JP2005086148A - Extreme ultraviolet ray optical system and exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extreme ultraviolet ray optical system capable of improving image formation performance by reducing the adverse effects of stray light, and an exposure device provided with such optical system. <P>SOLUTION: The projection optical system of an exposure device is provided with a total of six mirrors (multilayer mirrors) M1 to M6. Each of the mirrors M1 to M6 is held by a holding mechanism, respectively, and can be finely positioned by a position adjusting mechanism. In this optical system, a total of six stray light stops 41 to 46 are arranged. Each of the stray light stops 41 to 46 is for preventing the stray light from an EUV luminous flux E from reaching a wafer W located at the downstream of the optical system. According to this exposure device, stray light can be intercepted by the stray light stops 41 to 46. Thus, the adverse effects of the stray light to exposure are reduced, and the contrast of an exposure pattern can be improved. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an extreme ultraviolet (Extreme Ultra Violet line: EUV ray) optical system including a multilayer film reflecting mirror and an exposure apparatus including such an optical system.

  In recent years, with the miniaturization of semiconductor integrated circuits, a projection lithography technique using EUV light having a wavelength of about 13 nm has been developed in order to improve the resolution of an optical system limited by the diffraction limit of light. In such an exposure apparatus using EUV light, generally, a reflection optical system in which a reflecting mirror (mirror) is combined is used. An example optical system includes four or six EUV reflectors coated with a multilayer film. These reflecting mirrors achieve a high reflectance by the interference effect by matching the phases of reflected light at each interface of the multilayer film.

Hereinafter, an example of the EUV exposure apparatus will be described with reference to FIGS. 6 and 7.
FIG. 6 is a schematic block diagram showing an example of an EUV exposure apparatus.
FIG. 7 is a view showing a mirror arrangement of the projection optical system of the EUV exposure apparatus of FIG.
The EUV exposure apparatus shown in FIG. 6 includes an illumination system IL including a light source. EUV light radiated from the illumination system IL (generally, a wavelength of 5 to 20 nm is used, specifically, a wavelength of 13 nm or 11 nm is used) is reflected by the folding mirror 1 and applied to the reticle 2.

  The reticle 2 is held on the reticle stage 3. The reticle stage 3 has a stroke of 100 mm or more in the scanning direction (Y axis), has a minute stroke in the direction (X axis) perpendicular to the scanning direction in the reticle surface, and is also minute in the optical axis direction (Z axis). Have a stroke. The position in the XY direction is monitored with high accuracy by a laser interferometer (not shown), and the Z direction is monitored by a reticle focus sensor including a reticle focus light transmission system 4 and a reticle focus light reception system 5.

  The EUV light reflected by the reticle 2 enters the lower optical barrel 14 in the drawing. This EUV light includes information on a circuit pattern drawn on the reticle 2. The reticle 2 is formed with a multilayer film (for example, Mo / Si or Mo / Be) that reflects EUV light, and is patterned on the multilayer film with or without an absorption layer (for example, Ni or Al).

  In the optical barrel 14, six mirrors M1 to M6 are arranged as shown in FIG. Although not shown, each of the mirrors M1 to M6 is held by a hold mechanism and can be finely moved by the position adjusting mechanism. The EUV light reflected by the reticle 2 and entering the optical barrel 14 is reflected by the first mirror M1, and then the second mirror M2, the third mirror M3, the fourth mirror M4, the fifth mirror M5, and the sixth mirror. M6 is sequentially reflected, and finally enters the wafer 10 perpendicularly. The reduction magnification of the projection system is, for example, 1/4 or 1/5. In this example, there are 6 mirrors, but there are also 4 or 8 mirrors. An aperture stop 6 that defines the numerical aperture (NA) is disposed between the first mirror M1 and the second mirror M2.

