An oligosaprobic polishing composition

Abstract

The present invention relates to an oligosaprobic polishing composition. Particularly,the invention is an aqueous composition useful for chemical mechanical polishing of a patterned semiconductor wafer containing a copper interconnect metal. The aqueous composition includes an oxidizer, an inhibitor for the copper interconnect metal, 0.001 to 15 weight percent of a water soluble modified cellulose, non-saccaride water soluble polymer, 0 to 15 complexing agent for the copper interconnect metal, 0 to 15 weight percent phosphorus compound, 0.05 to 20 weight percent of an acid compound that is capable of complexing copper ions, and water; and the solution has an acidic pH.

Description

technical field [0001] The present invention relates to chemical mechanical polishing (CMP) of semiconductor wafer materials, and more particularly to CMP compositions and methods for polishing metal interconnect features on semiconductor wafers in the presence of dielectric or barrier materials. Background technique [0002] Typically the semiconductor wafer is a silicon wafer having a dielectric layer comprising a plurality of trenches arranged within the dielectric layer to form a pattern for circuit interconnection. The patterning typically has a corrugated structure or a double corrugated structure. A barrier layer overlies the patterned dielectric layer, and a metal layer overlies the barrier layer. The thickness of the metal layer is at least sufficient to fill the patterned trenches to form circuit interconnections. [0003] CMP processes often include multiple polishing steps. For example, the first step removes excess interconnect metal, such as copper, at an in...

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Problems solved by technology

These cleaning steps require powerful and expensive cleaning solutions and result in a "cost of ownership" by delaying wafer throughput

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