LAUSR

This letter reports an E-mode GaN MIS-HEMT using a composite La₂O₃/HfO₂ gate insulator for power device applications. The composite dielectric formed an amorphous LaHfOx layer after post-deposition annealing. The GaN MIS-HEMT with amorphous LaHfOx gate dielectric showed good oxide film quality and excellent HfLaOx/GaN interface properties, as demonstrated by the measured C–V characteristics. Consequently, the E-mode MIS-HEMT was determined to show good ${V} _{\mathrm {th}}$ stability with only a slight increase in the dynamic ${R} _{\mathrm {on}}$ after high drain bias stress.