A 3.3 kV 4H-SiC split gate MOSFET with a central implant region for superior trade-off between static and switching performance

A split gate MOSFET (SG-MOSFET) is widely known for reducing the reverse transfer capacitance ( C RSS ). In a 3.3 kV class, the SG-MOSFET does not provide reliable operation due to the high gate oxide electric field. In addition to the poor static performance, the SG-MOSFET has issues such as the punch through and drain-induced barrier lowering (DIBL) caused by the high gate oxide electric field. As such, a 3.3 kV 4H-SiC split gate MOSFET with a grounded central implant region (SG-CIMOSFET) is proposed to resolve these issues and for achieving a superior trade-off between the static and switching performance. The SG-CIMOSFET has a significantly low on-resistance ( R ON ) and maximum gate oxide field ( E OX ) due to the central implant region. A grounded central implant region significantly reduces the C RSS and gate drain charge ( Q GD ) by partially screening the gate-to-drain capacitive coupling. Compared to a planar MOSFET, the SG MOSFET, central implant MOSFET (CIMOSFET), the SG-CIMOSFET improve the R ON × Q GD by 83.7%, 72.4% and 44.5%, respectively. The results show that the device features not only the smallest switching energy loss but also the fastest switching time.