Analysis of the thermal resistance and performance degradation of 4H-SiC PiN power diode

The excellent physical and electronic properties of SiC recently takes itself to be the focused power device material for high temperature high power and high frequency application. In this paper, the model is established through simulation method Ansys14.0, studying the factors affecting the thermal resistance of PiN diode. Increasing the area or decreasing the thickness of the chip and the solder layer can reduce the thermal resistance effectively. At last we give a thermodynamic model of the device in Sentaurus TCAD software, modeling the temperature phenomenon and self-heating effects on performance degradation of 4H-SiC PiN diode, finally we analysis and forecast the failure mechanism of similar SiC devices. Results show that the higher the temperature, the higher heat flux generated by the section of the device will be to promote temperature, and the smaller the temperature gradient inside and outside the device which leads heat conducted, hence resulting in increased current degradation.