JP2011142150A - Illumination optical system, aligner using the same, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination optical system which ensures high illumination efficiency while using a discharge tube of a normal ultra-high-voltage mercury vapor lamp or a laser light source, without using a special light source. <P>SOLUTION: This invention relates to the illumination optical system 10 in which an object to be irradiated is irradiated with light introduced from a light source 18. The illumination optical system 10 includes a circulation optical system 17 which acquires part of light incident on a plane 14 conjugate to the object to be irradiated and guides again the acquired light to the plane 14 conjugate to the object to be irradiated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an illumination optical system, an exposure apparatus using the illumination optical system, and a device manufacturing method.

  In a lithography process, which is a manufacturing process for semiconductor devices, liquid crystal display devices, and the like, an exposure apparatus uses a pattern of an original (reticle or mask) as a photosensitive substrate (a resist layer is formed on the surface) via a projection optical system. A transfer device to a wafer, a glass plate, or the like). For example, in a projection exposure apparatus that transfers a pattern to a liquid crystal display device, in recent years, there has been a demand for an exposure apparatus that collectively exposes a larger area pattern on a mask onto a substrate. In order to meet this demand, a scanning projection exposure apparatus of a step-and-scan method capable of obtaining a high resolution and exposing a large screen has been proposed. In this scanning exposure apparatus, a pattern illuminated by a slit light beam is exposed and transferred onto a substrate by a scanning operation via a projection optical system.

  As such a scanning exposure apparatus, there is a method of scanning using arc-shaped light. In this method, a projection optical system exists between a first object having a pattern to be transferred and a second object that is an object to be transferred, and only a specific off-axis image point of the projection optical system is detected. The exposure process is performed in the arc-shaped exposure area used. At this time, as an illumination optical system for illuminating the first object in an arc shape, for example, Patent Document 1 discloses an illumination optical system that cuts out an arc from an area illuminated in a rectangular shape using an arc-shaped opening member. is doing.

Japanese Patent Publication No. 4-78002

  However, the arc cutting method shown in the technical document 1 cannot use light other than the arc opening for exposure, and the light use efficiency (illumination efficiency) is low.

  The present invention has been made in view of such circumstances, and provides an illumination optical system with good illumination efficiency without using a special light source and using a discharge tube or a laser light source of a normal ultrahigh pressure mercury lamp. With the goal.

  In order to solve the above problems, the present invention is an illumination optical system that irradiates an irradiation object with light introduced from a light source, and acquires a part of light incident on a surface conjugate with the irradiation object, It has a circulation optical system which guides the acquired light again to a surface conjugate with the irradiation object.

  According to the present invention, an illumination optical system with good illumination efficiency is obtained by using a circulation optical system, which conventionally does not reach a desired irradiation position and originally cannot be used as illumination light and is used again as illumination light. Can be provided.

It is the schematic which shows the structure of the illumination optical system which concerns on 1st Embodiment of this invention. It is the schematic which shows the structure of the illumination optical system which concerns on 2nd Embodiment of this invention. It is the schematic which shows the structure of a fly eye lens optical system. It is the schematic which shows the structure of a slit board. It is the schematic which shows the structure of the illumination optical system which concerns on 3rd Embodiment of this invention. It is the schematic which shows the structure of a slit board. It is the schematic which shows the injection | emission side cross section of a bundle fiber. It is the schematic which shows the structure of the exposure apparatus which concerns on embodiment of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
First, the configuration of the illumination optical system according to the first embodiment of the present invention will be described. Hereinafter, the illumination optical system of the present embodiment is mounted on an exposure apparatus, for example, and is an apparatus for guiding light from a light source to a mask (original plate) on which a pattern that is an irradiation target is formed. FIG. 1 is a schematic diagram illustrating a configuration of an illumination optical system according to the present embodiment. The illumination optical system 10 includes a first optical system 11, an integrator 13, a second optical system 15, and a third optical system 17.

