Investigation of Performance of Double-Trench SiC Power MOSFETs in Forward and Reverse Quadrant Operation

Abstract:
In this paper, dynamic switching performance at 1st quadrant and 3rd quadrant operation of Silicon and Silicon Carbide (SiC) trench, double-trench, superjunction and planar power MOSFETs is analysed through a wide range of experimental measurements. The devices are evaluated on a high voltage clamped inductive switching test rig and switched with a range of switching rates at elevated junction temperatures. It is shown experimentally that, at 1st quadrant, CoolSiC MOSFET and SiC Double trench MOSFET show good stability in regard to temperature variations. Silicon superjunction MOSFETs perform unacceptably at turn-OFF transient due to their large input capacitance and are unstable with temperature variation due to the more temperature-dependent CGD. SiC Planar MOSFET also performs poorly at turn-ON switching due to its low transconductance and gate threshold voltage variation leading to variations of switching rate with temperature at both turn-ON and turn-OFF transients. At 3rd quadrant, Silicon Superjunction MOSFET causes large switching loss due to its long reverse recovery process, while SiC Double trench MOSFET and CoolSiC MOSFET show stable performance with temperature variation due to the negligible reverse recovery charge.