| abstract |
A method for performing chemical-mechanical polishing/planarization providing highly selective, rapid removal of a Ta-containing barrier layer from a workpiece surface, such as a semiconductor wafer including a damascene-type Cu-based metallization pattern in-laid in a dielectric layer and including a Ta-containing metal diffusion barrier layer, comprises applying an aqueous liquid composition to the workpiece surface during CMP or to the polishing pad utilized for performing the CMP, the composition comprising at least one reducing agent for reducing transition metal ions to a lower valence state, at least one pH adjusting agent, at least one metal corrosion inhibitor, and water, and optionally includes ions of at least one transition metal, e.g., Cu and Fe ions. According to another embodiment, the aqueous liquid composition contains Ag ions and the at least one reducing agent is omitted. |