JP2002372668A - Catadioptric optical system and exposure apparatus having the optical system - Google Patents

Abstract

(57) Abstract: A simple configuration having a small distance between an object plane and an image plane and a small number of lenses, for example, having a wavelength of 180 n
A catadioptric optical system capable of achieving a high resolution of 0.1 μm or less using light in a vacuum ultraviolet wavelength region of m or less. SOLUTION: A concave reflecting mirror (CM2) and a plane reflecting mirror (M
1) and a first imaging optical system (G1) for forming a first intermediate image of the first surface based on light from the first surface (R).
And a concave reflecting mirror (CM3) and a plane reflecting mirror (M4), and a second surface of the first surface based on light passing through the first imaging optical system.
A second imaging optical system (G2) for forming an intermediate image, and a second imaging optical system (G2) for forming a final image of the first surface on the second surface (W) based on light passing through the second imaging optical system. A third image forming optical system (G3) of a refraction type.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catadioptric optical system and an exposure apparatus provided with the optical system, and more particularly, to a high-resolution optical system which is most suitable for an exposure apparatus used when a semiconductor element or the like is manufactured by a photolithography process. The present invention relates to a catadioptric projection optical system.

[0002]

2. Description of the Related Art In recent years, in the manufacture of semiconductor elements and the manufacture of semiconductor chip mounting substrates, miniaturization has been further advanced, and a projection optical system having a higher resolution has been required for an exposure apparatus for printing a pattern. To satisfy the demand for high resolution, it is necessary to shorten the wavelength of the exposure light and increase the NA (numerical aperture of the projection optical system). However, when the wavelength of the exposure light is shortened, the types of optical glass that can withstand practical use are limited due to light absorption. For example, when the wavelength is 180 nm or less, the only glass material that can be used practically is fluorite.

[0003] In this case, if the projection optical system is constituted only by the refractive optical member (a lens, a plane-parallel plate, etc.), it is impossible at all to correct the chromatic aberration in the formed refraction type projection optical system. In other words, it is very difficult to configure the projection optical system having the required resolution with only the refractive optical member. On the other hand, it has been attempted to configure a projection optical system only with a reflection optical member, that is, a reflection mirror.

However, in this case, the size of the reflection type projection optical system to be formed becomes large, and the reflection surface needs to be made aspherical. It is extremely difficult to make the reflecting surface aspherical with high precision in terms of manufacturing. Therefore, various so-called catadioptric reduction optical systems have been proposed in which a refracting optical member made of optical glass that can withstand use of short-wavelength light and a reflecting mirror are combined.

[0005]

SUMMARY OF THE INVENTION Among them, Japanese Patent Laid-Open No.
Japanese Patent No. 234722 and U.S. Pat. No. 4,779,966 disclose a catadioptric optical system that forms an intermediate image only once using only one concave reflecting mirror. In this type of catadioptric optical system, the reciprocating optical system including the concave reflecting mirror includes only a negative lens and does not include a refractive optical member having a positive power. As a result, since the light beam enters the concave reflecting mirror in a spread state, the diameter of the concave reflecting mirror tends to increase.

In particular, the optical system disclosed in Japanese Patent Laid-Open No. 4-234722 has a configuration in which a reciprocating optical system including a concave reflecting mirror is completely symmetric. In this case, the generation of aberrations in the reciprocating optical system portion is suppressed as much as possible, and the burden of aberration correction on the subsequent refractive optical system portion is reduced. However, since the symmetrical reciprocating optical system is adopted, the first
It was difficult to ensure a sufficient working distance near the surface, and a half prism had to be used to split the optical path.

Further, in the optical system disclosed in US Pat. No. 4,779,966, a concave reflecting mirror is used for a secondary imaging optical system disposed behind a position where an intermediate image is formed. . In this case, in order to ensure the necessary brightness of the optical system, the light beam enters the concave reflecting mirror in a spread state. As a result, the diameter of the concave reflecting mirror tends to be large, and it has been difficult to reduce its size.

On the other hand, an intermediate image is formed by using a plurality of reflecting mirrors.
A catadioptric optical system of the type formed only once is also known. In this type of catadioptric optical system, there is a possibility that the number of lenses in the refractive optical system can be reduced. However, this type of catadioptric optical system has the following disadvantages.

In the catadioptric optical system of the type in which the reciprocating optical system having the above-described configuration is arranged on the second surface side, which is the reduction side, the second optical system after being reflected by the reflector due to the reduction magnification. The distance to the surface (wafer surface) cannot be sufficiently long. For this reason, it was not possible to insert too many lenses into this optical path, and the resulting optical system had to have a limited brightness. Further, even if an optical system having a high numerical aperture can be realized, since many refractive optical members are arranged in an optical path having a limited length, the second surface, the wafer surface, and the It was not possible to secure a sufficiently long working distance WD between the two lens surfaces, that is, the so-called working distance WD.

In the conventional catadioptric optical system, it is necessary to bend the optical path and inevitably has a plurality of optical axes (refer to a straight line connecting the centers of curvature of the refraction curved surface or the reflection curved surface constituting the optical system). Will be. As a result, a plurality of lens barrels are required to form the optical system, and it is extremely difficult to adjust the optical axes with each other, and a highly accurate optical system cannot be realized. By using a pair of reflecting mirrors having an opening (light transmitting portion) at the center, a catadioptric optical system of a type in which all optical members are arranged along a single linear optical axis is also possible. However, in this type of catadioptric optical system, it is necessary to shield the central light flux, that is, the central shield, in order to block unnecessary light traveling along the optical axis without being reflected by the reflecting mirror. As a result, there is an inconvenience that the contrast is reduced in a specific frequency pattern due to the center shielding.

Further, in the conventional catadioptric optical system, it is not possible to secure a position where an effective field stop and an aperture stop should be installed. Further, as described above, the conventional catadioptric optical system cannot ensure a sufficiently long working distance. Further, as described above, in the conventional catadioptric optical system, the concave reflecting mirror tends to be large, and the optical system cannot be downsized.

Furthermore, in the conventional catadioptric optical system, the number of lenses tends to increase. In this case, particularly in an optical system for an F ₂ excimer laser, it is difficult to improve the performance of an anti-reflection film to be formed on the lens surface, and the amount of light used tends to be attenuated. Further, in order to realize a high-performance and high-precision optical system, it is necessary to reduce the distance between the object plane and the image plane. However, this distance is not sufficiently small in the conventional catadioptric optical system.

The present invention has been made in view of the above-mentioned problems, and has a simple configuration in which the distance between the object plane and the image plane is small and the number of lenses is small.
It is an object of the present invention to provide a catadioptric optical system capable of achieving a high resolution of 0.1 μm or less using light in a vacuum ultraviolet wavelength region of m or less.

Further, according to the present invention, it is possible to secure a position where an effective field stop and an aperture stop should be installed. For example, a high resolution of 0.1 μm or less can be obtained by using light in a vacuum ultraviolet wavelength region having a wavelength of 180 nm or less. It is an object to provide a catadioptric system capable of achieving an image.

Further, the present invention can ensure a sufficiently long working distance.
0.1 μm using light in the vacuum ultraviolet wavelength range of 0 nm or less
It is an object of the present invention to provide a catadioptric optical system capable of achieving the following high resolution.

