JPH10115933A - Light irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light irradiation device capable of improving the uniformity of illuminance distribution on an irradiated surface without increasing the cost, more than that in the conventional practice. SOLUTION: The light irradiation device is provided with an optical integrator 14 constituted of plural columnar lenses 14a arranged adjacent to each other, and a concave total-reflection mirror for reflecting light emitted from the light-emitting surface of the optical integrator 14, distributing and projecting the reflected light so that each main beam of the reflected light may be parallel to the irradiated surface which is separately positioned and also a collimating angle may become a prescribed angle. And, by using the columnar lens 14a whose light transmittance at one end surface is different in accordance with the position on the end face as a part of plural columnar lenses 14a and changing the light transmittance at the light incident surface of the optical integrator 14 in accordance with the position on the light incident surface, the illuminance distribution on the irradiated surface generated by light irradiated through the concave total-reflection mirror is made uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical integrator composed of a plurality of columnar lenses arranged adjacent to each other, and reflects light emitted from the optical integrator and separates the reflected light. And a concave mirror for distributing and irradiating each principal ray parallel to the illuminated surface so that the collimation angle becomes a predetermined angle, and in particular, such as a matrix circuit board for a liquid crystal display device The present invention relates to a light irradiation device suitable for an exposure device used in manufacturing a semiconductor or the like.

[0002]

2. Description of the Related Art Generally, in a manufacturing process of a semiconductor such as a matrix circuit board for a liquid crystal display device or a color filter for a liquid crystal display device, a mask pattern is exposed on an object to be exposed such as a circuit board and transferred. Exposure apparatus is used.

An example of this exposure apparatus will be described with reference to FIGS. FIG. 4 is a schematic diagram showing a main part configuration of a conventional exposure apparatus, FIG. 5 is a configuration diagram showing an optical integrator of FIG. 4, and FIG. 6 is an intensity distribution of incident light on an incident surface of the optical integrator of FIG. FIG. 4 is a diagram showing an illuminance distribution in FIG.

As shown in FIG. 4, a conventional exposure apparatus includes a mercury lamp 1 as a light source, and light emitted from the mercury lamp 1 is an elliptical mirror arranged so that the position of the mercury lamp 1 is set as a first focal position. 2 and is guided to the flat UV reflecting mirror 3. The flat UV reflecting mirror 3 reflects only the ultraviolet light contained in the incident light from the mercury lamp 1 toward a position corresponding to the second focal position of the elliptical mirror 2, and the reflected ultraviolet light passes through a light irradiation system. Irradiated on the irradiated surface 6.

The light irradiation system reflects an optical integrator 4 disposed at a position corresponding to the second focal position of the elliptical mirror 2 and ultraviolet light emitted from the optical integrator 4, and irradiates the reflected ultraviolet light. And a concave total reflection mirror 5 for guiding to the surface 6.

As shown in FIGS. 4 and 5, the optical integrator 4 is composed of a plurality of columnar lenses 4a. Each of the columnar lenses 4a has one end face reflected by an ultraviolet light reflected by the flat UV reflecting mirror 3. Are two-dimensionally arranged adjacent to each other so as to form an incident surface of the optical axis. One end surface of each columnar lens 4a is formed into a curved surface, and the side of each columnar lens 4a is directed toward the inside of the ultraviolet light that has traveled toward the side of the ultraviolet light incident from one end surface thereof. It is formed into a ground glass so as to reflect (scatter). The other end surface of each of the columnar lenses 4a is formed into a curved surface like the one end surface, and forms an emission surface for emitting ultraviolet light incident from one of the end surfaces. Each columnar lens 4a has a property of emitting ultraviolet light incident parallel to its optical axis so as to focus on the center position of the other end face of each columnar lens 4a, and is incident at an angle inclined with respect to the optical axis. Has the property of determining the emission direction of the ultraviolet light according to the incident position on one end face of the columnar lens 4a, and the curvature of each end face of each columnar lens 4a and each columnar lens 4a so as to obtain these properties. Is determined in the optical axis direction.

