JP3339592B2 - Catadioptric projection optical system, and exposure method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a projection optical system for equal-size or reduced-size projection of a projection exposure apparatus used for manufacturing, for example, a semiconductor device or a liquid crystal display device in a photolithography process. Regarding a preferred catadioptric projection optical system,
In particular, by using a reflection system as an element of the optical system,
The present invention relates to a catadioptric projection optical system having a submicron resolution in an ultraviolet wavelength region.

[0002]

2. Description of the Related Art When a semiconductor device or a liquid crystal display device is manufactured by a photolithography process, a pattern image of a photomask or a reticle (hereinafter, collectively referred to as a "reticle") is projected through a projection optical system to, for example, 1/5. Substrate (wafer, wafer) coated with photosensitive material (photoresist etc.)
A projection exposure apparatus for exposing on a glass plate or the like is used. As the degree of integration of semiconductor devices etc. improves,
The resolution required for a projection optical system used in a projection exposure apparatus is increasing more and more.

In order to satisfy this requirement, the wavelength of the illumination light must be shortened and the numerical aperture (NA) of the projection optical system must be increased. However, as the wavelength of the illumination light becomes shorter, the types of glass materials that can be practically used due to light absorption are limited. In particular, when the wavelength is 300 nm or less, practically usable glass materials are only synthetic quartz and fluorite. Since the Abbe numbers of the two are not sufficiently different from each other to correct chromatic aberration, when the wavelength becomes 300 nm or less, it is extremely difficult to correct chromatic aberration by constructing the projection optical system using only the refraction system. Further, fluorite has poor refractive index change characteristics due to temperature change, so-called temperature characteristics, and has many problems in lens polishing. Therefore, fluorite cannot be used in many parts. Therefore, it is very difficult to form a projection optical system having a required resolution only by a refraction system.

On the other hand, since the reflection system has no chromatic aberration,
Attempts have been made to construct a projection optical system using only a reflection system. However, in this case, the projection optical system is increased in size and an aspherical reflection surface is required. That is, it is extremely difficult to configure the projection optical system only with the reflection system. Therefore, various techniques have been proposed for configuring a reduction projection optical system by a so-called catadioptric system combining a reflection system and a refraction system. For example, Japanese Patent Application Laid-Open No. 63-163319 proposes a ring field optical system. In this ring field optical system, off-axis light is used so that incident light and reflected light do not interfere with each other, and only the off-axis orbicular zone is exposed.

[0005] As another example, Japanese Patent Publication No.
No. 27116 and JP-A-2-66510, a catadioptric optical system for projecting an image of a reticle collectively using a light beam near an axis by disposing a beam splitter formed of a semi-transparent mirror inside. Has been proposed.

[0006]

Among the conventional techniques described above, the ring field optical system reflects a light beam many times using many mirrors in order to avoid interference between incident light and reflected light. Is required, which makes the entire optical system complicated and makes it difficult to increase the numerical aperture.

Moreover, since the exposure area is narrow and the pattern of the reticle cannot be exposed collectively on, for example, a wafer, the reticle and the wafer are exposed while moving at different speeds according to the reduction magnification of the projection optical system. That is, it was necessary to perform so-called scan exposure. For this reason, the configuration of the mechanism of the projection exposure apparatus becomes complicated, which is disadvantageous in terms of manufacturing cost and exposure accuracy. That is, in the scan exposure method,
It is difficult to expose a superfine pattern onto a wafer with high precision, and the manufacturing cost must be very high.

On the other hand, in a conventional catadioptric optical system that projects an image of a reticle all at once using a light beam near the axis, internal reflection due to light reflected from the wafer surface, or a refraction surface of the optical system after the beam splitter. There is a disadvantage that there is a lot of flare due to internal reflection at the surface. Further, the non-uniformity of the reflection characteristics of the beam splitter due to the change in the incident angle of the light beam, the absorption of light by the reflection film, the change in the phase of light in the reflection film, and the non-uniformity of the reflection film itself deteriorate the imaging characteristics. Therefore, the overall resolving power of the projection optical system is deteriorated, and in particular, the resolving power is not sufficient for the projection optical system of an exposure apparatus for manufacturing a semiconductor. Further, the light use efficiency is 25% to 10% due to the light amount loss due to the beam splitter.
%, Which was not practical.

SUMMARY OF THE INVENTION In view of the above, the present invention employs a reflection system and a refraction system without using a beam splitter formed of a semi-transparent mirror, and exposes only an annular zone using an off-axis light beam. It is an object of the present invention to provide a catadioptric projection optical system having excellent image forming performance, which can adopt a collective exposure method unlike a ring field optical system. Also, the present invention
Exposure method using a catadioptric projection optical system such as
Providing an exposure apparatus equipped with such a catadioptric projection optical system
The purpose is also to do.

[0010]

According to a first catadioptric projection optical system according to the present invention, an image of a pattern on a first surface (1) is placed on a second surface (2), for example, as shown in FIG. An optical system for projecting, a first partial imaging optical system for forming an intermediate image (3) of the pattern on the first surface (1), and an intermediate image (3)
And a second partial imaging optical system for re-imaging the image on the second surface (2), and at least one of the two partial imaging optical systems is arranged with respect to the optical axis. intermediate image thereof first region or the second region while reflecting light of different second regions are arranged obliquely passed through the light <br/> first region and the first region Te The selection optical system M ₁ on which (3) is imaged.
When a concave reflector M ₂ for returning the light beam guided through the selected optical system again to the selected optical system, the first surface (1) or between selected optical system M ₁ of the selected optical system M ₁ The selective optical system and the concave reflecting mirror disposed between the second surface and the second surface ;
Those having both a converging group G ₁ for forming an image on the intermediate image or a second surface.

The optical system shown in FIG. 1 is an example in which the first partial imaging optical system has a concave reflecting mirror M ₂ , whereas the optical system in FIG. 1 has an example in which the second partial imaging optical system has a concave reflecting mirror M ₄ . Optical system. That is, both the optical system of FIG. 1 and the optical system of FIG. 2 belong to the first catadioptric projection optical system of the present invention.

The second catadioptric projection optical system projects an image of a pattern on the first surface (1) onto the second surface (2) as shown in FIG. 3, for example. A first partial imaging optical system for forming an intermediate image (3) of the pattern on the first surface (1), and a second partial imaging optical system for forming an image of the intermediate image (3) on the second surface (2). A first partial imaging optical system disposed at an angle with respect to the optical axis, the second partial imaging optical system passing light of the first region and different from the first region; and selecting optical system M ₁ for reflecting light region, a first converging group guiding a light beam from the pattern on the first surface (1) to the selected optical system M ₁ G ₁
When an intermediate image of the pattern on the first region or the second region thereof selected optical system M ₁ reflects the light beam reflected by the selected optical system M ₁ is converged by the first converging group ( 3) having a first and a concave reflecting mirror M ₂ which forms an, the second partial imaging optical system, again selecting optical system M ₁ a light beam from the intermediate image in the selected optical system M ₁ (3) a second concave reflecting mirror M ₄ back to,
And a second converging group G ₅ for forming again from the reflected light beam at the selected optical system M ₁ is converged by the second concave reflection mirror image of the intermediate image (3) on the second surface (2) Things.

The third catadioptric projection optical system is, for example,
For example, as shown in FIG. 4, the image of the pattern on the first surface (1) is
An optical system for projecting onto the second surface (2), wherein the first surface
Light flux from the pattern on the first surface (1) in order from (1)
Focal length f converging₁ First convergent group G₁ And the first area
A second region that is different from the first region by passing light of the region
The first convergent group G₁ Luminous flux from subsequent optics
First optical system M leading to the system ₁ And the first concave reflecting mirror M_Two To
Including the first selection optical system M₁ First choice by reflecting the luminous flux from
Selective optical system M₁ In its first region or its second region
Focal length f for forming a first intermediate image (3) of the pattern
_Two Second convergent group G_Two And the luminous flux from the first intermediate image (3)
A focus that converges to form a second intermediate image (4) of the pattern;
Point distance f_Three Third convergent group G_Three And the light in the first area
And reflects light in a second region different from the first region.
And a second intermediate in the first region or the second region.
Second selection optical system M on which image (4) is formed_Three And the second concave surface
Reflector M_Four And the light flux from the second intermediate image (4) is
Selective optical system M_Three Focal length f_Four Fourth convergent group G of_Four 
And the second selection optical system M_Three Converges the light flux guided by
To form a third intermediate image of the pattern on the second surface (2)
Focal length f_Five Fifth convergent group G_Five And having
is there.