  Returning to FIG. 6, the wafer 10 is placed on the wafer stage 11. The wafer stage 11 can freely move in a plane (XY plane) orthogonal to the optical axis, and the stroke is, for example, 300 to 400 mm. The wafer stage 11 can move up and down a minute stroke also in the optical axis direction (Z axis), and the position in the Z direction is monitored by a wafer focus sensor comprising a wafer autofocus light transmission system 12 and a wafer autofocus light reception system 13. ing. The position of the wafer stage 11 in the XY direction is monitored with high accuracy by a laser interferometer (not shown). In the exposure operation, the reticle stage 3 and the wafer stage 11 perform synchronous scanning at the same speed ratio as the reduction magnification of the projection system, that is, 4: 1 or 5: 1. An alignment off-axis microscope 15 is disposed in the vicinity of the optical barrel 14.

  The EUV exposure apparatus described above has an orderly smaller surface reflectance of an object having a normal surface than an exposure apparatus using ultraviolet rays. For this reason, the EUV exposure apparatus is less likely to generate stray light than the ultraviolet exposure apparatus. However, even in the EUV exposure apparatus, when the incident angle on the surface of the object is very small (so-called oblique incidence), the reflectance by the glass surface or metal surface becomes relatively large due to the total reflection phenomenon. Then, part of the EUV light reflected in such a state may reach the wafer 10 as stray light. When stray light reaches the wafer 10, the imaging performance of the optical system is deteriorated.

  In order to suppress such adverse effects of stray light, it is considered to provide a plate (stray light aperture) for blocking stray light in the optical barrel 14. However, the EUV optical system is a reflective optical system in which EUV light is reflected by a plurality of mirrors (six in FIG. 7), and the optical paths of the EUV light are likely to be complicated. For this reason, it is difficult to appropriately arrange the stray light aperture while securing the EUV optical path inside the optical system.

  The present invention has been made in view of the above problems, and provides an extreme ultraviolet optical system capable of reducing the adverse effects of stray light and improving imaging performance, and an exposure apparatus including such an optical system. The purpose is to do.

  A first extreme ultraviolet optical system according to the present invention includes a plurality of multilayer film reflecting mirrors (mirrors) that reflect extreme ultraviolet light, and a stray light stop disposed between or in the vicinity of the plurality of mirrors. The stray light stop is arranged along a surface that intersects the optical axis of the optical system and through which the light beam of the optical system passes only once.

  In this extreme ultraviolet optical system, a stray light stop is arranged along a surface through which the light beam of the optical system passes only once among the surfaces intersecting the optical axis of the optical system. Since stray light can be sufficiently blocked basically at one place in the optical system, it is preferable to block stray light with a smaller number of stray light stops because the configuration in the optical system is not complicated.

In the first extreme ultraviolet optical system of the present invention, the stray light stop is disposed along a surface where a cross-sectional area of the light beam of the optical system is a minimum value among surfaces intersecting the optical axis of the optical system. Can be.
The size of the stray light diaphragm itself can be reduced by being along the surface where the cross-sectional area of the light beam is minimized. Therefore, the coexistence arrangement of the stray light stop and a member in the vicinity of the mirror in the optical system (for example, a mirror holding mechanism or a position adjusting mechanism) is facilitated.

In the first extreme ultraviolet optical system of the present invention, the optical system may have at least one intermediate imaging plane, and the stray light stop may be disposed along the intermediate imaging plane. .
The intermediate image plane corresponds to an approximate conjugate position between the object plane (reticle) and the image plane (wafer), and here, the light beam is temporarily focused. In view of this, it is possible to efficiently block stray light by arranging a stray light stop on the intermediate image plane.

  In a more specific aspect of the first extreme ultraviolet optical system of the present invention, the optical system is a six-lens optical system including six mirrors, and follows the optical path from the imaging plane side of the six-optical system. Thus, the stray light stop may be disposed between the second and third mirrors.

