Patent ID: 7172963

Claim:
A manufacturing method of a semiconductor integrated circuit device, comprising the steps of: (a) forming an insulator over a semiconductor substrate; (b) forming trenches by etching of said insulator; (c) forming a first conductive film on the surface of said insulator and in said trenches; (d) forming a second conductive film with a removal rate higher than that of said first conductive film on the surface of said first conductive film and in said trenches so as to fill said trenches; (e) chemically and mechanically polishing said second conductive film outside said trenches with use of a first polishing pad so as to leave said second conductive film in said trenches; and (f) chemically and mechanically polishing said first conductive film outside said trenches with use of a second polishing pad so as to leave said first conductive film in said trenches, wherein said first polishing pad and said second polishing pad include pores therein, and the diameter of said pores included in said second polishing pad is larger than that included in said first polishing pad.