Single Event Gate Rupture in SiC MOS Capacitors with Different Gate Oxide Thicknesses

The leakage current through the gate oxide of MOS capacitors fabricated on n-type 4H-Silicon Carbide (SiC) was measured under accumulation bias conditions with heavy-ion irradiation. The Linear Energy Transfer (LET) dependence of the critical electric field (E-cr) at which dielectric breakdown occurred in these capacitors with two different oxide thicknesses was evaluated. The MOS capacitors with thin gate oxide showed higher E-cr values than those with thick gate oxide. The linear relationship between the reciprocal E and LET was observed for both MOS capacitors. The slope of LET dependence of 1/E-cr for SiC MOS capacitors was smaller than that for Si, suggesting that SiC MOS devices are less susceptible to single-event gate rupture (SEGR) than Si MOS devices.