Estimation of Thermal Resistance of AlGaN/GaN HEMT Using CAD

To ensure reliability and optimal temperatures in the AlGaN/GaN HEMT structure, it is necessary to evaluate the thermal resistance, which characterizes heat removal from the active region. Electrothermal modeling using commercial CAD software allows us to predict the thermal resistance during the design process of HEMT devices. However, this process requires qualified developers who can solve problems related to preparing data pre- and postprocessing, creating an accurate three-dimensional model of the semiconductor device and optimizing the time for solving the three-dimensional problem numerically. This paper presents approaches for engineering calculations of thermal resistance and temperature distribution in the AlGaN/GaN HEMT structure using both commercial universal CAD and specialized Q3D software. The results of modeling the thermal resistance and temperature distribution inside the HEMT structure are demonstrated. The calculated thermal resistance values are consistent with the estimates obtained in other works for GaN transistors fabricated on a Si substrate. The presented approaches have been utilized to calculate the temperature and thermal resistance for various semiconductor structures, including Si, SiGe, GaN, etc., as well as modern SiP structures, at the design stage.