Further, according to the present invention, the size of the optical system can be reduced by suppressing the enlargement of the concave reflecting mirror.
An object of the present invention is to provide a catadioptric optical system capable of achieving a high resolution of μm or less.

Further, by using the catadioptric optical system of the present invention as a projection optical system, it is possible to perform good projection exposure at a high resolution of 0.1 μm or less, for example, using exposure light having a wavelength of 180 nm or less. An object of the present invention is to provide an exposure apparatus.

[0018]

According to a first aspect of the present invention, there is provided at least one concave reflecting mirror and at least one flat reflecting mirror. A first imaging optical system for forming a first intermediate image of the first surface based on the first imaging optical system, at least one concave reflecting mirror and at least one flat reflecting mirror; A second imaging optical system for forming a second intermediate image of the first surface based on the transmitted light, and a final image of the first surface based on the light transmitted through the second imaging optical system. A catadioptric optical system comprising: a refraction-type third imaging optical system for forming on the second surface.

According to a preferred aspect of the first invention, all optical members except the plane reflecting mirror of the first imaging optical system and all optical members except the plane reflecting mirror of the second imaging optical system are: All the optical members of the third imaging optical system are arranged along a single first optical axis that extends linearly, and all the optical members of the third imaging optical system extend linearly so as to be orthogonal to the first optical axis. The light from the first surface is arranged along a second optical axis, and the light from the first surface passes through the first intermediate image through one planar reflecting mirror and one concave reflecting mirror in the first imaging optical system in order. The light that has been formed and passed through the first imaging optical system passes through the second imaging optical system through one planar reflecting mirror and one concave reflecting mirror in order, and
An intermediate image is formed.

According to a preferred aspect of the first invention,
Preferably, the first imaging optical system has at least one negative lens component disposed immediately before the concave reflecting mirror. Further, it is preferable that the second imaging optical system has at least one negative lens component disposed immediately before the concave reflecting mirror. Furthermore, it is preferable that the catadioptric system is telecentric on at least one of the first surface side and the second surface side. Further, it is preferable that a field lens is arranged in an optical path between the second imaging optical system and the third imaging optical system.

Further, according to a preferred aspect of the first invention, a field lens is disposed in an optical path between the first imaging optical system and the second imaging optical system. In this case, at least one of the field lenses arranged in an optical path between the first imaging optical system and the second imaging optical system is provided with the concave surface of the first imaging optical system. It is preferable to have a partially cut-out shape in order to pass only the reflected light from the concave reflecting mirror without passing the incident light to the reflecting mirror. In addition, at least one of the field lenses disposed in an optical path between the first imaging optical system and the second imaging optical system includes the concave reflection of the first imaging optical system. Preferably, it is formed so as to pass both the light incident on the mirror and the light reflected from the concave reflecting mirror.

According to a second aspect of the present invention, there is provided an illumination system for illuminating a mask set on the first surface, and a photosensitive substrate having an image of a pattern formed on the mask set on the second surface. There is provided an exposure apparatus comprising the catadioptric optical system according to the first aspect of the present invention. According to a preferred aspect of the second invention, it is preferable that the mask and the photosensitive substrate are relatively moved with respect to the catadioptric system to scan and expose the pattern of the mask on the photosensitive substrate.

[0023]

FIG. 1 is a diagram for explaining a basic configuration of a catadioptric optical system according to the present invention. In FIG.
The catadioptric optical system of the present invention is applied to a projection optical system of a scanning exposure type exposure apparatus. As shown in FIG. 1, the catadioptric optical system of the present invention includes a first imaging optical system G1 that forms a first intermediate image of a pattern of a reticle R as a projection master disposed on a first surface. . The first imaging optical system G1
Has at least one concave reflecting mirror and at least one flat reflecting mirror, that is, a first flat reflecting mirror M1 and a second concave reflecting mirror CM2. In the first imaging optical system G1, light from the reticle R forms a first intermediate image via the first plane reflecting mirror M1 and the second concave reflecting mirror CM2.

The light passing through the first imaging optical system G1 forms a second intermediate image of the pattern of the reticle R via the second imaging optical system G2. The second imaging optical system G2 has at least one
It has one concave reflecting mirror and at least one plane reflecting mirror, namely a third concave reflecting mirror CM3 and a fourth plane reflecting mirror M4. Therefore, in the second imaging optical system G2, the light passing through the first imaging optical system G1 forms a second intermediate image via the third concave reflecting mirror CM3 and the fourth plane reflecting mirror M4.

The light passing through the second imaging optical system G2 passes through the third imaging optical system G3 of a refraction type having a plurality of refracting optical members without including a reflecting mirror, and then the final image of the pattern of the reticle R is formed. W as a photosensitive substrate disposed on the second surface
Form on top. In an exposure apparatus equipped with the catadioptric optical system of the present invention as a projection optical system, a reticle R and a wafer W
Is moved along a predetermined direction (scan direction) while performing scanning exposure based on the rectangular illumination region IR and the effective exposure region ER.

According to a specific mode, the first imaging optical system G
All the optical members except the first first plane reflecting mirror M1 and all the optical members except the fourth plane reflecting mirror M4 of the second imaging optical system G2 have a single first optical axis AX1 extending linearly. Are arranged along. All the optical members of the third imaging optical system G3 are arranged along a single second optical axis AX2 that extends linearly so as to be orthogonal to the first optical axis AX1. The first plane reflecting mirror M1 and the fourth plane reflecting mirror M4 can be integrally formed as front and back mirrors. If the first plane reflecting mirror M1 and the fourth plane reflecting mirror M4 are integrally formed, the precision of the front and back surfaces is good and the manufacturing is easy. Further, when the first plane reflecting mirror M1 and the fourth plane reflecting mirror M4 are arranged at predetermined positions, angle adjustment is necessary. However, if they are integrally formed, the first plane reflecting mirror M1 will have a predetermined angle. Even if it is arranged with an error in the minus direction, the fourth plane reflecting mirror M4 cancels the error in the plus direction from the predetermined angle, so that it can enter the third imaging optical system G3 described later at a predetermined angle. it can.

According to a more specific mode, the field lens FL is disposed in the optical path between the first imaging optical system G1 and the second imaging optical system G2. Here, the field lens FL has a function of matching and connecting the first imaging optical system G1 and the second imaging optical system G2 without actively contributing to the formation of the first intermediate image. At least one lens of the field lens FL is configured to pass only the reflected light from the second concave reflecting mirror without passing the light incident on the second concave reflecting mirror of the first imaging optical system G1. It has a notched shape.

At least one of the field lenses FL is configured to transmit both light incident on the second concave reflecting mirror of the first imaging optical system G1 and light reflected from the second concave reflecting mirror. Is formed. It should be noted that a field lens is also arranged in the optical path between the second imaging optical system G2 and the third imaging optical system G3, if necessary.

According to a specific mode, at least one of each of the second concave reflecting mirror CM2 of the first imaging optical system G1 and the third concave reflecting mirror CM3 of the second imaging optical system G2 is provided immediately before the third concave reflecting mirror CM3. Two negative lens components are arranged. With this configuration, even when the refractive optical member (lens component) is formed of a single type of optical material, it is possible to excellently correct chromatic aberration. Further, it is possible to satisfactorily correct axial chromatic aberration and magnification chromatic aberration simultaneously.

