Test Methods and Principles of Thermal Resistance for GaN HEMT Power Devices

As a new generation of power devices, GaN HEMT power devices have the advantages of high operating temperature, high power density and high operating frequency, which can greatly improve the performance of power electronic systems. In order to give full play to the high operating temperature and high-power density characteristics of GaN HEMT power devices, it is necessary to reduce the thermal resistance of the device as much as possible. Due to the device structure and working principle are different from silicon-based devices, the test method of thermal resistance is also different. In this paper, the channel on-resistance (Ron) and the forward voltage drop between gate and source (Vf-gate) are used as temperature-sensitive electrical parameters (TSEPs) to test the thermal characteristics of the GaN HEMT device, and the test methods and principles of thermal resistance of the GaN HEMT device is given by analyzing the different structures. For GaN HEMT devices with junction-gate structure, Ron and Vf-gate can be used as TESP for the thermal resistance test; For GaN HEMT devices without junction-gate structure, Ron can be used as TSEP for the thermal resistance test.