Integrated plating and planarization process and apparatus therefor

Abstract

A method and apparatus are described for performing both electroplating of a metal layer and planarization of the layer on a substrate. Electroplating and electroetching of metal (such as copper) are performed in a repeated sequence, followed by chemical-mechanical polishing. An electroplating solution, electroetching solution, and a non-abrasive slurry are dispensed on a polishing pad in the respective process steps. The substrate is held against the pad with a variable force in accordance with the process, so that the spacing between substrate and pad may be less during electroplating than during electroetching.

Description

technical field

[0001] This invention relates to semiconductor processing, and more particularly to methods and apparatus for electroplating and planarizing copper layers on semiconductor wafers. Background technique

[0002] Deposition and selective removal of metal layers are important processes in semiconductor device fabrication. A typical semiconductor wafer has several layers of metal deposited or plated on its surface, each successive layer being polished or etched before additional layers are added. In general, electroplating copper on wafer surfaces is an extensively skilled process. Chemical-mechanical polishing (CMP) is usually performed after copper electroplating (usually a capping layer of copper is produced on the wafer) to remove unwanted portions of the electroplating. When fabricating damascene structures, the CMP process can also be used to electrically isolate damascene wiring.

[0003] Figure 1A is a schematic diagram of a typical apparatus for electr...

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