Demonstration of 3500-V 4H-SiC Lateral MOSFETs

High-voltage 4H-SiC lateral MOSFETs with different gate layouts, channel lengths, and drift region lengths were fabricated on the (0001) face of a high-purity semi-insulating substrate. A breakdown voltage of 3520 V was achieved on a circular gate device with a channel length of 5 μm and a drift region length of 80 μm. This is, to the best knowledge of the authors, the highest value among 4H-SiC lateral MOSFETs ever reported. The specific on-resistance is 600 mΩ-cm², which results in a figure-of-merit (BV²/R_onsp) of 20.6 MW/cm², which is comparable with other 4H-SiC lateral MOSFETs reported in the literature. It was found that the use of a circular gate layout effectively reduces the reverse leakage current at high voltages.