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.
N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall
M. Noborio et al., "Lateral 4H-SiC MOSFETs with Low On-Resistance by Using Two-Zone Double RESURF Structure", Materials Science Forum, Vols. 556-557, pp. 815-818, 2007