Plating method and apparatus

Abstract

A plating method comprising applying an ultraviolet ray to a surface of a substrate or exposing a surface of a substrate to an ozone gas or bringing a surface to a substrate into contact with ozone water or bringing a surface of a substrate into contact with electrolytic ionized water or performing a team treatment using steam on a surface of a substrate, and plating the surface of the substrate after said applying, exposing, bringing or performing process. A plating method comprising performing a team treatment using steam on a surface of a substrate, and performing a wet process on the surface of the substrate of a substrate with an acidic plating solution, cleaning the surface of the substrate with pure water and cleaning the surface of the substrate with an alkalescent aqueous solution. A plating apparatus adapted to perform at least one of said methods.

Description

TECHNICAL FIELD [0001] The present invention relates to a plating method and apparatus for sequentially performing a plating process on a substrate such as a lead frame, a printed board, a flexible circuit, a tape substrate, or a semiconductor wafer used for electronic devices, and more particularly to a plating method and apparatus used to deposit a metal film on a substrate for large-scale integrated circuits (LSI) or to form interconnections in such a substrate. Further, the present invention relates to a substrate processing method for sequentially performing a wet process, such as a plating process, a coating process, or an etching process, on fine recesses or trenches formed in a substrate. BACKGROUND ART [0002] Recently, a plating process has been employed to form metal films, organic films, interconnections, or bumps (protruding connecting electrode terminals) for semiconductor circuits in a substrate such as a silicon wafer. For example, it has widely been practiced to form...

AI Technical Summary

Benefits of technology

[0016] The present invention has been made in view of the above drawbacks. It is, therefore, a first object of the present invention to provide a plating method and apparatus which can achieve reliable and stable plating without plating defects.

[0017] A second object of the present invention is to provide a substrate processing method which can achieve reliable and stable deposition in fine or ultra-fine recesses or trenches formed in a surface of a substrate.

[0018] According to a first aspect of the present invention, there is provided a plating method which can achieve satisfactory plating without plating defects. In this plating method, an ultraviolet ray is applied to the surface of the substrate before the plating process.

Problems solved by technology

Nevertheless, their circuit patterns are so fine that serious defects may be caused by slight change in quality of a surface of a substrate or slight attachment of foreign matter to a surface of a substrate.

Specifically, resists have poor wettability.

If a resist has poor wettability, air bubbles are often produced and left in fine patterns in the resist so as to cause plating defects.

Specifically, if a resist has poor wettability, plating defects are likely to be caused.

When a plated film is to be formed in fine trenches or plugs for interconnections in a substrate such as a semiconductor wafer or in openings of a resist having poor wettability, a plating solution or a pre-treatment liquid cannot sufficiently enter the trenches, plugs, or openings.

Thus, air bubbles are likely to be produced in the plating solution or the pre-treatment liquid and left in the fine trenches, plugs, or openings.

Such air bubbles may cause plating defects or plating incompletion.

However, when the surface tension of the plating solution is lowered, air bubbles are likely to be produced in a plating solution during circulation.

Further, addition of the surface-active agent to the plating solution may cause abnormal plating deposition or increase the amount of organic matter contained in a plated film.

Thus, properties of the plated film may adversely be affected by addition of the surface-active agent to the plating solution.

Nevertheless, their circuit patterns become so fine that serious defects may be caused by slight attachment of air bubbles to the surface because photopolymer resists are generally hydrophobic.

Specifically, since plating defects may be caused by attachment of a resist residue or foreign matter to the surfaces of the underlying film exposed to the outside, it is necessary to perform a process for removing the resist residue or foreign matter, e.g. a descum process.

Further, if organic matter or a resist residue is attached to surfaces of an underlying film of the substrate which are exposed at bottoms of the resist pattern, then plating defects are more likely to be caused.

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