Simulation and Analysis of High Breakdown Voltage AlGaN/GaN MOSHEMTs with TiO2/Al2O3 Gate Dielectric

Abstract

Recently we have demonstrated the thermal oxidized TiO2/Al2O3 as gate dielectric for AlGaN/GaN metal-oxide-semiconductor high-electron-mobility-transistors (MOS-HEMTs) with enhanced breakdown voltage of 490 V compared with 60-100 V breakdown voltage for normal HEMTs. The characteristics of GaN-based MOS-HEMTs with TiO2/Al2O3 gate dielectrics are measured and simulated using Sentaurus Device Software. The significant improvement of breakdown voltage of MOS-HEMTs with TiO2/Al2O3 gate oxide was analyzed. It is shown that the effect of TiO2 on surface electric potential distribution results in the improvement of breakdown voltage. This work will represent a solid basis for improvement of breakdown voltage and enhancement of the device reliability.