Patent ID: 6930037

Claim:
A process for forming a metal interconnect comprising the steps of forming a concave in an insulating film formed on a substrate, forming a barrier metal film on the insulating film, forming an interconnect metal film over the whole surface such that the concave is filled with the metal and then polishing the surface of the substrate by chemical mechanical polishing, characterized in that the polishing step comprises a first polishing step of polishing the surface such that a portion of the interconnect metal film remains on the surface other than the concave, the portion of the interconnect film remaining on the surface not being insubstantial, and a second polishing step of polishing the surface using a polishing slurry controlling a polishing-rate ratio of the interconnect metal to the barrier metal of 1 to 3 inclusive, until the surface of the insulating film other than the concave is substantially completely exposed, wherein in the first polishing step, the polishing slurry comprises a polishing material, an oxidizing agent, an organic acid and an alkanolamine represented by general formula (1): NR 1 m (R 2 OH) n (1) wherein R 1 is hydrogen or alkyl having 1 to 5 carbon atoms; R 2 is alkylene having 1 to 5 carbon atoms; m is an integer of 0 to 2 inclusive; and n is a natural number of 1 to 3 inclusive, provided that m+n is 3.