Gate leakage in AlGaN/GaN HEMTs and its suppression by optimization of MOCVD growth

Yugang Zhou, Rongming Chu, Jie Liu, Kevin J. Chen, Kei May Lau

Research output: Contribution to journalArticle

10 Scopus citations

Abstract

Gate-drain current-voltage characteristics in unpassivated AlGaN/GaN high electron mobility transistors (HEMTs) grown by metal-organic chemical vapor deposition (MOCVD) on sapphire substrates were investigated. Under a fixed V/III ratio for AlGaN layer growth, the growth window for getting low gate leakage and good two-dimensional electron gas mobility is narrow. We designed a multi-step growth of the AlGaN for HEMTs, i.e., high-V/III-ratio AlGaN layer starting from the AlGaN/GaN interface, then low-V/m-ratio AlGaN layer, which yielded the best 2DEG mobility and also reduced gate leakage. It was also found that the forward current and reverse current before pinch off can be explained by the thin surface barrier (TSB) model, and the AlGaN layer grown under lower effective V/m ratio shows a larger surface donor density but smaller leaky area.

Original languageEnglish (US)
Pages (from-to)2663-2667
Number of pages5
JournalPhysica Status Solidi C: Conferences
Volume2
Issue number7
DOIs
Publication statusPublished - Nov 7 2005

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

Cite this