The optimised design and characterization of 1200 V / 2.0 mΩ cm2 4H-SiC V-groove trench MOSFETs

V-groove trench MOSFETs with the 4H-SiC{0-33-8} face as the trench sidewall for the channel region have been investigated. The on-resistance and breakdown voltage strongly depend on the aperture ratio of the buried p⁺ regions. The VMOSFETs with the buried p⁺ regions of 71% on a 6-inch wafer exhibited a low specific on-resistance of 2.0 mΩ cm² with 1200 V blocking voltage. The threshold voltage is 2.3 V at 175°C, which shows the VMOSFETs have tolerability for an erroneous ignition under high temperature. The switching capability showed low switching losses over DMOSFETs on 4° off 4H-SiC(0001) face and normal operation under fast switching repetitive test (40 Vns^-1). The stability of the threshold voltage was demonstrated by HTGB tests.