Optimization of gate insulator material for GaN MIS-HEMT

Abstract

Metal-insulator-semiconductor (M-I-S) structure has been employed for GaN HEMTs to suppress gate leakage current. In this work, various gate insulator materials including SiO2, HfO2, La2O3, HfO2/SiO2 and La2O3/SiO2 were investigated for GaN MIS-HEMT application. It is found that GaN MIS-HEMT with La2O3/SiO2 composite oxide results in better device performance and reliability as compared to other gate insulator materials.