High channel mobility in inversion layer of SiC MOSFETs for power switching transistors

A high channel mobility in inversion layers of 4H- and 6H-SiC metal-oxide-s emiconductor field-effect-transistors (MOSFETs) was successfully achieved b y using the (11 (2) over bar 0) face instead of the conventional (0001) Si- face. For 4N-SiC, the channel mobility on the (11 (2) over bar 0) face (95. 9 cm(2)/Vs) was dramatically improved to be 17 times higher than that on th e (0001) face (5.6 cm(2)/Vs). For 6H-SiC, the channel mobility on the (11 ( 2) over bar 0) face (115.7 cm(2)/Vs) was also improved to be 2.5 times high er than that on the (0001) face (44.8 cm(2)/Vs). These results suggest that the MOS interface quality on the (11 (2) over bar 0) face is superior to t hat on the (0001) face. In the case of the (0001) face, 15R-SiC MOSFETs sho wed a higher channel mobility (59.2 cm(2)/Vs) than 6H-SiC, due to a higher bulk mobility in 15R-SiC than 6H-SiC.