JPH11295605A - Cylindrical optical reflection and refraction system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical reflection and refraction system in which the control of respective optical components is facilitated in spite of having plural optical axes. SOLUTION: Concerning this optical reflection and refraction system, a concave mirror Mc is arranged on one end side of a main optical axis z1 , a second plane P2 is provided on the other end side, a reflection plane M is arranged between the concave mirror Mc and the second plane P2 , a first optical image forming system A is arranged between the reflection plane M and the concave mirror Mc , a second optical image forming system B is arranged between the reflection plane M and the second plane P2 , a first plane P1 is provided on a sub optical axis z2 while defining the direction of bending the main optical axis z1 of the first optical image forming system A on the reflection plane M as the sub optical axis z2 , an object RA is arranged or an image WA of the object is formed in any one area on the first plane P1 bisected by a crossing line Q1 between a plane orthogonal with the main optical axis z1 while including the sub optical axis z1 and the first plane P1 , the image WA is formed or the object RA is arranged in any one area on the second plane P2 bisected by a crossing line Q2 between a plane orthogonal with the sub optical axis z2 while including the main optical axis z1 and the second plane P2 , and an intermediate image C of the object RA is formed near the reflection plane M.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical system of a reduction exposure apparatus such as a stepper mainly used for manufacturing a semiconductor, and more particularly, to a submicron unit in an ultraviolet wavelength region by using a catadioptric optical system for the optical system. The present invention relates to a catadioptric reduction optical system of about 1/4 × having a resolution.

[0002]

2. Description of the Related Art In recent years, semiconductor circuit patterns have become increasingly finer, and an exposure apparatus for printing such patterns has been required to have a higher resolution. In order to satisfy this requirement, the wavelength of the light source is shortened and N
A (numerical aperture of the optical system) must be increased. However, as the wavelength becomes shorter, optical glass that can withstand practical use is limited due to light absorption. When the wavelength is 180 nm or less, the only glass material that can be used practically is fluorite. In such a case, if the projection optical system is constituted only by the refraction optical system, the chromatic aberration cannot be corrected at all. Therefore, it is very difficult to produce a projection optical system having the required resolving power and composed of only a refractive optical system.

Therefore, various techniques have been proposed for forming a reduction projection optical system by using a so-called catadioptric optical system in which a reflecting system and a refracting system made of optical glass usable for a used wavelength are combined. Among them, there have been proposed various types in which an intermediate image is formed one or more times in the middle of an optical system. -25170, JP-A-63-16331
9, JP-A-4-234722, USP-4,779,9
66, for example.

Among the above prior arts, those using only one concave mirror are disclosed in Japanese Patent Application Laid-Open No. 4-234722 and US Pat.
P-4, 779, 966. In these optical systems, a reciprocating optical system constituted by a concave mirror employs only a concave lens, and does not use an optical system having a convex power. As a result, the light beam spreads and enters the concave mirror, so that the diameter of the concave mirror tends to increase. In particular, the reciprocating optical system disclosed in Japanese Patent Application Laid-Open No. Hei 4-234722 is a completely symmetrical type. Since an optical system is employed, it is difficult to obtain a working distance near the second surface, and a half prism must be used. In the optical system disclosed in US Pat. No. 4,779,966, a mirror is used in a secondary imaging optical system behind the intermediate image. Therefore, in order to ensure the required brightness of the optical system, the light beam spreads and enters the concave mirror, making it difficult to reduce the size of the mirror.

In the case of using a plurality of mirrors, there is a possibility that the number of lenses in the refractive optical system can be reduced. However, these types have the following problems. That is, recently, a phase shift method for shifting the phase of a selected portion of a mask has been devised in order to increase the resolution while increasing the depth of focus.
The ratio σ between A and the NA of the imaging optical system is made variable. At this time, an aperture stop can be installed in the illumination optical system. However, when the above-described catadioptric optical system is used as an objective lens, an effective stop installation portion cannot be taken anywhere.

Further, in a catadioptric optical system of the type employing the reciprocating optical system having such an arrangement on the first surface side on the reduction side,
Since the distance to the wafer after reflection by the reflection mirror cannot be taken long due to the reduction magnification, the number of objective lenses inserted into this optical path cannot be so large, and the brightness of the obtained optical system is limited. It had to be something. Even if an optical system with a high NA can be realized, since many optical members are inserted into a limited length, the optical system cannot take a long distance between the wafer and the end surface of the objective lens, that is, a so-called working distance WD. I was Further, in such a conventional catadioptric system, it is necessary to bend the optical path halfway, and it is difficult to adjust the optical path bending member, so that a highly accurate system cannot be realized.

