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.

研究了 650 V SiC 二极管和 900 V SiC MOSFET 在不同偏置电压和不同质子能量下的质子诱导退化和灾难性故障。实验结果表明，当 SiC 二极管和 MOSFET 的偏置电压达到额定电压的 88% 时，20 MeV 质子不会导致两个 SiC 器件的单粒子烧毁（SEB）。SiC器件烧毁时，会出现波形脉冲电流，脉冲电流峰值逐渐减小，总脉冲电流宽度在5微秒以内。随着偏置电压的增加，SiC器件的SEB注量显着降低。SiC二极管烧坏后，其反向击穿电压低于1V，器件未开启时的正向电流比辐照前高8个数量级；SiC MOSFET 的反向击穿电压在烧坏后也低于 1 V，只有部分 SiC MOSFET 在 700 V 的偏压下仍保持传输特性，栅源电流相比增加了 7-8 个数量级辐照前。Monte Carlo模拟结果表明，外延层中20 MeV质子的线性能量转移（LET）低于2 MeV·cm² /mg，这不足以产生 SEB 所需的电荷。质子与器件材料相互作用的随机性导致不同质子能量下 SiC 器件的 SEB 通量不同。