Method and apparatus for local polishing control

Abstract

A method and apparatus for local polishing and deposition control in a process cell is generally provided. In one embodiment, an apparatus for electrochemically processing a substrate is provided that selectively polishes discrete conductive portions of a substrate by controlling an electrical bias profile across a processing area, thereby controlling processing rates between two or more conductive portions of the substrate.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of co-pending U.S. patent application Ser. No. 10 / 382,032, filed Mar. 4, 2003, which is hereby incorporated by reference in its entirety.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] Embodiments of the invention generally relate to a method and apparatus for local polishing control in an electrochemical mechanical polishing system. [0004] 2. Background of the Related Art [0005] Electrochemical mechanical polishing generally removes material from a semiconductor substrate through an electrochemical / chemical or a combined electrochemical / chemical and mechanical process. In one example of an electrochemical mechanical polishing system, a substrate or wafer is retained on a substrate support in a feature side up orientation. A polishing head having a conductive polishing pad and an internal counter electrode is placed in contact with the feature side of the substrate. The polishing he...

AI Technical Summary

Benefits of technology

[0010] In another aspect of the invention, a method for electrochemically processing a substrate is provided that includes the steps of contacting conductive features disposed on a substrate with a conductive polishing pad assembly, flowing electrolyte between the conductive features and a first counter electrode, and selectively processing discrete portions of the conductive features.

Problems solved by technology

However, the removal of copper residue may result in dishing of copper features below the plane of surrounding material, typically an oxide or other barrier layer.

As the copper layer does not have a uniform thickness across the substrate, it is difficult to removes all the copper residue without causing dishing over some features while not removing all of the copper residue over others.

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