JP2002202583A - Method for producing mask, method for producing optical element using the same, method for producing optical element, method for producing exposure system using optical element produced by this method and method for producing aberration measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an optical element with high mass productivity. SOLUTION: The method has a mask setting step (S20) in which a mask is set on the object surface of a projection system, a substrate setting step (S21) in which a photosensitive optical material is set on a stage, a defocusing step (S22) in which the surface of the photosensitive optical material is dislocated from the best imaging position of the projection system by a prescribed distance D by moving the stage, an exposure step (S23) in which the photosensitive optical material is exposed through the pattern shape of the mask, a developing step (S24) in which the photosensitive optical material exposed in the exposure step is developed and an etching step (S25) in which the photosensitive optical material developed in the developing step is etched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a mask for manufacturing an optical element, a method of manufacturing an optical element using the mask, and a method of manufacturing an exposure apparatus using the optical element manufactured by the manufacturing method. The present invention relates to a method and a method for manufacturing an aberration measuring device.

[0002]

2. Description of the Related Art Conventionally, there is a method in which a replica of a microlens is formed on a photosensitive material using a mask, and the substrate on which the replica is formed is subjected to dry etching, for example, ion beam etching, to form a microlens on the substrate. (See Japanese Patent Application Laid-Open No. Hei 8-504515). In this method, a gray scale mask is used to form a replica of a microlens on a photosensitive material.

[0003]

In a gray scale mask, a large number of dot patterns are formed to form a microlens replica on a photosensitive material, and the transmittance of light is controlled. It is difficult to manufacture a grayscale mask because the position where the dot pattern is to be formed must be accurately determined.

An object of the present invention is to provide a method of manufacturing a mask which can easily manufacture a mask for manufacturing an optical element, and a method of manufacturing an optical element with high productivity using the mask. . Another object of the present invention is to provide a method of manufacturing an optical element having high mass productivity, a method of manufacturing an exposure apparatus using the optical element manufactured by the method, and a method of manufacturing an aberration measuring apparatus.

[0005]

According to a first aspect of the present invention, there is provided a method of manufacturing a mask for manufacturing an optical element, the method comprising: forming an image related to a pattern image of the mask formed at a defocus position of a projection system. An image intensity distribution determining step of obtaining an intensity distribution based on the specifications of the optical element; and a simulation of simulating the image intensity distribution of the projection system in consideration of a pattern shape to be formed on the mask and a defocus amount of the projection system. And a pattern shape determining step of determining a pattern shape of the mask based on a simulation result of the simulation step.

According to the first aspect of the present invention, the image intensity distribution of the projection system is simulated in consideration of the pattern shape to be formed on the mask and the defocus amount of the projection system in the simulation step. In the pattern shape determining step, the mask pattern shape is determined from the pattern shapes simulated in the simulation step to, for example, a pattern shape having an image intensity distribution closest to the image intensity distribution obtained in the image intensity distribution determining step. I do. Therefore, a mask for manufacturing a desired optical element can be easily manufactured.

According to a second aspect of the present invention, there is provided a method of manufacturing an optical element, comprising: a mask setting step of setting a mask manufactured by the manufacturing method of the first aspect on an object plane of a projection system; A substrate setting process to be set on the stage,
A defocusing step of moving the stage to defocus the surface of the photosensitive optical material by a predetermined amount D from the best image forming position of the projection system, and exposing the pattern shape of the mask onto the photosensitive optical material. And a developing step of developing the photosensitive optical material exposed in the exposing step; and an etching step of etching the photosensitive optical material developed in the developing step.

The method of manufacturing an optical element according to claim 3, wherein: a mask setting step of setting a mask on an object plane of the projection system; a substrate setting step of setting a photosensitive optical material on a stage; A defocusing step of defocusing the surface of the photosensitive optical material from the best image forming position of the projection system by a predetermined amount D by moving the pattern, and exposing the pattern shape of the mask onto the photosensitive optical material. A developing step of developing the photosensitive optical material exposed in the exposing step; and an etching step of etching the photosensitive optical material developed in the developing step.

According to the optical element manufacturing method of the present invention, the surface of the photosensitive optical material is defocused by a predetermined amount D from the best imaging position of the projection system in the defocusing step. Image intensity distribution on the surface of the photosensitive optical material in the exposure step is based on the shape of the mask pattern,
This reflects the shape of the optical element to be manufactured. Then, an optical element is manufactured through a developing step and an etching step. Therefore, in this method for manufacturing an optical element, an optical element can be efficiently manufactured in a small number of steps.

According to a fourth aspect of the present invention, in the method of manufacturing an optical element, when the predetermined amount D is a wavelength of the illumination light λ and a numerical aperture of the projection system is NA, 0 <| D | <200 (λ / 2N
Wherein the condition is satisfied for A ^2).

According to a fifth aspect of the invention, in the method of manufacturing an optical element, when the predetermined amount D is a wavelength of the illumination light and a numerical aperture of the projection system is (λ / 2NA ² ) <| D | <2
It satisfies the condition of 00 (λ / 2NA ² ).

According to a sixth aspect of the present invention, there is provided a method of manufacturing an optical element, wherein a mask manufactured by the manufacturing method according to the first aspect is arranged on a mask stage and the mask is set on an object plane of a projection system. A substrate setting step of setting a photosensitive optical material on a stage; and moving the mask stage by a predetermined amount d to defocus the surface of the photosensitive optical material from the best imaging position of the projection system. A defocusing step, an exposure step of exposing the pattern shape of the mask on the photosensitive optical material, a developing step of developing the photosensitive optical material exposed by the exposure step, and a developing step of the developing step. An etching step of etching the photosensitive optical material.

According to a seventh aspect of the present invention, there is provided a method of manufacturing an optical element, comprising: a mask setting step of arranging a mask on a mask stage and setting the mask on an object plane of a projection system; Setting a substrate setting step, a defocusing step of moving the mask stage by a predetermined amount d to defocus the surface of the photosensitive optical material from the best imaging position of the projection system, and changing a pattern shape of the mask. An exposing step of exposing the photosensitive optical material, a developing step of developing the photosensitive optical material exposed in the exposing step, and an etching step of etching the photosensitive optical material developed in the developing step. It is characterized by having.

According to the optical element manufacturing method of the present invention, the mask stage is moved by the predetermined amount d from the defocusing step, and the surface of the photosensitive optical material is formed at the best image forming position of the projection system. When defocusing is performed, the image intensity distribution on the surface of the photosensitive optical material in the exposure step reflects the shape of the manufactured optical element based on the shape of the mask pattern. Then, an optical element is manufactured through a developing step and an etching step. Therefore, in this method for manufacturing an optical element, an optical element can be efficiently manufactured in a small number of steps.

The method of manufacturing an optical element according to claim 8, wherein the predetermined amount d is the wavelength of the illumination light λ, the numerical aperture of the projection system is NA, and the photosensitive optical material is obtained from the mask of the projection system. 0 <| d | <(200
/ Β ² ) (λ / 2NA ² ).

The method of manufacturing an optical element according to claim 9, wherein the predetermined amount d is the wavelength of the illumination light λ, the numerical aperture of the projection system is NA, and the photosensitive optical material is obtained from the mask of the projection system. Where β is the magnification to (λ / 2NA ² ) / β ²
<| D | <(200 / β ² ) (λ / 2NA ² ).