In this case, one example of the first selection optical system and the second selection optical system respectively have openings (H ₁ , H ₂ ) of predetermined shapes as shown in FIG. Are reflecting mirrors (M ₁ , M ₃ ) on which intermediate images (3, 4) of the respective patterns are formed.

Further, other examples of the first selection optical system and the second selection optical system have, for example, as shown in FIG. 5, reflection portions of a predetermined shape, respectively. These are small reflecting mirrors (M ₁ ′, M ₃ ′) on which intermediate images (3, 4) are formed. Therefore, the optical system of FIG. 4 and the optical system of FIG. 5 are optically equivalent.

In this case, the optical system of FIG. 1 is equivalent to the optical system of FIG. 4 except that the second selection optical system M ₃ to the fifth converging group G ₅ are omitted, and the optical system of FIG. From the optical system of
This is equivalent to omitting the convergent group G ₁ to the first selection optical system M ₁ . Further, the optical system of FIG. 3 is an equivalent to that omitting the third converging group G ₃ from the optical system of FIG. Therefore, the first and second catadioptric projection optical systems according to the present invention are different from the third catadioptric projection optical system according to the present invention, respectively, in that the convergent groups G ₁ -G ₁ .
It can be thought of as omitted any of the elements in the G ₅ and selecting optical system M _1, M _2. By regarding the Petzval sum of the convergent groups G _{1 to} G ₅ thus eliminated as 0, the following conditional expressions (1) to (10) are satisfied with respect to the third catadioptric projection optical system of the present invention. The conditions imposed are also applied to the first and second catadioptric projection optical systems of the present invention, respectively.

That is, when the individual Petzval sums of the _first to fifth convergent groups G ₁ to G ₅ are respectively p ₁ to p ₅ , it is desirable that the following conditions be satisfied. p ₁ + p ₃ + p ₅ > 0 and p ₂ + p ₄ <0 (1)

The first converging group G ₁ and the second converging group G ₂
When the imaging magnification of the first intermediate image (3) is β ₁₂ and the imaging magnification of the entire system is β, it is desirable that the following condition be satisfied. _{0.1 ≦ | β 12 | ≦ 2} (2) The second from the first intermediate image by the third converging group G ₃ (3)
When the magnification of forming the intermediate image (4) is β ₃ , it is desirable that the following condition be satisfied.

0.1 ≦ | β ₃ | ≦ 2 (3)

Further, a fourth converging group G ₄ and a fifth converging group G ₅
When the imaging magnification from the second intermediate image (3) to the third intermediate image (4) is β ₄₅ , it is desirable that the following condition be satisfied. 0.1 ≦ | β ₄₅ | ≦ 2 (4) In the first selection optical system M ₁ , the periphery of the region H ₁ where the intermediate image (3) is formed and the pupil plane of the third converging group G ₃ set in a conjugate relationship, setting the third intermediate image in the pupil plane of the converging group G ₃ and within the second selecting optical system M ₃ (4) the peripheral portion of the region H ₂ imaged in conjugate relationship It is desirable.

Furthermore, spacing the first focal length of the converging group G ₁ and the position where the intermediate image (3) is imaged by the rear principal point of the first converging group G ₁ and the first inner selecting optical system M ₁ It is desirable that the value is set to be substantially equal to f _1, and the first surface (1) becomes substantially a telecentric optical system. Further, substantially the distance between the position of the intermediate image in front principal point of the fifth converging group G ₅ and within the second selecting optical system M ₃ (4) is imaged to the focal length f ₅ of the fifth converging group G ₅ It is desirable that the distances are set to be equal, and the second surface (2) side becomes almost a telecentric optical system.

Further, spacing the first focal length of the converging group G ₁ and the position where the intermediate image (3) is imaged by the rear principal point of the first converging group G ₁ and the first inner selecting optical system M ₁ approximately equal to the f _1, the distance between the position the front principal point of the fifth converging group G ₅ and the intermediate image with the second inner selecting optical system M ₃ (4) is imaged in the fifth converging group G ₅ approximately equal to the focal length f _5, a first surface (1)
It is desirable that each side and the second surface (2) be substantially a telecentric optical system. Next, exposure according to the present invention
The apparatus comprises a catadioptric projection optical system according to the invention, the
A mask on the surface, a substrate on the second surface,
The mask pattern is exposed through its catadioptric projection optics.
The substrate is exposed. Also, according to the present invention,
The method includes disposing a mask on a first surface and applying a mask on a second surface.
A plate is arranged, and the plate is placed through the catadioptric projection optical system of the present invention.
The pattern of the mask is exposed on the substrate.

[0023]

According to the first catadioptric projection optical system of the present invention, the intermediate image (3) of the pattern on the first surface (1) by the first partial imaging optical system is converted into the second partial image. Second by optical system
Relayed on plane (2). Further, at least one of the first partial imaging optical system and the second partial imaging optical system has a reflecting mirror M _2.
There is used, a refraction system and a small reflecting mirror for reflecting as a means for bending the optical path, the light only or central portion (M ₁ in example 1) reflection mirror having a central opening between the reflector M ₂ ( for example, FIG M ₁ 5 ') are selected optical system M ₁ is used, such as an intermediate image in the central portion of the selected optical system M ₁ (3)
Is imaged. Therefore, since a half-mirror type beam splitter which causes a conventional flare and wastes illumination light is not used, most of the light beam can be effectively used. In the optical systems shown in FIGS. 1 to 5, the first surface (1) is displayed as an object surface, and the second surface (2) is displayed as an image surface.

Of course, the light flux near the optical axis of the selection optical system M ₁ is partially cut off and does not contribute to the image formation, so that the optical system has an annular pupil. It has the characteristic that it changes in various ways. However, recently, even in a projection exposure apparatus using a normal refraction optical system without a shielding portion as a projection optical system, a so-called deformed light source method has been proposed in which the light near the optical axis of the illumination optical system is shielded to increase the resolving power. The change in the image due to the change in the imaging characteristics can be compensated by the characteristics of the photosensitive material and the design of the reticle.

On the other hand, there is a greater advantage that the total light quantity loss is smaller than that using a half mirror, and that batch exposure can be performed and complicated scan exposure is not required. Further, according to the second catadioptric projection optical system of the present invention, for example as shown in FIG. 3, the first surface of the first part imaging optical system having a first concave reflecting mirror M ₂ (1) on the intermediate image of the pattern (3) is focused near the optical axis of the selected optical system M _2, the intermediate image (3) is a second concave reflecting mirror M ₄
Is relayed on the second surface (2) by a second partial imaging optical system having Therefore, since a half mirror type beam splitter is not used, most of the light beam can be used effectively. Further, the concave reflecting mirrors (M2, M4) are 2
Since a single concave reflecting mirror is used, the radius of curvature of each concave reflecting mirror can be doubled as compared with the case where one concave reflecting mirror is used, and various aberrations are reduced.

Further, according to the third catadioptric projection optical system of the present invention, as shown in FIG. 4, for example, the second convergence group G ₁ and the second convergence mirror M ₂ composed mainly of the first concave reflecting mirror M 2 Convergent group G ₂
The first intermediate image of the pattern of the first surface (1) on the (3) is focused near the optical axis of the first selective optical system M _1, the first intermediate image (3) is the third converging group G ₃ The second selection optical system M3
Of the relay as a second intermediate image (4) in the vicinity of the optical axis, the second intermediate image (4) fourth converging group G ₄ and the fifth converging group consisting primarily of second concave reflecting mirror M ₄ G ₅ relays on the second surface (2). Therefore, since a half mirror type beam splitter is not used, most of the light beam can be used effectively, and flare and the like can be reduced.

