A Unified 4H-SIC Mosfets TDDB Lifetime Model Based on Leakage Current Mechanism

The leakage currents of 4H-SiC MOSFET were measured at different gate voltages and temperatures, which revealed the critical condition of differentiating FN tunneling current from Ohmic current and FP emission. By assuming that the critical conditions indicated the applicable conditions of E model and l/E model, a unified time-dependent-dielectric-breakdown (TDDB) model was proposed, which predicted a TDDB lifetime longer than that of E model, and lower than that of l/E model. Keywords-TDDB lifetime model; FN tunneling; Ohmic current; FP emission; 4H-SiC MOSFETs; E model; l/Emodel