A field stop FS for defining an image area formed by the catadioptric optical system is connected to the first imaging optical system G1 and the second imaging optical system G1.
Near the field lens FL between the imaging optical system G2,
Alternatively, it can be arranged near the field lens between the second imaging optical system G2 and the third imaging optical system G3. In this case, it is possible to adopt a configuration in which the illumination optical system does not need to have a field stop. Further, an aperture stop AS can be arranged in the optical path of the third imaging optical system G3.

As described above, in the catadioptric optical system of the present invention, both the first imaging optical system G1 and the second imaging optical system G2 have at least one concave reflecting mirror and at least one plane reflecting mirror. The third imaging optical system G3 forms a refraction type optical system. Therefore, according to a typical embodiment, the first imaging optical system G1 and the second imaging optical system G2 are arranged along the first optical axis AX1, and the third imaging optical system G3 is arranged along the first optical axis AX1. Are arranged along a second optical axis AX2 orthogonal to the optical axis AX2. In addition, the reticle R and the wafer W are arranged along the second optical axis AX2.

As described above, in the present invention, only the third imaging optical system G3 is disposed along the second optical axis AX2 on which the reticle R and the wafer W are disposed, and the first imaging optical system G3 is disposed. The system G1 and the second imaging optical system G2 are arranged along a first optical axis AX1 orthogonal to the second optical axis AX2. Therefore, in the present invention, the distance between the reticle R and the wafer W, that is, the distance between the object plane and the image plane can be set small, and a high-performance and high-precision optical system can be realized. In particular, by making the first optical axis AX1 and the second optical axis AX2 orthogonal, the adjustment work between the optical axes becomes easy, and it becomes easy to realize a high-performance and high-precision optical system.

Further, by configuring the first imaging optical system G1 and the second imaging optical system G2 as catadioptric optical systems, even if the lens components are formed of a single kind of optical material, satisfactory correction of chromatic aberration can be achieved. Becomes possible. Furthermore, by disposing at least one negative lens component immediately before the second concave reflecting mirror CM2 of the first imaging optical system G1 and immediately before the third concave reflecting mirror CM3 of the second imaging optical system G2, The above chromatic aberration and the chromatic aberration of magnification can be satisfactorily corrected simultaneously.

Further, in the present invention, the Petzval sum that tends to be positive because the refractive optical system portion of the third imaging optical system G3 has a positive refractive power (power) is converted into the first imaging optical system G1.
And the concave reflecting mirror portion (C in the second imaging optical system G2)
M2, CM3) can be canceled by the negative Petzval sum, and the total Petzval sum can be completely suppressed to zero.
Furthermore, in the present invention, as shown in the Examples below, since little simple configuration of lenses is enabled, for example, hardly leads to even attenuation of used light quantity by using a F ₂ excimer laser beam, the exposure apparatus A decrease in throughput can be avoided.

[0035]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 2 is a diagram schematically illustrating an overall configuration of an exposure apparatus including a catadioptric optical system according to each embodiment of the present invention as a projection optical system. In FIG. 2, the Z axis is parallel to the reference optical axis of the catadioptric optical system constituting the projection optical system PL, that is, the second optical axis AX2, and is parallel to the plane of FIG. 2 in a plane perpendicular to the reference optical axis AX2. , And the X axis is set perpendicular to the paper surface.

The exposure apparatus shown supplies illumination light in the ultraviolet region.
F as a light source 100 for supplying _TwoLaser light source (oscillation
(A center wavelength of 157.6 nm). Light source 100?
The light emitted from the illumination optical system IL passes through a predetermined path.
Uniformly illuminates reticle (mask) R with turns formed
I do. The optical path between the light source 100 and the illumination optical system IL
Is sealed by a casing (not shown),
To the optical member closest to the reticle in the illumination optical system IL
Space is a helium gas, which is a gas with a low absorptance of exposure light.
Replaced by an inert gas such as nitrogen or nitrogen, or
Is maintained in a substantially vacuum state.

The reticle R is held on a reticle stage RS via a reticle holder RH in parallel with the XY plane. A pattern to be transferred is formed on the reticle R, and a rectangular pattern area having a long side along the X direction and a short side along the Y direction in the entire pattern area is illuminated. Reticle stage RS
It can be moved two-dimensionally along the reticle plane (that is, the XY plane) by the action of a drive system (not shown), and its position coordinate is an interferometer RIF using a reticle moving mirror RM.
And the position is controlled.

The light from the pattern formed on the reticle R forms a reticle pattern image on a wafer W as a photosensitive substrate via a catadioptric projection optical system PL. The wafer W is held on a wafer stage WS via a wafer table (wafer holder) WT in parallel with the XY plane. A rectangular exposure area having a long side along the X direction and a short side along the Y direction on the wafer W so as to correspond optically to the rectangular illumination area on the reticle R. A pattern image is formed on the substrate. The wafer stage WS can be moved two-dimensionally along the wafer surface (that is, the XY plane) by the action of a drive system (not shown), and its position coordinates are measured by an interferometer WIF using a wafer moving mirror WM. In addition, the position is controlled.

FIG. 3 is a diagram showing a positional relationship between a rectangular exposure area (ie, an effective exposure area) formed on a wafer and a reference optical axis. As shown in FIG. 3, in each embodiment,
Radius A centered on reference optical axis AX2 (corresponding to maximum image height)
, A rectangular effective exposure region ER having a desired size is set at a position decentered in the −Y direction from the reference optical axis AX2 in a circular region (image circle) IF having the following. Here, the length of the effective exposure area ER in the X direction is LX
And the length in the Y direction is LY.

Therefore, as shown in FIG. 1, on the reticle R, a rectangular illumination region IR having a size and shape corresponding to the effective exposure region ER is formed at a position eccentric from the reference optical axis AX2 in the + Y direction. It will be.
That is, within a circular area having a radius B (corresponding to the maximum object height) centered on the reference optical axis AX2, a rectangular illumination having a desired size is located at a position decentered in the + Y direction from the reference optical axis AX2. An area IR is set.

In the illustrated exposure apparatus, the projection optical system P
Among the optical members constituting L, the optical member disposed closest to the reticle side (first plane reflecting mirror M1 in each embodiment) and the optical member disposed closest to the wafer side (lens L312, second lens in the first embodiment) In the embodiment, the inside of the projection optical system PL is configured to maintain an airtight state with the lens L311),
The gas inside the projection optical system PL is replaced with an inert gas such as helium gas or nitrogen, or is kept in a substantially vacuum state.

Further, the illumination optical system IL and the projection optical system PL
A reticle R, a reticle stage RS, and the like are disposed in a narrow optical path between the reticle R and the reticle stage RS. It is filled with gas or kept in a substantially vacuum state.

In a narrow optical path between the projection optical system PL and the wafer W, the wafer W and the wafer stage WS are arranged.
An inert gas such as nitrogen or helium gas is filled in a casing (not shown) that hermetically surrounds S or the like, or is kept in a substantially vacuum state. Thus, an atmosphere in which the exposure light is hardly absorbed is formed over the entire optical path from the light source 100 to the wafer W.