According to a tenth aspect of the present invention, there is provided a method for manufacturing an exposure apparatus, comprising: an illumination optical system for illuminating a pattern of a reticle for manufacturing a micro device installed at a position to be illuminated; A method for manufacturing an exposure apparatus having a projection optical system for projecting an installed photosensitive substrate, wherein an optical element is manufactured by the method for manufacturing an optical element according to claim 2. An optical element incorporation step of incorporating the optical element into the illumination optical system, and a projection optical system installation step of installing the projection optical system between the illuminated position and the exposed position. Features.

According to the method of manufacturing an exposure apparatus according to the tenth aspect, since the optical element efficiently manufactured by a small number of steps in the optical element assembling step is incorporated into the illumination optical system, the production of the projection exposure apparatus is also reduced. It will be efficient. Also,
12. A method of manufacturing an aberration measuring apparatus according to claim 11, comprising: a condensing optical system that condenses light from the test optical system; and a photoelectric detector that photoelectrically detects light passing through the condensing optical system. 10. A method of manufacturing an optical device, comprising the steps of: manufacturing an optical element by the method of manufacturing an optical element according to claim 2; and integrating the optical element into the condensing optical system. The method is characterized by comprising an element assembling step and a photoelectric detector installation step of installing the photoelectric detector at a position for receiving the light via the condensing optical system.

According to the method of manufacturing an aberration measuring device according to the eleventh aspect, the optical element manufactured efficiently by a small number of steps in the optical element assembling step is incorporated into the converging optical system. Will also be efficient.

According to a twelfth aspect of the present invention, there is provided a method of manufacturing an optical element, comprising: a mask setting step of setting a mask on an object plane of a projection system; a substrate setting step of setting a substrate with a photosensitive material on a stage; An exposure step of exposing the pattern shape onto the photosensitive material on the substrate, a developing step of developing the photosensitive material exposed in the exposure step, and a photosensitive material curing step of curing the photosensitive material developed in the developing step An etching step of etching the photosensitive material in a state where the photosensitive material is cured by the photosensitive material curing step.

According to the method for manufacturing an optical element according to the twelfth aspect, an optical element having a precise shape can be manufactured because the photosensitive material developed in the developing step in the photosensitive material curing step is cured.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a flowchart illustrating a method of manufacturing a mask for manufacturing a microlens array as an optical element.

When manufacturing a mask for manufacturing a microlens array, first, the shape and the arrangement of the lenses to be manufactured are determined (step S10). For example, when manufacturing a microlens array MLA as shown in the plan view of FIG. 2A and the cross-sectional view of FIG. 2B (cross-sectional view taken along line AA of FIG. As the shape of the lens constituting the array MLA, the radius of curvature of the lens (for example, 20 mm) and the amount of swelling of the lens (for example, 0.
6 μm) and the size of each lens (for example, 0.3 mm on each side)
The number of arrays (5 × 5) is determined as an array of lenses.

Next, a mask is set on the object plane of the projection optical system of the exposure apparatus for exposing the pattern of the mask on the substrate coated with the photoresist, and a predetermined amount of defocus is performed from the best image forming position of the projection optical system. In this case, the image intensity distribution related to the pattern image of the mask formed at the position (defocus position) is determined based on the specifications of the lenses constituting the microlens array MLA, that is, the radius of curvature of the lenses (step S11). ). FIG. 3A shows FIG.
(A) and microlens array ML shown in FIG. 2 (b)
FIG. 7 shows an image intensity distribution (light intensity distribution) of one lens when a negative resist is used, with respect to a pattern image of a mask formed at a defocus position determined based on the specifications of the lens constituting A. FIG.

In order to obtain a microlens shape conforming to the specification, it is desirable that the image intensity distribution is optimal in consideration of the processing process, such as "photosensitivity to resist light intensity distribution (resist image correction coefficient)" or " It is preferable to perform processing process correction such as "ion beam etching rate (etching correction coefficient)". That is, an image intensity distribution is determined in consideration of a resist image correction coefficient, an etching correction coefficient, and the like, and a microlens is prototyped using a mask manufactured based on the image intensity distribution, and an image is formed based on the prototyped microlens shape. Correct the intensity distribution and redesign the mask pattern.

Next, the image intensity distribution of the projection optical system is simulated in consideration of the pattern shape to be formed on the mask and the defocus amount of the projection optical system of the exposure apparatus (step S12). That is, the simulation is performed while changing at least one of the two-dimensional shape and the defocus amount of the mask. FIG. 3B shows the micro lens array M
The light intensity immediately after passing through one pattern portion of the mask corresponding to one lens constituting the LA is shown in a one-dimensional direction. As shown in FIG. 3B, the light intensity immediately after passing through the mask includes a region where the light intensity is high and a region where the light intensity is zero corresponding to the pattern shape of the mask.
When a predetermined amount of defocusing is performed from the best image forming position of the projection optical system, the light intensity distribution at that position becomes a smooth light intensity reflecting the pattern shape of the mask.
(See FIG. 3A).

When the numerical aperture NA of the projection optical system, the illumination condition σ, the wavelength λ of the illumination light, and the two-dimensional shape of the mask are determined, the simulator used in the simulation determines the image intensity at a predetermined defocus amount. It is a device that can determine the distribution. In a specific simulation, first, the wavelength λ of the illumination light of the exposure apparatus, the numerical aperture NA of the projection optical system, and the illumination condition σ are determined, and the defocus amount D is set. Next, with respect to the mask area for forming the lens, a predetermined number of annular transmission areas having an appropriate width are set with reference to the center point of each pattern, and the width and the position of each annular zone from the center are appropriately changed. Obtain the image intensity distribution. Further, the simulation is performed for various pattern shapes by obtaining the image intensity distribution by the same method while changing the defocus amount.

It should be noted that a second simulation described below may be used instead of the first simulation described above. In the second simulation, first, the wavelength λ of the illumination light of the exposure apparatus, the numerical aperture NA of the projection optical system, the illumination condition σ are determined, and the defocus amount D is set. Next, for the mask area for forming the lens, a plurality of orbicular areas are set with an appropriate orbicular width based on the center point of each pattern. Switching to obtain the image intensity distribution. At this time, in the second simulation, the image intensity distribution can be obtained while changing the defocus amount in the same manner as in the first simulation.

Next, the defocus amount D and the pattern shape of the mask are determined based on the result of the simulation (step S13). That is, the pattern shape of the mask is determined when the image intensity distribution obtained by simulating the shape of the mask pattern is closest to the image intensity distribution based on the shape of the microlens to be manufactured determined in step S11.

Next, a mask is manufactured in which the pattern shape of the mask determined in step S13 is determined by the number of arrays determined in step S10 (step S14).
That is, a mask M for manufacturing a 5 × 5 microlens array shown in FIG. 4 is manufactured by writing a predetermined pattern on the determined mask pattern shape using an electron beam writing apparatus or a laser beam writing apparatus. Is done.

The mask pattern manufactured by this mask pattern manufacturing method has an annular shape reflecting the shape of the microlens to be manufactured.
A mask for manufacturing a desired optical element can be easily manufactured as compared with the manufacturing of a mask used in a binary manufacturing method for manufacturing a microlens.

