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

摘要

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 scubber.