Impact of heavy-ion irradiation on gate oxide reliability of silicon carbide power MOSFET

SiC power MOSFETs were exposed to Br-79, Cu-64, and Ti-47 ions with different biases. After irradiation, the static parameters of the device did not change significantly. The oxide reliability is also not affected after ON-state irradiation. However, noticeable degradation of gate oxide reliability has been found after heavy-ion exposure with extremely low drain bias(50 V). The degradation is attributed to defects in the gate oxide. According to the analysis of the experimental results, the defects are caused by the high electric field induced by the partial SEGR effect during heavy-ion irradiation.