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

Abstract

A copper interconnect polishing process begins by polishing ( ) a bulk thickness of copper ( ) using a first platen. A second platen is then used to remove ( ) a thin remaining interfacial copper layer to expose a barrier film ( ). Computer control ( ) 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 ( ) 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 ( ) 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 ( ). A scrubbing operation ( ) that is substantially void of light is used to reduce photovoltaic induced corrosion of copper in the drying chamber of the scubber.