Effects of Electron Irradiation and Thermal Cycling on Electrical Properties of SiC MOSFET

SiC MOSFET plays an important role in the application of power devices in the aerospace field due to its excellent physical properties, but its performance still faces severe challenges from temperature changes and high-intensity radiation in space. In this work, the effects of electron irradiation and thermal cycles on SiC MOSFET devices were studied. The experimental and simulation results show that the electron irradiation makes oxide capture a large number of positive charges, which leads to the negative drift of threshold voltage. When the irradiation dose is 1Mrad, the threshold voltage is reduced by 17%. The thermal cycling induced stress concentration at the SiC/SiO2 interface results in lattice dislocation and mismatch at the interface, which increases the amount of charge. After 120 cycles, the threshold voltage of the devices is reduced by 32.75%. On this basis, the same device was subjected to electron irradiation and thermal cycling in turn. The experimental results show that thermal cycling can further aggravate the threshold voltage drift induced by electron irradiation.