FIG. 5 shows a case where a negative lens (negative pattern) is used to manufacture a cylindrical lens array (each lens has a width of 260 μm, a radius of curvature of 25 mm, and a sag amount (lens height) of 0.3 μm). Image intensity distribution (light intensity distribution) at an appropriate defocus amount (220 μm) (FIG. 5)
(A)) and image intensity distribution immediately after transmission through the mask (or image intensity distribution at the best focus position) (light intensity distribution) (FIG. 5)
(B)) is shown. In this case, the printing conditions in the projection exposure apparatus are as follows: numerical aperture NA: 0.35, illumination σ: 0.50,
Exposure wavelength: g-line (436 nm). The transmission area on the mask (in terms of coordinates on the substrate, indicated by the distance from the center to the left and right) is 1.0.5 to 2 μm, 2.3 to 6 μm, and 3.
7-10 μm, 4.12-15 μm, 5.18-25 μm
m, 6.30 to 35 μm, 7.42 to 48 μm, 8.5
5-62 μm, 9.70-75 μm, 10.84-89
μm, 11.96 to 100 μm.

FIG. 5 assumes the case of an ideal negative resist in which the remaining shape of the photoresist is proportional to the exposure amount, and the vertical axis is normalized to 1. Further, by adjusting the exposure amount during printing so that the final sag amount becomes 0.3 μm, a photoresist three-dimensional structure having a curvature radius of 25 mm can be formed. Further, when the photoresist and the substrate are dry-etched (anisotropic) at the same speed, cylindrical lenses having the same shape can be formed on the substrate.

FIG. 6 shows a case where a cylindrical lens array (width of each lens is 260 μm, radius of curvature is 25 mm, amount of sag (lens height) 0.3 μm) is manufactured using a positive resist (positive pattern). Image intensity distribution (light intensity distribution) at an appropriate amount of defocus (70 μm) (FIG. 6)
(A)) and the image intensity distribution immediately after transmission through the mask (or the image intensity distribution at the best focus position) (light intensity distribution) (FIG. 6)
(B)) is shown. In this case, the printing conditions in the projection exposure apparatus are as follows: numerical aperture NA: 0.55, illumination σ: 0.60,
Exposure wavelength: i-line (365 nm). The transmission area on the mask (in terms of coordinates on the substrate, indicated by the distance from the center to the left and right) is 1.40 to 43 μm, 2.65 to 68 μm,
3.75 to 79 μm, 4.84 to 90 μm, 5.96 to
100 μm, 6.106 to 130 μm.

FIG. 6 assumes the case of an ideal positive resist in which the remaining shape of the photoresist is inversely proportional to the exposure amount, and the vertical axis is normalized to 1. Further, by adjusting the exposure amount during printing so that the final sag amount becomes 0.3 μm, a photoresist three-dimensional structure having a curvature radius of 25 mm can be formed. Further, when the photoresist and the substrate are dry-etched (anisotropic) at the same speed, cylindrical lenses having the same shape can be formed on the substrate.

FIG. 7 is a schematic structural view of an exposure apparatus for manufacturing an optical element. In FIG. 7, the projection optical system P
A mask M on which a predetermined pattern is formed is arranged on the object plane of L, and a glass substrate S coated with a photoresist is arranged on the image plane of the projection optical system PL. The mask M is held on a mask stage MS, and the substrate S is held on a substrate stage SS. An illumination optical system for uniformly illuminating the mask M is disposed above the mask M.

The illumination optical system includes an ultra-high pressure mercury lamp (g
A light source 2 composed of light of 436 nm (line: 365 nm) is provided. Illumination light generated by the light source 2 is incident on a collimator lens 4 and a fly-eye lens (optical integrator) 6. A variable stop 8 is provided on the exit side of the fly-eye lens. Illumination light passing through the variable stop 8 is reflected almost vertically downward by the mirror 12 via the relay lens 10 and the mirror 12 so as to make the mask M uniform. Light up. The light source is not limited to a mercury lamp, and may be an excimer laser (248 nm) or (193 nm), or a light source that supplies a shorter wavelength than the excimer laser light source.

The above-described mask stage MS is provided so as to be two-dimensionally movable in a plane orthogonal to the optical axis AX of the projection optical system PL. Further, the substrate stage SS is not only movable two-dimensionally in a plane orthogonal to the optical axis AX of the projection optical system PL, but also moves the image plane of the projection optical system PL and the substrate S
Is provided movably in the optical axis AX direction (Z direction) of the projection optical system PL in order to defocus the surface of the projection optical system PL.

Next, a method for manufacturing an optical element using this exposure apparatus will be described with reference to FIG. When a microlens array as an optical element is manufactured using this exposure apparatus, first, the mask M manufactured by the method shown in FIG. The mask M is set on the object plane (step S20).

Next, a glass substrate (photosensitive optical material) S coated with a photoresist is set on the substrate stage SS to set the substrate S on the image plane of the projection optical system PL (step S21). Further, positioning in the XY directions is performed.

Next, the substrate stage SS is connected to the projection optical system PL.
By moving the substrate S along the optical axis, the surface of the substrate S is defocused by a predetermined amount (defocus amount) D from the best image forming position of the projection optical system PL (step S22).

Here, the predetermined amount D is 0 <| D | <a, where λ is the wavelength of the illumination light and NA is the numerical aperture of the projection optical system.
(Λ / 2NA ² ), and (λ / NA / ²
2NA ² ) <| D | <a (λ / 2NA ² ). Under these conditions, a
= 200, but in order to obtain a more sufficient effect, a =
It is preferably set to 100.

The mask stage MS is connected to the projection optical system P
By moving along the optical axis of L, the surface of the substrate S may be defocused by a predetermined amount (defocus amount) D from the best imaging position of the projection optical system PL. In this case, the moving amount (predetermined amount) d of the mask stage MS is:
Assuming that the wavelength of the illumination light is λ and the numerical aperture of the projection system is NA, the amount satisfies the condition of 0 <| d | <(200 / β ² ) (λ / 2NA ² ). ² ) / β ² <| d
It is preferable that the amount satisfy the condition of | <(200 / β ² ) (λ / 2NA ² ). Here, β is a projection magnification of the projection system from the mask M to the substrate S.

Further, by moving both the substrate stage SS and the mask stage MS along the optical axis of the projection optical system PL, the surface of the substrate S is moved from the best image forming position of the projection optical system PL by a predetermined amount (defocus amount). ) Only D may be defocused.

As described above, the surface of the substrate S is projected onto the projection optical system PL.
Is defocused by a predetermined amount D from the best image forming position, the image intensity distribution of the projection optical system PL on the surface of the substrate S reflects the shape of the manufactured microlens based on the pattern shape of the mask.

Next, the mask M is illuminated by the illumination system,
Mask M formed on mask M using projection optical system PL
Is exposed on the substrate S coated with the photoresist (Step S23). FIG. 9A shows a state where the pattern of the mask M is exposed on the substrate S coated with the photoresist PR. As shown in this figure, when the pattern of the mask M is exposed on the substrate S coated with the photoresist PR, a chemically altered portion having a shape corresponding to the shape of the microlens is formed in the photoresist PR (FIG. 9A). Is formed.

Although a plurality of mask patterns (5 × 5) corresponding to the microlenses are formed on the mask M, only one mask pattern corresponding to the microlenses is formed on the mask. If so, the mask pattern is repeatedly exposed on the substrate by the step-and-repeat method.

Next, the photoresist PR on the substrate S is developed using a developing machine (Step S24). FIG.
(B) shows the state of the substrate S on which the photoresist PR has been developed. As shown in this figure, a photoresist PR having a shape corresponding to the shape of the microlens remains on the surface of the substrate S. The photoresist P
It is desirable that the R be formed in a shape that allows for processing process correction related to the ion beam etching rate.