Further, since the first intermediate image (3) is the third converging group G ₃ to relay the second intermediate image (4) is provided, spread control range, such as the projection magnification or aberrations. In addition,
As the first selection optical system and the second selection optical system, for example, as shown in FIG.
₁ , H ₂ ), and reflecting mirrors (M ₁ , M ₂ ) in which intermediate images (3, 4) of the pattern are formed in these openings, respectively.
_In the case where ₃ ) is used, for example, as shown in FIG. 5, a small reflecting mirror (which has a reflecting portion of a predetermined shape and in which an intermediate image (3, 4) of the pattern is formed in each of these reflecting portions). M ₁ ′ and M ₃ ′) are optically equivalent.

Next, in this third catadioptric projection optical system, in order to improve the imaging performance and to make the image plane flatter, the Petzval sum of the entire optical system must be set to near zero. If the Petzval sum is not close to 0, the projected image plane will not be flat, but will be curved.
Therefore, the focal lengths of the _first to fifth converging groups G ₁ to G ₅ are f ₁ , f ₂ , f ₃ , f ₄ and f ₅ , respectively, and the Petzval sum of each group is p ₁ , p ₂ , respectively. p ₃ , p ₄ and p ₅ ,
The apparent refractive index of each group (the value obtained by dividing the focal length of each group by the Petzval sum of each group) is n ₁ , n ₂ , n ₃ , n
When ₄ and n _5, it is desirable that the following relationship is established.

−0.01 <p ₁ + p ₂ + p ₃ + p ₄ + p ₅ <0.01 (5)

If this expression is not satisfied, the image surface will not be sufficiently flat. If the lower limit is exceeded, the image surface will be concavely curved with respect to the first surface (1). It curves convexly with respect to the first surface (1). In the present invention, the Petzval sum of the entire system is calculated as
(P ₁ + p ₃ + p ₅ ) and the second partial sum (p ₂ + p ₄ )
And the respective partial sums have the opposite signs as indicated by the condition of equation (1).

In this case, p ₁ , p ₃ and p ₅ in the Petzval sum of each group are represented as follows. _{p 1 = 1 / (f 1} n 1) (6) p 3 = 1 / (f 3 n 3) (7) p 5 = 1 / (f 5 n 5) (8)

In particular, Petzval sum p _{2 of} groups 2 and 4
And for p _4, it is desirable that the following condition is satisfied. 0 ≦ n ₂ p ₂ ≦ 2 // R ₂ | (9) 0 ≦ n ₄ p ₄ ≦ 2 // R ₄ | (10)

In these equations (9) and (10),
R ₂ is the radius of curvature of the first concave reflecting mirror M ₂ constituting a part of the second converging group G ₂ , n ₂ is the apparent refractive index of the second converging group G ₂ , and similarly, R ₄ is a curvature of the second concave reflecting mirror M ₄ radius constituting a part of the fourth converging group G _4, n ₄ is the refractive index of the apparent fourth converging group G _4. In equations (9) and (10), the Petzval sum of the entire system becomes too positive when the value exceeds the lower limit, and becomes too negative when the value exceeds the upper limit.

If the image forming magnification of the primary image formed by the first and second converging groups G ₁ and G ₂ of the optical system is β ₁₂ and the image forming magnification of the entire system is β, then (2) ) expression it is desirable to satisfy the condition, no longer have if (2) If the lower limit of the expression, to take a large imaging area H ₁ of the first intermediate image of the first on the selected optical system M _1, shielding The ratio increases, the loss of light amount increases, and the imaging performance deteriorates. If above the upper limit of the expression (2), the aberration is increased in the primary imaging by the first converging group G ₁ and the second converging group G _2, also imaging performance deteriorates.

Assuming that the imaging magnification of the secondary imaging by the third converging group G ₃ is β ₃ , it is desirable to satisfy the condition of the expression (3). If the lower limit of the expression (3) is exceeded, no longer have to take a large imaging area of H ₂ second intermediate image on the second selective optical system M3, Supposing exceeds the upper limit, it is increasing shielding ratio, not only the loss of the light amount is increased, sintering Image performance deteriorates. If (3) exceeds the upper limit of the expression, the aberration is increased in the second image formation according to the third converging group G _3, also imaging performance deteriorates.

If the imaging magnification of the tertiary imaging by the _fourth and fifth converging groups G ₄ and G ₅ is β ₄₅ , it is desirable that the condition of the formula (3) is satisfied. If the lower limit of the expression is exceeded, the third convergent group G ₄ and the fifth convergent group G ₅
Aberration in the next image formation increases, and the image formation performance deteriorates.
If (4) exceeds the upper limit of the expression, the second intermediate image on the second selective optical system M ₃ (4) is no longer have to take a large area H ₂ to be imaged, an increasing number of shielding ratio, the amount of light And the imaging performance deteriorates.

If the position of the aperture stop in the third convergent group G ₃ (here, the position where the light beam is not actually stopped and the principal ray intersects the optical axis) is defined as the pupil plane s. second converging group from the first peripheral portion of the region H ₁ of the selective optical system M ₁ G
Is reflected by the _second, third optical path reaching the pupil plane s in the converging group G ₃ through the area H ₁ again, a relationship of object and image.
In other words, it is desirable that the peripheral portion and the pupil plane s region H ₁ are located in an optically conjugate relationship. Further, from the pupil plane s, the second selection optical system M
Through ₃ of region H ₂ is reflected by the converging group G _4, also the optical path that reaches the periphery of the region H ₂ again, have a relationship of the object and the image, the peripheral portion of the pupil plane s and region H ₂ It is desirable to have a conjugate relationship.

In an optical system in which the third converging group G ₃ is omitted, as shown in FIG. 3, for example, the second converging group G ₂ passes through the periphery of the region H ₁ of the first selection optical system M _1. The light path which passes through the region H ₁ again, and then is reflected by the fourth convergent group G ₄ and reaches the periphery of the region H ₁ again has an object-image relationship. In other words, it is desirable that the other peripheral portion of the surface of the peripheral portion and the area H ₁ of one surface region H ₁ are located in an optically conjugate relationship.

In an optical system in which the fourth converging group G ₄ and the fifth converging group G ₅ are omitted as shown in FIG. 1, for example, the peripheral portion of the region H ₁ of the first selection optical system M ₁ is removed. Second
After being reflected by the converging group G _2, through the area H ₁ again, the third
Optical path reaching the pupil plane s in the converging group G ₃ have a relationship of object and image. In other words, it is desirable that the peripheral portion and the pupil plane s region H ₁ are located in an optically conjugate relationship.

In an optical system in which the first converging group G ₁ and the second converging group G ₂ are omitted, as shown in FIG. 2, for example, the light exits from the pupil plane s in the third converging group G _3. after being reflected by the fourth converging group G ₄ through the region of H ₂ second selected optical system M _3, also the optical path reaching the region H ₂ again, a relationship of object and image. In other words, it is desirable that the peripheral portion of the pupil plane s and region H ₂ are in conjugate relationship.

If the conjugate relationship as described above is broken, the occluded portion of the pupil plane s by the region H ₁ or H ₂ shifts from the center of the pupil in accordance with the image height. There is a disadvantage that the imaging characteristics of the optical system change. If the first surface (1) is substantially a telecentric optical system, the optical system of the illumination system does not become large, which is convenient. When the second surface (2) is substantially a telecentric optical system, even if the distance to the photosensitive substrate on the second surface (2) slightly changes, there is no change in magnification, and multiple overprints are performed. Is carried out, there is no dimensional deviation, which is convenient.

Furthermore, if the first surface (1) side and the second surface (2) side are substantially telecentric optical systems, respectively, the illumination optical system will not be large, and the light on the second surface (2) will not be large. Even if the distance to the substrate slightly changes, there is no change in the magnification, and even if multiple overprints are performed, there is no dimensional deviation, which is convenient.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the drawings. In this example, the present invention is applied to a projection optical system of a projection exposure apparatus that projects an image of a reticle pattern onto a wafer coated with a photoresist at a predetermined magnification (including equal magnification).

