4H-SiC MOSFETs with a novel channel structure are presented. In the novel MOSFETs, a buried n-channel is sandwiched by a thin p-layer and p-body (SC-MOSFET). By the introduction of properly-designed p-layer beneath the gate oxide, more electrons can travel apart from the MOS interface, leading to higher channel mobility especially at high gate voltage. In this study, the effects of channel structure on the 4H-SiC (0001) MOSFET performance are investigated, and the characteristics of inversion-type MOSFET, ACCUFET and SC-MOSFET were compared. The SC-MOSFET, processed by N2O oxidation, with a 0.10 mum-thick channel showed a high mobility of 40 cm(2)/Vs with a normally-off characteristic at 2.5 MV/cm.