Enhancement-mode n -channel GaN MOSFETs fabricated on p -GaN using HfO ₂ as gate oxide

Enhancement-mode n-channel GaN MOSFETs with overlap gate structure using thick HfO2 as a gate insulator have been fabricated. The maximum transconductance of 45 mS/mm is seven times larger, to our knowledge, than the best-reported value of GaN MOSFETs with SiO2 gate oxide.