Significantly improved SiC Metal-Insulator-Semiconductor (MIS) devices have been achieved by using a stacked dielectric consisting of silicon dioxide-silicon nitride-silicon dioxide (ONO). This stacked dielectric was used for both MIS Field Effect Transistors (MISFETs) and simple MIS capacitors, and compared to traditional SiC MOS devices with silicon dioxide: grown thermally and deposited via LPCVD. The devices with the ONO stacked dielectric had higher channel mobilities, lower interface states near the conduction band and longer lifetimes at 350 degreesC at a 15 V gate bias. 4H-SiC buried channel devices had 10X effective channel mobilities of identical devices without the implanted channel.