An Accurate Electrical and Thermal Co-Simulation Framework for Modeling High-Temperature DC and Pulsed I - V Characteristics of GaN HEMTs

High-electron mobility transistors (HEMTs) employing AlGaN/GaN heterostructures are suitable for high-power and high-frequency applications. To meet target specifications, GaN HEMTs must be designed and optimized by accurately considering the coupling of electrical and thermal characteristics, from the static to the pulsed regimes of operation. Toward this, we implement an electro-thermal modeling and simulation framework for experimentally fabricated GaN on SiC HEMTs and use the framework to predict the high-temperature performance of the technology, up to 448 K. We utilize the transient measurement data at different ambient temperatures to extract the trap characteristics, which are important to understand from the RF dispersion perspective. Our work highlights the significance of the thermal boundary conditions at the source, drain, and gate metal electrodes and the impact of heat dissipation paths on the lattice temperature rise and I-V characteristics. Overall, our work provides a physical insight into the thermal response of GaN HEMTs and can facilitate suitable thermal management strategies of the device over a broad range of DC and transient operating conditions.