Threshold-Voltage Instability in SiC MOSFETs Due to Near-Interfacial Oxide Traps

摘要

There are two basic mechanisms that affect the threshold-voltage (V_T) stability: oxide-trap activation and oxide-trap charging. Once additional oxide traps are activated, then they are free to participate in the charge-trapping processes that can, especially for older-vintage devices, result in large V_T shifts and potential device failure. More recent commercially-available devices show much smaller effects, and minimal trap activation. Given the dramatic improvements, it is now imperative that improved test methods be employed to properly separate out bad devices from good devices.