As described above, the illumination area on the reticle R and the exposure area on the wafer W (ie, the effective exposure area ER) defined by the projection optical system PL are rectangular in shape having short sides along the Y direction. is there. Therefore, the reticle R is formed by using a drive system and an interferometer (RIF, WIF).
While controlling the position of the wafer W, the reticle stage RS and the wafer stage WS, and thus the reticle R and the wafer W, are moved in opposite directions along the short side direction of the rectangular exposure region and the illumination region, that is, in the Y direction. By moving (scanning) synchronously (that is, in the opposite direction), the wafer W has a width equal to the long side of the exposure area and a length corresponding to the scanning amount (moving amount) of the wafer W. The reticle pattern is scanned and exposed in the region having the reticle.

In each of the embodiments, the projection optical system PL including the catadioptric optical system of the present invention is a catadioptric first optical system for forming a first intermediate image of the pattern of the reticle R disposed on the first surface. An imaging optical system G1; a catadioptric second imaging optical system G2 for forming a second intermediate image of the pattern of the reticle R based on light passing through the first imaging optical system G1; A refraction-type third imaging optical system G3 for forming a final image of the reticle pattern (reduced image of the reticle pattern) on the wafer W arranged on the second surface based on the light passing through the imaging optical system G2. And

In each embodiment, all optical members of the first imaging optical system G1 except for the first plane reflecting mirror M1 and all optical members of the second imaging optical system G2 except for the fourth plane reflecting mirror M4. The member is arranged along the first optical axis AX1. Further, all the optical members constituting the third imaging optical system G3 are arranged along a second optical axis AX2 orthogonal to the first optical axis AX1. Further, a first field lens is disposed in an optical path between the first imaging optical system G1 and the second imaging optical system G2, and the second imaging optical system G2 and the third imaging optical system G
A second field lens is disposed in the optical path between the first and second field lenses.

In each embodiment, fluorite (C) is used for all refractive optical members (lens components) constituting the projection optical system PL.
aF ₂ crystal). In addition, the exposure light F ₂
The oscillation center wavelength of the laser beam is 157.6 nm.
In the vicinity of 7.6 nm, the refractive index of CaF ₂ is +1 pm
Changes at a rate of -2.45 × 10 ^-6 per wavelength change of
It changes at a rate of + 2.45 × 10 ⁻⁶ per wavelength change of −1 pm. In other words, at around 157.6 nm,
The dispersion (dn / dλ) of the refractive index of CaF ₂ is 2.45 ×
10 ⁻⁶ / pm.

Therefore, in each embodiment, the refractive index of CaF ₂ with respect to the center wavelength of 157.6 nm is 1.560.
000. Then, 157.6 nm + 0.4 pm =
The refractive index of CaF ₂ for 157.6004 nm is 1.
55599902 ≒ 1.559999, and 157.
6 nm-0.4 pm = refractive index of CaF ₂ is for 157.5995 ≒ nm 1.56000098 ≒ 1.560
001.

In each embodiment, the height of the aspheric surface in the direction perpendicular to the optical axis is defined as y, and along the optical axis from the tangent plane at the vertex of the aspheric surface to a position on the aspheric surface at the height y. Distance (sag amount) as z, vertex curvature radius as r,
Assuming that the conic coefficient is κ and the n-th order aspherical coefficient is Cn, it is expressed by the following equation (a).

[0050]

## EQU1 ## z = (y ² / r) / [1+ ｛1- (1 + κ) ·
y ² / r ^{2} 1/2] _{+ C 4 · y 4 + C}} 6 · y 6 + C 8 · y 8 + C
₁₀ · y ¹⁰ (a) In each embodiment, an asterisk is attached to the right side of the surface number on the lens surface formed into an aspherical shape.

[First Embodiment] FIG. 4 is a diagram showing a lens configuration of a catadioptric optical system (projection optical system PL) according to a first embodiment. In the catadioptric optical system of FIG. 4, the first imaging optical system G1 is arranged along the traveling direction of light from the reticle side.
A first plane reflecting mirror M1, a positive meniscus lens L11 having a convex surface facing the first plane reflecting mirror M1, and a biconcave lens L12
And a second concave reflecting mirror CM2 having a concave surface facing the first plane reflecting mirror M1. Here, the positive meniscus lens L11, the biconcave lens L12, and the second concave reflecting mirror CM2 are arranged in order from the right side in the figure along the horizontal first optical axis AX1 in the figure.

The second imaging optical system G2 includes a negative meniscus lens L21 having a concave surface facing the first imaging optical system G1 along the traveling direction of light from the first imaging optical system G1. Third concave reflecting mirror CM having a concave surface facing the first imaging optical system G1
3 and a fourth plane reflecting mirror M4. Here, the negative meniscus lens L21 and the third concave reflecting mirror C
M3 are arranged in order from the left side in the figure along the first optical axis AX1.

Further, the third imaging optical system G3 includes, in order from the reticle side, a positive meniscus lens L31 having a convex surface facing the reticle side, a negative meniscus lens L32 having an aspherical concave surface facing the reticle side, and a wafer. Negative meniscus lens L33 having an aspherical concave surface on the side, and a biconvex lens L3
4, a negative meniscus lens L35 having an aspheric convex surface facing the reticle side, a positive meniscus lens L36 having a convex surface facing the reticle side, an aperture stop AS, and a lens having an aspheric convex surface facing the reticle side. A convex lens L37, a positive meniscus lens L38 having a convex surface facing the reticle side, a biconvex lens L39 having a aspheric convex surface facing the wafer side, a biconvex lens L310, and a positive lens having an aspheric concave surface facing the wafer side. It comprises a meniscus lens L311 and a biconvex lens L312. Here, the lenses L31 to L312
Are arranged in order from the upper side (the reticle side) in the figure along the second optical axis AX2 which is vertical in the figure.

In the optical path between the first image forming optical system G1 and the second image forming optical system G2, the first image forming optical system G1 extends along the traveling direction of light from the first image forming optical system G1 side. A positive meniscus lens L41 having a concave surface facing the optical system G1, and a first imaging optical system G
Partial lens L of positive meniscus lens with convex surface facing one side
And a first field lens composed of a first field lens and a second field lens. That is, the positive meniscus lens L41 and the partial lens L42 of the positive meniscus lens are connected to the first optical axis AX.
1 are arranged in order from the left side in the figure.

Here, the positive meniscus lens L41 is the same lens as the positive meniscus lens L11, and is the light incident on the second concave reflecting mirror CM2 and the second concave reflecting mirror CM2.
And the reflected light from both is passed. The partial lens L42 of the positive meniscus lens partially cuts the positive meniscus lens in order to pass only the light reflected from the second concave reflecting mirror CM2 without passing the light incident on the second concave reflecting mirror CM2. It has a chipped shape.

In the optical path between the second imaging optical system G2 and the third imaging optical system G3, a biconvex lens L51 having an aspherical convex surface facing the reticle side in order from the reticle side;
Positive meniscus lens L52 with the convex surface facing the reticle side
A second field lens including a positive meniscus lens L53 having an aspherical convex surface facing the wafer side is disposed. Here, the lenses L51 to L53 are
They are arranged in order from the upper side (reticle side) in the figure along the optical axis AX2.

