Electrochemical Mechanical Deposition (ECMD) is a novel technique that has the ability to deposit planar conductive films on non-planar substrate surfaces. Technique involves electrochemical deposition (ECD) and simultaneous polishing or mechanical sweeping of the substrate surface. Preferential deposition into the cavities on the substrate surface may be achieved through two different mechanisms. The first mechanism is more mechanical in nature and it involves material removal from the top surface. The second mechanism is more chemical in nature and it involves enhancing deposition into the cavities where mechanical sweeping does not reach, and reducing deposition onto surfaces that are swept. In this study we demonstrate that in an ECMD process, low-pressure mechanical sweeping of the wafer surface during copper plating can establish a differential in the activity of accelerator species between the surface and cavity regions of the substrate and thus give rise to bottom-up filing in even the lowest aspect-ratio cavities. Planar layers obtained by the ECMD technique have been successfully employed in an electrochemical polishing technique for stress-free removal of Cu.
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