  The first optical system 11 is an optical system that guides the light emitted from the light source 18 to the first irradiation surface 12, and includes a mirror 19 that deflects the traveling direction of the irradiation light, and a lens that collects the light from the mirror 19. 20. In the present embodiment, in addition to the above-described action, the mirror 19 has a function of guiding light from a third optical system 17 described later to the lens 20, so that light introduced from two directions is guided in the same direction. It is formed as a triangular prism. For example, a beam splitter or a prism may be used as an alternative member of the mirror 19 as long as the above-described action can be obtained. Further, although the lens 20 is described as one optical element for the sake of explanation, it may be composed of a plurality of optical elements. The light source 18 applied to the illumination optical system 10 of the present embodiment uses a laser light source such as an ArF excimer laser having a wavelength of about 193 nm, a KrF excimer laser having a wavelength of about 248 nm, or an F2 excimer laser having a wavelength of about 157 nm. . However, the type of laser is not limited to the excimer laser, and for example, a YAG laser may be used, and the number of lasers is not limited. Further, the light source 18 is not limited to the laser light source, and one or a plurality of lamps such as a mercury lamp and a xenon lamp can be used.

  The light from the first optical system 11 is guided to the integrator 13 that forms the secondary light source through the first irradiation surface 12. The first illumination surface 12 corresponds to the incident surface of the integrator 13. The integrator 13 is an optical system for increasing the illuminance uniformity of the second irradiation surface 16. For example, a lot-shaped or cylindrical-shaped fly-eye lens optical system, an optical system using an optical fiber, or the like is used. The light from the integrator 13 is guided to the second optical system 15 through the secondary light source surface 14. For example, when a fly-eye lens optical system is adopted for the integrator 13, a number of secondary light source distributions equivalent to the light source 18 are formed on the secondary light source surface 14. The second optical system 15 is an optical system arranged so that the second irradiation surface 16 substantially becomes a Fourier transform surface (pupil conjugate surface) of the secondary light source surface 14. By adopting the configuration as described above, the secondary light source surface 14 performs Koehler illumination on the second irradiation surface 16, and the illuminance distribution on the second irradiation surface 16 becomes substantially uniform. Moreover, the 1st irradiation surface 12 and the 2nd irradiation surface 16 become a conjugate relation substantially. The light transmitted through the second illumination surface 16 illuminates a mask disposed on a surface conjugate with the second illumination surface 16.

  The third optical system 17 is a circulating optical system that acquires a part of the light reaching the second irradiation surface 16 and guides it to the first optical system 11 again. The third optical system 17 includes a mirror 21 installed on a part of the second irradiation surface 16 and an optical element group 22 that guides light acquired from the mirror 21 to the mirror 19 in the first optical system 11 again. . The first mirror 21 is a reflection unit for acquiring a part of the light that has reached the second irradiation surface 16. In addition, in this embodiment, although this reflection part is made into the mirror, if the effect | action which acquires a part of light is acquired, it will not be limited to a mirror. The optical element group 22 is an optical path that guides the acquired light to the mirror 19 and includes, for example, optical elements such as a plurality of mirrors and lenses. The configuration of the optical element group 22 is not particularly limited as long as the obtained light can be guided to the mirror 19.