Next, microlenses corresponding to the pattern on the mask are formed on the substrate S by performing ion beam etching on the substrate S using the photoresist pattern as a mask (step S25). That is, a microlens array MLA as shown in FIG. 9C is formed on the substrate S. Note that various dry etchings can be used instead of the ion beam etching.

Therefore, according to the method of manufacturing a microlens array, a desired microlens array can be easily manufactured in a small number of steps as compared with a binary manufacturing method for manufacturing a microlens array. Therefore, mass productivity of the microlens array can be improved.

Note that, in the above embodiment, FIG.
Although the optical element is manufactured using the mask M manufactured by the method described in (1), a mask manufactured by another method may be used.

Next, a more preferred example of a method for manufacturing an optical element using this exposure apparatus will be described with reference to FIG. When a microlens array as an optical element is manufactured using this exposure apparatus, first, the mask M manufactured by the method shown in FIG. The mask M is set on the object plane (step S200).

Next, a glass substrate (photosensitive optical material) S coated with a photoresist is set on a substrate stage SS to set the substrate S on the image plane of the projection optical system PL (step S210). Further, positioning in the XY directions is performed.

Next, the substrate stage SS is connected to the projection optical system PL.
By moving the mask stage MS along the optical axis of the projection optical system PL, or by moving the mask stage MS along the optical axis of the projection optical system PL, the surface of the substrate S is shifted by a predetermined amount (defocus) from the best image forming position of the projection optical system PL. Defocus by D) (step S220).

Here, the substrate stage SS is connected to the projection optical system PL.
The predetermined amount D when moving along the optical axis of is 0 when the wavelength of the illumination light is λ and the numerical aperture of the projection optical system is NA.
<| D | <a (λ / 2NA ² )
Further, it is preferable that the amount satisfies the condition of (λ / 2NA ² ) <| D | <a (λ / 2NA ² ). Under these conditions, a = 200, but it is preferable to set a = 100 in order to obtain a more sufficient effect.

The mask stage MS is connected to the projection optical system P
The predetermined amount d when moving along the optical axis of L is 0 when the wavelength of the illumination light is λ and the numerical aperture of the projection system is NA.
<| D | <(200 / β ² ) (λ / 2NA ² ), and further, (λ / 2NA ² ) / β ² <| d | <
It is preferable that the amount satisfies the condition of (200 / β ² ) (λ / 2NA ² ). Here, β is a projection magnification of the projection system from the mask M to the substrate S. By satisfying this condition, the mask stage MS is moved along the optical axis of the projection optical system PL to defocus the surface of the substrate S by a predetermined amount (defocus amount) D from the best imaging position of the projection optical system PL. be able to.

Further, by moving both the substrate stage SS and the mask stage MS along the optical axis of the projection optical system PL, the surface of the substrate S is moved from the best image forming position of the projection optical system PL by a predetermined amount (defocus amount). ) Only D may be defocused. In the present invention, it is possible to move at least one of the mask stage MS and the substrate stage SS to defocus the surface of the photosensitive substrate S from the image plane (best image plane) of the projection optical system.

When the surface of the substrate S is defocused by a predetermined amount D from the best image forming position of the projection optical system PL, the image intensity distribution of the projection optical system PL on the surface of the substrate S is based on the pattern shape of the mask. In addition, the shape reflects the shape of the manufactured microlens.

Next, the mask M is illuminated by the illumination system,
Mask M formed on mask M using projection optical system PL
Is exposed on the substrate S coated with the photoresist (Step S230). In addition, the above-mentioned mask M includes:
A plurality of mask patterns (5
× 5), but when only one mask pattern corresponding to the microlens is formed on the mask, the substrate is repeatedly exposed to the mask pattern by a step-and-repeat method.

Next, the photoresist PR on the substrate S is developed using a developing machine (step S240). In addition, it is desirable that the photoresist PR be formed in a shape that allows for processing process correction relating to the ion beam etching rate.

Next, the photoresist P remaining on the substrate S
R is cured using a UV resist curing device (step S250). FIG. 11 schematically shows a UV resist curing device. This UV resist curing apparatus has a vacuum chamber VC, and holds a substrate S on which a developed photoresist PR remains above a heater H installed in the vacuum chamber VC. The substrate S with the photoresist PR is appropriately heated by a heater H, and UV
Ultraviolet rays are radiated from the lamp L via the quartz glass G to cure the photoresist PR. In this case, it is desirable to set an appropriate temperature atmosphere according to the type of the photoresist.

Next, a microlens corresponding to the pattern on the mask is formed on the substrate S by performing ion beam etching on the substrate S using the photoresist pattern as a mask (step S260). In addition,
Not only ion beam etching but also various types of dry etching can be used.

Therefore, according to the method for manufacturing a microlens array, a desired microlens array can be easily manufactured in a small number of steps as compared with a binary manufacturing method for manufacturing a microlens array. Therefore, mass productivity of the microlens array can be improved. Further, since the photoresist is hardened, a microlens array having a precise shape can be manufactured.

In the above embodiment, FIG.
Although the optical element is manufactured using the mask M manufactured by the method described in (1), a mask manufactured by another method may be used. In addition, the process of curing the photoresist can be applied to the production of a microlens array using gray scale. A lens array can be manufactured.

In the above embodiment, FIG.
A spherical microlens L1 (in the figure, L1 is a plan view) using a mask M1 (having a center line and a contour line in FIG. 12A) having an annular pattern shape as shown in FIG. Side view of L1 on the right side of L1,
A front view of L1 is described below L1), but the mask pattern is set assuming that the image intensity distribution of the mask pattern image corresponds to the aspherical shape, and simulation is performed by performing simulation. By changing the shape of the lens, an aspherical microlens can be easily manufactured.

Further, a prism P1 (FIG. 1) is formed by using a mask M2 having a rectangular band pattern as shown in FIG. 12 (b) (FIG. 12 (b) includes a center line and a contour line).
A plan view, a side view, and a front view of P1 may be manufactured in the same manner as in FIG. 2 (a), and shown in FIG. 12 (c) (FIG. 12 (c) includes the center line and the outline). The prism P2 (FIG. 1) is formed using a mask M3 having such a linear band pattern shape.
2 (a), a plan view, a side view, and a front view of P2) may be manufactured. Furthermore, the shape of each lens can be made different by changing the shape of the pattern corresponding to each microlens. Also,
A cylindrical lens array can also be easily realized.
Further, it is easy to form lenses having different powers in an array.

Using the two masks shown in FIGS. 13A and 14, the index plate shown in the plan view of FIG. 15A and the side view of FIG. 15B can be manufactured. This index plate has three plane line patterns (reflection portions), and the region other than the reflection portions has a fine slope shape. In this fine slope shape, the reflected light is not specularly reflected and the reflected light from other than the reflection area is not observed, so that the contrast can be easily improved. This index plate can be manufactured not only on a glass substrate but also on a silicon wafer. It is also possible to obtain a high-reflection and high-contrast pattern by applying a high-reflection coat on the entire surface.

When manufacturing this index plate, a photoresist is applied on the protective layer of a glass substrate having a protective layer (Cr film or the like) on the surface, and the pattern of the mask shown in FIG. develop. FIG. 13B shows the state of the glass substrate after the pattern of the mask has been transferred and developed. On this glass substrate, the photoresist remains only in the region indicated by oblique lines while the protective layer remains.

Next, the protective layer other than the shaded area is removed by etching, and the photoresist in the shaded area is removed. In this state, the protective layer remains on the glass substrate only in the shaded region.

