Trap Density Estimation for TDDB Testing in SiC Power MOSFETs

Abstract The trap density estimation of SiC power MOSFET in time-dependent dielectric breakdown (TDDB) was investigated by using experiment and TCAD simulation. 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 four-state nonradiative multi phonon (NMP) defect capture model, the mechanism and modeling of I GSS current spike was studied. Based on TCAD simulation, the characteristics of gate oxygen donor traps including trap energy level, trap density, and position distribution were estimated, and the trap density model in TDDB experiment was proposed and verified. This study may contribute to the estimation of trap density in SiC MOSFET.