Enhancement-Mode GaN MIS-HEMTs With LaHfOx Gate Insulator for Power Application

Abstract

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-th stability with only a slight increase in the dynamic R-on after high drain bias stress.