Analysis of Displacement Damage Induced by Silicon-Ion Irradiation in SiC MOSFETs

Silicon carbide metal-oxide-semiconductor field-effect transistors (SiC MOSFETs) are irradiated by Si ions with different energies. The drain current, current slope, and gate-drain capacitance ( $C_{\mathrm {gd}}$ ) decrease significantly. Also, the threshold voltage shifts. Gamma-ray experiments confirm that the shift in the threshold voltage ( $\Delta V_{\mathrm {TH}}$ ) results from the ionizing effect induced by Si ions. Simultaneously, the decreases in drain current, current slope, and $C_{\mathrm {gd}}$ are attributed to displacement damage (DD). Based on the results of analysis of nonionizing energy loss (NIEL) and primary knock-on atoms (PKAs), the decreases in current and slope are due to the defects in the bulk, which will lead to the decrease of carrier mobility and the increase of recombination rate. Through technology computer aided design (TCAD) simulation, it is found that the defects in the bulk will cause the drain current and the slope of the linear region to decrease. The defects at the interface cause the slope of the subthreshold curve to decrease. The variation law of simulation results is basically consistent with that of the experimental results. The mechanism of DD is verified. This research serves as a valuable reference for high-energy particle irradiation.