The electrical characteristics of a SiC-MESFET are affected by the channel structure characteristics, such as impurity density and thickness. MESFETs fabricated with ion implantation technique, can form thinner and higher doped channel layers than those fabricated with conventional epitaxial growth, thus improve RF characteristics of MESFETs. We calculated the doping profile of the channel layer for an ion implanted SiC-MESFET using a simulator and then fabricated a SiC-MESFET with the same doping profile as obtained from the simulation. The ion implanted SiC-MESFET operated successfully and had the same electrical characteristics as the epitaxial SiC-MESFET. We demonstrated the effectiveness of one-step implantation channel layer for the ion implanted SiC-MESFET.