Design Optimization of High Breakdown Voltage AlGaN/GaN High Electron Mobility Transistor with Insulator Dielectric Passivation Layer

Abstract

AlGaN/GaN high electron mobility transistors (HEMTs) possess favorable material properties and are compatible with large-scale manufacturing, making them promising as a next-generation power device. However, there is a lack of information available on the effect of an insulator dielectric passivation layer on the breakdown voltage (V_br) of AlGaN/GaN HEMTs. This study utilizes technology computer aided design to investigate the impact of different insulator dielectric passivation layers, such as SiO₂, SiN, Al₂O₃, and HfO₂, on V_br of AlGaN/GaN HEMTs. Furthermore, the study optimizes the parameters of the field plate length (L_FP) and insulator thickness to maximize V_br of AlGaN/GaN HEMTs. Results indicate that HEMTs with a field plate (FP-HEMTs) have greater V_br than HEMTs without a field plate (N-HEMTs). With the optimized conditions of a 1.8 µm L_FP and a 0.95 µm insulator thickness with HfO₂ passivation, V_br of 1120 V is achieved. The findings suggest that the field plate (FP) and passivation layer can significantly improve the efficiency and reliability of AlGaN/GaN HEMTs while the impact of AlGaN/GaN heterostructure parameters on V_br is minimal.