Titanium silicide was formed on the top of Si wafers by arsenic ion beam mixing and rapid thermal annealing. Three different arsenic-ion mixing conditions were examined in this work. The sheet resistance, residue As concentration post annealing and TiSi2 phase were characterized by using the* four-point probe, RBS and electron diffraction, respectively. TiSi2 of C54 phase was identified in the doubly implanted samples. The thickness of the Ti silicide and the TiSi2/Si interface were observed by the cross-sectional TEM.