JPH0980758A - Simultaneous exposure method for large area - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct the nonuniformity of the illuminance within an exposure surface by placing a photosensitive plate capable of forming a light shieldable layer on a transparent substrate near an exposure mask and placing a correction mask at the position where the photosensitive plate of the exposure device is exposed. SOLUTION: The correction mask 9 having light shieldable layers of the continuous gradations having the large extent of shielding light in the parts where the illuminance of the incident light on the exposure mask 6 surface is high and the small extent of shielding the light in the parts where the illuminance is low, formed on the transparent substrate, is placed on the position just before the incident light arriving from a light source 1 arrives at the exposure mask 6. As a result of it, the incident light passing the correction mask 9 is made into the uniform light corrected of the illuminance and the incident light on the exposure mask 6 has also the illuminance uniform over the entire surface of the mask. Therefore, the illuminance of the exposing light passing the exposure mask 6 becomes uniform without the uniformity by the sections. The exposing light arrives as the light of the uniform illuminance at a plate 8 to be worked. Such correction mask 9 is obtd. by exposure and development using the photosensitive plate 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern exposure method for manufacturing a color filter, an electrode plate or the like used in a large liquid crystal display device, plasma display or the like.

[0002]

2. Description of the Related Art In display devices such as liquid crystal display devices and plasma displays, their display screens are becoming larger in size, and the major parts of the display devices, that is, color filters, electrode plates, etc. are also becoming larger. Conventionally, when manufacturing these large color filters, electrode plates, etc., cost reduction,
In order to improve the throughput, the large area collective exposure method described below is used. That is, when performing pattern exposure on a substrate to be processed to form a pattern, an aligner is used to perform pattern exposure on the substrate to be processed all at once through a mask having a pattern area having a large area, in a single pattern exposure. This is a method using a large-area batch exposure machine). As a matter of course, a photosensitive layer is formed on the plate to be processed, and after this pattern exposure, a color filter, an electrode substrate, etc. are formed by a method known as so-called photofabrication such as development and etching. It is what is done. By the way, when performing the large-area batch exposure described above, the illuminance of the light incident on the exposure mask is
It can be said that the entire surface of the exposure mask needs to be uniform. That is, it is necessary that the amount of exposure to each pattern-exposed portion be uniform over the entire surface of the plate to be pattern-exposed through the exposure mask. Otherwise, the unevenness of the exposure dose causes unevenness in the pattern formed by exposure, so-called exposure unevenness.

For this reason, the optical system of the collective exposure apparatus is devised so that the illuminance of the light incident on the entire surface of the exposure mask is kept constant, for example, by using a fly-eye lens in the optical path.
However, since the size of the exposure mask is increased, the difference in the distance from the light source between the central portion and the peripheral portion of the exposure mask is larger than in the past, so that the central portion of the exposure mask tends to have higher illuminance than the peripheral portion. . There is also a problem that the illuminance of incident light may locally vary due to a structure peculiar to the exposure apparatus, for example, irregular reflection from the inner wall of the apparatus. For this reason, the manufactured color filter had uneven exposure.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for solving the problem of non-uniformity of illuminance on the exposed surface as described above, and to obtain a color filter, an electrode plate, etc. without uneven exposure. And

[0005]

In order to achieve the above object, the present invention provides a large-area package for exposing a plate to be processed with a desired pattern by light passing through a light transmitting portion of an exposure mask having a light shielding pattern. In the exposure method, in the middle of the optical path between the exposure mask of the exposure apparatus and the light source, near the exposure mask, there is a large degree of blocking the light at the high illuminance portion of the incident light on the exposure mask surface, and the light at the low illuminance portion is large. A photosensitive plate capable of forming a continuous gradation light-shielding layer having a small degree of blocking light on a transparent substrate, exposing the photosensitive plate, and developing the correction mask to the photosensitive plate of the exposure device. The large area collective exposure method is characterized in that the illuminance is averaged over all the pattern exposed portions of the plate to be processed by placing it on the exposed position.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing the mechanism of a collective exposure device for color filters for liquid crystal display devices. The conventional exposure mechanism is generally as follows, for example. That is, the light emitted from the light source 1 using a high-pressure mercury lamp or the like is regulated in one direction by the concave reflecting mirror 2. Next, the light is cut off by the infrared cut mirror 3 in order to prevent thermal expansion of the exposure mask 6 and the plate 8 to be processed. Then, after the difference in the amount of light within the cross section of the optical path is reduced by the fly-eye lens (compound eye lens) 4, the light passes through the condenser mirror 5 and becomes almost parallel incident light, which is incident on the exposure mask. Then, the light passes through the exposure mask 6 and becomes exposure light, which reaches the plate 8 to be processed on the stage 7. Here, in the present invention, at a position immediately before the incident light reaching from the light source 1 reaches the exposure mask 6, the degree of blocking the light at a high illuminance portion of the incident light on the exposure mask surface is large and at a low illuminance portion. A correction mask 9 in which a continuous gradation light-shielding layer having a small degree of blocking light is formed on a transparent substrate is placed. As a result, the incident light that has passed through the correction mask becomes uniform with the illuminance corrected, and the incident light on the exposure mask also has uniform illuminance over the entire mask. As a result, the illuminance of the exposure light that has passed through the exposure mask also reaches the processed plate 8 as light having a uniform illuminance in which unevenness due to parts is eliminated.

