Abstract
AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs) using Si3N4 film as a gate insulator have been successfully fabricated. The gate leakage current decreased by about three orders of magnitude compared to that of the conventional AlGaN/GaN HEMTs without the Si3N4 gate insulator. The low-frequency noise of the MIS-HEMTs was smaller than that of the conventional HEMTs. Current collapse has also been suppressed in the MIS-HEMTs.