SiO/sub 2//AlGaN/GaN MOSHFET with 0.7 /spl mu/m gate-length and f/sub max//f/sub T/ of 40/24 GHz

The performance of SiO/sub 2//AlGaN/GaN MOSHFETs is described. The C-V measurements showed slight increase in sheet carrier density after applying 12 nm-thick PECVD SiO/sub 2/. The devices exhibited gate leakage current of 5/spl times/10/sup -10/ A/mm. Small-signal RF characterisation of 0.7 /spl mu/m gate length devices yielded an f/sub T/ of 24 GHz and an f/sub max/ of 40 GHz, which are comparable to those typical for state-of-the-art AlGaN/GaN HFETs.