The correction mask 9 is obtained by exposing and developing, which will be described later, using the photosensitive plate 10. The photosensitive plate 10 used is as follows. (1) A silver salt photographic plate for gray scale. The silver salt photograph is preferable as a correction mask used in the present invention, because the halftone is clear and continuous gradation is obtained, and the density of the light-shielding layer is low and the exposure amount is small. It is desirable that the transparent substrate glass used as the substrate is an ultraviolet-transparent type and has a high transmittance. (2) Further, a quartz glass plate on which a weak ultraviolet light shielding film such as SiO ₂ is deposited is coated with a photosensitive resist.

At the same position as the position where the correction mask 9 is placed on the photosensitive plate 10, the incident light reaching from the light source 1 is exposed to the exposure mask
It is placed at a position just before reaching, and is exposed and then developed. However, in the case of using the above (2), since the obtained light-shielding layer has approximately continuous gradation, it is necessary to place the halftone dot mesh on it only during the exposure for obtaining the correction mask. Further, the SiO ₂ film portion exposed after development is removed by etching. If the distance between the photosensitive plate 10 and the exposure mask 6 is long, new light unevenness may occur between the correction mask 9 and the exposure mask 6 due to light entering from the outside. Is desirable.

The correction mask 9 created as described above
In accordance with the illuminance distribution of the incident light at the time of exposure described above, a continuous gradation light-shielding layer that forms a large degree of blocking light at a high illuminance portion and a small degree of blocking light at a low illuminance portion is formed. . By placing this correction mask 9 at the position where the photosensitive plate 10 has been exposed and exposing it, it is possible to average the illuminance on each part of the exposed portion of the plate 8 to be processed on the stage 7.

[0010]

According to the method of the present invention, the illuminance of the light to be exposed to each portion of the plate to be processed is changed according to the different exposure characteristics caused by the difference in the mechanical structure of each individual exposure apparatus or the modification. Non-uniformity can be corrected. As a result, the pattern formed by the pattern exposure is free from shape defects due to uneven exposure. Also, since the exposure amount is reduced by the amount of light passing through the correction mask, it takes a little longer exposure time to adjust the exposure amount to the work plate to an appropriate amount, but the effect of improving the product yield by eliminating uneven exposure Surpasses.

[0011]

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a batch exposure apparatus for color filters for liquid crystal display devices according to the present invention.

[Explanation of symbols]

 1 Light Source 2 Reflecting Mirror 3 Infrared Cut Mirror 4 Fly's Eye Lens 5 Condensing Mirror 6 Exposure Mask 7 Stage 8 Processed Plate 9 Correction Mask 10 Photosensitive Plate

Claims (1)

[Claims] 1. A large-area batch exposure method for exposing a desired pattern to a plate to be processed by light passing through a light transmitting portion of an exposure mask having a light-shielding pattern, in the middle of an optical path between an exposure mask of an exposure device and a light source. , Near the exposure mask,
Place a photosensitive plate that can form a continuous gradation light-shielding layer on a transparent substrate that has a large degree of blocking light in areas with high illuminance of incident light on the exposure mask surface and a small degree of blocking light in areas with low illuminance. , A correction mask obtained by exposing and developing the photosensitive plate was placed at the position where the photosensitive plate of the exposure device was exposed, and the illuminance to all pattern exposed portions of the plate to be processed was averaged. A large-area collective exposure method characterized by the above.