Analytical Thermal Model for AlGaN/GaN HEMTs Using Conformal Mapping Method

An analytical thermal model for AlGaN/GaN high-electron-mobility transistors (HEMTs) is proposed in this article. By means of the conformal mapping technique, the device structure is transformed into a simplified geometry, and the solution to the heat conduction equation is easily obtained. The model is capable of accurately predicting the maximum temperature rise of the device channel. Moreover, based on the superposition principle, this model provides an accurate estimation of thermal coupling between the gate fingers of multifinger devices, as well as the temperature rise of each gate finger. In addition, the temperature-dependent and orthotropic properties of thermal conductivity can also be taken into consideration. The proposed model provides an efficient prediction of hot spots in AlGaN/GaN devices. The accuracy of this model is verified by the simulation results and experimental data.