A MESFET structure has been used to determine the preferred annealing strategy for depletion mode devices in SiC. Based on Boron and Nitrogen implantation the device removes the need for multi-epitaxial layer growth. It is shown that the annealing strategy for the implants has a strong influence on the electrical characteristics of the device, and the adopted two step anneal technique increases the current density of the device by increasing the mobility of the carriers by an order of magnitude. Further, the reduction in temperature of the channel anneal step has reduced the surface roughness of the device to that of the unimplanted wafer. This decrease in the surface roughness gives a lower leakage current through the gate contact of the device, allowing a higher gate bias to be used.