Abstract
We measured the drain bias stress effects in normally off mode AlGaN/GaN (JHFETs) with a p-GaN gate, whose AlGaN barrier was exposed to air by dry etching. A large current collapse and a memory effect decreased the drain current (I-DS). I-DS of an unpassivated sample became the off leakage level of normally off mode JHFETs at a drain stress bias of 15 V. On the other hand, I-DS in SiN-passivated JHFETs decreased at a slow rate upon applying drain stress bias. The decrease in I-DS in SiN-passivated JHFETs was almost the same as that in as-grown HFETs. These drain stress and memory effects were perfectly deletable by light exposure, and were rewritable similarly in an EPROM. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim