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

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 (Vbr) 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 Vbr of AlGaN/GaN HEMTs. Furthermore, the study optimizes the parameters of the field plate length (LFP) and insulator thickness to maximize Vbr of AlGaN/GaN HEMTs. Results indicate that HEMTs with a field plate (FP-HEMTs) have greater Vbr than HEMTs without a field plate (N-HEMTs). With the optimized conditions of a 1.8 µm LFP and a 0.95 µm insulator thickness with HfO2 passivation, Vbr 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 Vbr is minimal.