In this paper we present a technique to improve the blocking capability of p-type 4H-SiC Schottky rectifiers by use of a shallow surface implant. Devices with near-ideal breakdown voltage as high as 900 V have been obtained with only 4 mum thick drift layer, corresponding to a critical breakdown held of similar to 3X10(6) V/cm. Not only does the breakdown voltage improve, the reverse leakage current is also significantly lowered. However, the forward voltage of the diodes with surface implants are slightly higher.