We report NiSi and Ni(Pt)Si films with excellent thermal stability showing a particular crystal orientation on Si(001). The Ni-silicide film with a deposition temperature of about 200 °C consists of a conformal domain structure. We examined detail crystallographic analysis of silicide and clarified the psudo-epitaxial growth of NiSi(202)//Si(220) [or NiSi(211)//Si(220)] was the key scheme of superior thermal stability. By using this optimized Ni-silicide formation process, we have fabricated Ni-silicide that is thermally stable up to 650 °C and shows low fluctuation in sheet resistance and low leakage current in electrical measurements. This process is a promising candidate for future silicidation technology.