Low on-resistance 4H-SiC UMOSFET with local floating superjunction

摘要

This paper introduces an improved on-resistance 4H-SiC UMOSFET structure. Compared to conventional p-shielding UMOSFETs, the proposed 4H-SiC UMOSFET with a local floating superjunction (LFS) exhibits lower on-resistance while maintaining a breakdown voltage of 1700 V. The structure has a superjunction located beneath the p-shielding. It was optimized for various parameters to reduce the on-resistance while maintaining the breakdown voltage. The on-resistances of a conventional UMOSFET and the optimized LFS-UMOSFET are 13.75 and 8.68 m Omega cm(2), respectively, when the gate voltage is 10 V. The proposed UMOSFET showed a 36.8% reduction in the specific on-resistance, the figure of merit was improved by 35.1%, and the maximum current density was improved by 29%. Also body diode characteristic and UIS test are confirmed. All the results are demonstrated by Sentaurus TCAD simulation.