Next, a photoresist is applied again to the entire glass substrate, and the mask pattern shown in FIG. 14, that is, the mask pattern for forming the inclined surface is exposed by defocus exposure and developed. Next, by performing dry etching to remove the protective layer, FIG.
The indicator plate shown in FIG. 15B is completed. In this example, the protective layer for forming the plane portion of the pattern is provided. However, in the present invention, the plane portion of the pattern may be formed by another method without using the protective layer.

Also, by applying a low-reflection coating such as a low-reflection Cr film on the back surface of the substrate S on which the microlens array is formed, when exposing the pattern of the mask M to the photoresist PR, Distortion of the resist shape due to reflection can be prevented. Furthermore, the same effect can be obtained by subjecting the back surface of the substrate S to lemon skin processing.

A phase shift reticle is used as a mask for manufacturing the microlens array shown in FIG. 8 or FIG.
(Mask), halftone reticle that imparts a light transmittance distribution by making it semi-transmissive without completely blocking light
By using a gray scale reticle (mask) that imparts a light transmittance distribution by controlling the density of the dot pattern or the thickness of the light-shielding object of the mask, a microlens array with a more precise shape is manufactured. be able to.

The illumination method of the exposure apparatus used for manufacturing the microlens array includes any one of circular illumination, annular illumination, multipole illumination, coherent illumination, and incoherent illumination under an appropriate σ value. Can be used. For example, in the exposure apparatus shown in FIG. 7, circular illumination, annular illumination, or multipolar illumination under an appropriate σ value (numerical aperture of the illumination system / numerical aperture on the mask side of the projection optical system PL) is performed. In order to change the shape and size of the pupil or secondary light source of the illumination system,
That is, the shape and size of the aperture of the variable stop 8 disposed on the emission side of the optical integrator 6 may be changed. In order to perform circular illumination while changing the σ value, the opening of the variable aperture 8 may be changed in size while keeping the aperture shape circular. For annular illumination, the aperture of the variable aperture 8 may be used. The part is an appropriate ring ratio (ring inner diameter / ring outer diameter)
What is necessary is just to change to the annular opening which has. Further, in order to perform multi-pole illumination, the opening of the variable stop 8 may be changed to a multi-pole opening (for example, a dipole or quadrupole) which is separated from the center by an appropriate distance.

In order to perform each illumination efficiently, a variable-magnification optical system (zoom optical system) with a variable σ value upstream of the optical integrator 6 and an annular light beam forming optical system (convex shape) for forming an annular light beam are provided. An optical system such as an axicon including an element having a conical surface and an element having a concave conical surface moving relatively thereto, or a diffractive optical element forming an annular light beam) or a multipolar light beam forming a multipolar light beam Forming optics (e.g.,
An optical system such as an axicon including an element having a convex quadrangular pyramid surface and an element having a concave quadrangular pyramid surface moving relatively thereto, or a diffractive optical element that forms a multipolar light beam can also be used. Further, the optical integrator 6 is not limited to a fly-eye lens, but may be a micro lens array, a diffractive optical element, an internal reflection type integrator (a rod type internal reflection integrator, a hollow type internal reflection integrator), or the like.

In the above-described embodiment, the microlenses are formed on the substrate S by the step-and-repeat type projection exposure. However, the microlenses are formed on the substrate S by the proximity type exposure. You may do it. In the proximity type exposure in this case, it is preferable to dispose the mask and the photosensitive substrate at an appropriate distance so that an appropriate intensity distribution in which the pattern of the mask is defocused is obtained. Further, using a scanning type exposure apparatus of a scan type (step and scan type) in which a mask pattern image is projected and exposed on a photosensitive substrate while moving the mask stage MS and the substrate stage SS, the exposure step in the present invention is performed. You may do it.

Next, an exposure apparatus incorporating the microlens array manufactured by the above-described method for manufacturing an optical element will be described. FIG. 16 is a diagram schematically showing the configuration of this exposure apparatus. In this figure, the Z axis is set along the normal direction of the wafer serving as the photosensitive substrate, the Y axis is set in a direction parallel to the plane of FIG. 16, and the X axis is set in a direction perpendicular to the plane of FIG. ing.

In this exposure apparatus, as a light source 21 for supplying exposure light (illumination light), for example, 248 nm (KrF)
Alternatively, an excimer laser light source for supplying light having a wavelength of 193 nm (ArF) is provided. A substantially parallel light flux emitted from the light source 21 in the Z direction has a rectangular cross section elongated in the X direction, and enters a beam expander 22 including a pair of cylindrical lenses 22a and 22b. Each of the cylindrical lenses 22a and 22b is
It has a negative refractive power and a positive refractive power in the paper plane of FIG. 16 (in the YZ plane), and functions as a parallel plane plate in a plane perpendicular to the paper plane (in the XZ plane) including the optical axis AX. Accordingly, the light beam that has entered the beam expander 22 is enlarged in the plane of the paper of FIG. 16 and shaped into a light beam having a predetermined cross section, for example, a light beam having a square cross section.

Beam Expander 2 as Shaping Optical System
After being deflected in the Y direction by the bending mirror 23, the light beam passing through 2 enters the diffractive optical element 24b and the afocal zoom lens 25 as a first variable power optical system. Here, the afocal zoom lens 25 is configured to be able to continuously change magnification within a predetermined range while maintaining an afocal system (a non-focus optical system). Here, in FIG. 16, the diffractive optical element 24b for annular illumination is used.
Is set in the optical path, but instead of this diffractive optical element 24b, a diffractive optical element for circular illumination (normal illumination) that forms a circular light intensity distribution on the pupil plane or 4 The diffraction optical element for quadrupole illumination which forms a polar light intensity distribution may be replaceable. Note that, during circular illumination (normal illumination), normal illumination can be performed without a diffractive optical element without setting a diffractive optical element for circular illumination (normal illumination) in the optical path.

The light beam incident on the afocal zoom lens 25 forms a ring-shaped (annular) light source image on its pupil plane. The light from the ring-shaped light source image is emitted from the afocal zoom lens 25 as a substantially parallel light flux, and enters a first fly-eye lens (microlens array) 26 as a first optical integrator. At this time, the incident surface of the first fly-eye lens 26 has an optical axis A
A light beam enters from an oblique direction almost symmetrically with respect to X. In other words, a light beam is obliquely incident along all directions at an equal angle around the optical axis AX. First fly-eye lens 2
Numeral 6 is manufactured by the manufacturing method of the optical element shown in FIG. 8 or FIG. 10, and is constituted by arranging a number of lens elements having a positive refractive power vertically and horizontally along the optical axis AX. . Note that the entrance side surface of each lens element is formed in a spherical shape with the convex surface facing the entrance side, and the exit side surface is formed in a planar shape.

Therefore, the light beam incident on the first fly-eye lens 26 is two-dimensionally divided by a number of lens elements, and one ring-shaped light source image is formed on the rear focal plane of each lens element. . Light beams from a number of ring-shaped light source images formed on the rear focal plane of the first fly-eye lens 26 pass through a zoom lens 27 as a second variable power optical element, and then pass through a second optical integrator as a second optical integrator. The two fly-eye lenses 28 are illuminated in a superimposed manner. The zoom lens 27 is a relay optical system that can continuously change the focal length within a predetermined range in order to make the size of the secondary light source formed on the pupil plane variable, and The rear focal plane of the eye lens 26 and the rear focal plane of the second fly-eye lens 28 are optically substantially conjugated. The zoom lens 27 forms a telecentric optical system on the rear side. In order to satisfy the above-described conjugate relationship and telecentricity, the zoom lens 27 is configured as a multi-unit zoom lens in which at least three lens groups can move independently.