Next, the operation of the illumination optical system 10 will be described. First, the light emitted from the light source 18 is introduced into the first irradiation surface 12 via the first optical system 11, and sequentially passes through the integrator 13, the secondary light source forming surface 14, and the second optical system 15, and then the second irradiation. The desired irradiation position on the surface 16 is irradiated. In addition, in the present embodiment, a part of the light reaching the second irradiation surface 16 is acquired by the mirror 21 and the third optical system 17, guided into the first optical system 11, and used again as irradiation light. . The light acquired from the second irradiation surface 16 is, for example, other than the opening when a slit plate (field stop) for defining an illumination area in which an opening having a desired shape is provided on the second irradiation surface 16 (non-opening) It is assumed that the light is incident on a light shielding portion that is a transmission region. At this time, the irradiation light that passes through the opening of the slit plate includes light (first illumination light) that first enters after exiting the light source 18, and light that reaches a part of the first illumination light through the third optical system 17 (first illumination light). The second illumination light) and the light that has passed through the third optical system 17 (nth illumination light) n-1 times (n is a natural number). That is, the total illuminance on the second irradiation surface 16 is represented by the sum from the first illumination light to the nth illumination light. Here, the illuminance of light reaching the second irradiation surface 16 first is p, and the ratio of the first illumination light on the second irradiation surface 16 incident on the opening of the slit plate is r (0 ≦ r ≦ 1). Assume. Further, it is assumed that the energy efficiency of the collected light in the third optical system 17 when the light incident on other than the opening is collected by the third optical system 17 is f. At this time, since the illumination optical system 10 is used for several seconds or more, n takes an infinitely large value. Therefore, the total illuminance W at the opening of the second irradiation surface 16 is expressed as a sum of an infinite series as shown in the following equation. Is done.
W = pr / (1-f + rf) (1)
Here, as an example, when r = 0.2 and f = 0.6 are substituted into the equation (1), the illumination optical system 10 can double the illumination efficiency.

  As described above, for example, when a field stop provided with a slit having a desired shape is arranged on the second irradiation surface 16, light incident on other than the slit opening is not normally used as illumination light. In the first embodiment, the light is collected and reused without being discarded. Therefore, the illuminance of light passing through the opening can be improved to illuminate the mask, and the illumination efficiency of the illumination optical system can be improved. Since the first irradiation surface 12 and the second irradiation surface 16 are substantially conjugated as described above, the first mirror 21 of the third optical system 17 is installed in the vicinity of the first irradiation surface 12. However, the same effect can be obtained.

(Second Embodiment)
Next, the configuration of the illumination optical system according to the second embodiment of the present invention will be described. FIG. 2 is a schematic diagram showing the configuration of the illumination optical system according to the present embodiment. The illumination optical system 30 includes a first optical system 31, a fly-eye lens optical system 32, a second optical system 33, and a third optical system 35. The first optical system 31 is an optical system that guides the light emitted from the light source 36 to the incident surface of the fly-eye lens optical system 32, and the incident surface of the fly-eye lens optical system 32 is a lamp unit 37 of the light source 36 described later. Are arranged so as to be substantially a Fourier transform plane. In addition, although the 1st optical system 31 is made into one optical element on description, it may be comprised with a some optical element. The light source 36 applied to the illumination optical system 30 of the present embodiment uses, for example, a mercury lamp or a xenon-mercury lamp. The light source 36 includes a lamp unit 37 and a condensing mirror 38. The lamp unit 37 employs a mercury lamp or the like, and the condensing mirror 38 employs, for example, an elliptical condensing mirror. The light generated from the lamp unit 37 is collected by the condenser mirror 38 and guided to the fly-eye lens optical system 32 through the first optical system 31.

  The fly-eye lens optical system 32 has the following configuration in order to illuminate the first irradiation surface 34 in an arc shape instead of a rectangular shape. FIG. 3 is a schematic view showing the configuration of the fly-eye lens optical system 32, FIG. 3 (a) is a side view, and FIG. 3 (b) is a plan view seen from the light incident side. As shown in FIG. 3A, the fly-eye lens optical system 32 has a first fly-eye paired with a large number of plano-convex lenses in a planar shape, with their curvature surfaces facing each other, and paired with the focal position of each lens. A lens 32a and a second fly-eye lens 32b are provided. In this case, the curvature surfaces of the plano-convex lenses constituting the first fly-eye lens 32a and the second fly-eye lens 32b may change the curvature radius depending on the direction with respect to the lens cross section. In addition, as shown in FIG. 3B, each plano-convex lens constituting the first fly-eye lens 32a includes a transmission region portion 50 and a reflection region portion (reflection portion) on the respective incident surfaces (light source side). ) 51. At this time, since each plano-convex lens has an incident surface that is a conjugate surface with the first irradiation surface 34, the first irradiation surface 34 is illuminated by making each transmission region 50 of each plano-convex lens have an arc shape. The illumination area has an arc shape.

