Thermal Effect on Dynamic R_on Degradation of p-GaN AlGaN/GaN HEMTs on SiC Substrates

Abstract

In this work, the thermal effect in the dynamic on-resistance (R_on) degradation of normally-off p-GaN AlGaN/GaN HEMTs on SiC substrates has been analyzed using pulse-mode voltage stress. Compare to the significant degradation characteristics of GaN-on-Si HEMTs, a suppressed dynamic R_on degradation is achieved in GaN-on-SiC due to higher thermal boundary conduction with less ionized acceptor-like buffer traps. Different electrical characteristics have been discussed to reveal the traps mechanisms related to thermal effect. Finally, two-dimension device simulation has been carried out to probe the physical insight into the thermal effect on the dynamic R_on degradation.