Very high breakdown voltage and large transconductance realized on GaN heterojunction field effect transistors

We report record high breakdown voltages up to 340 and 230 V realized on unintentionally doped (1.5 mu m gate length) and Si doped (1 mu m gate length) AlGaN/GaN modulation doped field effect transistors (MODFETs), respectively. The devices also have large transconductances up to 140 mS/mm and a full channel current of 150-400 mA/mm. The Si doped MODFET sample demonstrated a very high room temperature mobility of 1500 cm(2)/Vs. With these specifications, GaN held effect transistors as microwave power devices are practical. (C) 1996 American Institute of Physics.