Improved high-voltage lateral RESURF MOSFETs in 4H-SiC

High-voltage lateral RESURF metal oxide semiconductor field effect transistors (MOSFETs) in 4H-SiC have been experimentally demonstrated, that block 900 V with a specific on-resistance of 0.5 Ω-cm² . The RESURF dose in 4H-SiC to maximize the avalanche breakdown voltage is almost an order of magnitude higher than that of silicon; however this high RESURF dose leads to oxide breakdown and reliability concerns in thin (100-200 nm) gate oxide devices due to high electric field (>3-4 MV/cm) in the oxide. Lighter RESURF doses and/or thicker gate oxides are required in SiC lateral MOSFETs to achieve highest breakdown voltage capability