In the first extreme ultraviolet optical system of the present invention, an aperture stop is disposed between two of the plurality of mirrors, and the stray light aperture is disposed adjacent to the aperture stop. It can be.
In this case, there is an advantage that stray light generated by irradiating the aperture stop with extreme ultraviolet rays can be efficiently removed.

  In a more specific aspect of the first extreme ultraviolet optical system of the present invention, the optical system is a six-lens optical system including six mirrors, and follows the optical path from the imaging plane side of the six-optical system. Thus, the stray light stop may be arranged between a mirror group composed of the first and second mirrors and a mirror group composed of the third to sixth mirrors.

In the first extreme ultraviolet optical system of the present invention, the stray light stop is disposed between the imaging surface and a mirror closest to the imaging surface among the plurality of mirrors. Can do.
In this case, stray light can be blocked immediately before the light beam is imaged.

Further, the stray light stop may be disposed between the object plane irradiated with the extreme ultraviolet rays and a mirror closest to the object plane among the plurality of mirrors.
In this case, stray light can be blocked before the light beam enters the mirror.

  In the second extreme ultraviolet optical system of the present invention, an extreme ultraviolet optical system comprising: a plurality of multilayer film reflecting mirrors (mirrors) that reflect extreme ultraviolet light; and a stray light stop disposed between or in the vicinity of the plurality of mirrors. A stray light stop is disposed between the extreme ultraviolet light beam and an end face of the mirror disposed adjacent to the light beam.

  It is effective to arrange the stray light aperture in a place where stray light is likely to be generated. For example, stray light may be generated when a part of a light beam is reflected or scattered upon a member disposed adjacent to the optical path. For this reason, when the end face of the mirror is arranged so as to be substantially parallel to the traveling direction of the light beam, stray light may be generated when a part of the light beam is obliquely incident on the end face of the mirror and reflected. According to this aspect of the present invention, the effect of lowering the reflectance by setting the incident angle large and the effect of deviating the direction of the reflected light from the direction of the effective light beam are produced, so that the adverse effect of stray light can be reduced.

In the second extreme ultraviolet optical system of the present invention, the stray light stop may be formed of a cylindrical body having a truncated cone surface.
Such a stray light stop is arranged so that the cross-sectional diameter of the cone increases toward the downstream side of the light beam (that is, the larger mouth faces the downstream side of the light beam). Then, from the upstream side of the luminous flux, the surface area of the stray light diaphragm gradually increases, so that the area for blocking and absorbing stray light is widened, and part of the reflected light of stray light can be excluded from the optical path. It becomes possible. Furthermore, such a truncated cone shaped stray light stop has an advantage that it can be easily installed even in a place where the distance between adjacent optical paths is narrow.

In the second extreme ultraviolet optical system of the present invention, the stray light stops may be arranged in a plurality of stages along the optical axis of the optical system.
In this case, the number of stages of the stray light aperture varies depending on the arrangement space in the optical system, the stray light blocking efficiency, and the like.

In the second extreme ultraviolet optical system of the present invention, a temperature adjusting mechanism may be attached to the stray light diaphragm.
Since the extreme ultraviolet optical system is used in a vacuum, the stray light diaphragm is disposed in an environment close to a heat insulation state. It is also assumed that the stray light diaphragm rises in temperature by being irradiated with extreme ultraviolet rays and is thermally deformed. In this aspect of the present invention, a temperature adjustment mechanism (for example, an electronic cooling element) is attached to the stray light aperture, so that an increase in the temperature of the stray light aperture can be suppressed.

  An exposure apparatus of the present invention is an exposure apparatus that selectively irradiates extreme ultraviolet rays onto a sensitive substrate to form a pattern, and comprises the extreme ultraviolet optical system according to any one of claims 1 to 12. And

  According to such an exposure apparatus, since the stray light can be blocked by the stray light aperture, the adverse effect of the stray light on the exposure can be reduced and the contrast of the exposure pattern can be improved.

