In this paper, the dependency of silicide properties such as sheet resistance and cross-sectional profile of NiSi on the source/drain and gate dopants is described. There was minimal difference in sheet resistance among the dopants used, namely, As, P, BF2 and B11, just after the formation of NiSi using RTP. However, NiSi properties strongly depended on the dopants when additional thermal treatment was applied after silicidation. P-type dopants showed superior properties compared to n-type dopants, and BF2-doped silicon showed the most stable property, while As-doped silicon, the poorest. The principal reason for the excellent properties of the BF2-doped sample is the retarded Ni diffusion due to the existence of fluorine. In contrary, the As-doped sample showed severe agglomeration and abnormal oxidation of NiSi possibly due to the As sublimation.