Study on proton-induced single event effect of SiC diode and MOSFET

Proton-induced degradation and catastrophic failures in 650 V SiC diode and 900 V SiC MOSFET under different bias voltage and different proton energy are investigated. The experimental results show that when the bias voltage of SiC diode and MOSFET reaches 88% of rated voltage, 20 MeV protons will not cause the single event burnout (SEB) of two SiC devices. When SiC devices are burned out, a wave-shaped pulse current appears, the pulse current peak value gradually decreases, and the total pulse current width is within 5 microseconds. With the increase of bias voltage, the SEB fluence of SiC device is significantly reduced. After SiC diode is burned out, its reverse breakdown voltage is lower than 1 V, and the forward current when device has not been turned on is up to 8 orders of magnitude higher than before irradiation; the reverse breakdown voltage of SiC MOSFET is also lower than 1 V after burning out, only some SiC MOSFETs still maintain transfer characteristics under a voltage bias of 700 V, and the gate-source current has increased by 7–8 orders of magnitude compared to before irradiation. The Monte Carlo simulation results show that the linear energy transfer (LET) of 20 MeV proton in the epitaxial layer is lower than 2 MeV·cm²/mg, which is not enough to generate charge required for SEB. And the randomness of interaction between protons and device materials leads to different SEB fluences for SiC devices under different proton energies.