As shown in FIG. 4, the concave total reflection mirror 5 reflects the ultraviolet light emitted from the optical integrator 4 and converts the reflected ultraviolet light so that each principal ray is parallel to the irradiated surface 6 and the collimation angle α. Is arranged at a predetermined angle to irradiate the light. The concave mirror is positioned relative to the optical integrator 4 and the surface 6 to be irradiated.

Next, irradiation of the irradiated surface 6 with ultraviolet light by the above-described exposure apparatus will be described.

First, light emitted from a mercury lamp 1 is reflected by an elliptical mirror 2 and guided to a flat UV reflecting mirror 3.
The plane UV reflection mirror 3 reflects only the ultraviolet light toward the optical integrator 4, and the reflected ultraviolet light is
The light is incident on one end face of each of the columnar lenses 4a constituting the optical integrator 4.

The intensity of the ultraviolet light, that is, the illuminance on the incident surface of the optical integrator 4 formed at one end surface of each columnar lens 4a is, as shown in FIG. 6A, at each position of the incident surface of the optical integrator 4. Will change accordingly. Specifically, the optical integrator 4
The illuminance is maximized at the central position X (A) of the incident surface, and the illuminance at each peripheral position X (B) of the incident surface is lower than the illuminance at the central position X (A).

Ultraviolet light incident on each columnar lens 4a in parallel with its optical axis travels through each columnar lens 4a so as to focus on the center position of the other end surface, and from the focal point, the columnar lens 4a.
Inject outside of a. Light incident at an angle inclined within a certain angle with respect to the optical axis is emitted to the outside from the other end face,
The exit direction is determined according to the incident position on one end face of the columnar lens 4a. Note that the light that enters the columnar lens and reaches the side portion inside is scattered because the side portion is formed in a frosted glass shape.

Ultraviolet light emitted in a predetermined direction from each of the columnar lenses 4a constituting the optical integrator 4 is reflected by the concave total reflection mirror 5, whereby the principal rays are parallel and the collimation angle α becomes a predetermined angle. And irradiates the entire surface 6 to be irradiated. Specifically, of the ultraviolet light emitted from each of the columnar lenses 4a in a predetermined direction, the ultraviolet light emitted from each of the columnar lenses 4a in a direction parallel to the optical axis irradiates the central portion of the irradiated surface 6. Is done. On the other hand, ultraviolet light emitted from each columnar lens 4a in a direction inclined with respect to the optical axis is applied to a portion between the central portion and the peripheral portion of the irradiated surface 6. The portion of the irradiated surface 6 to be irradiated with ultraviolet light emitted from each columnar lens 4a in a direction inclined with respect to the optical axis thereof is determined according to the emission direction of the ultraviolet light.

As described above, the ultraviolet light from the mercury lamp 1 is incident on the incident surface of the optical integrator 4 with a non-uniform intensity distribution, but the ultraviolet light incident with the non-uniform intensity distribution is transmitted to the optical integrator 4 and the concave surface. Since the light is distributed to the irradiation surface 6 through the light irradiation system including the total reflection mirror 5, the illuminance is distributed over the entire irradiation surface 6 regardless of the uneven intensity distribution of the incident ultraviolet light. Can be made substantially uniform. For example, as shown in FIG. 6B, the illuminance on the irradiated surface 6 by the ultraviolet light is maximized at a central position X (a) of the irradiated surface 6 and at each peripheral position X.
In (b), an illuminance distribution in which the difference between the maximum value and the minimum value is small and the illuminance is symmetric about the center position is obtained.

In this configuration, as described above, the positioning of the elliptical mirror 2 of the optical integrator 4 to the position corresponding to the second focal position, the concave total reflection mirror 5
Optimizing the positional accuracy relationship such as relative positioning between the optical integrator 4 and the irradiated surface 6, and the manufacturing accuracy relationship such as the manufacturing accuracy of the columnar lens 4 a and the concave total reflection mirror 5 constituting the optical integrator 4. It is important that the uniformity of the illuminance distribution on the irradiated surface 6 is determined according to the position and the degree of optimization of the manufacturing accuracy relationship.

