Modeling, Simulation and Analysis of Thermal Resistance in Multi-finger AlGaN/GaN HEMTs on SiC Substrates

The effects of varying layout geometries and various thermal boundary resistances (TBRs) on the thermal resistance of multi-finger AlGaN/GaN HEMTs are thoroughly investigated using a combination of a two-dimensional electro-thermal model coupled with the three-dimensional thermal model. Temperature measurement using micro-Raman thermography is performed to verify and enhance the accuracy of the thermal model. Simulation results indicate that thermal resistance weakly depends on the layout design because of the high thermal conductivity of SiC. Meanwhile, the analysis reveals that optimizing the TBR of the device could efficiently reduce the thermal resistance since TBR takes a significant proportion of the total thermal resistance.