Therefore, in the first embodiment, the reticle R
Is reflected by the first plane reflecting mirror M1, and then enters the second concave reflecting mirror CM2 via the positive meniscus lens L11 and the biconcave lens L12. The light reflected by the second concave reflecting mirror CM2 is transmitted to the first field lens (L4
1, L42), a first intermediate image of the reticle pattern is formed. Light from the first intermediate image formed near the first field lenses (L41, L42) enters the third concave reflecting mirror CM3 via the negative meniscus lens L21.

The light reflected by the third concave reflecting mirror CM3 is
Through the negative meniscus lens L21, the fourth plane reflecting mirror M
4 is incident. The light reflected by the fourth plane reflecting mirror M4 is
A second intermediate image of the reticle pattern is formed in the second field lenses (L51 to L53). Light from the second intermediate image formed in the second field lenses (L51 to L53) is transmitted to each of the lenses L31 to L31 constituting the third imaging optical system G3.
A final image of the reticle pattern is formed on the wafer W via the L312.

The following Table (1) shows the values of the specifications of the catadioptric optical system according to the first embodiment. In the main specifications of Table (1), λ is the center wavelength of the exposure light, β is the projection magnification (the imaging magnification of the entire system), NA is the image-side (wafer-side) numerical aperture, and A is
Is the radius of the image circle IF on the wafer W, that is, the maximum image height, B is the maximum object height corresponding to the maximum image height A,
LX indicates the dimension (long side dimension) of the effective exposure area ER along the X direction, and LY indicates the dimension (short side dimension) of the effective exposure area ER along the Y direction.

Also, in the optical member specifications in Table (1),
The surface number of the first column indicates the order of the surface along the light traveling direction from the reticle side, r of the second column indicates the radius of curvature of each surface (vertical radius of curvature: mm for an aspheric surface), and third The d in the column indicates the on-axis interval of each surface, that is, the surface interval (mm), and the n in the fourth column indicates the refractive index with respect to the center wavelength. It should be noted that the sign of the surface distance d changes each time it is reflected. Therefore, the sign of the surface distance d is negative in the optical path from the first flat reflecting mirror M1 to the second concave reflecting mirror CM2 and in the optical path from the third concave reflecting mirror CM3 to the fourth flat reflecting mirror M4, It is positive in the optical path.

On the optical surface arranged along the first optical axis, the radius of curvature of the convex surface toward the left in the drawing is positive, and the radius of curvature of the concave surface toward the left in the drawing is negative. Further, on the optical surface disposed along the second optical axis, the radius of curvature of the convex surface toward the reticle side (upper side in the drawing) is positive, and the radius of curvature of the concave surface toward the reticle side is negative. In the following table (2), the above notation is the same.

[0062]

(Main Specifications) λ = 157.6 nm β = 1/5 NA = 0.845 A = 20 mm B = 100 mm LX = 22 mm LY = 5.5 mm (Optical member specifications) Surface number r dn ( (Reticle surface) 290.026586 1 -1-10.000000 (first plane reflecting mirror M1) 2 -375.61418 -69.999996 1.560000 (lens L11) 3 -8384.72157 -577.410812 4 3695.39575 -15.430078 1.560000 (lens L12) 5 -1011.27343 -20.000282 6 488.06850 20.000282 2-concave reflector CM2) 7 -1011.27343 15.430078 1.560000 (Lens L12) 8 3695.39575 577.410812 9 -8384.72155 69.999996 1.560000 (Lens L41) 10 -375.61418 1.000000 11 523.29394 26.651917 1.560000 (Lens L42) 12 7089.68959 776.202894 13-233.196. ) 14 -782.75388 20.000264 15 -397.38457 -20.000264 (Third concave reflector CM3) 16 -782.75388 -12.344063 1.560000 (Lens L21) 17 -233. 13196 -730.717730 18 ∞ 200.000000 (Fourth flat mirror M4) 19 * 485.08331 29.459002 1.560000 (Lens L51) 20 -3575.98802 1.000000 21 233.35657 29.671010 1.560000 (Lens L52) 22 486.59435 92.567882 23 -2726.09488 15.000000 1.560000 (Lens L53) 24 *- 905.37791 189.879636 25 171.44052 18.057863 1.560000 (Lens L31) 26 230.14097 81.533597 27 * -134.73026 23.510345 1.560000 (Lens L32) 28 -3198.32252 19.739819 29 200.39557 15.000000 1.560000 (Lens L33) 30 * 155.44391 11.006083 31 214.60791 43.760 (Lens) 4.884579 33 * 273.28545 15.000000 1.560000 (Lens L35) 34 169.26001 49.818640 35 206.47284 28.337440 1.560000 (Lens L36) 36 512.08579 56.625033 37 ∞ 29.862740 (Aperture stop AS) 38 * 307.92600 29.246184 1.560000 (Lens L37) 39 -1614.990271.000000 400000 Lens L38) 41 428.85314 1.0 00000 42 292.93034 55.380125 1.560000 (Lens L39) 43 * -365.29687 4.141093 44 394.28173 53.678655 1.560000 (Lens L310) 45 -1442.13457 2.718799 46 112.27860 28.030508 1.560000 (Lens L311) 47 * 314.25185 6.015629 48 666.58142 53.3557151.5600000 (Lens L3111.5600000) (Wafer surface) (Aspherical surface data) 19 surfaces κ = 0.000000 C ₄ = −0.178149 × 10 ⁻⁸ C ₆ = 0.405049 × 10 ⁻¹³ C ₈ = 0.468516 × 10 ⁻¹⁸ C ₁₀ = 0.885923 × 10 ⁻²⁴ 24 faces κ = 0.00000 C ₄ = 0.18099 × 10 ⁻⁷ C ₆ = 0.319921 × 10 ⁻¹³ C ₈ = 0.582249 × 10 ⁻¹⁸ C ₁₀ = −0. 416199 × 10 ^-22 27 surface _{κ = 0.000000 C 4 = 0.130981 ×} 10 -7 C 6 = 0.14709 × 10 -11 C 8 = 0.286138 × _{^{0 -16 C 10 = 0.824171 × 10}} -21 30 surface _{κ = 0.000000 C 4 = -0.221086 ×} 10 -7 C 6 = 0.485234 × 10 -12 C 8 = -0.443606 × 10 ^-16 C ₁₀ = 0.674127 × 10 ^-21 33 faces κ = 0.00000 C ₄ = −0.387569 × 10 ^-7 C ₆ = −0.117576 × 10 ⁻¹¹ C ₈ = −0.216249 × 10 ^-16 C ₁₀ = -0.135314 x 10 ^-20 38 planes κ = 0.000000 C ₄ = -0.324171 x 10 ^-7 C ₆ = -0.6008565 x 10 ^-12 C ₈ = -0.868014 x 10 ⁻¹⁷ C ₁₀ = −0.206122 × 10 ⁻²¹ 43 faces κ = 0.00000 C ₄ = 0.419536 × 10 ⁻⁸ C ₆ = −0.141122 × 10 ⁻¹² C ₈ = 0.403164 × 10 ^{_{-17 C 10 = 0.307861 × 10 -21}} 47 surface κ ^{_{0.000000 C 4 = 0.366932 × 10 -7}} C 6 = 0.458258 × 10 -12 C 8 = -0.386388 × 10 -16 C 10 = -0.274150 × 10 -19

FIGS. 5 and 6 are diagrams showing the lateral aberration of the catadioptric optical system according to the first embodiment. In the aberration diagrams, Y indicates the image height (mm). As is clear from the aberration diagram, in the first embodiment, the wavelength width is 157.6 nm ±.
For exposure light of 0.4 pm, that is, when the center wavelength is 15
Against the F ₂ laser beam of half width 0.7pm at 7.6 nm, it can be seen that the chromatic aberrations are satisfactorily corrected. In addition, it has been confirmed that spherical aberration, coma, astigmatism, and distortion (distortion) are satisfactorily corrected to a state close to almost no aberration, and that excellent imaging performance is obtained.