Accordingly, the present applicant forms an intermediate image on the second surface by the first image forming optical system, forms a re-image of the intermediate image on the first surface by the second image forming optical system, A reflecting surface for guiding a light beam from the imaging optical system to the second imaging optical system, and a lens group through which the first imaging optical system transmits a concave mirror and both incident light and reflected light to the concave mirror A two-time imaging optical system formed to have a reciprocating optical system consisting of This 2
According to the rotational imaging optical system, the diameter of the concave mirror can be reduced, and the ratio σ of the NA of the illumination optical system and the NA of the imaging optical system for the phase shift method can be made variable. It is possible to realize an optical system that can take an effective diaphragm installation part and can take a long distance between the wafer and the end face of the objective lens, that is, a so-called working distance WD, while sufficiently maintaining the brightness of the optical system. it can. Further, the adjustment work of the optical path bending member is relatively easy, and a highly accurate optical system is realized.

[0008]

SUMMARY OF THE INVENTION As described above, 2
Although the imaging optical system has many excellent points, these optical systems
In order to separate the light beam entering the concave mirror from the light beam emerging from the concave mirror, a method such as using a light beam splitting prism, a perforated mirror, or using an off-axis light beam and separating it with a reflecting mirror is required It becomes. In either method, it is necessary to bend the optical axis of the optical system, for example, at a right angle using a reflective surface. Although this is much easier than conventional catadioptric systems,
As compared with the conventional optical system using only the refraction system, the adjustment mechanism of the optical system also has a large burden. That is,
Most optical systems, including refractive optical systems, are configured on a single linear optical axis, so if the mounting method of the lens is shifted or tilted with respect to the optical axis, By rotating the lens about this linear optical axis, the reflected light from the lens and the like can be examined and improved.

However, if the optical axis is bent, such an adjusting means cannot be adopted, and the adjusting method becomes difficult. Further, in an optical system composed of one optical axis, a tilt (tilt) and a positional shift (shift) from the optical axis.
There are only two types of adjustment items. However, in an optical system having a plurality of optical axes, a lens deviated from one optical axis serving as a reference among them has positional coordinates X, Y, Z, and X, Y, Z axes in a three-dimensional space. Rotation angle α,
Six degrees of freedom, β and γ, occur, and the number of items that need to be adjusted greatly increases. Therefore, adjustment time also increases,
In addition to the increase in cost, it is often difficult to achieve a design performance with a precision optical system. As described above, how to eliminate such troublesome adjustments has been an important issue for some time. An object of the present invention is to provide a catadioptric optical system which has a plurality of optical axes but allows easy adjustment of each optical component.

[0010]

According to the present invention, in order to eliminate the difficult adjustment of each optical component, an optical system for forming an image is provided with one optical system.
It is configured to be the optical axis of a book. That is, according to the present invention, a concave mirror is arranged at one end of the main optical axis, a second surface orthogonal to the main optical axis is provided at the other end of the main optical axis, and a reflecting surface is provided between the concave mirror and the second surface. Are arranged, and a plurality of lenses forming a first imaging optical system together with the concave mirror are arranged between the reflecting surface and the concave mirror, and a second image is formed between the reflecting surface and the second surface. A plurality of lenses forming an optical system are arranged, and a direction in which a main optical axis of the first imaging optical system is bent by the reflection surface is defined as a sub optical axis, and the sub optical axis is orthogonal to the sub optical axis. A first surface is provided, and an object is arranged in one of the regions of the first surface that is bisected by an intersection line between the plane including the sub optical axis and orthogonal to the main optical axis and the first surface, or Any one of the second surfaces that forms an image of the object and is bisected by an intersection of a plane including the main optical axis and orthogonal to the sub optical axis and the second surface In the region, to form the image or placing the object, a straight barrel type catadioptric system, characterized in that an intermediate image of the object formed in the vicinity of the reflecting surface.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1A shows an embodiment of a straight cylindrical catadioptric optical system according to the present invention, and FIGS.
FIG. 1 (A) shows a view taken along line BB and line CC, respectively. In this embodiment, an optical system according to the present invention is applied to a projection optical system of a scanning exposure apparatus. As shown in FIG. 1, a concave mirror M _C is arranged on the upper end side of the main optical axis z ₁ ,
The lower end of the main optical axis z _1, the second surface perpendicular to the main optical axis z ₁ P ₂
Is provided. Main optical axis z between concave mirror M _C and second surface P _{2
In 1} , a plurality of lenses and a reflection surface M are arranged. In the example shown in FIG. 1, the reflecting surface M is formed by a plane mirror, but the reflecting surface may be formed by a prism.

A first imaging optical system A is constituted by a lens arranged in the optical path from the reflecting surface M to the concave mirror M _C and the concave mirror M _C, and is provided in the optical path from the reflecting surface M to the second surface P _2. The second imaging optical system B is configured by the disposed lenses. A first imaging optical system A second imaging optical system B, and are arranged the same optical axis, that is, on the main optical axis z _1. The first imaging optical system A is a reciprocating optical system. Reflective surface M
It is arranged to bend the main optical axis z ₁ of the first imaging optical system A, and the folded direction Fukuhikarijiku z _2. The Fukuhikarijiku z _2, the first side P ₁ perpendicular to the Fukuhikarijiku z ₂ is provided.

