Semiconductor devices having a high performance channel and method of fabrication thereof are disclosed. Preferably, the semiconductor devices are Metal-Oxide-Semiconductor (MOS) devices, and even more preferably the semiconductor devices are Silicon Carbide (SiC) MOS devices. In one embodiment, a semiconductor device includes a SiC substrate of a first conductivity type, a first well of a second conductivity type, a second well of the second conductivity type, and a surface diffused channel of the second conductivity type formed at the surface of semiconductor device between the first and second wells. A depth and doping concentration of the surface diffused channel are controlled to provide increased carrier mobility for the semiconductor device as compared to the same semiconductor device without the surface diffused channel region when in the on-state while retaining a turn-on, or threshold, voltage that provides normally-off behavior.
