Dry etching apparatus, etching method, and method of forming a wiring

Abstract

An etching apparatus is provided, in which a plurality of electrodes are disposed for placing a substrate, high-frequency power sources as many as electrodes are provided, and the electrodes and the high-frequency power sources are connected to each other independently. Among a plurality of electrodes, a high-frequency power applied to an electrode disposed below the central portion of the substrate and a high-frequency power applied to electrodes disposed below corner portions of the substrate are controlled respectively, whereby in-plane uniformity of etching can be enhanced.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional application of U.S. application Ser. No. 09 / 966,689, filed Sep. 27, 2001, now allowed, and claims the benefit of foreign priority applications filed in Japan as Serial No. 2000-305564 on Oct. 4, 2000 and as Serial No. 2001-289534 on Sep. 21, 2001. This application claims priority to each of these prior applications, and the disclosures of the prior applications are considered part of (and are incorporated by reference in) the disclosure of this application.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a dry etching apparatus. In particular, the present invention relates to an etching apparatus using plasma generated by applying a magnetic field or an electric field to a reaction gas introduced into a low-pressure chamber, and an etching method. [0004] 2. Description of the Related Art [0005] Conventionally, there is a limit to a treatment ability of ...

AI Technical Summary

Benefits of technology

[0017] Therefore, with the foregoing in mind, it is an object of the present invention to provide a dry etching apparatus capable of treating a large substrate, and an etching method capable of enhancing in-plane uniformity of a rectangular substrate to be treated.

[0018] In order to solve the above-mentioned problem, according to the present invention, an etching apparatus is used, in which a plurality of electrodes are disposed for placing a substrate, high-frequency power sources as many as the electrodes are provided, and the electrodes and the high-frequency power sources are connected to each other independently. Among a plurality of electrodes, a high-frequency power applied to an electrode disposed below the central portion of the substrate and a high-frequency power applied to electrodes disposed below corner portions of the substrate are controlled respectively, whereby in-plane uniformity of etching is enhanced.

[0019] When controlling high-frequency powers applied to the plurality of electrodes, various parameters (bias power, ICP power, substrate temperature, etc.) in the high-frequency powers can be respectively regulated. However, it is preferable to regulate only one parameter. Typically, by regulating only a bias power (electric power density) of a high-frequency power per unit area applied to the plurality of electrodes, a taper angle obtained by etching processing, an etching rate of etching processing, and uniformity of a selection ratio can be enhanced. In an ICP etching apparatus provided with a coil electrode (area of a quartz plate: disk with a diameter of 25 cm) and an electrode (area: 12.5 cm×12.5 cm), etching processing can be controlled by varying a bias power as shown in FIGS. 11 to 13. FIG. 11 shows dependence of a taper angle on a bias power. FIG. 12 shows dependence of an etching rate of a W film and an SiON film on a bias power. FIG. 13 shows dependence of a selection ratio between a W film and an SiON film on a bias power.

Problems solved by technology

Conventionally, there is a limit to a treatment ability of a dry etching apparatus, which causes problems in terms of enhancement of productivity.

More specifically, in the case of using a rectangular substrate, a substantial electric power applied to the entire surface of a substrate becomes non-uniform, and an electric power density is varied between the central portion of the substrate and the corner portions thereof.

Therefore, in the case of using a conventional etching apparatus, the selection ratio at corner portions of an electrode becomes lowest, causing etching defects.

The etching defects may decrease a yield.

If a substrate is enlarged in the future, this problem is considered to become more conspicuous.

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