Therefore, on the entrance surface of the second fly-eye lens 28, a square illumination field similar to the cross-sectional shape of each lens element of the first fly-eye lens 26 is infinitely located at a position equidistant from the optical axis AX. An illumination field having a shape arranged in a number, that is, an annular illumination field centered on the optical axis AX is formed. Like the first fly-eye lens 26, the second fly-eye lens 28 is configured by arranging a number of lens elements having a positive refractive power vertically and horizontally along the optical axis AX. However, each lens element constituting the second fly-eye lens 28 has a rectangular cross section similar to the shape of the illumination field to be formed on the mask (and, consequently, the shape of the exposure region to be formed on the wafer). The entrance side surface of each lens element constituting the second fly-eye lens 28 is formed in a spherical shape with a convex surface facing the incident side, and the exit side surface is formed in a spherical shape with a convex surface facing the exit side. ing.

Accordingly, the light beam incident on the second fly-eye lens 28 is two-dimensionally divided by a number of lens elements, and the lens of the first fly-eye lens 26 is provided on the rear focal plane of each lens element on which the light beam has entered. A large number of light source images of the number of elements are respectively formed. Thus, on the rear focal plane of the second fly-eye lens 28, a number of light sources (hereinafter, referred to as "secondary light sources") having the same annular shape as the illumination field formed by the light beam incident on the second fly-eye lens 28. It is formed. The luminous flux from the annular secondary light source formed on the rear focal plane of the second fly-eye lens 28 enters an aperture stop 29 arranged in the vicinity thereof.

The aperture stop 29 has a ring-shaped aperture (light transmitting portion), and the light from the secondary light source passing through the aperture stop 29 is subjected to the light condensing operation of the condenser optical system 30 before being condensed.
The reticle R on which a predetermined pattern is formed is uniformly illuminated in a superimposed manner. Here, the reticle R is set on the object plane of the projection optical system 32 by being set on the reticle stage RS. The light beam transmitted through the pattern of the reticle R forms an image of the reticle pattern on the wafer W as a photosensitive substrate via the projection optical system 32. Here, the wafer W is set on the wafer stage WS so that the projection optical system 3
2 image planes. Thus, the projection optical system 32
Is performed in a plane (XY plane) orthogonal to the optical axis AX by performing batch exposure or scan exposure while driving and controlling the wafer W two-dimensionally, so that the pattern of the reticle R is sequentially exposed in each exposure region of the wafer W. Is done.

In the batch exposure, a so-called step
The reticle pattern is collectively exposed to each exposure region of the wafer by the AND repeat method. in this case,
The shape of the illumination area on the reticle R is a rectangular shape close to a square, and the cross-sectional shape of each lens element of the second optical integrator is also a rectangular shape close to a square. On the other hand, in the scan exposure, the reticle pattern is scanned and exposed on each exposure region of the wafer while the reticle and the wafer are relatively moved with respect to the projection optical system according to a so-called step-and-scan method. In this case, the shape of the illumination area on the reticle R is a rectangular shape having a ratio of the short side to the long side of, for example, 1: 3, and the cross-sectional shape of each lens element of the second optical integrator is similar to this. Becomes

Next, a method of manufacturing the exposure apparatus shown in FIG. 16 will be described with reference to FIG. When manufacturing this exposure apparatus, first, a microlens array as an optical element is manufactured by the manufacturing method shown in FIG. 8 or FIG. 10 (step S30).

Next, the microlens array is incorporated as a first fly-eye lens 26 as a first optical integrator between the afocal zoom lens 25 and the zoom lens 27 of the illumination optical system (step S3).
1).

Next, a projection optical system PL is set between the reticle R (the position to be illuminated) and the wafer W (the position to be exposed).
(Step S32) The projection exposure apparatus is completed.

Therefore, according to the method of manufacturing the projection exposure apparatus, since the manufacturing method shown in FIG. 8 or FIG. Is also efficient.

Next, an aberration measuring apparatus using a microlens array manufactured by the above-described method for manufacturing an optical element will be described. FIG. 18 is a diagram schematically showing a configuration of an exposure apparatus provided with the aberration measuring device. In this figure, Z along the normal direction of the wafer W as a photosensitive substrate
The axis is set as the Y axis in a direction parallel to the paper of FIG. 18, and the X axis is set as the direction perpendicular to the paper of FIG. In addition,
FIG. 18 shows a state at the time of aberration measurement in which the marking plate of the aberration measurement device is positioned on the image plane of the projection optical system PL.
During position detection and projection exposure using an FIA system (not shown) or an oblique incidence type autofocus system (not shown), the wafer W is positioned on the image plane of the projection optical system PL.

The exposure apparatus shown in FIG. 18 has a light source 41 for supplying exposure light (illumination light) of, for example, 248 nm (Kr).
F) or an excimer laser light source for supplying light having a wavelength of 193 nm (ArF). The substantially parallel light beam emitted from the light source 41 is shaped into a light beam having a predetermined cross section via the beam shaping optical system 42, and then enters the coherence reducing unit 43. The coherence reducing unit 43 has a function of reducing the occurrence of an interference pattern on the mask M (and, consequently, on the wafer W), which is the irradiated surface.

The light beam from the coherence reducing unit 43 forms a large number of light sources on the rear focal plane via the first fly-eye lens 44. After being deflected by the oscillating mirror 45, the light from these multiple light sources illuminates the second fly-eye lens 46 in a superimposed manner via the relay optical system 46. here,
The vibrating mirror 45 is a bending mirror that rotates around the X axis, and has a function of reducing the occurrence of an interference pattern on the irradiated surface. Thus, on the rear focal plane of the second fly-eye lens 47, a secondary light source including a large number of light sources is formed. The luminous flux from the secondary light source is restricted by an aperture stop 48 disposed in the vicinity thereof, and is then reflected almost vertically downward by a mirror 50 via a condenser optical system 49 and a mirror 50 to form a predetermined pattern. The illuminated mask M is superimposed and uniformly illuminated.

The light beam transmitted through the pattern of the mask M forms an image of the mask pattern on the wafer W as a photosensitive substrate via the projection optical system PL. The mask M is mounted on a mask stage MS via a mask holder (not shown). The mask stage MS is driven by a mask stage controller (not shown) based on a command from a main control system (not shown).

On the other hand, the wafer W is vacuum chucked by the wafer holder WH on the wafer stage WS. Wafer stage WS is driven by a wafer stage control unit (not shown) based on a command from a main control system (not shown).

In the aberration measuring apparatus provided in this exposure apparatus, a test mask TM for measuring aberration is set on the mask stage MS when measuring the wavefront aberration of the projection optical system PL as the optical system to be measured. . Test mask T
As shown in FIG. 19, M has a plurality of circular openings 60a for measuring aberration along the X and Y directions (see FIG. 1).
7 are 9). Also,
Square opening 6 substantially larger than opening 60a
0b is formed.

Further, this aberration measuring apparatus includes a sign plate 51 mounted on the wafer stage WS at a position substantially equal to the exposure surface of the wafer W (position in the Z direction). The indicating plate 51 is made of, for example, a glass substrate, and has a reference plane 51a perpendicular to the optical axis X of the projection optical system PL, and further perpendicular to the optical axis of an aberration measuring system described later.
As shown in FIG. 20, a calibration opening (light transmitting portion) 51b is formed in the center of the reference plane 51a, as shown in FIG.
A plurality (four in FIG. 20) of alignment marks 51c are formed around the periphery.

