US Patent 7429525 Fabrication process of a semiconductor device

A method of fabricating a semiconductor device includes the steps of forming a metallic nickel film on a silicon substrate such that the metallic nickel film covers an insulation film on the silicon substrate and a silicon surface of the silicon substrate, annealing the silicon substrate in a silane gas ambient at a temperature not exceeding 220° C. to form a first nickel silicide layer having a composition primarily of Ni2Si on the silicon surface and a surface of the metallic nickel film, removing the metallic nickel film after the step of forming the nickel silicide layer by a wet etching process, and converting the first nickel silicide layer to a second nickel silicide layer primarily of nickel monosilicide (NiSi) by applying a thermal annealing process.