Insulating gate III-N heterostructure field-effect transistors for highpower microwave and switching applications

Describes the properties of novel III-N-based insulating gate heterostructure fieldeffect transistors (HFETs). For the gate isolation, these devices use either SiO/sub 2/ layer (in metal-oxide-semiconductor HFET (MOSHFET) structures) or Si/sub 3/N/sub 4/ layer (in metal-insulator-semiconductor HFET structures). These insulating gate HFETs have the gate-leakage currents 4-6 orders of magnitude lower than HFETs, even at elevated temperatures up to 300(degree)C. A doubleheterostructure MOSHFET with SiO/sub 2/ gate isolation exhibits current collapsefree performance with extremely low gate-leakage current. Insulating gate devices, including large periphery multigate structures, demonstrate high-power stable operation and might find applications in high-performance power amplifiers and microwave and high-power switches with operating temperatures up to 300(degree) C or even higher.