Patent ID: 7230284

Claim:
A high electron mobility transistor (HEMT), comprising: a GaN based high resistivity semiconductor layer; a GaN based barrier semiconductor layer on said high resistivity semiconductor layer, said barrier layer having a wider bandgap than said high resistivity semiconductor layer; a two-dimensional electron gas between said barrier layer and said high resistivity semiconductor layer; respective source and drain contacts directly contacting said barrier layer and said GaN based high resistivity semiconductor layer; an insulating layer positioned on said barrier layer; and a gate contact on said insulating layer, said insulating layer forming a barrier against gate leakage current and increasing the HEMT's maximum current drive, wherein said insulating layer comprises a layer of silicon nitride and a layer of aluminum nitride, said aluminum nitride layer providing a spacer between said barrier layer and said silicon nitride insulating layer to reduce doping and degradation of said barrier layer during growth of said silicon nitride layer.