In the following embodiment, the lens arrangement is, for example, shown in FIG.
As shown in FIG. In the developed optical path diagram, the reflection surface is represented as a transmission surface, and each optical element is arranged in the order in which light from the reticle 10 passes. In addition, a plane virtual surface (for example, r ₁₀ ) is used in the portion of the concave reflecting mirror (for example, r ₉ ). Then, in order to represent the shape and interval of the lens, for example, as shown in FIG.
Is defined as a zeroth surface, and a surface through which light emitted from the reticle 10 passes before reaching the wafer 11 is sequentially defined as an i-th surface (i = 1, 2,...).
The sign of _i is positive when it is convex with respect to the reticle 10 in the developed optical path diagram. Also, the surface interval between the i-th surface and the (i + 1) -th surface, and d _i. As glass materials, CaF ₂ represents fluorite and SiO ₂ represents quartz glass. The refractive indexes of quartz glass and fluorite with respect to the reference wavelength for use (248 nm) are as follows. Quartz glass: 1.508327 Fluorite: 1.467845

When the reference wavelength used is 193 nm, the refractive index of quartz glass is as follows. Quartz glass: 1.56100

[First Embodiment] The first embodiment is an equal-magnification projection optical system. The first embodiment to the following third embodiment correspond to the optical system shown in FIG. FIG. 6 is a developed optical path diagram of the projection optical system of the first embodiment.
As shown in the figure, the light from the pattern on the reticle 10 is
After passing through the first converging group G ₁ , the light is reflected at the periphery of the first plane mirror M ₁ having an opening at the center and inclined at 45 ° with respect to the optical axis, and thereafter is formed of the first concave reflecting mirror M ₂ . reaches the second converging group G _2, the light reflected by the second converging group G ₂ is imaged a first intermediate image of the pattern in the first opening of the plane mirror M _1. Light from the first intermediate image, through the third converging group G ₃ having a concave reflection mirror M _31, second plane mirror M _3, which is obliquely disposed at 45 ° to have optical axis central opening of the second intermediate image of the pattern imaged on the opening reaches the fourth converging group G ₄ which light from the second intermediate image is formed of the second concave reflecting mirror M _4,
The light reflected by the fourth converging group G ₄ is reflected by the periphery of the second plane mirror M _3. Thus reflected light, images the third intermediate image of the pattern on the surface of the wafer 11 through the fifth converging group G _5.

Further, FIG. 7 shows a first detailed configuration of the converging group G ₁ in FIG. 6, as shown in FIG. 7, the first converging group G
Reference numeral ₁ denotes a positive meniscus lens L ₁₁ having a convex surface facing the reticle 10, a biconvex lens (hereinafter simply referred to as a “convex lens”) L ₁₂ , a positive meniscus lens L ₁₃ having a concave surface facing the reticle 10, and the reticle 10 in order from the reticle 10 side. It is composed of a positive meniscus lens L ₁₄ having a convex surface directed toward the. In addition, as shown in FIG. 6, the third converging group G ₃ includes the reticle 1
A positive meniscus lens L _{31 having} a concave surface directed to 0, a concave reflecting mirror M ₃₁ and a positive meniscus lens L ₃₂ having a concave surface directed to the reticle 10, and the fifth converging group G ₅ is the first converging group G
It is configured symmetrically with ₁ .

That is, in the present embodiment, the light emitting device having the aperture near the optical axis is used.
It has a symmetrical optical system composed of three plane mirrors, three concave reflecting mirrors, and ten refractive lenses, and has a numerical aperture of 0.4.
5. The image height is 10 mm and the maximum mirror radius is 486 mm. However, since the optical performance has almost no aberration, it is obvious that the image height can be increased to 2 to 3 times by proportional enlargement of the optical system.

All the refractive lenses use one kind of optical glass made of fused silica, but on-axis and off-axis achromatization is performed for a wavelength of 1 nm at a wavelength of 193 nm of ultraviolet excimer laser light. ing. Also, spherical aberration, coma, astigmatism, and distortion are well corrected. The radius of curvature r _i of the first embodiment of FIG. 6, the surface spacing d _i and glass materials shown in Table 1 below. In the following tables, the tenth, fourteenth, and eighteenth surfaces are virtual surfaces for expressing the concave reflecting mirror in a developed optical path diagram.

[0050]

[Table 1]

8 (a) to 8 (c) are longitudinal aberration diagrams of the first embodiment, FIG. 8 (c) is chromatic aberration of magnification of the first embodiment, and FIG. 8 (e) is a diagram of the first embodiment. FIG. In these aberration diagrams, symbols J, P and Q indicate that the wavelengths used are 2 respectively.
48.4 nm, 247.9 nm and 248.9 nm. From these aberration diagrams, it can be seen that in the present example, despite the large numerical aperture of 0.45, various aberrations are satisfactorily corrected within a wide image circle area. In addition, chromatic aberration is well corrected.

In FIG. 6, an equivalent optical system can be realized by using small plane mirrors M ₁ ′ _and M ₃ ′ as shown in FIG. 5 instead of the plane mirrors M _{1 and} M ₃ having openings. Is as described above. Further, the plane mirrors M _{1 and} M
Instead of ₃ , a concave mirror or a convex mirror having an opening may be used, and further, a small concave mirror or a small convex mirror may be used.

[Second Embodiment] The second embodiment is also an example of a 1 × projection optical system. FIG. 9 is a development optical path diagram of the projection optical system of the second embodiment. As shown in FIG.
After the light from the pattern on 0 passes through the first converging group G ₁ and is reflected at the periphery of the first plane mirror M ₁ having an opening at the center and inclined at 45 ° with respect to the optical axis, the first 1 concave reflector M ₂
Reaches the second converging group G ₂ including a first light reflected by the second converging group G ₂ is the pattern in the first opening of the plane mirror M ₁
An intermediate image is formed. Light from the first intermediate image, through the third converging group G _3, the second plane mirror M _3, which is obliquely disposed at 45 ° to have the optical axis an opening in the center of the pattern in the opening A second intermediate image is formed, and light from the second intermediate image reaches a fourth converging group G ₄ including a second concave reflecting mirror M ₄ ,
The light reflected by the fourth converging group G ₄ is reflected by the periphery of the second plane mirror M _3. Thus reflected light, images the third intermediate image of the pattern on the surface of the wafer 11 through the fifth converging group G _5.

As shown in FIG. 9, the first convergent group G ₁
Denotes a convex lens L ₁₁ , a biconcave lens (hereinafter simply referred to as “concave lens”) L ₁₂ , and a reticle 10 in this order from the reticle 10 side.
Positive meniscus with its concave surface facing the lens L ₁₃ and the reticle 1
0 convex is composed of a negative meniscus lens L ₁₄ with its, the second converging group G ₃ is a man-Jin mirror formed of a negative meniscus lens L ₂₁ and the concave reflector M ₂ having a concave surface facing the reticle 10. The third converging group G ₃ includes a concave lens L ₃₁ , a convex lens L ₃₂ , a concave lens L ₃₃ , a positive meniscus lens L ₃₄ having a concave surface facing the reticle 10, a negative meniscus lens L ₃₅ having a convex surface facing the reticle 10, and a reticle 10 Meniscus lens L ₃₆ , convex lens L ₃₇ having a concave surface facing the lens, negative meniscus lens L ₃₈ , convex lens L ₃₉ having a convex surface facing reticle 10, and lenses L _{3A to} L _3I symmetrical to these lenses L _{31 to} L _39. It is configured.

The fourth convergence group G ₄ includes the reticle 10
Is a mangin mirror composed of a negative meniscus lens L ₄₁ having a concave surface facing the lens and a second concave reflecting mirror M ₄ , and a fifth converging group G
₅ is configured to first converging group G ₁ and symmetrically. That is,
This example is a symmetrical optical system including two plane mirrors having an opening at the center, two concave reflecting mirrors, and 28 refractive lenses. The numerical aperture is 0.45, the image height is 5 mm, The maximum mirror radius is 75 mm. However, since the optical performance in this example is also almost no aberration, it is clear that the image height can be further increased to 2 to 3 times by proportional enlargement of the optical system.

