The post implantation annealing process has been investigated to improve the electrical properties of n-type-implanted 4H-SiC. The n-type dopants such as phosphorus and arsenic were implanted into 4H-SiC at 500degreesC, and the implanted samples were subsequently annealed under the same conditions for comparison of their electrical properties. The high-temperature rapid thermal annealing (HT-RTA) process minimizes the sublimation of SiC in the surface region and the roughening of the SiC surface morphology during the annealing at a higher temperature of 1700degreesC. It also results in the higher electrical activation of dopants implanted into 4H-SiC and the lowering of R-s. The minimum R-s of 38 Omega/sq. has been achieved in phosphorus-implanted 4H-SiC with a dose of 2x10(16)cm(2) using the HT-RTA process for a short time.