In recent years, as the size of the liquid crystal display device has increased, the area of the irradiated surface 6 has been required to be increased, and with the improvement in productivity of the liquid crystal display device, simultaneous exposure of a plurality of circuit boards on the irradiated surface 6 has been required. In order to satisfy these requirements,
It is necessary to further improve the uniformity of the illuminance distribution on the irradiated surface 6.

[0016]

However, in the conventional configuration, it is necessary to further optimize the relationship between the position and the manufacturing accuracy described above, for example, the large area of the elliptical mirror 2, the flat UV reflecting mirror 3, and the concave total reflecting mirror 5. Coating uniformity, optical axis adjustment of optical integrator 4,
There is a very high cost and a limit to further improving the accuracy such as adjusting the focal position of each columnar lens 4a, and there is a limit. By optimizing the position and the manufacturing accuracy relation, the illuminance distribution on the irradiated surface 6 is improved. It cannot be expected that the uniformity will be further improved.

According to the present invention, there is provided a light irradiation apparatus capable of further improving the uniformity of the illuminance distribution on a surface to be irradiated as compared with the prior art, without increasing the cost, in order to solve the above problems. The purpose is to:

[0018]

SUMMARY OF THE INVENTION The present invention comprises a plurality of columnar lenses arranged adjacent to each other, and one end face of each of the columnar lenses causes a light incident surface to be the other of the columnar lenses. An optical integrator in which an exit surface of light is formed by an end face of the optical integrator, and reflects light emitted from the exit surface of the optical integrator,
A light-irradiating device comprising: a concave mirror for distributing and irradiating the reflected light such that each principal ray is parallel to a surface to be illuminated and a collimation angle is a predetermined angle; and As a part of the plurality of columnar lenses, the light transmittance at one end surface is different depending on the position on the end surface, so that the illuminance distribution on the irradiation surface by the light to be irradiated is uniform. The optical transmittance of the optical integrator at the light incident surface is changed according to the position on the light incident surface.

In the light irradiation apparatus according to the present invention, the light transmittance at one end face is changed according to the position on the end face so that the illuminance distribution on the irradiation target surface by the light irradiated through the concave mirror becomes uniform. Since different columnar lenses are used as a part of the plurality of columnar lenses and the light transmittance of the optical integrator on the light incident surface is changed according to the position on the incident surface, the surface to be illuminated from the optical integrator via the concave mirror is used. The amount of light irradiated upward can be adjusted for each position of the incident surface according to the light transmittance at that position. Further, the light transmittance at the light incident surface of the optical integrator is determined by changing the light transmittance at the light incident surface of the optical integrator to a position on the light incident surface by using a columnar lens whose light transmittance at one end surface varies depending on the position on the end surface as a part of the plurality of columnar lenses. However, the cost required for the configuration to change according to is not high.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a structural view showing a main part of a first embodiment of a light irradiation apparatus according to the present invention, and FIG. 2 is a diagram for adjusting light transmittance at an incident surface of the optical integrator of FIG. It is a front view showing the state performed.

As shown in FIG. 1, the light irradiation device includes a light source (not shown), an elliptical mirror (not shown), and a plane U.
An optical integrator 14 that receives ultraviolet light guided through a V reflection mirror (not shown), and reflects ultraviolet light emitted from the optical integrator 14;
A concave total reflection mirror (not shown) for guiding the reflected ultraviolet light to a surface to be irradiated (not shown). The positional relationship between the elliptical mirror and the flat UV reflecting mirror with respect to the light source, and the positional relationship between the concave total reflection mirror with respect to the optical integrator 14 are the same as the positional relationship shown in FIG. The first
The flat UV reflecting mirror is arranged so as to be at the focal position, and is arranged so as to reflect only the ultraviolet light contained in the light from the incident light source toward the position corresponding to the second focal position of the elliptical mirror. The concave total reflection mirror has the same configuration as that shown in FIG.
A concave mirror for reflecting the ultraviolet light emitted from the mirror and distributing the reflected ultraviolet light so that each principal ray is parallel to the surface to be irradiated and the collimation angle is a predetermined angle, and the concave mirror is optical. It is positioned relatively to the integrator 14 and the irradiation surface.