The second convergent group G_Two And the fourth convergent group G_Four 
Include one negative meniscus lens,
Mangin Mira with separate lens and concave reflector
-It has a configuration. Thus, the second concave reflecting mirror M
_Two A second convergent group G containing_Two Is the negative meniscus lens L_{twenty one}To
Including mangin mirrors, fewer types of optical glass
However, axial chromatic aberration can be easily removed. As well
The second concave reflecting mirror M _Four Fourth convergent group G containing_Four But the negative
Niscus lens L₄₁If it is a mangin mirror containing
Easily removes axial chromatic aberration with a few types of optical glass.
You can leave.

Therefore, as in the second embodiment, the second converging group G ₂ is a mangin mirror including a negative meniscus lens, and the fourth converging group G ₄ is also a mangin mirror including a negative meniscus lens. In this case, axial chromatic aberration can be easily removed with a small number of types of optical glass as a whole. Also in the optical system of this example, the refractive lens uses one kind of optical glass made of fused silica, but it is 1 nm in the wavelength of 248 nm of the ultraviolet excimer laser light.
On-axis and off-axis achromatism are performed for the wavelength width of. In addition, the optical system is excellent in image forming performance, in which spherical aberration, coma, astigmatism, and distortion are well corrected.

[0058] indicates the radius of curvature r _i, the surface distance d _i and glass materials in the following Table 2 in the second embodiment. In the following tables, the twelfth surface and the fifty-third surface are virtual surfaces for expressing the concave reflecting mirror in a developed optical path diagram, respectively.

[0059]

[Table 2]

10 (a) to 10 (c) are longitudinal aberration diagrams of the second embodiment, FIG. 10 (c) is chromatic aberration of magnification of the second embodiment, and FIG. 10 (e) is a diagram of the second embodiment. FIG. From these aberration diagrams, it can be seen that in the present example as well, despite the large numerical aperture of 0.45, various aberrations are favorably corrected within a wide image circle area. In addition, chromatic aberration is well corrected.

[Third Embodiment] The third embodiment is directed to reduction projection.
Is an example of a projection optical system that performs the following. FIG. 11 shows the third embodiment.
FIG. 12 is a developed optical path diagram of the shadow optical system, as shown in FIG.
The light from the pattern on the reticle 10 is
G₁ Through the center, with an opening at the center and inclined at 45 ° to the optical axis.
First plane mirror M provided₁ After being reflected at the periphery of
Concave reflector M_TwoA second convergent group G containing_Two And the second convergence
Group G_Two Is reflected by the first plane mirror M₁In the opening of the
Forming a first intermediate image of the pattern; And during this first
The light from the intermediate image is in the third convergent group G_Three Through the opening in the center
Second plane mirror M inclined at 45 ° to the holding optical axis_Three of
Forming a second intermediate image of the pattern in the aperture;
Light from the intermediate image is reflected by the second concave mirror M_Four Fourth convergent group containing
G_Four And the fourth convergent group G _Four Light reflected by the second plane
Mirror M_Three Is reflected around. Light reflected in this way
Is the fifth convergent group G_Five Through the pattern on the surface of the wafer 11
A third intermediate image of the image.

As shown in FIG. 11, the first convergence group G
₁ Indicates a concave surface on the reticle 10 in order from the reticle 10 side.
Positive meniscus lens L₁₁Facing the reticle 10
Sign negative meniscus lens L₁₂, Convex lens L₁₃And reticks
Negative meniscus lens L with convex surface facing lens 10₁₄More composed
And the second convergent group G_Three Turned concave surface to reticle 10
Negative meniscus lens L_{twenty one}And concave mirror M_Two Ma
It is a engine mirror. Also, the third convergent group G_Three Is a retic
Meniscus lens L with concave surface facing lens 10₃₁, Retic
Meniscus lens L with concave surface facing lens 10₃₂, Retic
Meniscus lens L with concave surface facing lens 10₃₃, Retic
Meniscus lens L with concave surface facing lens 10₃₄, Retic
Negative meniscus lens L with convex surface facing lens 10₃₅, Retic
Meniscus lens L with concave surface facing lens 10₃₆, Retic
Meniscus lens L with concave surface facing lens 10₃₇, Convex len
Z L₃₈, Convex lens L₃₉, Convex lens L_3ATo the reticle 10
Positive meniscus lens L with convex surface_3BTo the reticle 10
Negative meniscus lens L with concave surface_3CTo the reticle 10
Positive meniscus lens L with convex surface_3D, Concave lens L _3E,
Convex lens L_3FMeniscus with convex surface facing reticle 10
Cas lens L_3GIt is composed of

The fourth convergence group G ₄ includes the reticle 10
Is a mangin mirror composed of a negative meniscus lens L ₄₁ having a concave surface facing the lens and a second concave reflecting mirror M ₄ , and a fifth converging group G
Reference numeral ₅ denotes a positive meniscus lens L ₅₁ having a convex surface facing the reticle 10, a negative meniscus lens L ₅₂ having a convex surface facing the reticle 10, a positive meniscus lens L ₅₃ having a convex surface facing the reticle 10, and a negative meniscus lens L ₅₃ having a concave surface facing the reticle 10. It is composed of a positive meniscus lens L ₅₅ having a convex surface directed toward the meniscus lens L ₅₄ and the reticle 10.

That is, this embodiment is composed of two plane mirrors having an opening at the center, two concave reflecting mirrors, and 27 refractive lenses, and has an imaging magnification of 0.25 times and a numerical aperture of 0. .4
5. The object height is 20 mm and the maximum mirror radius is 75 mm. Also in this example, since the optical performance is almost an aberration-free, it is apparent that the image height can be further increased to 2 to 3 times by proportionally enlarging the optical system. The _second and fourth convergent groups G ₂ and G ₄ are each 1
It includes a negative meniscus lens and has a configuration of a mangin mirror of a type in which a refraction lens and a reflection mirror are separated.

The optical system of this embodiment also uses one kind of optical glass made of fused silica for the refraction lens, but uses 1n at the wavelength of 193 nm of the ultraviolet excimer laser light.
On-axis and off-axis achromatism is performed for a wavelength width of m. In addition, the optical system is excellent in image forming performance, in which spherical aberration, coma, astigmatism, and distortion are well corrected.

[0066] indicates the radius of curvature r _i, the surface distance d _i and glass materials in the following Table 3 in the third embodiment. In the following tables, the twelfth surface and the forty-ninth surface are imaginary surfaces for expressing the concave reflecting mirror in a developed optical path diagram, respectively.

[0067]

[Table 3]

FIGS. 12A to 12C are longitudinal aberration diagrams of the third embodiment, FIG. 12C is a chromatic aberration of magnification of the third embodiment, and FIG. 12E is a diagram of the third embodiment. FIG. From these aberration diagrams, it can be seen that in the present example as well, despite the large numerical aperture of 0.45, various aberrations are favorably corrected within a wide image circle area. In addition, chromatic aberration is well corrected.

[0069] [Fourth Embodiment] The fourth embodiment is a third type of projection optical system is omitted converging group G ₃ performs reduction projection. That is, this embodiment is an embodiment corresponding to the optical system of FIG. Figure 13 is a development optical path diagram of a projection optical system of the fourth embodiment, as shown in FIG. 13, the light from the pattern on the reticle 10, through the first converging group G _1, having a central opening Plane mirror M ₁ inclined at 45 ° to the optical axis
After being reflected at the peripheral portion of the surface, the light reaches the second converging group G ₂ including the first concave reflecting mirror M ₂ , and the light reflected by the second converging group G ₂ enters the pattern in the opening of the plane mirror M _1. Is formed. Light from the intermediate image reaches the fourth converging group G ₄ including a second concave reflecting mirror M _4, the light reflected by the fourth converging group G ₄ is reflected by the periphery of the rear surface of the plane mirror M ₁ . Thus reflected light, images the image of the pattern on the surface of the wafer 11 through the fifth converging group G _5. The plane mirror M ₁ of the present example is, for example, a first plane mirror M ₁ and a second plane mirror M of FIG.
_This is equivalent to bonding ₃

As shown in FIG. 13, the first convergence group G
Reference numeral ₁ denotes a negative meniscus lens L _{11 having} a convex surface facing the reticle 10, a convex lens L ₁₂ , a negative meniscus lens L ₁₃ having a convex surface facing the reticle 10, and a positive meniscus lens L ₁₄ having a convex surface facing the reticle 10. A negative meniscus lens L ₁₅ having a convex surface facing the reticle 10, a positive meniscus lens L ₁₆ having a concave surface facing the reticle 10, a convex lens L ₁₇ , a negative meniscus lens L ₁₈ having a concave surface facing the reticle 10, and a convex surface facing the reticle 10. is composed of a positive meniscus lens L ₁₉ with a second converging group G ₃ includes a reticle 10
To a man Jin mirror formed of a negative meniscus lens L ₂₁ and the concave reflector M ₂ having a concave surface.