The sub optical axis z_TwoAnd the main optical axis z₁Plane orthogonal to
And the first surface P₁Intersecting line with Q₁Then, as shown in FIG.
As you can see, intersection Q₁First surface P divided by₁Below
Object, that is, the illumination area RA of the reticle R
Be placed. Also, the main optical axis z ₁And the auxiliary optical axis z_TwoOrthogonal to
Plane and the second plane P_TwoIntersecting line with Q_TwoThen, FIG. 1
As shown in FIG._TwoSecond divided by
Plane P_TwoAn image of reticle R is formed in the left area of
Accordingly, the exposure area WA of the wafer W is formed at that position.
You.

The luminous flux emitted from the reticle R in the illumination area RA has its traveling direction bent by the reflection surface M and enters the first imaging optical system A. The light beam that has entered the first imaging optical system A is reflected by the concave mirror M _C and travels backward on the outward path, forming an intermediate image C near the reflection surface M, that is, the light beam diameter is minimized.
The light beam having the minimum light beam diameter passes by the reflection surface C, passes through the second imaging optical system B, and forms a re-image of the intermediate image C on the exposure area WA of the wafer W. In this way, a portion of the pattern of reticle R within illumination area RA is transferred to exposure area WA on wafer W. On the other hand, reticle R
Scans moved in a direction parallel to the main optical axis z _1, the wafer W in the direction parallel to the Fukuhikarijiku z _2, for scanning movement in synchronization with the scanning of the reticle R. As a result, the entire pattern of the reticle R is transferred onto the wafer W.

[0015] In the example shown in FIG. 1, but are arranged illuminated area RA of the reticle R to the lower region of the first surface P ₁ of the line of intersection Q ₁ is 2 minutes, the line of intersection Q ₁ The illumination area RA can also be arranged in an area above the first surface P ₁ divided into _two , and in this case, the wafer W is placed in a region on the right side of the second surface P ₂ divided by the intersection line Q ₂ . Exposure area WA
Is formed. However the light beam toward the reflecting surface M from the illumination region RA, since spreads with distance from the illuminated area RA, according to this configuration, the area of the reflecting surface M is increased, may interfere occurs and the reflected light from the concave mirror M _C. Thus, as shown in FIG. 1, it is preferable to arrange the illumination region RA in the lower region of the first surface P _1.

[0016] Thus, in the present invention, a light beam incident on the concave mirror M _C, in order to separate the light flux reflected from the concave mirror M _C, although a reflective surface M, the reflective surface M is imaged optical system a, is arranged outside the B, the optical axis of the concave mirror M _C and a plurality of lenses constituting the imaging optical system a, B has become one, i.e. only the main optical axis z _1. Therefore, it is possible to examine the entire optical system in the optical axis z ₁ center, it is possible to detect the inclination and displacement of the inner lens.

The reflecting surface M arranged outside the imaging optical systems A and B may be arranged after the adjustment of the imaging optical systems A and B. The adjustment of the reflective surface M, relative to the optical axis z _1,
Only two types of adjustment items, ie, position (shift) and angle (tilt) are required. Further, in this case, the shift and the angle error of the reflection surface M are not directly related to the image forming characteristics, but merely become the position shift or the inclination of the image. Therefore, it is very advantageous to secure the image forming performance. It becomes. That is, if the bending of the optical axes z ₁ and z ₂ is performed inside the optical systems A and B, it becomes very difficult to adjust the reflection surface M. However, the reflection surface M is arranged outside the optical systems A and B. This greatly facilitates adjustment of the entire optical system. However, when such a reflection surface M is arranged outside the optical system, the following is required for aberration correction and arrangement of the optical system.

First, in the present invention, only the optical path bending member constituting the reflection surface M is included in the portion from the object (reticle R) to the reflection surface M. Therefore, the size of the reflection surface M is basically determined by the distance D from the object R to the reflection surface M and the NA (numerical aperture) on the object side. If the distance D is long, but also increases the size of the inevitably reflecting surface M, at this time, resulting in a possibility the light beam and the reflecting surface M interferes toward the second imaging optical system B is reflected by the concave mirror M _C Is not preferred. When the reflecting surface M is configured by a prism,
When the distance D increases and the reflection surface M increases, the size of the prism itself also increases. Therefore,
The shorter the distance D from the object to the reflection surface, the better.

However, if it is too short, reticle R
However, the reticle R cannot be scanned because of interference with the optical path bending member and other optical systems constituting the reflection surface M. In order to avoid this, the value according to the following equation was found to be appropriate. 1 <| D / H | < 3 ‥‥ (1) where, H is the maximum height from the secondary optical axis z ₂ of the illumination region RA, i.e. the radius of the reticle field RF. Above the upper limit of condition (1), the separation of the return of the light beam reflected by the forward light beam and the concave mirror M _C toward the concave mirror M _C becomes difficult, and the lower limit, it becomes difficult to scan the reticle R Therefore, neither is preferred.