  The second optical system 33 is an optical system arranged such that the first irradiation surface 34 is substantially the Fourier transform surface of the exit surface of the fly-eye lens optical system 32. By adopting such a configuration, the light source 36 performs Kohler illumination on the first irradiation surface 34, and the illuminance distribution on the first irradiation surface 34 becomes substantially uniform. Further, the incident surface of the fly-eye lens optical system 32 and the first irradiation surface 34 are substantially conjugated. Furthermore, the 1st irradiation surface 34 has the slit board 52 for extracting the area | region of the illumination light to be used. FIG. 4 is a schematic view (plan view) showing the slit plate 52. The slit plate 52 is a field stop that cuts out an arc region from a rectangular region when the first irradiation surface 34 is illuminated in a rectangular shape, and includes an arc-shaped opening 53 and a light-shielding unit positioned on the outer periphery of the opening 53. 54.

  The third optical system 35 is a circulating optical system that acquires light that has reached the reflection region portion 51 from light incident on the fly-eye lens optical system 32 and introduces the light into the fly-eye lens optical system 32 again. The third optical system 35 includes an optical element group 39 that guides the light acquired from the reflection region portion 51 of the fly-eye lens optical system 32 to the fly-eye lens optical system 32 and a parallel plate 40. The optical element group 39 is an optical path that guides the acquired light to the fly-eye lens optical system 32, and includes a plurality of optical elements such as mirrors and lenses. Note that the configuration of the optical element group 39 is not particularly limited as long as the function of guiding the acquired light to the fly-eye lens optical system 32 can be obtained. The parallel plate 40 is a transmission plate installed so as to be inclined with respect to the optical axis, and shifts the light returned to the fly-eye lens optical system 32 from the reflection region 51 to the transmission region 50 as much as possible. Make it incident. At this time, the shift amount can be adjusted by the inclination angle, refractive index, or thickness of the parallel plate 40. The optical element group 39 and the parallel plate 40 are arranged so that the light reflected from the reflection region 51 and the light returned to the fly-eye lens optical system 32 are in a conjugate relationship.

Next, the operation of the illumination optical system 30 will be described. First, the light emitted from the light source 36 is introduced into the fly-eye lens optical system 32 through the first optical system 31 and sequentially passes through the second optical system 33 and the first irradiation surface 34 to obtain a desired irradiation position. Is irradiated. However, in the slit plate 52 installed on the first irradiation surface 34, the light normally passes through the opening 53, but the light incident on the light shielding part 54 is discarded, and the illumination efficiency is lowered. Therefore, in the present embodiment, the light that has reached the reflection region 51 is acquired by the fly-eye lens 32 and the third optical system 35, is guided again to the incident surface of the fly-eye lens optical system 32, and is used as irradiation light. . At this time, the light reaching the first irradiation surface 34 is first incident on the transmission region 50 and is first reflected by the reflection region 51 and passes through the third optical system 35 to fly eye lens optical system. Of the light returned to 32, the sum of the light incident on the transmission region 50 is represented. Here, the illuminance of the light that first irradiates the fly-eye lens optical system 32 is p, the ratio of the light that first enters the transmission region 50 in the fly-eye lens optical system 32 is r (0 ≦ r ≦ 1), It is assumed that the energy efficiency of light considering the optical vignetting of the three optical system 35 is f. Further, if the ratio of the light incident on the transmission region 50 out of the light returned to the fly-eye lens optical system 32 is g (0 ≦ g ≦ 1), the total illuminance W of the light reaching the first irradiation surface 34 Is expressed by the following equation.
W = p (r + fg−rfg) (2)
Here, as an example, when r = 0.2, f = 0.5, and g = 0.5 are substituted into Equation (2), the illumination optical system 30 can double the illumination efficiency.