The fourth convergent group G_Four On the reticle 10
Negative meniscus lens L with concave surface ₄₁And second concave reflection
Mirror M_Four The fifth convergent group G_Five 
Is a convex lens L₅₁, A negative menu with a concave surface facing the reticle 10
Sukas lens L₅₂, Positive lens with convex surface facing reticle 10
Sukas lens L₅₃, Positive lens with convex surface facing reticle 10
Sukas lens L₅₄, A negative lens with a convex surface facing the reticle 10
Sukas lens L₅₅, Convex lens L₅₆, Concave on reticle 10
Negative meniscus lens L₅₇, Convex lens L ₅₈And concave
Lens L₅₉It is composed of

That is, in this example, one plane mirror having an opening in the center (more precisely, a plane mirror in which two plane mirrors are bonded together)
Consisting of two concave reflecting mirrors and 20 refractive lenses, the imaging magnification is 0.2 times, the numerical aperture is 0.5, and the object height is 2
5 mm, the maximum mirror radius is 115 mm. However, since the optical performance of this example is also almost aberration-free,
It is clear that the image height can be further increased to 2 to 3 times by proportional enlargement of the optical system. Further, each of the second converging group G ₂ and the fourth converging group G ₄ includes one negative meniscus lens, the refractive lens and the reflector are taking the configuration of the man-Jin mirrors separated type.

In the optical system of this embodiment, the refractive lens uses two types of optical glass, namely fused silica and fluorite.
On-axis and off-axis achromats are provided for a 1 nm wavelength width. In addition, the optical system is excellent in image forming performance, in which spherical aberration, coma, astigmatism, and distortion are well corrected.

Table 4 below shows the radius of curvature r _i , the spacing d _i, and the glass material in the fourth embodiment. In the following table, the twenty-first surface and the twenty-seventh surface are imaginary surfaces for expressing the concave reflecting mirror in a developed optical path diagram.

[0075]

[Table 4]

FIGS. 14A to 14C are longitudinal aberration diagrams of the fourth embodiment, FIG. 14C is a chromatic aberration diagram of magnification of the fourth embodiment, and FIG. 14E is a diagram of the fourth embodiment. FIG. From these aberration diagrams, it can be seen that in the present example as well, despite the large numerical aperture of 0.45, various aberrations are favorably corrected within a wide image circle area. In addition, chromatic aberration is well corrected.

[0077] [Fifth Embodiment] The fifth embodiment is the fourth converging group G ₄ and the type of a projection optical system 5 is omitted converging group G ₅ performs reduction projection. That is, the present embodiment is an embodiment corresponding to the optical system of FIG. Figure 15 is a development optical path diagram of a projection optical system of the fifth embodiment, as shown in FIG. 15, light from a pattern on the reticle 10, through the first converging group G _1, the central opening 45 ° to the holding optical axis
In after being reflected by the periphery of obliquely to the plane mirror M _1, reaches the second converging group G ₂ including a concave reflecting mirror M _2, the second converging group G
The light reflected by the ₂ images the intermediate image of the pattern in the opening of the plane mirror M _1. And the light from this intermediate image
After passing through the third converging group G ₃ , an image of the pattern is formed on the surface of the wafer 11.

As shown in FIG. 15, the first convergence group G
₁ includes, in order from the reticle 10 side, a positive meniscus lens L ₁₁ with a convex surface on the reticle 10, a negative meniscus lens L ₁₂ with a convex surface to the reticle 10, is composed of a convex lens L ₁₃ and a concave lens L _14, a second converging group G ₃ is reticle 10
To a man Jin mirror formed of a negative meniscus lens L ₂₁ and the concave reflector M ₂ having a concave surface. The third converging group G ₃ includes a positive meniscus lens L ₃₁ having a concave surface facing the reticle 10, a positive meniscus lens L ₃₂ having a concave surface facing the reticle 10, a convex lens L ₃₃ , and a negative meniscus lens having a convex surface facing the reticle 10. L _34, a convex lens L _35, a convex lens L _36,
A negative meniscus lens L ₃₇ having a concave surface facing the reticle 10,
The convex lens L ₃₈ , the positive meniscus lens L ₃₉ with the convex surface facing the reticle 10, the negative meniscus lens L _3A with the concave surface facing the reticle 10, the convex lens L _3B , the negative meniscus lens L _3C with the convex surface facing the reticle 10, and the reticle 10 It comprises a positive meniscus lens L _3D with a convex surface and a negative meniscus lens L _{3E with} a convex surface facing the reticle 10.

That is, this example is composed of one plane mirror having an opening at the center, one concave reflecting mirror and 19 refractive lenses, and has an imaging magnification of 0.25 and a numerical aperture of 0.45. , The image height is 5 mm and the maximum mirror diameter is 75 mm. However,
Since the optical performance of this example is also almost an aberration-free, it is clear that the image height can be further increased to 2 to 3 times by proportional enlargement of the optical system. The second converging group G ₂ comprises one negative meniscus lens, the refractive lens and the reflector are taking the configuration of the man-Jin mirrors separated type.

The optical system of this embodiment also uses one kind of optical glass made of fused silica for the refractive lens.
On-axis and off-axis achromatism is performed for a wavelength width of m. In addition, the optical system is excellent in image forming performance, in which spherical aberration, coma, astigmatism, and distortion are well corrected.

Table 5 below shows the radius of curvature r _i , the spacing d _i and the glass material in the fifth embodiment. In the table below, the twelfth surface is a virtual surface for expressing the concave reflecting mirror in a developed optical path diagram.

[0082]

[Table 5]

FIGS. 16A to 16C are longitudinal aberration diagrams of the fifth embodiment, FIG. 16C is a chromatic aberration of magnification of the fifth embodiment, and FIG. 16E is a diagram of the fifth embodiment. FIG. From these aberration diagrams, it can be seen that in the present example as well, despite the large numerical aperture of 0.45, various aberrations are favorably corrected within a wide image circle area. In addition, chromatic aberration is well corrected.

[0084] [Sixth Embodiment] The sixth embodiment performs reduction projection, a first converging group G ₁ and the second projection optical system is omitted converging group G _2. That is, this example corresponds to the optical system of FIG. Figure 17 is a development optical path diagram of a projection optical system of the sixth embodiment, as shown in FIG. 17, light from a pattern on the reticle 10, through the third converging group G _3, has a central opening forms an intermediate image of the pattern on the obliquely been the opening of the plane mirror M ₃ in 45 ° with respect to the optical axis,
The second light from the intermediate image reaches the fourth converging group G ₄ including a concave reflecting mirror M _4, the light reflected by the fourth converging group G ₄ is reflected at the periphery of the plane mirror M _3. Thus reflected light, images the image of the pattern on the surface of the wafer 11 through the fifth converging group G _5.

As shown in FIG. 17, the third convergent group G
Reference numeral ₃ denotes a negative meniscus lens L ₃₁ having a convex surface facing the reticle 10, a negative meniscus lens L ₃₂ having a convex surface facing the reticle 10, a negative meniscus lens L ₃₃ having a concave surface facing the reticle 10, and a convex surface facing the reticle 10. a negative meniscus lens L ₃₄ with its positive meniscus lens L ₃₅ with its concave surface facing the reticle 10, a convex lens L _36, a reticle 1
Positive meniscus lens L ₃₇ with concave surface facing 0, convex lens L
₃₈ , positive meniscus lens L with concave surface facing reticle 10
₃₉ , a convex lens L _3A , a convex lens L _3B , a negative meniscus lens L _3C having a concave surface facing the reticle 10, a negative meniscus lens L _3D having a convex surface facing the reticle 10, a concave lens L _3E , a convex lens L _3F and a convex lens L _3G. ing.

