High-temperature ion implantation of arsenic (As+) into the 4H-silicon carbide (SiC) substrates with high dose of 7 x 10(15) cm(-2) has been investigated as an effective doping method of n-type dopant for SiC power electron devices fabrication, Regardless of the ion implantation temperature, the sheet resistances (R-s) decrease below 1600 degrees C post-annealing and increase above 1700 degrees C as the post-annealing temperature increases. The low R-s value (213 Omega/square) is achieved in the sample implanted at 500 degrees C and annealed at 1600 degrees C, an order of magnitude smaller than that implanted at room temperature (RT), Atomic force microscopy (AFM) images reveal that the surface roughness of ion-implanted SiC increases with the increase of post-annealing temperature. Secondary ion mass spectroscopy (SIMS) results show that As+ dopant depth profiles of the sample implanted at 500 degrees C do not change before and after the post-annealing. On the other hand; for the sample implanted at RT, the As+ concentration in the ion-implanted layer decreases due to the outer-diffusion. These results indicate that high-temperature ion implantation is an effective method to prevent the outer-diffusion of As+ dopants during high-temperature post-annealing. It is considered that these post-annealing temperature dependences are caused by the evaporation of SIC surface layer.