Electrolytic processing apparatus and method

Abstract

There is provided an electrolytic processing apparatus and method which can produce products having various specifications with enhanced productivity, thus reducing the production cost, and which can respond flexibly to the movement toward finer interconnects in semiconductor devices. An electrolytic processing apparatus according to the present invention includes: an electrolytic processing unit including a substrate holder for holding a substrate, and a counter electrode plate disposed opposite the substrate held by the substrate holder, said electrolytic processing unit carrying out electrolytic processing by filling the space between the substrate held by the substrate holder and the counter electrode plate with an electrolysis solution while feeding electricity; and a plurality of electrolysis solution supply facilities for supplying different types of electrolysis solutions; wherein the electrolytic processing unit is selectively connectable to one of the plurality of electrolysis solution supply facilities.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention: [0002] The present invention relates to an electrolytic processing apparatus and method, and more particularly to an electrolytic processing apparatus and method useful for forming, by plating, a film of an interconnect material, such as copper, on a substrate having fine interconnect patterns (recesses) formed in a surface, or for removing, by electrolytic etching, a metal film formed in a surface of a substrate. [0003] 2. Description of the Related Art: [0004] In recent years, instead of using aluminum or aluminum alloys as an interconnect material for forming electrical interconnects on a semiconductor substrate, there is an eminent movement toward using copper (Cu) which has a low electric resistivity and high electromigration endurance. It is generally difficult with copper to form interconnects by anisotropic etching as practiced with aluminum. Accordingly, copper interconnects are generally formed by the so-called ...

AI Technical Summary

Benefits of technology

[0020] The present invention has been made in view of the above situation in the related art. It is therefore an object of the present invention to provide an electrolytic processing apparatus and method which can produce products having various specifications with enhanced productivity, thus reducing the production cost, and which can respond flexibly to the movement toward finer interconnects in semiconductor devices.

[0022] By making the electrolytic processing unit selectively connectable to one of the plurality of electrolysis solution supply facilities for supplying different electrolysis solutions, the flexibility of the electrolytic processing apparatus can be enhanced. Since a plurality of chemical liquids (electrolysis solutions) having different chemical natures are supplied to a single electrolytic processing unit, it may be necessary to carry out operations, such as cleaning, blowing, cleaning with the same liquid, etc., upon a switch between liquids. Such operations, however, can be automated with ease. Depending upon the chemical liquid (electrolysis solution), these operations may not be necessary.

[0024] According to this apparatus, information about the substrate, such as the type of the substrate, the layer to be processed, the elapsed processing time, etc. is inputted by the operator of the input device, for example on a screen. This makes it possible to make a switch to an appropriate electrolysis solution with proper timing based on the information. For example, it becomes possible to make a shift of electrolysis solution for every substrate or for every layer. It also becomes possible to carry out different electrolytic processing for one layer.

[0028] The provision of a plurality of flexible electrolytic processing units in the electrolytic processing apparatus can broaden the range of application. The electrolytic processing facility is not necessarily a device. Thus, for example, the electrolysis solution may be supplied from an infrastructure of a production plant via a line.

[0030] When the number of substrates to be processed is small, the plurality of electrolytic processing units in one electrolytic processing apparatus may be operated so that substrates which satisfy a variety of requirements can be produced. When the number of substrates to be processed is large, a necessary number of substrate processing apparatuses may be operated. Further, the electrolytic processing units in each substrate processing apparatus may be finely classified, thereby enhancing the productivity.

Problems solved by technology

It is generally difficult with copper to form interconnects by anisotropic etching as practiced with aluminum.

The development of plating solutions is being confronted with such a difficult technical problem.

Ultrafine interconnects technology is a technology primarily for local interconnects, i.e. interconnects of the lower layers of a multi-layer interconnect structure, and probably may not be optimal, from a technical viewpoint and also in terms of cost, as a technology for forming global interconnects having an interconnect width of about 10 to 100 μm and a low aspect ratio.

It is therefore difficult to form interconnects of all the layers and efficiently produce a variety of devices with the use of a single plating solution as in the conventional electroplating apparatus.

Even when an apparatus construction that enables the use of two or more types of plating solutions, is adopted, if the operation is such that a specified electroplating unit is used solely for a particular plating solution, the apparatus can be operated only in an inflexible manner and at a high production cost.

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