Lateral 4H-SiC MOSFETs with Low On-Resistance by Using Two-Zone Double RESURF Structure
4H-SiC lateral MOSFETs with a double reduced surface field (RESURF) structure have been fabricated in order to reduce drift resistance. A two-zone RESURF structure was also employed in addition to double RESURF structure for achieving both high breakdown voltage and low on-resistance. After device simulation for dose optimization, 4H-SiC two-zone double RESURF MOSFETs have been fabricated. The fabricated MOSFETs block 1380 V and exhibit a low on-resistance of 66 m1cm2 (including a drift resistance of 24 m1cm2) at a gate oxide field of 3 MV/cm. The figure-of-merit of present device is about 29 MW/cm2, which is the best performance among any lateral MOSFETs. The drift resistance of the fabricated double RESURF MOSFETs is only 50 % or even lower than that of single RESURF MOSFETs. Temperature dependence of device characteristics is also discussed.