Patent ID: 7067427

Claim:
A method of manufacturing a semiconductor device, comprising the steps of: forming a sunken section in an insulating film formed on a substrate; forming a barrier metal film on said insulating film inclusive of said sunken section, said barrier metal film is a tantalum-based metal film; forming a copper-based film over the entire surface so as to fill up said sunken section; and polishing this substrate surface by the chemical mechanical polishing method to form a copper-based metal interconnection, wherein said step of polishing comprises the steps of: a first polishing which is performed until at least a part of said barrier metal film is exposed, while using a first polishing slurry containing a silica polishing material, an oxidizing agent, an amino acid, a triazole-based compound and water, wherein a content ratio of said amino acid to said triazole-based compound (amino acid/triazole-based compound (weight ratio)) is in a range of 5 to 8, said triazole-based compound is one of 1,2,3-triazole, 1,2,4-triazole and their derivatives, a content of said triazole-based compound is not less than 0.05% by weight but not greater than 0.5% by weight, said amino acid is glycine, and a pH value of said polishing slurry is in a range of 5 to 7; and a second polishing which is performed until the surface of the insulating film other than said sunken section is exposed, while using a second polishing slurry having a composition different from the first polishing slurry.