The optical integrator 14 is arranged at a position corresponding to the second focal position of the elliptical mirror. As shown in FIGS. 1 and 2, the optical integrator 14 includes a plurality of columnar lenses 14a. Each of the columnar lenses 14a has an incident surface of ultraviolet light whose one end surface is reflected by a flat UV reflecting mirror. Are arranged two-dimensionally adjacent to each other in a direction perpendicular to the optical axis. In the present embodiment, 64 columnar lenses 14a are two-dimensionally arranged in 8 rows and 8 columns, and the arrangement forms the optical integrator 14 having a cross-sectional shape of 80 mm × 80 mm.

One end surface of each columnar lens 14a is formed into a curved surface, and the side of each columnar lens 14a receives ultraviolet light that has traveled toward the side out of the ultraviolet light incident from one end surface. It is formed in a frosted glass shape so as to be scattered. The other end surface of each columnar lens 14a is formed in a curved shape like the one end surface, and forms an exit surface for emitting ultraviolet light incident from one end surface. Each columnar lens 14a
The ultraviolet light incident parallel to the optical axis is
a has a property of emitting light so as to be focused on the center position of the other end face of a, and the emission direction of ultraviolet light incident at an angle inclined with respect to the optical axis depends on the incident position on one end face of the columnar lens 14a. The curvature of each end face of each columnar lens 14a and the length of each columnar lens 14a in the optical axis direction are determined so that these properties can be obtained.

In particular, in the optical integrator 14 according to the present invention, a part of each of the columnar lenses 14a is formed of a columnar lens whose light transmittance at one end surface is different depending on the position on the end surface. Is disposed at a position near the center, which is advantageous for effectively changing the light transmittance on the light incident surface of the optical integrator 14. The light transmittance according to the position on one end surface of the columnar lens 14a is determined by adjusting the surface roughness corresponding to the position. By using a part of the columnar lens 14a, the optical integrator 14
Is configured so that the light transmittance therethrough changes according to the position on the incident surface.
The number of used portions of 4a, the arrangement thereof, and the adjustment position of the surface roughness for determining the light transmittance at one end surface thereof are determined based on the measurement result of the illuminance distribution on the surface to be irradiated which has been measured in advance. You. The measurement result of this illuminance distribution
4A is a measurement result of an illuminance distribution by light irradiated through a concave total reflection mirror before the light transmittance of 4a is adjusted.

The number of parts of the columnar lens 14a to be used is determined according to the following procedure. In this determination procedure, first, the number of columnar lenses 14a is m, the surface to be irradiated is divided into a plurality of regions, and the number of the divided regions is n,
The end surface of each columnar lens 14a is associated with each of the divided areas of the irradiated surface, and is divided into n areas as an incident area of light to be applied to each area, and the amount of light lpq transmitted through the divided areas (P = 1,..., M, q = 1,..., N)
The sum of the light amounts lpq in each area of the end face of each columnar lens associated with each of the divided areas of the irradiated surface is ls.
(S = q), and before the light transmittance of the columnar lens 14a is adjusted, the average illuminance of each of the divided areas of the irradiated surface is measured by an illuminometer, and the measurement result is obtained.

Next, the light transmittance of one end face of the optical integrator 14 is adjusted based on the measurement result. That is, each columnar lens 14 is set such that the average illuminance Ls (s = q) of each region on the irradiated surface, which is obtained from the adjusted total light amount ls, becomes equal to a constant value.
The surface roughness for determining the number of used portions of a, its disposition, and the light transmittance at one end face are determined, and adjustment is performed in accordance with the surface roughness. Specifically, the average illuminance at another position (region) on the illuminated surface is set to a specific value based on the average illuminance value at a low illuminance position (region) on the illuminated surface based on the measurement result. The difference between the specific value and the reference value is calculated, and the total amount ls of the light amount in the end surface area of each columnar lens 14a, which is the incident area of the light irradiating the other position on the irradiated surface, is calculated according to the difference. The number of parts of each columnar lens 14a to be used, their arrangement, and their surface roughness are determined so as to reduce the required amount.

