Effect of ON-State Stress on SiC DMOSFET Subthreshold I-V Characteristics

We have observed a noticeable increase in the instability of the I-V characteristics following an ON-state current stress, especially in the subthreshold region. An increased stretch-out and negative shift can give rise to increased leakage current in the OFF-state if proper precautions are not met to provide a proper margin for the threshold voltage. State-of-the-art 50-A MOSFETs exhibit less instability than previous 20-A devices, and devices that run hotter show a larger degradation.