TDDB and HTGB Study of SiC MOSFET with Excessive Channel Leakage

We identify one type of outlier SiC MOSFET device from massive parametric test that shows excessive channel leakage and abnormal subthreshold swing (S S-TH ) at low V G (<1 V) and low I D (<100 nA). Time-dependent dielectric breakdown (TDDB) and high temperature gate bias stress (HTGB) tests have been performed on these outlier devices to check their reliability. TDDB lifetime is shorter for a device with a higher S S-TH , but there is no indication that the S S-TH outliers would lead to an extrinsic failure. The post-PBTI I D -V G curve of the outlier device is overall shifted rightward and the off-state leakage at V G =0 V is lower. The post-NBTI S S-TH is reduced at I D <100 nA and the off-state leakage is almost unchanged.