In the present embodiment, the number of columnar lenses 14a is 64, and the area required as the surface to be irradiated is 450 mm long.
× A region of 550 mm in width, the irradiated surface is equally divided into a plurality of regions, the number of the equally divided regions is 25, and the end surface of each columnar lens 14a is associated with each divided region of the irradiated surface. The light incident on each area is equally divided into 25 areas, and the amount of light lpq (p = 1,..., 64, q = 1,..., 25) transmitted through the equally divided areas. ,
The sum of the light amounts lpq in each region of the end surface of each columnar lens 14a associated with each of the divided regions of the irradiation surface is ls (s = 1,..., 25), and the light transmittance of the columnar lens 14a is When the average illuminance of each of the divided regions of the irradiated surface is measured in the state before the adjustment, the measurement results shown in Table 1 are obtained, and the evaluation data shown in Table 2 is calculated based on the measurement results. . The evaluation data includes the average value Ave., the maximum value MAX., And the minimum value MI of the average illuminance of each area on the irradiated surface.
N. and uniformity Uni. Are included, and the uniformity Uni. Is a parameter indicating the uniformity of the illuminance distribution on the irradiated surface. Uniformity Un
i. is calculated by the following equation (1).

Uniformity Uni. = (Maximum value MAX.-minimum value MIN.) / (Maximum value MAX. + Minimum value MIN.) × 100 (%) (1)

[0030]

[Table 1]

[0031]

[Table 2] Next, based on the measurement results shown in Table 1 above, each of the average illuminances Ls obtained from the total light amount ls is equal to a constant value, that is, the uniformity Uni. In the evaluation data shown in Table 2 is as small as possible. The number of parts of each columnar lens 14a to be used, the arrangement thereof, and the surface roughness for determining the light transmittance at one end face of the columnar lens 14a are determined. On one end face of the columnar lens 14a selected as the object of light transmittance adjustment by this determination, the position of the end face obtained by the above determination is rubbed, that is, processed into a frosted glass, and the degree of rubbing is determined. The light transmittance at the corresponding position is adjusted to a predetermined value by the corresponding surface roughness.

For example, based on the measurement results shown in Table 1 above, the value at the position of low illuminance on the irradiated surface, that is, the minimum value
MIN. (= 21.3) as a reference value, and the illuminance at another position on the irradiated surface, that is, the maximum value MAX. (= 25.9)
Are selected as specific values, and the maximum value on the irradiated surface
Each columnar shape is set such that the sum ls of the light amounts in the region of the end face of each columnar lens 14a, which is the incident region of the light irradiated to the position indicating MAX., Is reduced by a necessary amount according to the difference between the specific value and the reference value. The number of used lenses 14a, their arrangement, and their surface roughness are determined. In the present embodiment, it is calculated that about 20% reduction is required as the target reduction in illuminance at the position indicating the maximum value MAX. On the irradiated surface.

In the case of this example, first, as shown in FIGS. 1 and 2, one of the columnar lenses 14a located at the center is selected as an object of light transmittance adjustment. The selection of the columnar lens 14a located at the center is such that the transmitted light amount of the columnar lens 14a located at the center is larger than the transmitted light amount of the columnar lens 14a at the peripheral portion, and the columnar lens 14a located at the center is selected.
This is because it is considered that it is efficient to correct the amount of transmitted light. On one end face of the columnar lens 14a at the center position, first, a center portion corresponding to a position indicating the maximum value MAX. On the irradiated surface is selected as a region where light transmittance is adjusted, and the region is specified. Is rubbed with the strength C1.

When the light transmittance at the center is adjusted according to the intensity of the rubbing, the illuminance distribution is measured again. As a result of the measurement, the illuminance at the position showing the maximum value MAX. On the irradiated surface has decreased by about 4%.
The light transmittance is sequentially adjusted with the same rubbing strength to the central portion of the four columnar lenses 14a located around “a”. As a result, the light transmittance with respect to the central portion of each of the columnar lenses 14a was reduced by almost the target reduction amount.

Next, adjustment was sequentially performed on the area around the adjusted area in the same manner. In these areas, the difference from the minimum value MIN. Is smaller than that in the center, so that the rubbing strength is a strength C weaker than the strength C1.
2 and C3 were used. The following relationship is established between the light transmittances of the areas corresponding to C1, C2, and C3.