The luminous flux from the reticle R to the reflecting surface M spreads as the distance from the reticle R increases, but after the light is reflected by the reflecting surface M, it is incident on the first lens surface of the first imaging optical system A. Spread between. Therefore, in order to reduce the effective diameter of the first imaging optical system A, the distance D ₂ of the main optical axis z ₁ from the reflective surface M to the first lens surface of the first imaging optical system A, the following It is preferable to satisfy the formula. | D ₂ /H|<2.5 (2) If the upper limit of conditional expression (2) is exceeded, the effective diameter of the first imaging optical system A becomes undesirably large.

Further, since there is no optical system in a portion from the object (reticle R) to the reflecting surface, it becomes difficult to correct distortion, and the second imaging optical system B almost needs to correct distortion. It is advantageous to configure the intermediate image C so as to be in the vicinity of the reflection surface M from the viewpoint of light flux separation. In particular, the luminous flux from the reticle R to the reflection surface M is the reticle R
As the distance from the reticle R increases, the reflection surface M needs to be formed larger. Therefore, it is preferable that the position of the intermediate image C where the light beam diameter is minimum is formed near the upper end of the reflection surface M.

Further, since the two-time imaging optical systems A and B are formed on _one optical axis z _{1 as described} above, the length L of the optical system itself becomes considerably long. Must be shortened in order to shorten the length of the first imaging optical system A. For this purpose, the first imaging optical system A includes a concave mirror M
From _C sequentially, at least, it is preferred to have a negative meniscus lens L _1, and a positive lens L _4. Further, the concave mirror M _C
In order from the side, at least, a negative meniscus lens L _1,
A positive lens L _2, a negative lens L _3, preferably has a positive lens L _4. With such an arrangement, the length of the first imaging optical system A can be reduced. However, if it is too short, the aberration of the optical system cannot be completely corrected,
It is preferable that the following conditional expression is satisfied, since the optical performance is deteriorated. 20 <| L / H | <30 (3) Exceeding the upper limit of conditional expression (3) leads to an excessively large system, while exceeding the lower limit causes deterioration of optical performance.

In the second image forming optical system B, it is preferable to arrange the positive lens L ₅ in order from the intermediate image C.
Accordingly, it is possible to prevent the luminous flux from diverging, and to prevent the optical system from increasing in diameter. Further then, in order to correct distortion, it is preferable to dispose the negative lens L _6. Also in the second imaging optical system B is the aperture stop AS is disposed in the vicinity of the aperture stop AS, in order to correct the spherical aberration, that a positive lens L _7, placing the meniscus lens L ₈ preferable. In addition, near the image plane, a large NA
To achieve, it is preferable to dispose the positive lens L ₉ having a convex surface facing the reflective surface M side. In order to correct spherical aberration near the stop, an aspherical surface is adopted.
It is preferable to employ an aspheric surface for distortion correction in the nearby positive lens.

As described above, in a place suitable for the purpose,
By arranging a lens for that purpose, almost all aberrations can be corrected simultaneously. As a result, it is possible to finally obtain a dramatically small optical system with a great reduction in the number of lenses, and finally use one optical axis z ₁ while using the smallest aspherical element. It can be configured. In the above embodiment, the illumination area RA of the reticle R as an object is arranged on the first plane P ₁ orthogonal to the sub optical axis z _2, and is arranged on the second plane P ₂ orthogonal to the main optical axis z _1. was formed an image of an object, on the contrary, the object on the second surface P ₂ are arranged, it can be formed an image on the first surface P _1. Further, there is a difficulty somewhat Deformation and the optical axis adjustment of the lens, between the first surface P ₁ and the reflecting surface M, a small number of lenses, for example, a positive lens is arranged, including the small number of lenses By using the first imaging optical system A, the size of the entire system can be reduced.

[0025]

Embodiments of the present invention will be described below. FIGS. 2, 5 and 8 show first, second and third embodiments of the straight cylindrical catadioptric optical system according to the present invention. This is applied to a projection optical system. In the projection optical system of the first embodiment shown in FIG. 2, a light beam splitting mirror M is disposed after the reticle R.
The first image forming optical system A includes two light beam separating mirrors M in order from the light beam separating mirror M side.
The positive lenses A ₁ and A ₂ , the meniscus lens A ₃ , the negative meniscus lens A ₄ , the positive lens A ₅ , the negative lens A ₆ , the positive lens A ₇ , and the negative meniscus lens A having a concave surface facing the light beam separating mirror M side _8, and is composed of a reciprocating optical system disposed concave mirror M _C. The second imaging optical system B includes a light beam splitting mirror M
In order from the side, a positive lens B ₁ , a negative lens B ₂ , a positive lens B ₃ , a negative lens B ₄ , a positive lens B ₅ , an aperture stop AS, a meniscus lens B ₆ , three positive lenses B ₇ , B ₈ , B _9, and a negative lens B ₁₀ and the light beam splitting mirror M side positive lens B ₁₁ having a convex surface facing the.

