SiC vertical power MOSFETs are one of the most attractive topics in electric power device field. Compared to traditional semiconductor material Ge, Si and GaAs, the third generation wide band-gap material SiC has better physical and electrical properties, which is a great potential for the fabrication of the high temperature, high power and low power consumption electrical devices. In the great power and low consumption aspect, the 4H-SiC vertical MOSFETs with hign temperature and low on-resistance have wide application prospect.In this article an improvement has been presented for the traditional SiC-IEMOSFET and super junction MOS structure, which is based on the theory of power devices, inspired by the design idea of the IEMOS and ACCUFET. The three improved noval accumulation-mode IEMOS, up-epitaxy IEMOS and up-epitaxy superjunction structures have been researched by ISE TCAD 10.0.The accumulation-mode IEMOS has lower specific on-resistance of 2.1 mΩ·cm~2 than 4.3 mΩ·cm~2 of traditional IEMOS, higher effective channel mobility of 71.3 cm~2/(V·s) than 49.7 cm~2/(V·s). Compared to the accumulation-mode IEMOS, up-epitaxy IEMOS can greatly increase the inverse breakdown voltage from 1500V to 2300V, but the specific on-resistance is increased from 2.1 mΩ·cm~2 to 3.2 mΩ·cm~2, the effective channel mobility is 89 cm~2/(V·s). The up-epitaxy super junction structure which is improved on the base of the up-epitaxy IEMOS and traditional super junction structures, has a greater voltage of 2650V than the up-epitaxy IEMOS, but the specific on-resistance is 6.3 mΩ·cm~2 almost twice of the former's, the effective channel mobility is 112cm~2/(V·s).The research work in this paper has reference value for optimize design of SiC vertical power MOSFET. |