  Thus, according to the present embodiment, the same effects as in the first embodiment can be obtained. In the present embodiment, the illumination with respect to the arc-shaped opening is exemplified. However, the present invention can also be applied to the case of illuminating an opening with a shape other than the arc shape. In this case, the same effect can be obtained by setting the region shapes of the transmissive region portion 50 and the reflective region portion 51 to desired regions, respectively. In the present embodiment, each lens constituting each fly-eye lens 32a, 32b is a plano-convex lens and employs a pair of fly-eye lenses 32 having curved surfaces facing each other. However, the present invention is not limited to this. . For example, as a configuration of the pair of fly-eye lenses 32, a form in which the planes of the plano-convex lenses face each other or a form in which each lens is a biconvex lens may be adopted. Furthermore, in the present embodiment, the third optical system 35 is arranged so that the light reflected from the reflection region 51 and the light returned to the fly-eye lens optical system 32 are in a conjugate relationship. This is a desirable example. Even when the conjugate relationship deviates, the effects of the present invention can be obtained.

(Third embodiment)
Next, the configuration of the illumination optical system according to the third embodiment of the present invention will be described. FIG. 5 is a schematic diagram showing the configuration of the illumination optical system according to the present embodiment. The illumination optical system 60 includes a first optical system 61, a second optical system 62, a fly-eye lens optical system 63, a third optical system 64, a slit plate 65, and a fourth optical system 66. First, the first optical system 61 is an optical system that guides the light emitted from the two light sources 67a and 67b to the second optical system 62. The first mirror 61 includes two mirrors 68a and 68b and a light source to the mirrors 68a and 68b. One or a plurality of optical elements 69a and 69b for guiding light from 67a and 67b. The two mirrors 68a and 68b are formed as triangular prisms in which one mirror guides light introduced from one direction to the other direction, and has an optical path that allows light from a fourth optical system 66 described later to pass therethrough. Installed on both sides. The second optical system 62 is an optical system that condenses light from the two mirrors 68a and 68b. The second optical system 62 is described as a single optical element for the sake of explanation, but it may be composed of a plurality of optical elements. Further, as in the second embodiment, for example, a mercury lamp or a xenon-mercury lamp is used as the light sources 67a and 67b applied to the illumination optical system 60 of the present embodiment.

  Similar to the integrator 13 in the first embodiment, the fly-eye lens optical system 63 is formed by, for example, arranging a plurality of rod-shaped or cylindrical lenses in a planar shape. The third optical system 64 is an optical system disposed so that the slit plate 65 substantially becomes a Fourier transform plane (pupil conjugate plane) of the exit surface of the fly-eye lens optical system 63. By adopting such a configuration, the exit surface of the fly-eye lens optical system 63 irradiates the slit plate 65 with Koehler illumination, and the illuminance distribution of light incident on the slit plate 65 becomes substantially uniform. Further, the entrance surface of the fly-eye lens optical system 63 and the slit plate 65 are substantially conjugate surfaces. Further, the slit plate 65 is a field stop for extracting a region of illumination light to be used, and FIG. 6 shows a schematic configuration diagram (plan view) of the slit plate 65. The slit plate 65 has an action of cutting out an arc region from a rectangular region, and includes an arc-shaped opening 70 and a fourth optical system introduction unit 71 located on the outer periphery of the opening 70.