In the projection optical system of the second embodiment shown in FIG.
After the reticle R, a light beam splitting prism P is arranged. The first imaging optical system A includes two positive lenses A ₁ and A ₂ , a meniscus lens A ₃ , and
Negative meniscus lens A ₄ , positive lens A ₅ , negative lens A ₆ ,
Positive lens A _7, and a negative meniscus lens A _8, and the reciprocating optical system disposed concave mirror M _C a concave surface facing the light flux separating prism P side. The second imaging optical system B includes a positive lens B ₁ , a negative lens B ₂ , a positive lens B ₃ , a negative lens B ₄ , a positive lens B ₅ , and an aperture stop A in this order from the light beam splitting prism P side.
S, meniscus lens B ₆ , three positive lenses B ₇ , B ₈ ,
B ₉ , a negative lens B ₁₀ , and a positive lens B ₁₁ having a convex surface facing the light beam splitting prism P side.

In the projection optical system of the third embodiment shown in FIG.
After the reticle R, a light beam splitting mirror M is arranged. The first imaging optical system A includes two positive lenses A ₁ and A ₂ , a meniscus lens A ₃ , and
Negative meniscus lens A ₄ , positive lens A ₅ , negative lens A ₆ ,
Positive lens A _7, the negative lens A _8, the positive lens A _9, and a negative meniscus lens A _10, and a reciprocating optical system disposed concave mirror M _C a concave surface facing the beam splitting mirror M side. The second imaging optical system B includes, in order from the light beam splitting mirror M side, a positive lens B ₁ , a negative lens B ₂ , a positive lens B ₃ , a negative lens B ₄ , a positive lens B ₅ , an aperture stop AS, and a meniscus lens B _6. It comprises three positive lenses B ₇ , B ₈ , B ₉ , a negative lens B ₁₀ , and a positive lens B ₁₁ having a convex surface facing the light beam splitting mirror M side.

The following Tables 1 to 3 respectively show the first to third
The specifications of the embodiment will be described. In [Main Specifications] of each table, [lambda] represents a wavelength used, [beta] represents a projection magnification, NA represents an image-side numerical aperture, and [phi] _max represents a maximum effective diameter of a lens. In [optical member specifications], the first column No is the number of each optical surface from the reticle R side, the second column r is the radius of curvature of each optical surface, and the third column r is the third column r.
Column d shows the interval on the optical axis from each optical surface to the next optical surface, and column 4 shows the number of each optical surface or optical member. In each of the embodiments, the glass material of all the lenses and prisms is fused silica, and the refractive index n of the fused silica at the wavelength used (λ = 193 nm) is n = 1.60333.

The optical surface marked with * in the first column No indicates an aspherical surface, and the second column r for the aspherical surface is the radius of curvature of the vertex. The shape of the aspheric surface is y: height from the optical axis z: distance in the optical axis direction from the tangent plane to the aspherical surface r: radius of curvature of the vertex κ: conical coefficient A, B, C, D: aspherical surface coefficient Data] shows the aspherical coefficients A, B, C, and D. For each aspheric surface, the cone coefficient κ is κ = 0.0.

In each of the embodiments, the exposure area WA of the projection optical system has a rectangular opening of 25 × 6.6 mm. By scanning the wafer W relative to the exposure area WA,
As the entire exposure area on the wafer W, for example, 25 × 3
An area of 3 mm can be exposed. In each of the embodiments, the effective diameter of the lens used is as small as about 屈折 of the refractive spherical optical system normally used in this specification, and the number of lenses used is about half that of the refractive spherical optical system. .

[0031]