  In the exposure apparatus of the present invention, further comprising an illumination optical system for illuminating the original on which the pattern to be transferred on the sensitive substrate is irradiated with extreme ultraviolet rays, the stray light stop according to any one of claims 1 to 12, The opening for ensuring the optical path of the said illumination optical system shall be opened.

  In the exposure apparatus of the present invention, a sensitive substrate stage for moving / positioning the sensitive substrate, an original stage for placing and moving / positioning the original plate, and an optical sensor for detecting the position / posture of these stages, The stray light diaphragm according to any one of claims 1 to 12, further comprising an opening for securing an optical path of the optical sensor.

  ADVANTAGE OF THE INVENTION According to this invention, the extreme ultraviolet optical system etc. which can reduce the bad influence of stray light and can improve imaging performance can be provided.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram schematically showing a projection optical system of an EUV exposure apparatus according to an embodiment of the present invention.
The basic configuration of the entire EUV exposure apparatus can be the same as that shown in FIG.

  The projection optical system of the exposure apparatus shown in FIG. 1 includes a total of six mirrors M1 to M6. Although not shown, each of the mirrors M1 to M6 is held by a hold mechanism and can be finely moved by the position adjusting mechanism. The code | symbol attached | subjected to each mirror M1-M6 means that it is located in the downstream from the upstream of the EUV light beam E as a number becomes large. Each of the mirrors M1 to M6 is a multilayer mirror in which a multilayer film formed by alternately laminating Mo / Si, for example, is coated on the surface (mirror reflection surface) of a substrate such as low thermal expansion glass.

  In the optical system of FIG. 1, an aperture stop 20 that defines the numerical aperture (NA) is disposed between the first mirror M1 and the second mirror M2. The aperture stop 20 in this example is a plate having an opening 20a through which an effective light beam passes. As such an aperture stop 20, for example, the one disclosed in Japanese Patent Application No. 2003-012306 can be used.

In this example, a total of six stray light stops 41 to 46 are arranged in the optical system of FIG. Each of the stray light stops 41 to 46 is for preventing stray light from the EUV light flux E from reaching the wafer W downstream of the optical system (same as reference numeral 10 in FIG. 6).
Hereinafter, these stray light stops 41 to 46 will be described in detail. In addition, the specific aspect of each stray light stop is demonstrated later, referring FIGS.

  The stray light stop 41 is disposed on the intermediate image plane between the fourth mirror M4 and the fifth mirror M5. The intermediate imaging plane corresponds to a conjugate position between the reticle R (object plane) and the wafer W (image plane), and is a plane on which the EUV light beam E is temporarily focused. The stray light stop 41 disposed on the intermediate imaging plane efficiently blocks stray light that is reflected by the fourth mirror M4 and generated when reaching the fifth mirror M5 through the intermediate imaging plane.

  The stray light stop 42 is disposed adjacent to the aperture stop 20 between the first mirror M1 and the second mirror M2. The stray light stop 42 blocks stray light that is reflected when the light is reflected by the first mirror M1 and reaches the second mirror M2. The configuration of the stray light stop 42 will be described in detail later with reference to FIG.

  The stray light stop 43 is disposed between the reticle R (same as reference numeral 2 in FIG. 6) and the upper end of the optical system. The stray light stop 43 includes a hole 43a through which an EUV light beam is emitted while being emitted from the illumination optical system (symbol IL in FIG. 6) and irradiating the reticle R, and while being reflected by the reticle R and incident on the projection optical system. A hole 43b through which the EUV light beam passes is formed. When the EUV light beam passes through the holes 43a and 43b, most of stray light is blocked before entering the projection optical system.

  The stray light stop 44 is disposed between the back surface of the first mirror M1 and the back surface of the sixth mirror M6. The stray light stop 44 blocks stray light generated when reaching the fifth mirror M5 through the upstream stray light stop 41 (intermediate imaging plane). The stray light stop 44 is arranged along a surface through which the light beam of the optical system passes only once among the surfaces intersecting the optical axis C of the optical system. Since stray light can be sufficiently blocked basically at one place in the optical system, a sufficient blocking effect can be obtained even if only this stray light stop 44 is provided.

