Patent ID: 6864183

Claim:
A method for manufacturing a semiconductor device, comprising the steps of: forming a gate electrode, made of polysilicon, on a silicon substrate through a gate insulating film; forming a sidewall, comprising a combination of a silicon oxide film, and a silicon nitride film on a side of said gate electrode; removing a native oxide film on the surfaces of said silicon substrate and said gate electrode in a reduced pressure vapor phase system by plasma etching with a mixed gas of a) at least one fluorine containing gas selected from the group consisting of a hydrogen fluoride gas, and a dicarbon hexafluoride gas, and b) an argon gas, wherein said at least one fluorine containing gas is at a concentration of not less than 0.5 vol.% relative to said argon gas; and forming a metal silicide film on said silicon substrate and said gate electrode after removing said native oxide film while maintaining said system in vacuum.