[Table 1] [Main specifications] λ = 193nm (ArF excimer laser) β = 1/4 NA = 0.7 H = 70.36mm D = 160.1mm D 2 = 10.0mm L = 1534mm φ max = 220mm exposure area: 25 × 6.6 mm (rectangle) | D / H | = 2.28 | D ₂ /H|=0.14 | L / H | = 21.8 [Optical member specifications] Nor d 0 ∞ 160.100000 R 1 ∞ -10.000000 M 2 -1788.71639 -29.000000 A ₁ L ₄ 3 419.30758 -0.097200 4 -250.61403 -33.000000 A ₂ L ₄ 5 -6136.00339 -138.422781 6 244.13129 -27.000000 A ₃ 7 236.86664 -0.200000 8 -441.03076 -17.000000 A ₄ 9 -130.33902 -13.232045 10 -391.22278-1 _{5 11 -4917.23961 -18.600000 12 245.26287 -17.000000 A} 6 L 3 13 -1615.89591 -1.843450 14 -241.95870 -25.000000 A 7 L 2 15 14452.00549 -62.163582 16 145.04293 -18.000000 A 8 L 1 17 347.29355 -19.661891 18 248.23614 19.661891 M C 19 347.29355 18.000000 A ₈ 20 145.04293 62.163582 21 14452.00549 25.000000 A ₇ 22 -241.95870 1.843450 23 _{-1615.89591 17.000000 A 6 24 245.26287 18.600000 25} -4917.23957 19.000000 A 5 26 -391.22278 13.232045 27 -130.33902 17.000000 A 4 28 -441.03076 0.200000 29 236.86664 27.000000 A 3 30 244.13129 138.422781 31 -6136.00339 33.000000 A 2 32 -250.61403 0.097200 33 419.30758 29.000000 A _{1 34 -1788.71639 291.668555 * 35 8637.19547 32.000000} B 1 L 5 36 -278.32248 120.501173 37 -284.21267 21.000000 B 2 L 6 38 380.00000 7.640330 39 977.55302 45.000000 B 3 40 -289.72006 188.674290 41 -782.07989 24.000000 B 4 42 275.00000 2.199165 43 311.81819 56.000000 B _{5 L 7 44 -375.13741 11.588720 45 -} 10.000000 AS 46 196.65458 25.000000 B 6 L 8 * 47 180.51391 10.087193 48 253.87648 40.000000 B 7 49 8600.70931 2.214198 50 157.11074 48.000000 B 8 51 1256.41165 55.106219 52 113.93043 33.000000 B 9 53 886.99217 8.485632 54 -18818.69933 12.000000 B ₁₀ 55 207.40711 0.100000 56 109.31199 45.000000 B ₁₁ L ₉ 57 14193.19706 6.000000 58 ∞ W [Aspherical data] No = 35 A = -0.123690 × 10 -7 B = 0.129803 × 10 -13 C = -0.212874 × 10 -18 D = -0.943396 × 10 -22 No = 47 A = 0.136582 × 10 -7 B = 0.193143 × 10 - ¹² C = 0.306903 × 10 ^-17 D = 0.487055 × 10 ^-22

[0032]

[Main specifications] λ = 193 nm (ArF excimer laser) β = 1/4 NA = 0.75 H = 70.36 mm D = 190.1 mm D ₂ = 20.0 mm L = 1693 mm φ _max = 234 mm Exposure area: 25 × 6.6 mm (rectangle) | D / H | = 2.70 | D ₂ /H|=0.28 | L / H | = 24.1 [Specifications of optical members] Nor d 0 ∞ 85.100000 R 1 ∞ 105.000000 P 2 -1 -15.000000 PM 3 ∞ -5.000000 4 -1788.71639 -29.000000 A ₁ L ₄ 5 419.30758 -0.097200 6 -310.64095 -33.000000 A ₂ L ₄ 7 -2807.83665 -152.548704 8 287.16506 -27.000000 A ₃ 9 255.48240 -0.200000 10 -367.14810 -17.000000 A ₄ 11- _{141.19742 -14.911131 12 -398.90704 -19.000000 A 5 13} -608.94218 -18.600000 14 232.39912 -17.000000 A 6 L 3 15 1698.12647 -15.952383 16 -327.74499 -25.000000 A 7 L 2 17 6237.96729 -61.535574 18 166.40938 -18.000000 A 8 L 1 19 395.75289 _{-55.022688 20 301.44131 55.022688 M C 21 395.75289} 18.000000 A 8 22 166.40938 61.535574 23 6237.96729 2 _{5.000000 A 7 24 -327.74499 15.952383 25 1698.12647} 17.000000 A 6 26 232.39912 18.600000 27 -608.94218 19.000000 A 5 28 -398.90704 14.911131 29 -141.19742 17.000000 A 4 30 -367.14810 0.200000 31 255.48240 27.000000 A 3 32 287.16506 152.548704 33 -2807.83665 33.000000 A 2 34 -310.64095 0.097200 35 419.30758 29.000000 A ₁ 36 -1788.71639 303.707152 * 37 -20585.21661 32.000000 B ₁ L ₅ 38 -292.08517 141.774594 39 -331.57665 21.000000 B ₂ L ₆ 40 380.00000 6.23928641 61
5.003205 45.000000 B ₃ 42 -350.96686 195.254624 43 -860.60392 24.000000 B ₄ 44 277.65121 2.310597 45 304.34780 56.000000 B ₅ L ₇ 46 -515.18847 46.552459 47-18.195879 AS AS 48 226.73175 25.000000 B ₆ L ₈ * 49 231.03852.71 11.787 B ₇ 51 -1674.49168 4.412329 52 169.98274 48.000000 B ₈ 53 1665.64536 63.416012 54 124.88297 33.000000 B ₉ 55 711.33878 8.237993 56 2405.86425 12.000000 B ₁₀ 57 164.17050 0.100000 58 117.66988 45.000000 B ₁₁ L ₉ 59 1593.84226 6.000000 60 ∞ 37 A = -0.888458 × 10 ^-8 B = 0.557250 × 10 ^-14 C = -0.314040 × 10 ^-18 D = -0.462916 × 10 ^-22 No = 49 A = 0.168833 × 10 ^-7 B = 0.172714 × 10 ^-12 C = 0.225018 × 10 ^-17 D = 0.368469 × 10 ^-22

