The impact of 10 MeV electron irradiation on switching characteristics of SiC MOSFET devices

The rigorous requirements of applications such as deep space exploration, nuclear power plants, and nuclear submarines, pose stringent demands on the radiation resistance of power devices. SiC exhibits excellent radiation resistance compared to Si, while the application of SiC power devices in electron radiation environments still requires further theoretical and experimental refinement. In particular, there is a lack of research on the impact of electron radiation on the switching characteristics of SiC power devices. In this work, we studied the electron radiation effects on the dynamic and static characteristics of SiC VDMOSFET via theoretical modeling, simulation analysis, and 10 MeV irradiation experiments. We further analyzed their radiation damage mechanisms, especially for the damage on the gate structure and drift region. Radiation-induced damage to the gate oxide is the main cause of changes in device characteristics. The experimental results demonstrate a nonlinear correlation between the radiation dose and the threshold voltage of SiC MOSFET devices. With the increase in radiation dose, the switching-on delay time and switching-off voltage/current change rate of the devices decrease, while the switching-off delay time and switching-on voltage/current change rate increase. Consequently, there is a reduction in switching-on losses and an increase in switching-off losses, which affect the thermal generation during the switching process of the device. We also conducted a comparative analysis with Si MOSFET devices. The dynamic and static characteristics of SiC MOSFET devices are found to be less affected by radiation compared to Si MOSFET devices, exhibiting superior radiation resistance.