Method and apparatus for two-step polishing

A method for processing a substrate, comprising:

• providing a substrate having a barrier layer and a copper containing material disposed thereon to a first platen containing an abrasive-free polishing pad;
• polishing the substrate at a first removal rate with an abrasive-free first polishing composition to substantially remove the copper containing material disposed thereon;
• providing the substrate to a second platen containing a fixed abrasive polishing pad;
• and
• polishing the substrate at a second removal rate less than the first removal rate with a second polishing composition to remove residual copper containing materials disposed thereon.

A system for processing substrates, comprising:

• a first platen adapted for polishing a substrate with an abrasive-free first polishing composition;
• an abrasive-free polishing pad disposed on the first platen;
• a second platen adapted for polishing the substrate with a second polishing composition;
• a fixed abrasive polishing pad disposed on the second platen;
• and
• a computer based controller configured to cause the system to perform a method comprising:
• polishing the substrate with an abrasive-free polishing pad until it is substantially planarized;
• and then
• polishing the substrate with a fixed abrasive polishing pad to remove residual materials disposed thereon.