The amount of decrease in light transmittance due to C1> the amount of decrease in light transmittance due to C2> the amount of decrease in light transmittance due to C3 As described above, the light transmittance is adjusted at one end face of the selected columnar lens 14a. Accordingly, the light L1, L2, L incident on each part of the rubbing strength C1, C2, C3
3 enters the columnar lens 14a with its light amount reduced, and the following relational expression is established between the light amounts of the lights L1, L2, and L3.

In this embodiment, three types of rubbing intensity are used, and the combination of the intensity and the number of lenses to be adjusted is determined by the illuminance. While confirming the measured values, the respective regions were adjusted by making appropriate selections. FIG. 2 schematically shows the incident side of the optical integrator after the adjustment is completed. In this way, for all the regions, the illuminance at the position on the irradiated surface is adjusted so as to be substantially equal to the minimum value MIN.

By adjusting the light transmittance, the amount of light emitted from the selected columnar lens 14a is adjusted. That is, the amount of light emitted from the optical integrator 14 onto the irradiated surface via the concave total reflection mirror is adjusted. For each position of the incident surface of the integrator 14, adjustment can be made according to the light transmittance at that position. After this light transmittance adjustment, the illuminance distribution shown in Table 3 is obtained. Table 4 shows evaluation data for the illuminance distribution.

[0039]

[Table 3]

[0040]

[Table 4] From the above Tables 3 and 4, the illuminance of each area of the irradiated surface is almost equal to the average value Ave, and the uniformity Uni is lower than before the light transmittance adjustment (from 9.7%). 3.4%), that is, the difference between the maximum value MAX. And the minimum value MIN. Is suppressed to a very small value. Therefore, it can be seen that by adjusting the light transmittance at the end face of the selected columnar lens 14a, the light transmittance was improved about three times by the ultraviolet light radiated through the concave total reflection mirror as compared with the related art. In addition, since the light transmittance is adjusted by adjusting the surface roughness corresponding to the position on one end face of the columnar lens 14a, the uniformity of the illuminance distribution on the irradiated surface is further improved. The cost of doing so is not high.

In this embodiment, the surface to be irradiated is 25
And the light transmittance at the end face of the columnar lens 14a selected based on the measurement result of the illuminance in each area is adjusted. By obtaining the distribution and continuously adjusting the light transmittance to the end face of the columnar lens 14a based on the illuminance distribution, the uniformity of the illuminance distribution on the surface to be irradiated can be further improved. However, since the degree of uniformity of the illuminance distribution is determined according to the manufacturing specification of the irradiation target, the number of divided regions on the irradiation surface is adaptively adjusted according to the degree of uniformity of the corresponding illuminance distribution. It is preferable to select.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a diagram schematically showing a configuration of a main part of a contact exposure apparatus in which the light irradiation apparatus of FIG. 1 is incorporated. In the present embodiment,
A contact exposure apparatus in which the light irradiation apparatus of the first embodiment described above is incorporated will be described.

As shown in FIG. 3, the contact exposure apparatus includes a mercury lamp 1 as a light source, and the light emitted from the mercury lamp 1 is an elliptical mirror 2 arranged so that the position of the mercury lamp 1 is the first focal position. And is guided to the flat UV reflection mirror 3. The flat UV reflecting mirror 3 reflects only the ultraviolet light included in the light from the mercury lamp 1 incident thereon toward a position corresponding to the second focal position of the elliptical mirror 2, and the reflected ultraviolet light passes through a light irradiation device. Irradiated on the irradiated surface 6.

The light irradiation device reflects the optical integrator 14 disposed at a position corresponding to the second focal position of the elliptical mirror 2, the ultraviolet light emitted from the optical integrator 14, and receives the reflected ultraviolet light. And a concave total reflection mirror 5 for guiding on the irradiation surface. As in the first embodiment, the optical integrator 14 has a light transmittance at one end surface such that the illuminance distribution on the surface to be irradiated by the light irradiated through the concave total reflection mirror 5 is uniform. Is formed using a columnar lens that is different depending on the position on the end face as a part of the plurality of columnar lenses, and the light transmittance of the optical integrator 14 at the light incident surface changes according to the position on the light incident surface. .

