Influence of Distributed Capacitance on Switching Characteristics of 6500V SiC MOSFET

Compared with silicon power devices, SiC devices have attracted much attention due to their advantages in high voltage, frequency, and operating temperature. With the continuous improvement of the voltage level and switching speed of SiC MOSFET devices, a higher transient electric field will be generated, during the turn-on and turn-off process of the device. When a semiconductor device dynamic test system is used to evaluate the switching characteristics, the distributed capacitance in the test circuit will introduce an additional current difference under a high transient electric field, thereby affecting the evaluation of the switching characteristics of the device. In order to study the influence of distributed capacitance on the switching characteristics of high-voltage SiC MOSFET devices, this paper establishes an equivalent circuit model considering distributed capacitance, theoretically analyzes the influence of distributed capacitance on the switching characteristics of the device, and the influence law of distributed capacitance is studied with the simulation tools. Finally, The switching waveforms of the 6500V SiC MOSFET device are obtained through actual measurement to verify the correctness of the theory.