Here, the calibration opening 51b is formed in the opening 6 of the test mask TM formed through the projection optical system PL.
It is set larger than the image of 0a. Each set of the alignment marks 51c is composed of a line and space pattern formed along the X direction and a line and space pattern formed along the Y direction. Further, a reflection surface 51d is formed in a region excluding the calibration opening 51b and the plurality of alignment marks 51c. The reflection surface 51d is formed, for example, by depositing chromium (Cr) on a glass substrate.

Further, this aberration measuring apparatus includes an aberration measuring system as an optical system for measuring the wavefront aberration of the projection optical system PL. In the aberration measurement system, light from the image of the opening 60 a of the test mask TM formed on the image plane via the projection optical system PL passes through the micro fly eye 54 via the collimator lens 52 and the relay lens 53.
Incident on. Here, the micro fly's eye 54 is manufactured by the manufacturing method shown in FIG. 8 or FIG. 10, and is an optical element composed of a large number of minute lenses having positive refracting power arranged vertically and horizontally and densely.

Therefore, the light beam incident on the micro fly's eye 54 is two-dimensionally split by a large number of microlenses.
An image of one aperture 60a is formed near the rear focal plane of each microlens. Many images thus formed are detected by the CCD 55 as a two-dimensional image sensor. The output of the CCD 55 is supplied to a signal processing unit (not shown). As described above, the micro fly's eye 54 wavefront-divides light from the primary image of the opening 60a of the test mask TM formed on the image plane of the projection optical system PL to form many secondary images of the opening 60a. Wavefront splitting element for the purpose.

The CCD 55 has an opening 60 formed by a micro fly's eye 54 as a wavefront dividing element.
A photoelectric detection unit for photoelectrically detecting a large number of secondary images a. As shown in FIG. 18, the collimating lens 52, the relay lens 53, the micro fly's eye 54, and the CCD 55 are provided inside the mask stage MS, and measure the wavefront aberration of the projection optical system PL. (Optical optical system). Further, the marking plate 51 is integrally attached to the aberration measurement system (52 to 55).

Hereinafter, the operation of measuring the wavefront aberration of the projection optical system PL using this aberration measuring device will be described. In this aberration measuring device, an aberration measuring system (52 to 55)
There is provided a sign board 51 integrally attached to the rim. An alignment mark 51c is formed on the reference plane 51a of the sign plate 51 by etching a chrome film or the like, and a reflection surface 51d processed with necessary and sufficient surface accuracy is formed. Therefore,
Using a FIA system mounted on the exposure apparatus, a sign board 51 along the XY plane is formed based on the alignment mark 51c.
, And the position of the aberration measurement system along the XY plane can be detected.

Further, using the oblique incidence type two-dimensional AF system mounted on the exposure apparatus, the surface position of the sign plate 51 along the Z direction, and hence the Z direction position of the aberration measurement system, and the tilt around the X axis , And a tilt about the Y axis. Furthermore, the wafer interferometer WIF (not shown) mounted on the exposure apparatus and the wafer stage
Alignment (position alignment) and position control can be performed quickly with the same high accuracy as that of (1). In this manner, the aberration measurement system is positioned at a position where the image of the first opening 60a arbitrarily selected from the plurality of openings provided in the test mask TM is formed via the projection optical system PL. Is initially positioned.

That is, in a state where the aberration measuring system is accurately positioned, the first optical system formed via the projection optical system PL
Center point of the image of the aperture 60a and the optical axis A of the aberration measurement system
X1 matches in the XY plane. That is, as shown in FIG. 21, the center point of the image 60i of the opening 60a and the center point of the calibration opening 51b of the sign board 51 coincide in the XY plane. In this initial state, the wavefront aberration of the projection optical system PL is measured based on the output of the CCD 55. The specific method of measuring the wavefront aberration is described in International Publication W.
It is disclosed in O99 / 60361.

The above-described operation of measuring the wavefront aberration is similarly performed sequentially on the remaining plural openings provided in the test mask TM. After the position setting of the aberration measurement system with respect to the first opening of the test mask TM using the marking plate 51 is completed, the marking is performed by the two-dimensional AF system in the same manner as the original printing operation of the exposure apparatus. The height position of the plate 51 is always aligned, and the position of the wafer stage WS along the XY plane is controlled based on the output information of the wafer interferometer, so that the wavefront aberration of the projection optical system PL at an arbitrary coordinate position is reduced. Measurement (ie, measurement of wavefront aberration for the remaining plurality of openings of the test mask TM) can be performed.

In the case of manufacturing the aberration measuring device provided in this exposure apparatus, first, as shown in FIG. 22, a microlens array as an optical element is manufactured by the manufacturing method shown in FIG. 8 or FIG. (Step S40).

Next, a micro fly's eye is placed on the exit side of the relay lens 53 of the condensing optical system.
(Step S41). Next, a CCD (photoelectric detector) 55 is installed at a position for receiving the light via the condensing optical system, that is, at the exit side of the micro fly's eye 54 (step S42), and the aberration measuring device is completed.

Therefore, according to the method of manufacturing this aberration measuring apparatus, the manufacturing method shown in FIG. 8 or FIG. The manufacture of the device is also efficient.

[0107]

According to the mask manufacturing method of the present invention,
In order to determine the shape of the mask pattern from the simulated pattern shape to the pattern shape or the like having the image intensity distribution closest to the image intensity distribution determined by the image intensity distribution determining step, it is necessary to manufacture a desired optical element. The mask can be easily manufactured.

According to the optical element manufacturing method of the present invention, the surface of the photosensitive optical material is defocused by a predetermined amount D from the best imaging position of the projection system in the defocusing step, and the developing step and the etching step are performed. Thus, the optical element is manufactured through the steps described above, so that the optical element can be efficiently manufactured in a small number of steps in the method for manufacturing the optical element.

Further, according to the method of manufacturing a projection exposure apparatus of the present invention, since an optical element efficiently manufactured by a small number of steps in an optical element assembling step is incorporated into an illumination optical system, the projection exposure apparatus can be manufactured. It will be efficient.

Further, according to the method of manufacturing an aberration measuring apparatus of the present invention, an optical element efficiently manufactured by a small number of steps in an optical element assembling step is incorporated into a condensing optical system. It will be efficient.

Further, according to the optical element manufacturing method of the present invention, an optical element having a precise shape can be manufactured because the photosensitive material developed in the developing step in the photosensitive material curing step is cured.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining a mask manufacturing method according to an embodiment.

FIG. 2 is a diagram illustrating a microlens array manufactured using a mask manufactured by the mask manufacturing method according to the embodiment;

FIG. 3 shows the light intensity at a position defocused by a predetermined amount from the best image forming position of the projection optical system of the light transmitted through the mask when the negative resist pattern according to the embodiment is used, and the light intensity immediately after transmitting through the mask. FIG.

FIG. 4 is a view showing a mask manufactured by the mask manufacturing method according to the embodiment;

FIG. 5 shows the light intensity at a position defocused by a predetermined amount from the best image forming position of the projection optical system of the light transmitted through the mask when the negative resist pattern according to the embodiment is used, and the light intensity immediately after transmitting through the mask. FIG.

FIG. 6 shows the light intensity at a position defocused by a predetermined amount from the best image forming position of the projection optical system of the light transmitted through the mask when the positive resist pattern according to the embodiment is used, and the light intensity immediately after transmitting through the mask. FIG.