[0033]

[Main specifications] λ = 193 nm (ArF excimer laser) β = 1/4 NA = 0.8 H = 70.36 mm D = 176.0 mm D ₂ = 20.0 mm L = 1731 mm φ _max = 246 mm Exposure area: 25 × 6.6 mm (rectangle) | D / H | = 2.50 | D ₂ /H|=0.28 | L / H | = 24.6 [Optical member specifications] Nor d 0 ∞ 176.024677 R 1 ∞ -20.000000 M 2 -1788.71639 -33.000000 _{A 1 L 4 3 419.30758 -0.097200 4} -268.74569 -40.000000 A 2 L 4 5 -3732.51475 -132.767922 6 239.37693 -27.000000 A 3 7 244.82836 -0.216094 8 -2548.31604 -25.000000 A 4 9 -143.32698 -8.449526 10 -204.90390 -45.000000 A _{5 11 -272.57153 -0.100000 12 327.21563 -17.000000 A} 6 13 -181.11096 -5.571460 14 -266.20425 -25.000000 A 7 15 -1015.69653 -18.600000 16 194.20523 -17.000000 A 8 L 3 17 997.00876 -6.595016 18 -338.50796 -25.000000 A 9 L 2 _{19 -3625.68572 -29.822032 20 222.83295 -18.000000 A 10} L 1 21 455.81520 -42.796334 22 295.50430 42.796334 M C _{23 455.81520 18.000000 A 10 24 222.83295 29.822032} 25 -3625.68572 25.000000 A 9 26 -338.50796 6.595016 27 997.00876 17.000000 A 8 28 194.20523 18.600000 29 -1015.69652 25.000000 A 7 30 -266.20425 5.571460 31 -181.11096 17.000000 A 6 32 327.21563 0.100000 33 272.57153 45.000000 A 5 _{34 -204.90390 8.449526 35 -143.32698 25.000000 A 4} 36 -2458.31604 0.216094 37 244.82836 27.000000 A 3 38 239.37693 132.767922 39 -3732.51475 40.000000 A 2 40 -268.74569 0.097200 41 419.30758 33.000000 A 1 42 -1788.71639 322.860627 * 43 1988.13960 40.000000 B 1 L 5 44 _{-346.17707 118.096619 45 -314.01518 21.000000 B 2 L} 6 46 380.00000 7.483728 47 692.44628 45.000000 B 3 48 -337.77571 215.989100 49 -792.05453 24.000000 B 4 50 285.31369 2.593128 51 316.36067 56.000000 B 5 L 7 52 -463.77046 38.289875 53 - 11.964033 AS 54 233.30662 25.000000 B ₆ L ₈ * 55 234.22897 13.010023 56 255.52550 45.000000 B ₇ 57 -2621.18382 12.423981 58 181.15092 55.000000 B ₈ 59 3385.6644 1 57.958719 60 120.24350 33.000000 B ₉ 61 683.24154 5.786488 62 1209.78340 12.000000 B ₁₀ 63 174.98798 0.101872 64 125.78514 45.000000 B ₁₁ L ₉ 65 1885.85548 6.000000 66 Ｗ W [Aspherical data] No = 43 A = -0.619385 × 10 ^-8 B = 0.1817 × 10 ^-13 C = -0.197420 × 10 ^-18 D = -0.295727 × 10 ^-22 No = 55 A = 0.174263 × 10 ^-7 B = 0.204171 × 10 ^-12 C = 0.268111 × 10 ^-17 D = 0.477853 × 10 ^{− twenty two}

FIG. 3 shows the spherical aberration, astigmatism and distortion of the first embodiment, and FIG. 4 shows the lateral aberration of the first embodiment.
Similarly, FIGS. 6 and 7 show various aberrations of the second embodiment, and FIGS. 9 and 10 show various aberrations of the third embodiment. In each aberration diagram, NA represents the image-side numerical aperture, and Y represents the image height. In the astigmatism diagram, a dotted line M represents a meridional image plane, and a solid line S represents a sagittal image plane. As is clear from each figure, 193n
It can be seen that, at a single wavelength of m, each of the examples has excellent performance that is satisfactorily corrected to a state close to almost no aberration.

[0035] In the first embodiment and the third embodiment uses the reflective surface M to separate the reflected light beam from the light beam and the concave mirror M _C toward the concave mirror M _C, of the reflective surface M the shape may be a perforated reflecting mirror for passing only the light beam reflected from the concave mirror M _C. Further, by combining the polarization beam splitter and a quarter-wave plate, the polarized light incident from the reticle R is reflected, polarized light incident from the concave mirror M _C may be configured to transmit.