An object 11 to be exposed held by a work holding mechanism 12 is placed on the surface to be irradiated, and a resist 10 is applied to the surface of the object 11 to be exposed. Further, a glass mask 8 having a mask pattern 9 on the surface is provided by a mask holding mechanism 7.
Is held in. Then, the mask holding mechanism is positioned by a positioning mechanism (not shown), the exposure object 11 and the glass mask are aligned, and the pattern surface and the resist coating surface are brought into close contact. The mask pattern 9 is exposed and transferred to the surface of the exposure object 11 by ultraviolet light irradiated through the concave total reflection mirror 5.

As described above, by using the optical integrator 14, the uniformity of the illuminance distribution on the surface to be irradiated by the light irradiated through the concave total reflection mirror 5 is further improved without increasing the cost. As a result, it is possible to improve the exposure performance of the exposure target 11 at low cost. In addition, it satisfies these requirements for requirements such as an increase in the area of the surface to be irradiated due to the enlargement of the liquid crystal display device, and simultaneous exposure of a plurality of circuit boards on the surface to be irradiated due to the improvement in productivity of the liquid crystal display device. Thus, the uniformity of the illuminance distribution on the surface to be irradiated can be further improved.

In this embodiment, the contact exposure apparatus in which the light irradiation device of the first embodiment is incorporated has been described. It is also possible to incorporate it in a proximity exposure apparatus having a gap of, for example, several tens of microns between the object and the object. Needless to say, the same effects as described above can be obtained in this proximity exposure apparatus.

[0048]

As described above, according to the light irradiation apparatus of the present invention, the light transmission on one end face is made uniform so that the illuminance distribution on the surface to be irradiated by the light irradiated through the concave mirror becomes uniform. Since the light transmittance of the optical integrator at the light incident surface was changed according to the position on the incident surface using a columnar lens having a different ratio depending on the position on the end surface as a part of the plurality of columnar lenses, The amount of light emitted from the optical integrator onto the surface to be irradiated via the concave mirror can be adjusted for each position of the incident surface according to the light transmittance at that position, and the light transmittance at one end surface can be adjusted. The light transmittance at the light incident surface of the optical integrator is changed according to the position on the incident surface by using a different columnar lens depending on the position on the end surface as a part of the plurality of columnar lenses. It costs to be configured so that does not become high. Therefore, it is possible to further improve the uniformity of the illuminance distribution on the surface to be irradiated by the light irradiated through the concave mirror, as compared with the related art, without increasing the cost. In addition, since the above adjustment is performed based on the data of the illuminance directly measured on the irradiated surface, high-precision uniformization can be easily achieved despite low cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a main part of a first embodiment of a light irradiation device of the present invention.

FIG. 2 is a front view showing a state where light transmittance on an incident surface of the optical integrator of FIG. 1 is adjusted.

FIG. 3 is a diagram schematically illustrating a configuration of a main part of a contact exposure apparatus in which the light irradiation apparatus of FIG. 1 is incorporated.

FIG. 4 is a schematic view showing a main part configuration of a conventional exposure apparatus.

FIG. 5 is a configuration diagram illustrating the optical integrator of FIG. 4;

6 is a diagram showing an intensity distribution of incident light on an incident surface and an illuminance distribution on an irradiated surface of the optical integrator of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mercury lamp 2 Elliptical mirror 3 Planar UV reflection mirror 5 Concave total reflection mirror 6 Illuminated surface 9 Mask pattern 11 Exposed object 14 Optical integrator 14a Columnar lens

Claims (1)

[Claims] 1. A light incident surface is formed by one end face of each of the columnar lenses, and a light emission surface is formed by the other end face of each of the columnar lenses. Each formed optical integrator reflects light emitted from the emission surface of the optical integrator, and each principal ray is parallel to the irradiated surface separating the reflected light and the collimation angle is a predetermined angle. A concave mirror for distributing and irradiating the light so that the light radiated through the concave mirror has a uniform illuminance distribution on the surface to be illuminated. The light at the light incident surface of the optical integrator is formed by using a columnar lens having a transmittance different depending on the position on the end face as a part of the plurality of columnar lenses. A light irradiation device wherein transmittance is changed according to a position on the incident surface.