FIG. 7 is a schematic configuration diagram of an exposure apparatus for manufacturing the microlens array according to the embodiment.

FIG. 8 is a flowchart illustrating a method for manufacturing a microlens array according to the embodiment.

FIG. 9 is a diagram for explaining a manufacturing process of the microlens array according to the embodiment.

FIG. 10 is a flowchart showing a method for manufacturing a microlens array according to the embodiment.

FIG. 11 is a schematic view of a UV resist curing device according to an embodiment.

FIG. 12 is a diagram showing a mask pattern according to the embodiment and an optical element manufactured by the mask pattern.

FIG. 13 is a diagram for explaining a mask pattern and the like for manufacturing the index plate according to the embodiment;

FIG. 14 is a diagram for explaining a mask pattern for manufacturing the index plate according to the embodiment;

FIG. 15 is a diagram for explaining an index plate according to the embodiment.

FIG. 16 is a schematic configuration diagram of an exposure apparatus in which an optical element manufactured by the manufacturing method according to the embodiment is incorporated.

FIG. 17 is a flowchart showing a method of manufacturing an exposure apparatus incorporating an optical element manufactured by the manufacturing method according to the embodiment.

FIG. 18 is a schematic configuration diagram of an exposure apparatus provided with an aberration measuring device in which an optical element manufactured by the manufacturing method according to the embodiment is incorporated.

FIG. 19 is a schematic diagram illustrating a configuration of a test mask installed on a mask stage when measuring aberration according to the embodiment.

FIG. 20 is a schematic diagram showing a configuration of a sign plate attached to an aberration measurement system of the aberration measurement device according to the embodiment.

FIG. 21 is a diagram showing a state in which an image of the opening of the test mask is formed at the center of the calibration opening of the sign plate according to the embodiment;

FIG. 22 is a flowchart illustrating a method of manufacturing an exposure apparatus including an aberration measuring device in which an optical element manufactured by the manufacturing method according to the embodiment is incorporated.

[Explanation of symbols]

MLA: micro lens array, M: mask, MS: mask stage, PL: projection optical system, S: substrate, SS: substrate stage, 21: light source, 26: first fly-eye lens, R: reticle, W: wafer, 52: Collimating lens, 54: Micro fly eye, 55: CCD.

Claims (12)

[Claims] 1. A method for manufacturing a mask for manufacturing an optical element, comprising: determining an image intensity distribution relating to a pattern image of the mask formed at a defocus position of a projection system based on specifications of the optical element. A simulation step of simulating an image intensity distribution of the projection system in consideration of a pattern shape to be formed on the mask and a defocus amount of the projection system; and A pattern shape determining step of determining a pattern shape. 2. A mask setting step for setting a mask manufactured by the manufacturing method according to claim 1 on an object plane of a projection system; a substrate setting step for setting a photosensitive optical material on a stage; and moving the stage. A defocusing step of defocusing the surface of the photosensitive optical material by a predetermined amount D from the best image forming position of the projection system; and an exposing step of exposing the pattern shape of the mask on the photosensitive optical material. An optical element manufacturing method, comprising: a developing step of developing the photosensitive optical material exposed in the exposure step; and an etching step of etching the photosensitive optical material developed in the developing step. 3. A mask setting step of setting a mask on an object plane of a projection system; a substrate setting step of setting a photosensitive optical material on a stage; and moving the stage to change the surface of the photosensitive optical material. A defocusing step of defocusing by a predetermined amount D from the best image forming position of the projection system; an exposing step of exposing a pattern shape of the mask onto the photosensitive optical material; and the photosensitivity exposed by the exposing step. A method for manufacturing an optical element, comprising: a developing step of developing an optical material; and an etching step of etching a photosensitive optical material developed in the developing step. 4. The optical system according to claim 2, wherein the predetermined amount D satisfies the following condition when the wavelength of the illumination light is λ and the numerical aperture of the projection system is NA. Device manufacturing method. 0 <| D | <200 (λ / 2NA ² ) 5. The optical system according to claim 2, wherein the predetermined amount D satisfies the following condition when the wavelength of the illumination light is λ and the numerical aperture of the projection system is NA. Device manufacturing method. (Λ / 2NA ² ) <| D | <200 (λ / 2NA ² ) 6. A mask setting step of arranging a mask manufactured by the manufacturing method according to claim 1 on a mask stage and setting the mask on an object plane of a projection system, and setting a photosensitive optical material on the stage. A substrate setting step of performing, a defocusing step of moving the mask stage by a predetermined amount d to defocus the surface of the photosensitive optical material from a best imaging position of the projection system, and changing a pattern shape of the mask. An exposure step of exposing the photosensitive optical material to light, a development step of developing the photosensitive optical material exposed in the exposure step, and an etching step of etching the photosensitive optical material developed in the development step A method for producing an optical element, comprising: 7. A mask setting step of arranging a mask on a mask stage and setting the mask on an object plane of a projection system; a substrate setting step of setting a photosensitive optical material on the stage; A defocusing step of defocusing the surface of the photosensitive optical material from the best image forming position of the projection system by moving by a fixed amount d, and an exposure step of exposing the pattern shape of the mask on the photosensitive optical material. An optical element manufacturing method, comprising: a developing step of developing the photosensitive optical material exposed in the exposure step; and an etching step of etching the photosensitive optical material developed in the developing step. 8. The predetermined amount d, when the wavelength of the illumination light is λ, the numerical aperture of the projection system is NA, and the magnification from the mask of the projection system to the photosensitive optical material is β, The method for manufacturing an optical element according to claim 6, wherein the condition is satisfied. 0 <| d | <(200 / β ² ) (λ / 2NA ² ) 9. The predetermined amount d is as follows when the wavelength of the illumination light is λ, the numerical aperture of the projection system is NA, and the magnification from the mask of the projection system to the photosensitive optical material is β. The method for manufacturing an optical element according to claim 6, wherein the condition is satisfied. (Λ / 2NA ² ) / β ² <| d | <(200 / β ² ) (λ
/ 2NA ² ) 10. An illumination optical system for illuminating a pattern of a reticle for manufacturing a micro device installed at a position to be illuminated, and a projection optical system for projecting a pattern image of the reticle onto a photosensitive substrate installed at the position to be exposed. A manufacturing method of an exposure apparatus, comprising: an optical element manufacturing step of manufacturing an optical element by the optical element manufacturing method according to any one of claims 2 to 9; and the optical element in the illumination optical system. A method of manufacturing an exposure apparatus, comprising: a step of incorporating an optical element to be incorporated; and a step of installing the projection optical system between the position to be illuminated and the position to be exposed. 11. A method for manufacturing an aberration measuring device, comprising: a condensing optical system for condensing light from an optical system, and a photoelectric detector for photoelectrically detecting light passing through the condensing optical system. 10. An optical element manufacturing step of manufacturing an optical element by the optical element manufacturing method according to any one of claims 9 to 9, an optical element assembling step of incorporating the optical element into the condensing optical system, and A step of installing the photoelectric detector at a position to receive light via an optical system. 12. A mask setting step of setting a mask on an object plane of a projection system, a substrate setting step of setting a substrate with a photosensitive material on a stage, and exposing a pattern shape of the mask on a photosensitive material of the substrate. An exposing step, a developing step of developing the photosensitive material exposed in the exposing step, a photosensitive material curing step of curing the photosensitive material developed in the developing step, and a photosensitive material cured in the photosensitive material curing step An etching step of etching in a state.