Demonstration of Constant-Gate-Charge Scaling to Increase the Robustness of Silicon Carbide Power MOSFETs

We introduce the concept of constant-gate-charge scaling to increase the short-circuit withstand time of SiC power MOSFETs without increasing their ON-state resistance, gate charge, or oxide field. In gate-charge scaling, we scale the oxide thickness and gate drive voltage, keeping the oxide field constant. Short-circuit measurements on 1200 V SiC double-implanted MOSFETs (DMOSFETs) confirm that short-circuit withstand times can be increased by 2- 4× without increasing ON-resistance, simply by reducing the oxide thickness and the gate drive voltage.