Patent ID: 7390714

Claim:
A method of manufacturing a semiconductor device having tungsten gate electrodes, comprising; (a) forming a gate oxide film on a semiconductor substrate, a polysilicon film above the gate oxide film, and a nitride film above the polysilicon film, and then patterning the nitride film, the polysilicon film, and the gate oxide film to form a plurality of poly gates; (b) forming a spacer at a side of at least one of the poly gates; (c) forming a sacrificial nitride film on the entire resulting surface including the poly gates and the spacer, and then forming an interlayer insulation film on the entire resulting surface including the sacrificial nitride film; (d) removing a portion of the interlayer insulation film to expose a portion of the sacrificial nitride film formed on the poly gates, and then polishing the sacrificial nitride film formed on the poly gates to expose the nitride film; (e) removing a top portion of the sacrificial nitride film while removing the nitride film; (f) forming an insulation film spacer at the side exposed through removal of the nitride film, and filling a portion from which the sacrificial nitride film is removed with an insulation film; and (g) forming tungsten gates in portions from which the nitride films are removed.