JPH05335206A - Projection aligner - Google Patents

Abstract

PURPOSE:To achieve a normal projection exposure operation by a method wherein foreign bodies or impurities which have adhered to a holder used to hold an object, to be treated, on which an exposure pattern in a projection aligner is projected are removed effectively and the flattening accuracy of the object to be treated is increased. CONSTITUTION:The title aligner is provided with the following: an illumination optical system 1 which outputs illumination light; an exposure mask 4 on which an exposure pattern is formed; a projection optical system 5 which is user to project the exposed pattern on an object 10 to he treated; a holder 6 on which the object 10, to be treated, on which the exposure pattern is projected is mounted; and a means (a UV filter 2) by which the surface of the holder 6 is irradiated with ultraviolet rays. When an ordinary projection exposure operation is not performed, the surface of the holder 6 is irradiated with the ultraviolet rays and organic substances (foreign bodies or impurities) which have adhered to the surface of the holder 6 are oxidized and removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type exposure machine, and more particularly to a projection type exposure machine having a holder for holding a processed product as an exposure object.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram of a conventional projection type exposure machine. As shown in the figure, an illumination optical system 1 for outputting illumination light, a filter 3 that transmits only a wavelength effective for exposure of illumination light, an exposure mask 4 on which a required exposure pattern is formed, and its A projection optical system 5 for projecting an exposure pattern onto an object 10 to be exposed, a holder 6 for mounting the object 10 to be processed, and the holder 6 for the projection optical system 5
It has a stage 7 for moving and positioning with respect to. In this projection exposure apparatus, the illumination light output from the illumination optical system 1 passes through the filter 3 and is selected only as a wavelength effective for exposure. The illumination light after passing through the filter 3 passes through the exposure mask 4 and the projection optical system 5 and projects the exposure pattern of the mask 4 onto the object to be processed 10. The workpiece 10 is accurately positioned by the holder 6, and the holder 6 is accurately moved to the projection position by the stage 7 for processing.

[0003]

In this conventional projection type exposure apparatus, if foreign matter or impurities are present on the upper surface of the holder 6, the flatness of the object to be processed 10 placed on the holder 6 is lost and the focus is reduced. Exposure defects occur due to misalignment and the like. Although these foreign matters and impurities can be removed to some extent by cleaning, organic foreign matters and impurities tend to remain, and as described above, the flatness of the object to be processed is lost and normal exposure becomes impossible. It is an object of the present invention to provide a projection type exposure apparatus capable of effectively removing foreign matters and impurities attached to a holder.

[0004]

The present invention is directed to an illumination optical system,
A projection type exposure machine having an exposure mask, a projection optical system, and a holder for mounting an object to be processed has means for irradiating the surface of the holder with ultraviolet rays.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1A is a block diagram of a projection type exposure apparatus according to an embodiment of the present invention. As shown in FIG. 1 (A), an illumination optical system 1 for outputting illumination light, a filter 3 that transmits only a wavelength effective for exposure of the illumination light, a wavelength effective for removing oxidation of organic matter, for example, ultraviolet light. UV filter 2 that transmits only light
And an exposure mask 4 on which a required exposure pattern is formed,
A projection optical system 5 for projecting the exposure pattern onto the object 10 to be processed, a holder 6 for mounting the object 10 to be processed, and a stage 7 for moving the holder 6 with respect to the projection optical system 5. Have. The ultraviolet filter 2 is the filter 3
Are arranged in parallel, and the filter 3 and the exposure mask 4 can be selectively moved back and forth with respect to the optical path.

According to this structure, at the time of normal exposure, since the filter 2 is retracted as shown in FIG. 1A, the normal exposure processing by the filter 3 and the exposure mask 4 can be performed. While this normal exposure process is not being performed, as shown in FIG. 1B, the filter 3 and the exposure mask 4 are retracted, and the ultraviolet filter 2 is positioned in the optical path instead. In this state, the illumination light output from the illumination optical system 1 passes through the filter 2 and is selected only as a wavelength (ultraviolet light) effective for removing oxidation of organic substances. Then, the illumination light after passing through the ultraviolet filter 2 passes through the projection system 5 and is directly applied to the holder 6. As a result, the holder 6
The organic foreign matter and impurities adhering to the upper portion are oxidized and removed, and the flatness accuracy of the processing object 10 placed on the holder 6 during the exposure processing is maintained and normal exposure can be performed.

FIG. 2A is a block diagram of a projection type exposure apparatus according to the second embodiment of the present invention. As shown in FIG. 2 (A), an illumination optical system 1 for outputting illumination light, a filter 3 that transmits only a wavelength effective for exposure of the illumination light, an exposure mask 4 on which an exposure pattern is formed, Exposure pattern to be processed 1
Projection optical system 5 for projecting onto 0, a holder 6 on which the object to be processed 10 is placed, a stage 7 for moving the holder 6 with respect to the projection optical system 5, and ultraviolet rays effective for removing oxidation of organic substances. And an ultraviolet projection optical system 9 for irradiating the holder 6 and the stage 7 with the ultraviolet light output from the ultraviolet illumination optical system 8.
The system including the illumination optical system 1, the filter 3, the exposure mask 4, and the projection optical system 5, and the system including the ultraviolet illumination optical system 8 and the ultraviolet projection optical system 9 are a holder 6 and a stage 7. It is configured to be selectively opposed to.

According to this structure, in the state shown in FIG. 2A, since the holder 6 and the stage 7 are present below the projection optical system 5, normal exposure processing is possible. As long as the normal exposure process is not performed, FIG.
As shown in (B), the ultraviolet illumination optical system 8 and the ultraviolet projection optical system 9 are moved and positioned on the holder 6 and the stage 7.
Then, by directly irradiating the holder 6 with the ultraviolet light output from the ultraviolet illumination optical system 8 through the ultraviolet projection optical system 9, it is possible to oxidize and remove the foreign matters and impurities of the organic substances adhering to the holder 6. It is possible to maintain the flatness accuracy of the object to be processed 10 placed on the holder 6 during the exposure processing and perform normal exposure.

[0009]

As described above, according to the present invention, the holder surface for mounting the object to be processed 10 on which the exposure pattern is projected is provided with means capable of irradiating the holder surface with the ultraviolet rays effective for removing the oxidation of the organic matter. It is possible to oxidize and remove the foreign matters and impurities above the organic substance, and the flatness of the object to be processed placed on the holder during the exposure processing is maintained and normal exposure becomes possible.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of a projection type exposure apparatus of the present invention.

FIG. 2 is a block diagram of a second embodiment of the projection type exposure apparatus of the present invention.

FIG. 3 is a block diagram of a conventional projection type exposure apparatus.

[Explanation of symbols]

 1 Illumination Optical System 2 Ultraviolet Filter 3 Filter 4 Exposure Mask 5 Projection Optical System 6 Holder 7 Stage 8 Ultraviolet Illumination Optical System 9 Ultraviolet Projection Optical System 10 Workpiece

Claims (1)

[Claims] 1. An illumination optical system for outputting illumination light, an exposure mask on which an exposure pattern is formed, a projection optical system for projecting the exposure pattern onto an object to be processed, and an exposure pattern. A projection type exposure machine having a holder for mounting an object to be processed, comprising a means for irradiating the surface of the holder with ultraviolet light.