Unifying Model for Estimating SELC/SEB in SiC Power Devices Using a Nonlinear Ion Track Resistance

Switching energy measurements, such as those found on datasheets, are used to estimate ion-induced leakage and burnout thresholds in SiC power devices with voltage ratings ranging from 600 V to 10 kV. This method, plus knowledge of the device area, provides an inexpensive and efficient evaluation of the radiation tolerance of these devices prior to irradiation at heavy ion facilities. The comparison made between switching energy measurements and heavy ion data validates the depletion capacitance energy storage model published in literature over the entire range of low- and high-LET leakage and burnout, suggesting that leakage and burnout are the same mechanism with varying levels of severity. In addition, TCAD simulation/analysis in this work indicate that thevariable, non-linear, ion-induced carrier mobility modulation explains the leakage and burnout threshold trends vs. LET seen in measured data for SiC power devices. Specifically, the track resistance saturation at high LET, combined with the capacitive energy and discharge model, explains why both SELC and SEB voltages saturate at high LET, and allows the entire SELC or SEB vs. LET curve to be estimated analytically from structural parameters.