[0036]

As described above, according to the present invention, the optical system constituting the image forming portion is arranged on one optical axis, and the reflection surface for separating the light beam is arranged outside the image forming optical system. ing. Therefore, the entire optical system can be examined at the center of the optical axis, and the inclination and displacement of each internal lens can be detected. That is, if the bending of the optical axis is performed inside the optical system, the adjustment of the optical system becomes very difficult. However, in the present invention, since the reflecting surface for bending the optical path is arranged outside the optical system, Adjustment becomes very easy.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is an optical path diagram of a projection optical system according to a first embodiment.

FIG. 3 is a diagram illustrating spherical aberration, astigmatism, and distortion of the first embodiment.

FIG. 4 is a lateral aberration diagram of the first example.

FIG. 5 is an optical path diagram of a projection optical system according to a second embodiment.

FIG. 6 is a diagram of spherical aberration, astigmatism, and distortion of the second embodiment.

FIG. 7 is a lateral aberration diagram of the second embodiment.

FIG. 8 is an optical path diagram of a projection optical system according to a third embodiment.

FIG. 9 is a diagram of spherical aberration, astigmatism, and distortion of the third embodiment.

FIG. 10 is a lateral aberration diagram of the third example.

[Explanation of symbols]

z ₁ ... main optical axis z ₂ ... Fukuhikarijiku P ₁ ... first surface P ₂ ... second surface Q _1, Q ₂ ... line of intersection C ... intermediate image M ... reflecting surface M _C ... concave mirror R ... reticle W ... wafer RA: illumination area WA: exposure area A: first imaging optical system B: second imaging optical system

Claims (10)

[Claims] 1. A concave mirror is disposed at one end of a main optical axis, a second surface orthogonal to the main optical axis is provided at the other end of the main optical axis, and a reflecting surface is provided between the concave mirror and the second surface. Are arranged, and a plurality of lenses forming a first imaging optical system together with the concave mirror are arranged between the reflecting surface and the concave mirror, and a second image is formed between the reflecting surface and the second surface. A plurality of lenses forming an optical system are arranged, and a direction in which a main optical axis of the first imaging optical system is bent by the reflection surface is defined as a sub optical axis, and the sub optical axis is orthogonal to the sub optical axis. Providing a first surface, disposing an object in one of the regions of the first surface which is bisected by an intersection line between the plane including the sub optical axis and orthogonal to the main optical axis and the first surface; or Forming an image of the object, any one of the areas of the second surface being bisected by an intersection of a plane including the main optical axis and orthogonal to the sub-optical axis and the second surface; To form the image or the object placed, a straight barrel type catadioptric system, characterized in that an intermediate image of the object formed in the vicinity of the reflecting surface. 2. The method according to claim 2, further comprising: arranging the object on the first surface;
The catadioptric optical system according to claim 1, wherein the image is formed on a surface. 3. The method according to claim 1, wherein the following conditional expression is satisfied:
The straight-tube catadioptric optical system according to claim 1. 1 <| D / H | <3 20 <| L / H | <30 where H is an object placed on the first surface or a shape on the first surface
The maximum height D of the image formed from the sub-optical axis D : Distance on the sub optical axis from the first surface to the reflecting surface L: distance on the main optical axis from the concave mirror to the second surface Wherein said first imaging optical system comprises, in order from the concave mirror side, at least, according to claim 1, 2 or 3, characterized in that it has a negative meniscus lens L _1, and a positive lens L ₄
The straight cylindrical catadioptric optical system as described in the above. During the method according to claim 5 wherein said first imaging optical system and a negative meniscus lens L ₁ and the positive lens L _4, in order from the concave mirror side, by having at least a positive lens L ₂ and the negative lens L ₃ The straight-tube catadioptric optical system according to claim 4, characterized in that: Wherein said second imaging optical system has an aperture stop, in the vicinity of the aperture stop, at least a positive lens L _7, immediately before the second surface, at least on the reflecting surface side claim 1, 2, 3, 4 or 5 straight barrel type catadioptric optical system according to characterized in that it has a positive lens L ₉ with a convex surface. Wherein said second imaging optical system, after the reflecting surface, at least a positive lens L _5, in the vicinity of the aperture stop, and at least the positive lens L ₇ and the meniscus lens L ₈ , claim 6 immediately before the second surface, characterized in that it has a positive lens L ₉ having a convex surface on at least the reflecting side
Item 10. A straight-tube catadioptric optical system according to Item 7. 8. A straight cylindrical catadioptric optical system according to claim 1, wherein the following conditional expression is satisfied. | D ₂ /H|<2.5, where H: the maximum height of the object arranged on the first surface or the image formed on the first surface from the sub optical axis D ₂ : the height from the reflection surface This is the distance on the main optical axis to the first lens surface of the first imaging optical system. 9. The straight cylindrical catadioptric optical system according to claim 1, comprising at least two aspheric surfaces. 10. The straight cylindrical catadioptric optical system according to claim 1, wherein all the lenses are formed of the same glass material.