Patent ID: 7375013

Claim:
A process for manufacturing a semiconductor integrated circuit device, comprising the steps of: (a) forming a gate insulating film over a silicon-base surface region having silicon as one of principal constituents over a first main surface of a wafer; (b) forming, over the gate insulating film, a first silicon-base film having silicon as one of principal constituents; (c) doping an impurity into the first silicon-base film by ion implantation; (d) after the step (c), forming, over the first silicon-base film, a non-doped second silicon-base film having silicon as one of principal constituents; (e) forming, over the second silicon-base film, a first tungsten film to be a film having tungsten silicide as a principal component; (f) forming, over the first tungsten film, a tungsten nitride film, which will have a nitrogen content of 7% or greater upon completion of the element, by sputtering; and (g) forming, over the nitride film, a refractory metal film thicker than the first tungsten film and having tungsten or molybdenum as a principal component.