Self-consistent electro-thermo-mechanical analysis of AlN passivation effect on AlGaN/GaN HEMTs

In this article, the effect of AlN materials as passivation over AlGaN layer on AlGaN/GaN HEMTs performance was investigated firstly using electro-thermo-mechanical coupled methodology by both TCAD simulation and analytic calculation. It suggested that AlN passivation layer over AlGaN layer effectively spread the surface heat from the channel resulting in reduction of the lattice temperature and enhances the mechanical properties. The drain current in the AlN-passivated device significantly increases about 30% higher than that in un passivated AlN layer device which is consistent with previous experimental data and demonstrates that the current collapse can be suppressed by dielectric AlN passivation process.