  The fourth optical system 66 is an optical system that acquires light that has reached the fourth optical system introduction unit 71 out of light incident on the slit plate 65 and introduces it again into the upstream fly-eye lens optical system 63. The fourth optical system 66 includes a bundle fiber 72 and an optical element 73 that guides light emitted from the bundle fiber 72 to the second optical system 62. Although the optical element 73 represents one lens in FIG. 5, it may be a plurality of optical element groups. The bundle fiber 72 is a light transmission element composed of a plurality of optical fibers. At this time, as shown in FIG. 6, the incident side surface of the bundle fiber 72 is laid flat in the fourth optical system introduction unit 71. The light incident on the fourth optical system introducing portion 71 is transmitted by the bundle fiber 72 and reaches the emission side surface 72a shown in FIG. FIG. 7 is a schematic view showing the exit side surface 72 a of the bundle fiber 72. As shown in FIG. 7, on the emission side surface 72a, each line constituting the bundle fiber 72 is arranged in a circular shape. The light emitted from the emission side surface 72a passes between the two mirrors 68a and 68b and is incident on the second optical system 62 again.

Next, the operation of the illumination optical system 60 will be described. First, the light emitted from the light sources 67a and 67b is introduced into the second optical system 62 through the first optical system 61, and sequentially passes through the fly-eye lens optical system 63 and the third optical system 64, and the slit plate 65. The desired irradiation position is irradiated. However, in the slit plate 65, although the light normally passes through the opening 70, the light incident on the light shielding portion corresponding to the non-transmissive region of the fourth optical system introducing portion 71 is discarded, and the illumination efficiency is reduced. . Therefore, in the present embodiment, the light that has reached the fourth optical system introduction unit 71 is acquired by the fourth optical system 66, is guided again to the second optical system 62, and is used as irradiation light. Here, the illuminance of the light that first irradiates the slit plate 65 is p, and the area of the opening 70 is divided by the entire area of the slit plate 65 (the total area of the opening 70 and the fourth optical system introducing portion 71). And r is assumed to be f, and the energy efficiency of light by the bundle fiber 72 is assumed to be f. At this time, if the light that first irradiates the slit plate 65 is the first illumination light, and the light that passes through the bundle fiber 72 n times and then returns to the slit plate 65 is the (n + 1) th illumination light, The illuminance W is the sum of the (n + 1) th illumination light from the first illumination light. Furthermore, since n takes an infinitely large value by using the illumination optical system 60 of this embodiment for several seconds or more, the total illuminance W is expressed by the sum of an infinite series as shown in the following equation.
W = pr / (1-f + rf) (3)
Here, as an example, when r = 0.2 and f = 0.6 are substituted into the expression (3), the illumination optical system 60 can double the illumination efficiency.

  Thus, according to the present embodiment, the same effects as in the first embodiment can be obtained. In this embodiment, the emission side surface 72a of the bundle fiber 72 is arranged in a circular shape, but various shapes can be obtained by changing the optical element 73. In the present embodiment, the number of light sources is two, but it may be one or three or more. A part of the light incident on the surface conjugate with the irradiation object (irradiation surface) may be guided to another upstream irradiation surface or may be guided again to the same irradiation surface.

(Exposure equipment)
Next, an exposure apparatus that employs the illumination optical system of the present invention will be described. FIG. 8 is a schematic view showing the arrangement of an exposure apparatus that is an embodiment of the present invention. The exposure method of the exposure apparatus is a projection method in which a mask (original plate) pattern is projected and exposed on a substrate using a lens or a mirror, and a fine gap is provided between the mask and the substrate so that the mask pattern is applied to the substrate. There is a proximity method to transfer. In general, the projection method has higher accuracy in pattern resolution performance and substrate magnification correction than the proximity method, and is suitable for production. Therefore, in the present embodiment, a description will be given assuming that a projection type exposure apparatus using a reflective projection optical system for a glass substrate is employed. The exposure apparatus 90 projects and transfers a pattern (for example, a TFT circuit) formed on the mask M onto the substrate P coated with a photosensitive agent. The exposure apparatus 90 includes an illumination optical system 92 that introduces light from a light source 91, an optical system 93 that guides light from the illumination optical system 92 onto the mask M, an original stage 94 on which the mask M is placed, A projection optical system 95 and a substrate stage 96 on which the substrate P is placed are provided.

