To minimize the bridging problem In the self-aligned titanium slllcide (SALICI DE) processes, a titanium nitride (TiN) cap has been suggested. The objective of this work was to study the impact of such a TiN cap layer on a Ti-based SALICI DE process. The slllcide formation was carried out by Rapid Thermal Annealing (RTA). The Ti-Si Interaction, the dopant loss during silicide formation, the contact resistance between the formed TiSi2 and SI substrates, the leakage current, and the lateral diffusion of SI atoms over the spacers of MOS devices were investigated with and without a TiN layer on top of Tl films. The dependence of these factors on the annealing temperature was also investigated. The results showed that: a) An increased dopant loss was a direct result of more silicide formation, due to a larger SI substrate consumption. This was observed both with and without TiN cap. b) The specific contact resistance increased with annealing temperature, regardless the TiN cap. c) Sheet resistance, specific contact resistance and leakage current were not sensitive to the selective etch procedure. And d) A lower yield for bridging test structures was found where a TiN cap was employed, Indicating that the TiN layer did not suppress the Si lateral diffusion.