Constant-Gate-Charge Scaling for Increased Short-Circuit Withstand Time in SiC Power Devices

Abstract

SiC unipolar power devices have ~350× lower drift region resistance than silicon devices at a given blocking voltage, but their higher power density reduces their short-circuit withstand time (SCWT). We propose to increase the SCWT of SiC MOSFETs and IGBTs by reducing their oxide thickness and gate drive voltage, keeping the gate charge and oxide field constant. This increases their SCWT with no impact on on-state or blocking performance, and requires no changes to existing designs or mask sets.