Pattern formation method and exposure system

Abstract

After forming a resist film made from a chemically amplified resist material, pattern exposure is carried out by irradiating the resist film with exposing light while supplying, between a projection lens and the resist film, a solution of water (having a refractive index of 1.44) that includes an antifoaming agent and is circulated and temporarily stored in a solution storage. After the pattern exposure, the resist film is subjected to post-exposure bake, and the resultant resist film is developed with an alkaline developer. Thus, a resist pattern made of an unexposed portion of the resist film can be formed in a good shape.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to a pattern formation method for use in semiconductor fabrication and an exposure system employing the pattern formation method. [0002] In accordance with the increased degree of integration of semiconductor integrated circuits and downsizing of semiconductor devices, there are increasing demands for further rapid development of lithography technique. Currently, pattern formation is carried out through photolithography using exposing light of a mercury lamp, KrF excimer laser, ArF excimer laser or the like, and use of F2 laser lasing at a shorter wavelength is being examined. However, since there remain a large number of problems in exposure systems and resist materials, photolithography using exposing light of a shorter wavelength has not been put to practical use. [0003] In these circumstances, immersion lithography has recently been proposed for realizing further refinement of patterns by using conventional exposin...

AI Technical Summary

Benefits of technology

[0015] In the first pattern formation method, even when foams are formed in the solution supplied onto the resist film, the foams are vanished by the antifoaming agent. Therefore, the exposing light can be prevented from scattering, so that the resist pattern can be formed in a good shape.

[0029] When the outlet for allowing the solution to flow out of the solution storage has a smaller cross-sectional area than the inlet for allowing the solution to flow into the solution storage, the pressure of the solution temporarily stored in the solution storage is high. Therefore, the size of foams formed in the solution supplied onto the resist film can be reduced and the formed foams can be rapidly vanished. Accordingly, the exposing light can be prevented from scattering, so that a resist pattern can be formed in a good shape.

Problems solved by technology

However, since there remain a large number of problems in exposure systems and resist materials, photolithography using exposing light of a shorter wavelength has not been put to practical use.

However, as shown in FIG. 7D, the resist pattern 6 formed by the conventional method is in a defective shape.

When a resist pattern in such a defective shape is used for etching a target film, the resultant pattern is also in a defective shape, which disadvantageously lowers the productivity and the yield in the fabrication process for semiconductor devices.

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