  In the exposure apparatus 90, the light source 91 and the illumination optical system 92 employ the light source and illumination optical system described in the above embodiment. The optical system 93 is an optical system that maintains a substantially conjugate relationship between an irradiation surface (not shown) of the illumination optical system 92 and the mask surface. Therefore, the illumination optical system 92 illuminates the illumination surface of the illumination optical system 92 uniformly, and if there is no vignetting, the mask surface is almost uniform and is illuminated in the same shape as the illumination shape of the illumination optical system 92. It becomes possible to do. The original stage 94 is a stage device that is movable in the XY directions while placing and holding the mask M. The projection optical system 95 forms a pattern image drawn on the irradiation area of the mask M on the substrate P while changing the deflection characteristics by the reflecting mirror 97 installed inside the projection optical system 95. . The substrate stage 96 is a stage device that can move in the three-dimensional directions of XYZ while placing and holding the substrate P. According to the exposure apparatus 90 of the present embodiment, an illumination optical system with good illumination efficiency is adopted, which contributes to energy saving of the exposure apparatus.

(Device manufacturing method)
Next, a method for manufacturing a device (semiconductor device, liquid crystal display device, etc.) according to an embodiment of the present invention will be described. A semiconductor device is manufactured through a pre-process for producing an integrated circuit on a wafer and a post-process for completing an integrated circuit chip on the wafer produced in the pre-process as a product. The pre-process includes a step of exposing a wafer coated with a photosensitive agent using the above-described exposure apparatus, and a step of developing the wafer. The post-process includes an assembly process (dicing and bonding) and a packaging process (encapsulation). A liquid crystal display device is manufactured through a process of forming a transparent electrode. The step of forming the transparent electrode includes a step of applying a photosensitive agent to a glass substrate on which a transparent conductive film is deposited, a step of exposing the glass substrate on which the photosensitive agent is applied using the above-described exposure apparatus, and a glass substrate. The process of developing is included. According to the device manufacturing method of the present embodiment, it is possible to manufacture a higher quality device than before.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 10 Illumination optical system 11 1st optical system 12 1st irradiation surface 13 Integrator 14 Secondary light source surface 15 2nd optical system 16 2nd irradiation surface 17 3rd optical system 18 Light source 90 Exposure apparatus 91 Light source 92 Illumination optical system 94 Original stage 96 Substrate stage

Claims (7)

An illumination optical system for irradiating an irradiation object with light introduced from a light source,
An illumination optical system comprising: a circulation optical system that acquires a part of light incident on a surface conjugate with the irradiation object and guides the acquired light again to the surface conjugate with the irradiation object. A reflective part is provided on a surface conjugate with the irradiation object,
The illumination optical system according to claim 1, wherein the circulation optical system guides the light reflected by the reflection unit to a surface conjugate with the irradiation object again. Having an integrator to form a secondary light source,
3. The circulating optical system according to claim 1 or 2, wherein a part of light transmitted through the integrator and incident on a surface conjugate with the irradiation object is acquired and guided again to the incident surface of the integrator. The illumination optical system described. A field stop disposed on a plane conjugate with the irradiation object and defining an illumination area of the irradiation object;
The illumination optical system according to claim 1, wherein the circulation optical system guides light incident on a non-transmission region of the field stop to a surface conjugate with the irradiation target.   5. The illumination optical system according to claim 1, wherein the circulation optical system is disposed so that an emission surface and the irradiation surface are in a conjugate relationship. 6. An illumination optical system that illuminates the original with light from a light source, an original stage that can be moved by placing the original, a projection optical system that guides light from the original to the substrate, and the substrate that is moved An exposure apparatus having a possible substrate stage,
The exposure apparatus according to claim 1, wherein the illumination optical system is the illumination optical system according to claim 1. Exposing the substrate using the exposure apparatus according to claim 6;
Developing the exposed substrate;
A device manufacturing method comprising:

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