Trap density estimation for TDDB testing in SiC power MOSFETs

Abstract The trap density estimation of SiC power MOSFETs in time-dependent dielectric breakdown (TDDB) was investigated using experiments and TCAD simulations. The gate leakage current ( I GSS ) under negative voltage was measured and a current spike was found which was linearly shifted with TDDB stress. Based on a four-state nonradiative multi-phonon defect capture model, the mechanism and modeling of the I GSS current spike was studied. Based on TCAD simulations, the characteristics of the gate oxygen donor traps, including trap energy level, trap density, and position distribution, were estimated, and the trap density model for the TDDB experiment was proposed and verified. This study may contribute to the estimation of trap density in SiC MOSFETs.