  The stray light stop 45 is disposed between the wafer W and the lower end of the optical system. The stray light diaphragm 45 blocks stray light that is reflected when reaching the wafer W by being reflected by the sixth mirror M6. The stray light stop 45 is also arranged along the surface through which the light beam of the optical system passes only once among the surfaces intersecting the optical axis C of the optical system, like the stray light stop 44 described above. Therefore, even if only the stray light diaphragm 45 is disposed in some cases, a sufficient blocking effect can be obtained. The configuration near the stray light stop 45 will be described in detail later with reference to FIG.

  The stray light stop 46 is disposed in the vicinity of the end face of the third mirror M3. The stray light may be generated when a part of the light beam hits the mirror end face and is reflected or scattered. According to the stray light stop 46, it is possible to block stray light that is reflected or scattered especially on the end face of the third mirror M3. The stray light stop 46 will be described in detail later with reference to FIG.

  Each of these stray light stops 41 to 46 is provided with a temperature adjustment mechanism H such as a Peltier element (only the temperature adjustment mechanism H of the stray light stop 41 is shown in FIG. 1). Since the inside of the projection optical system of the EUV exposure apparatus is evacuated, the stray light stops 41 to 46 are arranged in an environment close to a heat insulation state. For this reason, when a part of the EUV light flux E is irradiated on the stray light stops 41 to 46, the temperature easily rises and thermal deformation is assumed to occur. However, by cooling with the temperature adjusting mechanism H, the stray light stop 41 is cooled. The temperature rise of -46 can be suppressed.

Next, specific examples of each stray light stop will be described.
2A to 2C are diagrams showing examples of the stray light diaphragm according to the present invention.
The stray light stop 51 shown in FIG. 2A has a hole 51a formed at the center of a rectangular plate. In the stray light stop 51, the effective light beam E passes through the central hole 51a, and the stray light E ′ is blocked around the hole 51a. The stray light stop 51 is the most standard form, and can be applied to the stray light stops 41 and 44 in FIG.

  The stray light stop 53 shown in FIG. 2B is a cylindrical body having a truncated cone surface 53a. In such a stray light stop 53, the cone has a cross-sectional diameter that increases toward the downstream side of the effective light beam E (that is, the large opening 53b is on the downstream side of the effective light beam E, and the small opening 53c is on the upstream side of the effective light beam E). So that it faces). Then, since the area of the truncated cone surface 53a of the stray light stop 53 gradually increases from the upstream side of the effective light beam E, the area for blocking / absorbing the stray light E ′ is increased and the reflected light of the stray light E ′ is increased. It is also possible to exclude a part of the optical path outside the optical path. Such a stray light stop 53 has an advantage that it is easy to install even in a place where the distance between adjacent optical paths is narrow (for example, a place where the stray light stop 42 in FIG. 1 is disposed).

  The stray light stop 55 shown in FIG. 2C is a structure in which the stray light stop 51 shown in FIG. 2A is arranged in a plurality of stages (in this example, three stages) along the direction of the effective light beam E. The number of stages can be appropriately selected according to the arrangement space in the optical system, the blocking efficiency of stray light E ′, and the like.