Then, the fourth convergent group G_Four Is the reticle 10
Meniscus lens L with concave surface facing₄₁And concave reflector
M_Four The fifth convergent group G_Five 
Is a positive meniscus lens L having a convex surface facing the reticle 10
₅₁Meniscus lens L having a convex surface facing reticle 10
₅₂Meniscus lens L having a convex surface facing reticle 10
₅₃Meniscus lens L having a concave surface facing reticle 10
₅₄Meniscus lens with convex surface facing reticle 10
L₅₅It is composed of

That is, this embodiment is composed of one plane mirror having an opening at the center, one concave reflecting mirror and 22 refractive lenses, and has an imaging magnification of 0.25 times and a numerical aperture of 0.3. The image height is 3 mm and the maximum mirror diameter is 41 mm. However, since the optical performance of this example is also almost aberration-free,
It is clear that the image height can be further increased to 2 to 3 times by proportional enlargement of the optical system. The fourth converging group G ₄ includes one negative meniscus lens, the refractive lens and the reflector are taking the configuration of the man-Jin mirror type separated.

The optical system of this embodiment also uses one kind of optical glass made of fused silica for the refraction lens. However, the refractive index of 1 n at the wavelength of 193 nm of the ultraviolet excimer laser light is used.
On-axis and off-axis achromatism is performed for a wavelength width of m. In addition, the optical system is excellent in image forming performance, in which spherical aberration, coma, astigmatism, and distortion are well corrected.

Table 6 below shows the radius of curvature r _i , spacing d _i and glass material in the sixth embodiment. In the table below, the thirty-fifth surface is a virtual surface for expressing the concave reflecting mirror in a developed optical path diagram.

[0090]

[Table 6]

18 (a) to 18 (c) are longitudinal aberration diagrams of the sixth embodiment, FIG. 18 (c) is chromatic aberration of magnification of the sixth embodiment, and FIG. 18 (e) is a diagram of the sixth embodiment. FIG. From these aberration diagrams, it can be seen that also in this example, the numerical aperture is 0.3 and various aberrations are favorably corrected within the image circle area. In addition, chromatic aberration is well corrected.

Next, in the present invention, the formulas (1) to (4)
It is said that it is desirable to satisfy
The correspondence between the above embodiments and their conditions will be described.
You. First, the first convergent group G in each of the above-described embodiments.₁ ~ No.
5 convergent group G_Five Let f be the focal length of each_i(i = 1 ~
5), each Petzval sum is p_i(i = 1-5),
Let n be the apparent refractive index of each_i(i = 1-5), each
The imaging magnification is β_i(i = 1 to 5). In addition, the second
Convergent group G_Two First concave reflector M inside_Two And the fourth convergent group G_FourDuring ~
Second concave reflecting mirror M_Four Radius of curvature of R_i(i =
2, 4), the first convergent group G₁ And the second convergent group G_Two of
The composite imaging magnification is β₁₂, Fourth convergent group G_Four And the fifth convergent group
G_Five Β is the composite imaging magnification of₄₅As these imaging magnification
β₁₂And β₄₅To β _ijExpressed by First to Sixth Embodiments
The specifications of the examples are summarized in Tables 7 to 12 below.
However, the whole system is G_T And the whole system G_T Petzba corresponding to
RU sum p_iAnd the imaging magnification is β_i Column of the whole system
The Petzval sum and the imaging magnification are shown.

[0093]

[Table 7]

[0094]

[Table 8]

[0095]

[Table 9]

[0096]

[Table 10]

[0097]

[Table 11]

[0098]

[Table 12]

Next, based on the above Tables 7 to 12, the following table shows what values of the parameters of the conditional expressions (1) to (4) are in each embodiment. Shown together.

[0100]

[Table 13]

In the present invention, conditional expressions (9) and (1)
0) but there is a also desirable to satisfy the respective parameters R ₂ thereof conditional expression (9) and (second converging group appearing in 10) G ₂ and the fourth converging group G _4, p _2, n _{2 ,} R _4, p _4, n
_The following table shows what the value of ₄ is in each example.

[0102]

[Table 14]

[0103] From Table 14, in each example, quantities n ₂ p ₂ of the condition (9) and (10), 2 / | R 2 |,
n ₄ p _4, 2 / | R ₄ | is as follows.

[0104]

[Table 15]

From these tables, in each of the above embodiments, the conditions of the expressions (1) to (4), the expressions (9) and (1)
It can be seen that the condition of the expression (0) is satisfied. In addition,
In each of the above embodiments, optical glass such as quartz or fluorite is used as a glass material constituting the refractive optical system.
An optical glass such as quartz or fluorite is convenient because it can transmit ultraviolet light.

However, when the illumination light to be used is infrared light, silicon (S) is used as the glass material constituting the refractive optical system.
Optical glass such as i), germanium (Ge), zinc sulfide (ZnS) or zinc selenide (ZnSe) can also be used. This is because these glass materials have high transmittance to infrared rays. Further, as a material constituting the refractive optical system, a plastic optical material such as acryl, polystyrene, or polycarbonate may be used. As a result, a mass-productive, low-cost optical system can be realized.

Further, instead of the reticle 10 at a finite distance, the present invention can be applied to a so-called general imaging lens for forming an image of an object at an infinite distance on a predetermined observation surface. Further, the optical system of each of the above-described embodiments projects an off-axis orbicular object using only the off-axis light beam, and moves the reticle 10 and the wafer 11 at different speeds corresponding to the magnification of the projection optical system. It is also possible to apply to an exposure apparatus for so-called scanning exposure for exposing. As a result, the size of the projection optical system can be reduced.

Although the above-described embodiment is an example of the same-size or reduced-size projection optical system, it is apparent that the relationship between the reticle 10 and the wafer 11 can be reversed to be used as an enlarged projection optical system. As an application of such a magnifying optical system, an ultraviolet microscope or the like is promising. As described above, the present invention is not limited to the above-described embodiment, and can take various configurations without departing from the gist of the present invention.

[0109]

According to the first catadioptric projection optical system of the present invention, the optical path of the light beam is bent by the selection optical system, and the intermediate image is formed near the optical axis of the selection optical system by the light beam from the concave reflecting mirror. An image is formed or light from an intermediate image near the optical axis of the selected optical system is guided to the concave reflecting mirror. Therefore,
Petzval sum and axial chromatic aberration can be corrected well. Also, distortion and chromatic aberration of magnification, which are common in asymmetric optical systems, can be satisfactorily corrected by combination with some refracting optical systems, and spherical aberration and coma can also be satisfactorily corrected. Therefore, there is an advantage that it is possible to provide a catadioptric projection optical system having excellent image forming performance and capable of adopting a batch exposure method without using a beam splitter.

Further, according to the second catadioptric projection optical system of the present invention, it is not necessary to use a beam splitter, the image forming performance is excellent, and a batch exposure method can be adopted. Further, by using two concave reflecting mirrors, there is an advantage that the radius of curvature of each concave reflecting mirror can be increased and aberration can be reduced. Further, according to the third catadioptric projection optical system of the present invention, the imaging performance is excellent without using a beam splitter, and a batch exposure method can be adopted. Further, by using two concave reflecting mirrors, there is an advantage that the radius of curvature of each concave reflecting mirror can be increased and aberration can be reduced. Furthermore, since the third converging group is provided between the first selection optical system and the second selection optical system, there is an advantage that the imaging magnification and various aberrations can be controlled in a wide range. In addition, the present invention
According to the exposure method or the exposure apparatus of the present invention, the catadioptric projection of the present invention is used.
Exposure is performed through shadow optics, so most of the light beam is effective
Exposure with excellent imaging performance
At the same time, a batch exposure method can be adopted.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first basic configuration of a catadioptric projection optical system according to the present invention.

