To improve Ti SALICIDE process, Si preamorphization by arsenic before Ti sputtering has been studied in two parts: process characterization and fundamental studies. Sheet resistance (Rs) reduction by the preamorphization is more pronounced on thinner and narrower-line silicide formation. At 60keV implantation energy, there is an optimum arsenic dose for the improvement Through the treatment, more uniform silicide layer can be formed, indicated by the improved Rs uniformity. In the fundamental study, preamorphization appears to have little effect on promoting C49-to-C54 phase transformation. It is suggested that the treatment is able to enhance the reaction rate between Ti and amorphous Si, and results in C54-TiSi2 with larger grains and consequently slightly lower resistivity.