Improved on-state resistance with reliable reverse characteristics in 1.2 kV 4H-SiC MOSFET by selective nitrogen implantation assisted current spreading layer

In this study, we developed a superior 1.2 kV 4H-SiC metal-oxide-semiconductor field-effect transistor (MOSFET) with epi-grown current spreading layer (CSL) assisted by selective nitrogen implantation. This MOSFET is experimentally demonstrated to have improved on-state resistance with reliable reverse characteristics compared to the MOSFET which adopts conventional single CSL (epi-grown or implanted only). Based on the systematic study of SiC MOSFETs with epi-grown CSLs, it was found that the global high donor concentration of epi-grown CSLs weakens the blocking performance of edge termination structure in the peripheral region. Incorporation of nitrogen-implantation at the active region in epi-grown CSL can reduce the specific on-state resistance by 1 m omega cm(2) without degradation in the edge termination.