AlN/GaN insulated gate HEMTs with HfO2 gate dielectric
AlN/GaN single heterojunction MOS-HEMTs grown by molecular beam epitaxy have been fabricated utilising HfO2 high-K dielectrics deposited by atomic layer deposition. Typical DC transfer characteristics of 1.3 µm gate length devices show a maximum drain current of 950 mA/mm and a transconductance of 210 mS/mm with gate currents of 5 µA/mm in pinch-off. Unity gain cutoff frequencies, ft and fmax, were measured to be 9 and 32 GHz, respectively.