Method of forming a metal silicide film

摘要

Films of desired metal, e.g., Ni or Co, and of Si are laminated alternately on a single crystal silicon substrate to form a multi-layered structure, and thereafter the substrate is heated to grow an epitaxial NiSi2 or CoSi2 film in solid phase with less diffusion of Ni or Co atoms into the silicon substrate. Each layer in the multi-layered structure has a thickness selected in the range of 30-300 A with the overall composition ratio Si/Ni (or Si/Co) in the range of 1.8-2.0. The lamination process is done at a substrate temperature which does not cause the laminated films to react with the substrate and does not cause the multi-layered structure to become polycrystalline, e.g. below 350 DEG C. for the formation of an NiSi2 film or below 450 DEG C. for the formation of a CoSi2 film. The solid phase epitaxy is achieved at a substrate heating temperature in a range of 350 DEG -750 DEG C. for the formation of an epitaxial NiSi2 film or 450 DEG -1000 DEG C. for the formation of a CoSi2 film.