AlGaN表面坑状缺陷及GaN缓冲层位错缺陷对AlGaN/GaN HEMT电流崩塌效应的影响

利用金属有机气相外延(MOVPE)技术生长了具有不同AlGaN表面坑状缺陷和GaN缓冲层位错缺陷密度的AlGaN/GaN 高电子迁移率晶体管(HEMT)样品，并对比研究了两种缺陷对器件栅、漏延迟电流崩塌效应的影响.栅延迟测试表明，AlGaN表面坑状缺陷会引起栅延迟电流崩塌效应和源漏电阻的增加，而且表面坑状缺陷越多，栅延迟电流崩塌程度和源漏电阻的增加越明显.漏延迟测试显示，AlGaN表面坑状缺陷对漏延迟电流崩塌影响不大，而GaN缓冲层位错缺陷主要影响漏延迟电流崩塌.研究结果表明，AlGaN表面坑状缺陷和Ga 关键词： AlGaN/GaN HEMT 电流崩塌 坑状缺陷 位错缺陷

Influence of pit defects on AlGaN surface and dislocation defects in GaN buffer layer on current collapse of AlGaN/GaN HEMTs

The influence of pit defects on AlGaN surface and dislocation defects in GaN buffer layer on the current collapse of MOVPE-grown AlGaN/GaN high electron mobility transistors (HEMTs) is studied in this paper. Pulsed gate voltage measurements show that the surface pit defects result in gate lag current collapse and increased of source/drain resistance. And the more pit defects exist, the more obvious current collapse and increased source/drain resistance are observed. Pulsed drain voltage measurements show that the drain lag current collapse, which is almost unaffected by the surface pit defects, can be associated with the dislocation defects in GaN buffer layer. Our experimental results indicate that pit defects on AlGaN surface and dislocation defects in GaN buffer layer can be one of the origins of gate lag and drain lag current collapse, respectively.