The Novel 4H-SiC Power MOSFETs Research

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.