[Second Embodiment] FIG. 7 is a diagram showing a lens configuration of a catadioptric optical system (projection optical system PL) according to a second embodiment. In the catadioptric optical system of FIG. 7, the first image forming optical system G1 is arranged along the traveling direction of light from the reticle side.
A first plane reflecting mirror M1, a positive meniscus lens L11 having a convex surface facing the first plane reflecting mirror M1, and a biconcave lens L12
And a second concave reflecting mirror CM2 having a concave surface facing the first plane reflecting mirror M1. Here, the positive meniscus lens L11, the biconcave lens L12, and the second concave reflecting mirror CM2 are arranged in order from the right side in the figure along the horizontal first optical axis AX1 in the figure.

The second imaging optical system G2 includes a negative meniscus lens L21 having a concave surface facing the first imaging optical system G1 along the traveling direction of light from the first imaging optical system G1. Third concave reflecting mirror CM having a concave surface facing the first imaging optical system G1
3 and a fourth plane reflecting mirror M4. Here, the negative meniscus lens L21 and the third concave reflecting mirror C
M3 are arranged in order from the left side in the figure along the first optical axis AX1.

Further, the third imaging optical system G3 includes, in order from the reticle side, a negative meniscus lens L31 having a concave surface facing the reticle side, a biconvex lens L32 having an aspherical convex surface facing the reticle side, and a wafer side. , A biconcave lens L34 having an aspherical concave surface facing the reticle side, a biconcave lens L35 having an aspherical convex surface facing the reticle side, a positive meniscus lens L36 having a convex surface facing the reticle side, and an aperture stop. AS, a biconvex lens L37 having an aspherical convex surface facing the reticle side, a biconvex lens L38 having an aspherical convex surface facing the wafer side, a biconvex lens L39, and an aspheric concave surface facing the wafer side. A positive meniscus lens L310,
And a biconvex lens L311. Here, the lenses L31 to L311 are arranged in order from the upper side in the figure (the reticle side) along the second vertical optical axis AX2 in the figure.

In the optical path between the first image forming optical system G1 and the second image forming optical system G2, the first image forming optical system G1 extends along the first image forming optical system G1 along the light traveling direction. A positive meniscus lens L41 having a concave surface facing the optical system G1, and a first imaging optical system G
Partial lens L of positive meniscus lens with convex surface facing one side
And a first field lens composed of a first field lens and a second field lens. That is, the positive meniscus lens L41 and the partial lens L42 of the positive meniscus lens are connected to the first optical axis AX.
1 are arranged in order from the left side in the figure.

Here, the positive meniscus lens L41 is the same lens as the positive meniscus lens L11, and is the light incident on the second concave reflecting mirror CM2 and the second concave reflecting mirror CM2.
And the reflected light from both is passed. The partial lens L42 of the positive meniscus lens partially cuts the positive meniscus lens in order to pass only the light reflected from the second concave reflecting mirror CM2 without passing the light incident on the second concave reflecting mirror CM2. It has a chipped shape.

In the optical path between the second imaging optical system G2 and the third imaging optical system G3, a biconvex lens L51 having an aspherical convex surface facing the reticle side in order from the reticle side;
Positive meniscus lens L52 with the convex surface facing the reticle side
And a biconvex lens L having an aspherical convex surface facing the reticle side
And a second field lens 53. Here, the lenses L51 to L53 are connected to the second optical axis A.
They are arranged in order from the upper side (reticle side) in the figure along X2.

Therefore, in the first embodiment, the reticle R
Is reflected by the first plane reflecting mirror M1, and then enters the second concave reflecting mirror CM2 via the positive meniscus lens L11 and the biconcave lens L12. The light reflected by the second concave reflecting mirror CM2 is transmitted to the first field lens (L4
1, L42), a first intermediate image of the reticle pattern is formed. Light from the first intermediate image formed near the first field lenses (L41, L42) enters the third concave reflecting mirror CM3 via the negative meniscus lens L21.

The light reflected by the third concave reflecting mirror CM3 is
Through the negative meniscus lens L21, the fourth plane reflecting mirror M
4 is incident. The light reflected by the fourth plane reflecting mirror M4 is
A second intermediate image of the reticle pattern is formed near the second field lenses (L51 to L53). Light from the second intermediate image formed in the vicinity of the second field lenses (L51 to L53) passes through the lenses L31 to L311 constituting the third imaging optical system G3 to form a reticle pattern on the wafer W. Form the final image.

Table 2 below summarizes the data values of the catadioptric optical system according to the second embodiment.

[0073]