FIG. 2 is a configuration diagram showing a modification of the basic configuration of FIG. 1;

FIG. 3 is a configuration diagram showing a second basic configuration of the catadioptric projection optical system according to the present invention.

FIG. 4 is a configuration diagram showing a third basic configuration of the catadioptric projection optical system according to the present invention.

FIG. 5 is a configuration diagram showing a modification of the basic configuration of FIG. 4;

FIG. 6 is a developed optical path diagram showing the projection optical system according to the first embodiment of the present invention.

7 is an optical path diagram showing a first detailed configuration of the converging group G ₁ in the first embodiment.

FIG. 8 is an aberration diagram of the first example.

FIG. 9 is a developed optical path diagram showing a projection optical system according to a second embodiment of the present invention.

FIG. 10 is an aberration diagram of the second example.

FIG. 11 is a developed optical path diagram showing a projection optical system according to a third embodiment of the present invention.

FIG. 12 is an aberration diagram of the third example.

FIG. 13 is a developed optical path diagram showing a projection optical system according to a fourth embodiment of the present invention.

FIG. 14 is an aberration diagram of the fourth example.

FIG. 15 is a developed optical path diagram showing a projection optical system according to a fifth embodiment of the present invention.

FIG. 16 is an aberration diagram of the fifth embodiment.

FIG. 17 is a developed optical path diagram showing a projection optical system according to a sixth embodiment of the present invention.

FIG. 18 is an aberration diagram of the sixth example.

[Explanation of symbols]

1 the object plane 2 image plane 10 reticle 11 wafer G ₁ first converging group G ₂ second converging group G ₃ third converging group G ₄ fourth converging group G ₅ 5 converging group M _1, M ₃ plane mirrors H having an opening ₁ , H ₂ aperture M ₂ , M ₄ concave reflecting mirror M ₁ ′, M ₃ ′ minute plane mirror

Claims (15)

(57) [Claims] 1. An optical system for projecting an image of a pattern on a first surface onto a second surface, wherein the first partial imaging optical system forms an intermediate image of the pattern on the first surface. A second partial imaging optical system for re-imaging the image of the intermediate image on the second surface; and at least one of the two partial imaging optical systems is located on the optical axis. The light of the first area is disposed obliquely with respect to the first area and reflects the light of the second area different from the first area, and the intermediate image is formed on the first area or the second area. A selection optical system to be imaged, a concave reflecting mirror that returns the light beam guided through the selection optical system to the selection optical system again,
The selective optical system and the front optical system are disposed between the first surface and the selective optical system or between the selective optical system and the second surface.
The intermediate image or the image on the second surface together with the concave reflecting mirror;
A catadioptric projection optical system comprising: a converging group that forms an image . 2. An optical system for projecting an image of a pattern on a first surface onto a second surface, wherein the first partial imaging optical system forms an intermediate image of the pattern on the first surface. A second partial imaging optical system that forms an image of the intermediate image on the second surface; and the first partial imaging optical system is disposed obliquely with respect to an optical axis in a first region. And a first converging group that guides a light beam from a pattern on the first surface to the selection optical system by passing light of the second region and reflecting light in a second region different from the first region. Reflecting the light flux converged by the first converging group and reflected by the selection optical system to form an intermediate image of the pattern in the first region or the second region of the selection optical system. A first concave reflecting mirror, wherein the second partial imaging optical system returns a light beam from the intermediate image in the selection optical system to the selection optical system again. A second concave reflecting mirror, and a second converging group that forms an image of the intermediate image on the second surface from a light beam converged by the second concave reflecting mirror and reflected again by the selection optical system. A catadioptric projection optical system, comprising: 3. An optical system for projecting an image of a pattern on a first surface onto a second surface, wherein the focal length f converges light beams from the pattern on the first surface in order from the first surface. ₁₎ a first converging group, and passing light of a first area and reflecting light of a second area different from the first area, and transmitting a light beam from the first converging group to a subsequent optical system. A first selection optical system for guiding the light, a first concave reflecting mirror, and reflecting the light beam from the first selection optical system to be in the first area or the second area of the first selection optical system. a second converging group of focal length f ₂ for imaging the first intermediate image of the pattern, the focal length f ₃ which converge the light flux from the first intermediate image to image the second intermediate image of the pattern first 3 convergent groups, while transmitting light in the first area and reflecting light in a second area different from the first area, A second selection optical system in which the second intermediate image is formed in a second area; and a focal length that includes a second concave reflecting mirror and returns a light beam from the second intermediate image to the second selection optical system. a fourth converging group f _4, and converging the light beam guided by said second selecting optical system, a fifth convergence of the focal length f ₅ which forms a third intermediate image of the pattern on the second surface A catadioptric projection optical system, comprising: 4. The apparatus according to claim 1, wherein the first selection optical system and the second selection optical system each have an opening having a predetermined shape, and each of the first and second selection optical systems is a reflecting mirror on which an intermediate image of the pattern is formed. 4. A catadioptric projection optical system according to claim 3, wherein: 5. The small-sized reflecting mirror, wherein each of the first selection optical system and the second selection optical system has a reflecting portion having a predetermined shape, and an intermediate image of the pattern is formed in each of the reflecting portions. 4. The catadioptric projection optical system according to claim 3, wherein: 6. When the individual Petzval sums of the first to fifth convergent groups are p ₁ to p ₅ , respectively, p ₁ + p ₃ + p ₅ > 0 and p ₂ + p ₄ <0. The condition of (3), (4) or (5) is satisfied.
A catadioptric projection optical system as described. 7. When the imaging magnification of the first intermediate image by the first converging group and the second converging group is β ₁₂ , the condition 0.1 ≦ | β ₁₂ | ≦ 2 is satisfied. A catadioptric projection optical system according to claim 3, 4, 5, or 6. 8. When the imaging magnification of the first intermediate image to the second intermediate image by the third converging group is β ₃ , the condition 0.1 ≦ | β ₃ | ≦ 2 is satisfied. 8. A catadioptric projection optical system according to claim 3, wherein: 9. The condition of 0.1 ≦ | β ₄₅ | ≦ 2, where β ₄₅ is the imaging magnification of the second intermediate image to the third intermediate image by the fourth and fifth converging groups. 9. The catadioptric projection optical system according to claim 3, wherein the optical system satisfies the following conditions. 10. The third converging group, wherein a peripheral portion of an area where the first intermediate image is formed in the first selection optical system and a pupil plane of the third converging group are set to have a conjugate relationship. 10. The catadioptric projection optical system according to claim 3, wherein a pupil plane of the second selective optical system and a peripheral portion of a region where the second intermediate image is formed in the second selection optical system are set to have a conjugate relationship. system. 11. The first convergent group having a rear principal point and the first convergent group and
Approximately equal to the focal length f ₁ of the first converging group the distance between the position where the first intermediate image in the selection optical system is imaged, so that the telecentric optical system substantially at the first surface side The catadioptric projection optical system according to any one of claims 3 to 10, wherein: 12. The front principal point of the fifth convergent group and the second principal point
Approximately equal to the focal length f ₅ of the fifth converging group the distance between the position where the second intermediate image in the selection optical system is imaged, so that the telecentric optical system substantially in the second surface side The catadioptric projection optical system according to any one of claims 3 to 11, wherein: 13. The method according to claim 13, wherein a rear principal point of the first converging group and the first
Substantially equal sets, the second selection with the front principal point of the fifth converging group to the focal length f ₁ of the first converging group the distance between the position where the first intermediate image in the selection optical system is imaged In the optical system, the distance from the position where the second intermediate image is formed is set to the fifth position.
Claim 3-12 substantially equal to the focal length f ₅ of the converging group, characterized in that set to be substantially telecentric optical system, respectively the first surface side and the second surface side
A catadioptric projection optical system as described. 14. A catadioptric projection optical system according to claim 1, wherein a mask is arranged on the first surface, a substrate is arranged on the second surface, and the pattern of the mask is changed. An exposure apparatus for exposing the substrate via the catadioptric projection optical system. 15. A mask is arranged on a first surface, and a substrate is arranged on a second surface, and the pattern of the mask is changed via the catadioptric projection optical system according to any one of claims 1 to 13. An exposure method comprising exposing a substrate.