Reliability Study of AlN Passivation Effects on AlGaN/GaN HEMT Using Fully-Coupled Self-Consistent Electro-Thermo-Mechanical Analysis

[[abstract]]In this study, the effect of AlN materials as passivation over AlGaN layer on AlGaN/GaN HEMTs performance was investigated using fully-coupled electro-thermo-mechanical analysis by TCAD simulations and analytic calculations. It found that AlN passivation layer on AlGaN/GaN HEMTs effectively spread the surface heat resulting in reduction of the maximum lattice temperature and enhances the electrical and mechanical properties. The drain current in the AlGaN/GaN device with AlN-passivation significantly increases about 30% higher than AlGaN/GaN unpassivated device which is in a good agreement with previous study. This study also demonstrates that the current collapse can be suppressed by dielectric AlN passivation