Reflector, optical element, interferometer system, stage device, exposure apparatus, and device fabricating method

Abstract

A reflecting member has: a first reflecting surface, which extends in a second direction that includes a first direction component; a second reflecting surface, which extends in a third direction that includes the first direction component, that is substantially symmetric to the first reflecting surface; and a third reflecting surface, which extends in a fourth direction, that is substantially orthogonal to the first direction.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is a divisional of U.S. patent application Ser. No. 11 / 475,034, filed Jun. 27, 2006, which claims priority to Japanese Patent Application Nos. 2005-188228 and 2005-188269, both filed on Jun. 28, 2005, the disclosures of which are hereby incorporated by reference in their entirety.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a reflector, an optical element, an interferometer system, a stage device, an exposure apparatus, and a device fabricating method.[0004]2. Description of Related Art[0005]In a process of fabricating an electronic device, such as a semiconductor device or a liquid crystal display device, a projection exposure apparatus is used that projects a pattern image of a mask or a reticle (hereinafter, generically referred to as a reticle), wherein a pattern is formed through a projection optical system onto each projection region (shot region) on a substrate (su...

AI Technical Summary

Benefits of technology

[0009]It is an object of the present invention to provide: a reflecting member that makes it possible to detect the position of a movable stage without inviting an increase in the size of an apparatus; a stage apparatus comprising that reflecting member; and an exposure apparatus. It is another object of the present invention to enable an interferometer system that measures height position to reduce the incidence of detection failures and measurement error with respect to changes in the attitude of a movable body, and to perform high precision position measurement.

[0012]According to a second aspect of the invention, if the movable stage is displaced in the first direction, then the optical path length of the beam that was reflected by the first reflecting surface of the first reflecting member and the optical path length of the beam that was reflected by the second reflecting surface change in accordance with the displacement of the movable stage in the first direction, which consequently makes it possible to measure positional information of the movable stage in the first direction by measuring the displacements of these optical path lengths. Consequently, there is no longer a need to provide the first reflecting member above the stage, and it is possible to avoid a needless increase in the size of the apparatus, which is no longer limited by the position of a fixed mirror.

[0014]According to a third aspect of the invention, it is possible to measure positional information of the substrate via a movable stage while avoiding an increase in the size of the apparatus.

[0016]According to a fourth aspect of the invention, the measuring beam is reflected twice at both the first reflecting part and the second reflecting part, which prevents angular deviation in the return direction of the measuring beam. Furthermore, the optical axis of the measuring beam is shifted by the second reflecting part, which shortens the optical path length of the measuring beam, and, as a result, suppresses deviation of the return position of the measuring beam. Consequently, according to the fourth aspect of the invention, it is possible to reduce measurement error and the incidence of detection failures with respect to changes in the attitude of the movable body.

[0018]According to a fifth aspect of the invention, measurement sensitivity is low with respect to changes in the inclination of the movable body about the irradiation direction or the measurement direction of the measuring beam, and it is therefore possible to reduce measurement error and the incidence of detection failures with respect to changes in the attitude of the movable body.

[0020]According to a sixth aspect of the invention, the first beam and the second beam mutually interfere by entering a first surface or a second surface from positions that differ from the initial emergent positions. Accordingly, the sixth aspect is preferably used in an interferometer that has a function that uses the shifting of the optical axis to reduce measurement error and the incidence of detection failures with respect to changes in the attitude of the movable body.

Problems solved by technology

With a constitution wherein a reflecting plate is provided above a movable stage, it is difficult to secure a location for installing downflow equipment.

In addition, if a measuring instrument, which is used to measure the position of the projection optical system and the wafer, is disposed above the movable stage in order to avoid the reflecting plate, then there is a risk that this will invite an increase in the size of the apparatus.

With such an interferometer system, the optical path length of the beam is comparatively long, and changes in the attitude of the stage therefore tend to affect the measurement result.

For example, a change in the inclination of the stage results in a comparatively large positional deviation of the beam that returns from the stage and / or a comparatively large angular deviation in the return direction, and there is consequently a possibility that this will invite a detection failure and / or measurement error.

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