On the use of TCAD for the thermal analysis of RF power transistors and its application to a GaN-on-SiC HEMT with a diamond composite flange

This paper reports on the use of TCAD for thermal simulation of GaN-on-SiC HEMT RF power transistors. Firstly, the results are compared with those obtained using ANSYS Mechanical Pro, then the advantages of TCAD for thermal analysis are detailed, and finally it is used to analyze a GaN HEMT on a diamond composite flange which offers a very substantial reduction in thermal resistance. This is believed to be the first report of a kW-level GaN HEMT RF power transistor manufactured on a diamond composite flange.