Numerical investigation on thermal characteristics of GaN HFETs for high power applications

In this paper, numerical investigation on GaN HFETs is carried out using hybrid finite element method (FEM) which combines the FEM with the preconditioned conjugated gradient technique. The maximum temperatures of the HFETs operating under continious-waves (CW) and pulsed-waves (PW) are both captured accurately. The effects of temperaturedependent thermal conductivities of the materials on the temperature distribtion are also studied and compared for different substrate materials, such as sapphire, silicon, and SiC.