(Main specifications) λ = 157.6 nm β = 1/5 NA = 0.845 A = 20 mm B = 100 mm LX = 22 mm LY = 5.5 mm (optical member specifications) Surface number r dn ( (Reticle surface) 290.027792 1 -1-10.000000 (first plane reflector M1) 2 -375.77476 -70.000000 1.560000 (lens L11) 3 -8471.57979 -571.612419 4 880.34723 -20.000002 1.560000 (lens L12) 5 -1526.15631 -20.000068 6 430.44124 20.000068 (first 2 Concave reflector CM2) 7 -1526.15631 20.000002 1.560000 (Lens L12) 8 880.34723 571.612419 9 -8471.57979 69.999999 1.560000 (Lens L41) 10 -375.77476 1.000002 11 392.76058 40.629139 1.560000 (Lens L42) 12 1108.55246 695.632956 13 -228.9080000 20.00 ) 14 -747.58067 20.000181 15 -395.97377 -20.000181 (Third concave reflector CM3) 16 -747.58067 -20.000000 1.560000 (Lens L21) 17 -228.90 899 -664.125014 18 ∞ 200.000000 (Fourth flat mirror M4) 19 * 307.73876 45.812627 1.560000 (Lens L51) 20 -657.97921 1.000012 21 149.69136 20.574935 1.560000 (Lens L52) 22 169.28022 26.746170 23 * 536.30443 21.501552 1.560000 (Lens L8120) 24 -133 75.390674 25 -614.40516 20.000000 1.560000 (Lens L31) 26 14606.79185 71.837998 27 * 435.66480 30.326782 1.560000 (Lens L32) 28 -284.06632 11.648712 29 -125.54617 20.000000 1.560000 (Lens L30) 30 * 114.73493 44.208284 31 228.79734. 43.802275 33 * -362.74483 20.000000 1.560000 (Lens L35) 34 705.62394 1.145699 35 210.45845 20.000001 1.560000 (Lens L36) 36 348.14561 29.558007 37 ∞ 8.302787 (Aperture stop AS) 38 * 348.07912 36.473270 1.560000 (Lens L37) 39 -364.89841 1.000000 409216.953 (Lens L38) 41 * -323.09677 5.937 773 42 778.36526 29.012042 1.560000 (Lens L39) 43 -451.33562 1.000000 44 187.68025 25.248610 1.560000 (Lens L310) 45 * 221.00795 16.525885 46 109.74451 70.000000 1.560000 (Lens L311) 47 -777.78439 6.000000 (Wafer surface) (Aspherical surface data) 19 surface κ = 0.000000 C ₄ = −0.668929 × 10 ⁻⁸ C ₆ = −0.479397 × 10 ⁻¹³ C ₈ = −0.673132 × 10 ⁻¹⁸ C ₁₀ = 0.106140 × 10 ⁻²² 23 planes κ = 0.000000 C ₄ = −0.132984 × 10 ⁻⁷ C ₆ = −0.177789 × 10 ⁻¹³ C ₈ = 0.337448 × 10 ⁻¹⁷ C ₁₀ = −0.807302 × 10 ⁻²² 27 planes κ = 0.000000 C ₄ = −0.803336 × 10 ⁻⁷ C ₆ = 0.146061 × 10 ⁻¹¹ C ₈ = −0.114820 × 10 ⁻¹⁵ C ₁₀ = −0.349779 × 10 ⁻²⁰ 30 Surface κ = 0.000000 C ₄ = −0.183841 × 10 ⁻⁶ C ₆ = 0.731671 × 10 ⁻¹¹ C ₈ = −0.495189 × 10 ⁻¹⁵ C ₁₀ = 0.335532 × 10 ⁻¹⁹ 33 surfaces κ = 0.000000 C ₄ = −0.513433 × 10 ⁻⁷ C ₆ = −0.369543 × 10 ⁻¹¹ C ₈ = −0.899155 × 10 ⁻¹⁶ C ₁₀ = −0.433261 × 10 ⁻²⁰ 38 Surface κ = 0.000000 C ₄ = −0.438078 × 10 ⁻⁷ C ₆ = −0.442827 × 10 ⁻¹² C ₈ = −0.562647 × 10 ⁻¹⁷ C ₁₀ = −0.499761 × 10 ⁻²² 41 surface κ = 0.000000 C ₄ = 0.264225 × 10 ⁻⁷ C ₆ = −0.224965 × 10 ⁻¹² C ₈ = 0.211478 × 10 ⁻¹⁶ C ₁₀ = 0.235538 × 10 ⁻²¹ 45 surface κ = 0.000000 C ₄ = 0.481954 × _{^{0 -7 C 6 = 0.419266 × 10}} -11 C 8 = 0.121152 × 10 -15 C 10 = 0.344811 × 10 -20

FIGS. 8 and 9 show lateral aberrations of the catadioptric optical system according to the second embodiment. In the aberration diagrams, Y indicates the image height (mm). As is clear from the aberration diagrams, in the second embodiment as well as in the first embodiment,
For exposure light having a wavelength width of 157.6 nm ± 0.4 pm, that is, a center wavelength of 157.6 nm and a half width of 0.7.
respect pm of the F ₂ laser beam, it can be seen that the chromatic aberrations are satisfactorily corrected. In addition, it has been confirmed that spherical aberration, coma, astigmatism, and distortion (distortion) are satisfactorily corrected to a state close to almost no aberration, and that excellent imaging performance is obtained.

As described above, in each of the above-described embodiments, the F ₂ laser light having the center wavelength of 157.6 nm
In addition to securing a large image-side NA of 45, an image circle having a radius of 20 mm on which a variety of aberrations including chromatic aberration are sufficiently corrected on the wafer W can be secured. Therefore, in each example, 22 mm × 5.5
It is possible to achieve a high resolution of 0.1 μm or less while securing a rectangular effective exposure area sufficiently large in mm.
Then, in the wafer W, for example, 22 mm × 33 m
The pattern of the reticle R can be transferred with high precision to each exposure region having a size of m by scanning exposure. In each of the above embodiments, a sufficiently long working distance on the wafer side of about 6 mm can be ensured.

In the first embodiment, the diameter of the two concave reflecting mirrors CM1 and CM3 is 335 mm or less, and
The effective diameter (diameter) of the largest lens is 335 mm or less, and the effective diameter of most other lenses is 240 mm or less. On the other hand, in the second embodiment, two concave reflecting mirrors C
The diameters of M1 and CM3 are 340 mm or less, the effective diameter (diameter) of the two largest lenses is 340 mm or less, and the effective diameter of most other lenses is 230 mm or less. As described above, in each embodiment, the size of the concave reflecting mirror and the lens is suppressed, and the size of the optical system is reduced.

Further, in each of the above-described embodiments, the configuration is such that the number of lenses is very small (19 in the first embodiment, and 18 in the second embodiment), even though the optical system is of the three-time imaging system.
Sheets). In an optical system using F ₂ laser light,
Since a good antireflection coating cannot be obtained, a large number of lenses tends to cause a loss of light quantity on the lens surface. From this viewpoint, each of the above-described embodiments has a configuration in which the number of lenses is small and the loss of light amount on the lens surface is suppressed.

In the first embodiment, the distance between the object plane (reticle plane) and the image plane (wafer plane) is about 1.5 m.
In the second embodiment, the distance between the object plane and the image plane is about 1.3 m. As described above, in each embodiment, since the distance between the object plane and the image plane is kept small, a high-performance and high-precision optical system can be realized, and the size of the apparatus can be further reduced. . In each of the above embodiments, the number of aspheric surfaces introduced is very small (eight in each embodiment).

In the exposure apparatus according to the above-described embodiment, the reticle (mask) is illuminated by the illumination optical system (illumination step), and the pattern for transfer formed on the reticle is scanned on the photosensitive substrate using the projection optical system. By exposing (exposure step), the micro device (semiconductor element, imaging element,
Liquid crystal display elements, thin-film magnetic heads, etc.). Hereinafter, an example of a method for obtaining a semiconductor device as a micro device by forming a predetermined circuit pattern on a wafer or the like as a photosensitive substrate using the exposure apparatus of the present embodiment will be described with reference to the flowchart of FIG. Will be explained.

First, in step 301 of FIG.
A metal film is deposited on one lot of wafers. In the next step 302, a photoresist is applied on the metal film on the l lot of wafers. Then, step 30
In 3, the image of the pattern on the reticle is sequentially exposed and transferred to each shot area on the wafer of the lot through the projection optical system using the exposure apparatus of the present embodiment. Thereafter, in step 304, the photoresist on the one lot of wafers is developed, and in step 305, etching is performed on the one lot of wafers using the resist pattern as a mask, thereby forming a pattern on the reticle. The corresponding circuit pattern is
It is formed in each shot area on each wafer. Thereafter, a device such as a semiconductor element is manufactured by forming a circuit pattern of an upper layer and the like. According to the above-described semiconductor device manufacturing method, a semiconductor device having an extremely fine circuit pattern can be obtained with high throughput.

