A method of making a Schottky diode comprising the steps of: providing a single crystal diamond comprising a surface; placing the single crystal diamond in a CVD system; heating the diamond to a temperature of at least about 950° C.; providing a gas mixture capable of growing diamond film and comprising a sulfur compound through the CVD system; growing an epitaxial diamond film on the surface of the single crystal diamond; baking the diamond at a temperature of at least about 650° C. in air for a period of time that minimizes oxidation of the diamond; and fabricating a Schottky diode comprising the diamond film. A Schottky diode comprising an epitaxial diamond film and capable of blocking at least about 6 kV in a distance of no more than about 300 &mgr;m.