Electrolytic processing apparatus

Abstract

An electrolytic processing apparatus is used to remove a metal film formed on a surface of a substrate. The electrolytic processing apparatus includes a feeding electrode 31 for feeding electricity to a metal film 6 on a substrate W, a processing electrode 32 for processing the metal film 6, a substrate carrier 11 for holding the substrate W, a first supply passage 51 for supplying a first electrolytic processing liquid, a second supply passage 52 for supplying a second electrolytic processing liquid, an insulating member 36 for electrically isolating the first electrolytic processing liquid and the second electrolytic processing liquid, a table 12 on which the feeding electrode 31, the processing electrode 32, and the insulating member 36 are disposed, and a relative movement mechanism 17 for making a relative movement between the table 12 and the substrate carrier 11.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an electrolytic processing apparatus, and more particularly to an electrolytic processing apparatus for removing a metal film formed on a surface of a substrate such as a semiconductor wafer to a flat finish. [0003] 2. Description of the Related Art [0004] In recent years, there has been an eminent movement towards using copper (Cu), which has a low electric resistivity and high electromigration endurance, as a material for forming circuits on a substrate such as a semiconductor wafer instead of using aluminum or aluminum alloys. Copper interconnections are generally formed by filling copper into fine recesses formed in a surface of a substrate. There are known various techniques for forming such copper interconnections, including chemical vapor deposition, sputtering, and plating. In any such technique, a copper film is formed on a substantially entire surface of a substrate, and th...

AI Technical Summary

Benefits of technology

[0012] The present invention has been made in view of the above drawbacks. It is therefore an object of the present invention to provide an electrolytic processing apparatus which can flatten a surface of a metal film having fine irregularities on a substrate with a low processing pressure upon formation of interconnections using damascene process, and can process the metal film with a uniform processing rate over an entire surface of the metal film.

Problems solved by technology

As submicron manufacturing technology has commonly been used, the properties of materials are greatly influenced by the processing method itself Under these circumstances, in a conventional machining method in which a desired portion in a workpiece is physically destroyed and removed from the surface thereof by a tool, a large number of defects may be produced by the processing, thus deteriorating the properties of the workpiece.

Chemical mechanical polishing (CMP), for example, generally requires a complicated operation and control, and needs a considerably long processing time.

This process also imposes a considerable load on the waste disposal of the slurry and the cleaning liquid.

However, the low-k material has a low mechanical strength and therefore is hard to endure the stress applied during the CMP process.

In such a case, a surface of a substrate becomes likely to be scratched or chemically damaged.

Further, dishing or recesses are likely to be produced to cause lean interconnections.

Accordingly, the resistance of interconnections is problematically increased, and the reliability of interconnections is lowered by defects of the interconnections.

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