TCAD analysis of self heating in AlGaN/GaN HEMTs under pulsed conditions

The purpose of this work was to develop a TCAD device model to study the electrical and thermal characteristics of the AlGaN/GaN HEMT in the time domain in contrast to a DC thermal equilibrium analysis. We first examined a channel temperature technique that utilizes temperature dependence of gate voltage on gate current to predict channel temperature. The predicted channel temperature of Method 3104 of MIL-STD 750D is then compared to the simulated temperature profile to determine the corresponding temperature location in the HEMT structure. Second, we investigated the performance of single and multiple pulses effects on heating of the HEMT. Third, we studied and compared the heating between the DC analysis and a RF transient (multiple pulses) analysis with the same average device power. Finally, we observed large temperature gradients in the device in initial device heating not capable of being observed with conventional DC TCAD analysis.