the midgap is considered. The deep-acceptor density is varied between 10¹⁷ cm¯³ and 8x10¹⁷ cm¯³. It is studied how the deep-acceptor density and the field plate affect the buffer-related drain lag, gate lag and current collapse. It is shown that the lags and current collapse are reduced by introducing a field plate. This reduction occurs because electron trapping by the deep acceptors is weakened by the field plate. It is also shown that without a field plate, the drain lag and current collapse increase with increasing the deep-acceptor density as expected, although the gate lag decreases when the deep-acceptor density becomes high in the region between 2x10¹⁷ cm¯³ and 8x10¹⁷ cm¯³. On the other hand, with a field plate, surprisingly, the lags and current collapse decrease when the deep-acceptor density becomes high. This is attributed to the fact that the reduction in drain lag and current collapse by introducing a field plate becomes more significant when the deep-acceptor density becomes higher.

Original languageEnglish
JournalIEEE Transactions on Device and Materials Reliability
Publication statusAccepted/In press - 2017 Nov 30



  • AlGaN/GaN HEMT
  • Aluminum gallium nitride
  • buffer layer
  • Buffer layers
  • current collapse
  • deep acceptor
  • field plate
  • HEMTs
  • Logic gates
  • Mathematical model
  • two-dimensional analysis.
  • Wide band gap semiconductors

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Safety, Risk, Reliability and Quality
  • Electrical and Electronic Engineering

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