In the exposure apparatus of the present embodiment, a predetermined pattern (circuit pattern,
By forming an electrode pattern or the like, a liquid crystal display element as a microdevice can be obtained. Hereinafter, an example of the technique at this time will be described with reference to the flowchart in FIG. In FIG. 11, in a pattern forming step 401, a so-called photolithography step of transferring and exposing a reticle pattern to a photosensitive substrate (a glass substrate coated with a resist or the like) using the exposure apparatus of each embodiment is executed. By this optical lithography process,
A predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. Thereafter, the exposed substrate is subjected to various steps such as a developing step, an etching step, and a reticle peeling step, whereby a predetermined pattern is formed on the substrate, and the process proceeds to the next color filter forming step 402.

Next, in the color filter forming step 402, three colors corresponding to R (Red), G (Green), and B (Blue)
Many sets of dots are arranged in a matrix,
Alternatively, a color filter in which a plurality of sets of three stripe filters of R, G, and B are arranged in the horizontal scanning line direction is formed. Then, after the color filter forming step 402, a cell assembling step 403 is performed. In the cell assembly step 403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern formation step 401, the color filter obtained in the color filter formation step 402, and the like. In the cell assembling step 403, for example, a liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern forming step 401 and the color filter obtained in the color filter forming step 402, and a liquid crystal panel (liquid crystal cell) is formed. ) To manufacture.

Thereafter, in a module assembling step 404, components such as an electric circuit and a backlight for performing a display operation of the assembled liquid crystal panel (liquid crystal cell) are attached to complete a liquid crystal display element. According to the above-described method for manufacturing a liquid crystal display device, a liquid crystal display device having an extremely fine circuit pattern can be obtained with high throughput.

In the above embodiment, when the wavelength is 15
Although an F ₂ laser that supplies 7.6 nm light is used,
Without being limited to this, for example, a KrF excimer laser that supplies light having a wavelength of 248 nm, an ArF excimer laser that supplies light having a wavelength of 193 nm, an Ar ₂ laser that supplies light having a wavelength of 126 nm, or the like can be used.

In the above embodiment, the present invention is applied to the projection optical system of the scanning exposure type exposure apparatus. However, the present invention is not limited to this. The present invention can be applied to a general image forming optical system other than the projection optical system of the exposure apparatus.

[0086]

As described above, the catadioptric optical system of the present invention has a simple configuration in which the distance between the object plane and the image plane is small and the number of lenses is small, so that the light quantity loss on the lens plane can be reduced. A suppressed high-performance and high-precision optical system can be realized. For example, a high resolution of 0.1 μm or less can be achieved by using light in a vacuum ultraviolet wavelength region having a wavelength of 180 nm or less. Further, for example, it is possible to secure a position where an effective aperture stop is to be installed, to secure a sufficiently long working distance, and to suppress the enlargement of the concave reflecting mirror to reduce the size of the optical system.

Further, by applying the catadioptric optical system of the present invention to a projection optical system of an exposure apparatus, for example, a projection exposure system having a high resolution of 0.1 μm or less can be obtained by using exposure light having a wavelength of 180 nm or less. It can be performed. In addition, a high-precision micro device is manufactured by performing good projection exposure at a high resolution of, for example, 0.1 μm or less using an exposure apparatus equipped with the catadioptric optical system of the present invention as a projection optical system. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a basic configuration of a catadioptric optical system of the present invention.

FIG. 2 is a diagram schematically illustrating an overall configuration of an exposure apparatus including a catadioptric optical system according to each embodiment of the present invention as a projection optical system.

FIG. 3 is a diagram showing a positional relationship between a rectangular exposure area (ie, an effective exposure area) formed on a wafer and a reference optical axis.

FIG. 4 is a diagram showing a lens configuration of a catadioptric optical system (projection optical system PL) according to the first example.

FIG. 5 is a diagram illustrating lateral aberration of the catadioptric optical system according to the first example.

FIG. 6 is a diagram illustrating lateral aberration of the catadioptric optical system according to the first example.

FIG. 7 is a diagram illustrating a lens configuration of a catadioptric optical system (projection optical system PL) according to a second example.

FIG. 8 is a diagram illustrating lateral aberration of the catadioptric optical system according to the second example.

FIG. 9 is a diagram illustrating lateral aberration of the catadioptric optical system according to the second example.

FIG. 10 is a flowchart of a method for obtaining a semiconductor device as a micro device.

FIG. 11 is a flowchart of a method for obtaining a liquid crystal display element as a micro device.

[Explanation of symbols]

 G1 first imaging optical system G2 second imaging optical system G3 third imaging optical system CM concave reflecting mirror M plane reflecting mirror L each lens 100 laser light source IL illumination optical system R reticle RS reticle stage PL projection optical system W wafer WS wafer stage

Claims (9)

[Claims] 1. A first imaging device having at least one concave reflecting mirror and at least one planar reflecting mirror for forming a first intermediate image of the first surface based on light from the first surface. An optical system, having at least one concave reflecting mirror and at least one planar reflecting mirror, for forming a second intermediate image of the first surface based on light passing through the first imaging optical system. A second imaging optical system; and a refraction-type third imaging optical system for forming a final image of the first surface on the second surface based on light passing through the second imaging optical system. A catadioptric optical system, comprising: 2. All the optical members except for the plane reflecting mirror of the first imaging optical system and all the optical members except for the plane reflecting mirror of the second imaging optical system are a single linearly extending single member. All the optical members of the third imaging optical system are arranged along a first optical axis, and are arranged along a single second optical axis extending linearly so as to be orthogonal to the first optical axis. The light from the first surface forms the first intermediate image via one planar reflecting mirror and one concave reflecting mirror in the first imaging optical system in sequence, and the first imaging The light passing through an optical system forms the second intermediate image sequentially through one plane reflecting mirror and one concave reflecting mirror of the second imaging optical system. Catadioptric optics. 3. The catadioptric optical system according to claim 2, wherein the first imaging optical system has at least one negative lens component disposed immediately before the concave reflecting mirror. 4. The catadioptric optical system according to claim 2, wherein said second imaging optical system has at least one negative lens component disposed immediately before said concave reflecting mirror. 5. A field lens is disposed in an optical path between the first image forming optical system and the second image forming optical system. 3. The catadioptric optical system according to item 1. 6. The optical system according to claim 1, wherein at least one of the field lenses disposed in an optical path between the first imaging optical system and the second imaging optical system is provided in the first imaging optical system. 6. The light-emitting device according to claim 5, wherein the light-emitting device has a partially cut-out shape so as to allow only light reflected from the concave reflecting mirror to pass therethrough without passing light incident on the concave reflecting mirror.
3. The catadioptric optical system according to item 1. 7. At least one of the field lenses disposed in an optical path between the first imaging optical system and the second imaging optical system, the at least one lens of the first imaging optical system 7. The catadioptric optical system according to claim 5, wherein said catadioptric optical system is formed so as to pass both light incident on said concave reflecting mirror and light reflected from said concave reflecting mirror. 8. The apparatus according to claim 1, wherein a field lens is disposed in an optical path between the second imaging optical system and the third imaging optical system. 3. The catadioptric optical system according to item 1. 9. An illumination system for illuminating a mask set on the first surface, and an illumination system for forming an image of a pattern formed on the mask on a photosensitive substrate set on the second surface. An exposure apparatus comprising the catadioptric optical system according to any one of claims 1 to 8.