Method for forming a copper interconnect using a multi-platen chemical mechanical polishing (CMP) process

Abstract

A copper interconnect polishing process begins by polishing (17) a bulk thickness of copper (63) using a first platen. A second platen is then used to remove (19) a thin remaining interfacial copper layer to expose a barrier film (61). Computer control (21) monitors polish times of the first and second platen and adjusts these times to improve wafer throughput. One or more platens and/or the wafer is rinsed (20) between the interfacial copper polish and the barrier polish to reduce slurry cross contamination. A third platen and slurry is then used to polish away exposed portions of the barrier (61) to complete polishing of the copper interconnect structure. A holding tank that contains anti-corrosive fluid is used to queue the wafers until subsequent scrubbing operations (25). A scrubbing operation (25) that is substantially void of light is used to reduce photovoltaic induced corrosion of copper in the drying chamber of the scrubber.

Dependencies are inferred from the claim text.