FIG. 3A is a schematic diagram for explaining the behavior of stray light in the conventional case where no stray light stop is provided near the mirror end face, and FIG. 3B relates to the present invention in which the stray light stop is provided near the mirror end face. It is a schematic diagram explaining the behavior of the stray light in the case.
As shown in FIG. 3A, when the end surface M ′ of the mirror M in the optical system is arranged so as to be substantially parallel to the traveling direction of the effective light beam E, a part of the effective light beam E is part of the mirror end surface. The stray light E ′ may be generated by obliquely incident on M ′ and reflected. Therefore, as shown in FIG. 3B, a stray light stop 57 is disposed between the effective light beam E and the end face M ′ of the mirror M disposed adjacent thereto. Then, the effect of lowering the reflectance by setting the incident angle of the stray light E ′ to be large (increase the oblique incident angle) and the effect of deviating the direction of the reflected light of the stray light E ′ from the direction of the effective light flux E are generated. The adverse effect of stray light E ′ can be reduced. The stray light stop 46 of FIG. 1 employs the stray light stop 57 of FIG. 3B.

4A and 4B are views showing other examples of the stray light diaphragm according to the present invention, respectively.
FIG. 4 shows a specific example of the stray light stop 42 in FIG. 4A are semi-cylindrical plate-like stray light stops 61 and 62 that are integrally formed point-symmetrically with respect to the center of the aperture stop 20 above and below the aperture stop 20, respectively. A temperature adjustment mechanism H such as a Peltier element is provided on the back surface of each of the stray light apertures 61 and 62. On the other hand, the semi-cylindrical plate-like stray light stops 61 and 62 in FIG. 4B are arranged close to the center of the aperture stop 20 in a point-symmetrical manner above and below the aperture stop 20, and each stray light stop 61, Semi-ring shaped end plates 61 a and 62 a are provided at the end of 62.

  4A can block the stray light E ′, but it may not be able to block the stray light E ″. The stray light in FIG. 4B may not be blocked. The diaphragm can also block such stray light E ″ by the end plates 61a and 62a. Therefore, in practice, FIG. 4B is preferable to FIG. 4A, and this is preferably used as the stray light stop 42 in FIG.

FIG. 5 is a schematic diagram showing a configuration in the vicinity of the wafer stage of the exposure apparatus according to the present invention.
FIG. 5 shows a specific example of the stray light stop 45 in FIG. In FIG. 5, the wafer stage 11, the wafer autofocus light transmission system 12, the wafer autofocus light reception system 13, and the off-axis microscope 15 for alignment described above with reference to FIG. 6 are shown. On the wafer stage 11, a wafer W (10) is placed.

  The stray light stop 45 disposed between the fifth mirror M5 and the wafer W may have an opening that secures the optical path of the optical sensor. Holes 45a, 45b, and 45c for securing the optical paths of the autofocus light transmission system 12, the autofocus light reception system 13, and the off-axis microscope 15 are formed. By providing these holes 45a, 45b, and 45c, stray light from the EUV light beam E can be blocked without impairing the performance of the autofocus light transmission system 12, the autofocus light receiving system 13, and the off-axis microscope 15.

  As described above, when the stray light stop according to the present embodiment was used, according to the findings, the intensity of the stray light reaching the wafer could be reduced to 1/50 or less compared to the conventional case. As a result, the adverse effect of stray light on the exposure is reduced, and the contrast of the exposure pattern can be improved.

It is a figure which shows typically the projection optical system of the EUV exposure apparatus which concerns on one Example of this invention. It is a figure which shows the example of the stray-light stop which concerns on this invention. FIG. 3A is a schematic diagram for explaining the behavior of stray light in the conventional case where no stray light stop is provided near the mirror end face, and FIG. 3B relates to the present invention in which the stray light stop is provided near the mirror end face. It is a schematic diagram explaining the behavior of the stray light in the case. It is a figure which shows the other example of the stray light aperture_diaphragm | restriction based on this invention. It is a schematic diagram which shows the structure of the wafer stage vicinity of the exposure apparatus which concerns on this invention. It is a schematic block diagram which shows an example of EUV exposure apparatus. It is a figure which shows the mirror arrangement | positioning of the projection optical system of the EUV exposure apparatus of FIG.

Explanation of symbols

M1 to M6 Mirror IL Illumination system 2 (R) Reticle 3 Reticle stage 4 Reticle focus light transmission system 5 Reticle focus light reception system 14 Optical barrel 10 (W) Wafer 11 Wafer stage 12 Wafer autofocus light transmission system 13 Wafer autofocus light reception System 15 Off-axis microscope 20 Aperture stop 20a Apertures 41 to 46, 51, 53, 57, 61, 62 Stray light stops 43a, 43b, 45a, 45b, 45c, 51a Hole 53a Frustum surface 53b Large aperture 53c Small aperture 61a, 62a End Board

Claims (15)

A plurality of multilayer mirrors that reflect extreme ultraviolet radiation;
A stray light stop disposed between or near the plurality of mirrors;
An extreme ultraviolet optical system comprising:
An extreme ultraviolet optical system, wherein the stray light stop is disposed along a surface through which a light beam of the optical system passes only once among surfaces intersecting the optical axis of the optical system.   2. The extreme ultraviolet light according to claim 1, wherein the stray light stop is disposed along a surface where a cross-sectional area of a light beam of the optical system becomes a minimum value among surfaces intersecting the optical axis of the optical system. Optical system.   The extreme ultraviolet optical system according to claim 1, wherein the optical system has at least one intermediate imaging plane, and the stray light stop is disposed along the intermediate imaging plane.   The optical system is a six-lens optical system including six of the mirrors, and the stray light diaphragm is disposed between the second and third mirrors along the optical path from the imaging plane side of the six-optical system. The extreme ultraviolet optical system according to claim 1, 2, or 3.   5. The aperture stop is disposed between two of the plurality of mirrors, and the stray light stop is disposed adjacent to the aperture stop. 6. The extreme ultraviolet optical system described.   The optical system is a six-lens optical system including six of the mirrors, a mirror group including a first and a second mirror along the optical path from the imaging plane side of the six-optical system, and a third The extreme ultraviolet optical system according to any one of claims 1 to 5, wherein the stray light stop is disposed between the first to sixth mirror groups.   7. The extreme according to claim 1, wherein the stray light stop is disposed between the imaging plane and a mirror closest to the imaging plane among the plurality of mirrors. UV optical system.   The stray light diaphragm is arranged between the object surface irradiated with the extreme ultraviolet light and the mirror closest to the object surface among the plurality of mirrors. The extreme ultraviolet optical system according to item. A plurality of multilayer mirrors that reflect extreme ultraviolet radiation;
A stray light stop disposed between or near the plurality of mirrors;
An extreme ultraviolet optical system comprising:
The extreme ultraviolet optical system, wherein the stray light stop is disposed between the extreme ultraviolet light beam and an end face of the mirror disposed adjacent to the light beam.   The extreme ultraviolet optical system according to any one of claims 1 to 9, wherein the stray light stop is formed of a cylindrical body having a truncated cone surface.   The extreme ultraviolet optical system according to claim 1, wherein the stray light diaphragm is arranged in a plurality of stages along an optical axis of the optical system.   The extreme ultraviolet optical system according to claim 1, wherein a temperature adjusting mechanism is attached to the stray light diaphragm. An exposure apparatus that selectively irradiates extreme ultraviolet rays onto a sensitive substrate to form a pattern,
An exposure apparatus comprising the extreme ultraviolet optical system according to claim 1. Further comprising an illumination optical system for illuminating the original on which the pattern to be transferred on the sensitive substrate is irradiated with extreme ultraviolet rays,
14. The exposure apparatus according to claim 13, wherein the stray light stop according to any one of claims 1 to 12 is provided with an opening for securing an optical path of the illumination optical system. A sensitive substrate stage for moving and positioning the sensitive substrate;
An original stage for placing and moving and positioning the original;
An optical sensor for detecting the position and orientation of these stages;
Further comprising
The exposure apparatus according to claim 14 or 15, wherein an opening for securing an optical path of the optical sensor is formed in the stray light stop according to any one of claims 1 to 12.

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