JP2009267390A - Optical integrator, illumination optical system, exposure device, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination optical system capable of almost uniformly adjusting the pupil intensity distribution on respective points of a surface-to-be-illuminated. <P>SOLUTION: An optical integrator (9) arranged in an optical path of an illumination optical system for illuminating surfaces-to-be-illuminated (M; W) by light from a light source (1) comprises a plurality of first refraction surfaces having a predetermined refractive power in a Z direction and a plurality of second refraction surfaces formed behind them and having a predetermined refractive power in the Z direction. At least between two adjacent second refraction surfaces, a dimming section is arranged which has a dimming rate property with a dimming rate increased as a position in the surface-to-be-illuminated to which the light reaches is away from the center of the surface-to-be-illuminated along the Y direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical integrator, an illumination optical system, an exposure apparatus, and a device manufacturing method. More specifically, the present invention relates to an illumination optical system suitable for an exposure apparatus for manufacturing a device such as a semiconductor element, an imaging element, a liquid crystal display element, and a thin film magnetic head in a lithography process.

  In a typical exposure apparatus of this type, a secondary light source (generally an illumination pupil), which is a substantial surface light source composed of a number of light sources, passes through a fly-eye lens as an optical integrator. A predetermined light intensity distribution). Hereinafter, the light intensity distribution in the illumination pupil is referred to as “pupil intensity distribution”. The illumination pupil is a position where the illumination surface becomes the Fourier transform plane of the illumination pupil by the action of the optical system between the illumination pupil and the illumination surface (a mask or a wafer in the case of an exposure apparatus). Defined.

  The light from the secondary light source is condensed by the condenser lens and then illuminates the mask on which a predetermined pattern is formed in a superimposed manner. The light transmitted through the mask forms an image on the wafer via the projection optical system, and the mask pattern is projected and exposed (transferred) onto the wafer. The pattern formed on the mask is highly integrated, and it is indispensable to obtain a uniform illumination distribution on the wafer in order to accurately transfer the fine pattern onto the wafer.

  In order to accurately transfer the fine pattern of the mask onto the wafer, for example, an annular or multipolar (bipolar, quadrupolar, etc.) pupil intensity distribution is formed to improve the depth of focus and resolution of the projection optical system. The technique to make it is proposed (refer patent document 1).

US Patent Publication No. 2006/0055834

  In order to faithfully transfer the fine pattern of the mask onto the wafer, not only the pupil intensity distribution is adjusted to the desired shape, but also the pupil intensity distribution for each point on the wafer as the final irradiated surface is almost uniform. It is necessary to adjust to. If there is a variation in the uniformity of the pupil intensity distribution at each point on the wafer, the line width of the pattern varies from position to position on the wafer, and the fine pattern of the mask has the desired line width over the entire exposure area. It cannot be faithfully transferred onto the wafer.

  An object of the present invention is to provide an illumination optical system capable of adjusting the pupil intensity distribution at each point on the irradiated surface almost uniformly. The present invention also provides an exposure apparatus that can perform good exposure under appropriate illumination conditions using an illumination optical system that adjusts the pupil intensity distribution at each point on the irradiated surface substantially uniformly. The purpose is to provide.

In order to solve the above-described problem, in the first embodiment of the present invention, in the wavefront division type optical integrator used in the illumination optical system that illuminates the illuminated surface,
A plurality of first refracting surfaces having a predetermined refractive power in a first direction within a plane orthogonal to the optical axis of the illumination optical system;
A plurality of second refracting surfaces provided at a rear side of the plurality of first refracting surfaces so as to correspond to the plurality of first refracting surfaces, and having a predetermined refractive power in the first direction;
A decrease in light attenuation rate which is provided between at least two adjacent second refracting surfaces and increases as the position of light reaching the irradiated surface moves away from the center of the irradiated surface along the first direction. An optical integrator is provided that includes a light reduction unit having a light rate characteristic.

In the second embodiment of the present invention, in the illumination optical system that illuminates the illuminated surface based on the light from the light source,
Provided is an illumination optical system comprising the optical integrator of the first form.

  According to a third aspect of the present invention, there is provided an exposure apparatus comprising the illumination optical system according to the second aspect for illuminating a predetermined pattern, and exposing the predetermined pattern onto a photosensitive substrate.

In the fourth embodiment of the present invention, using the exposure apparatus of the third embodiment, an exposure step of exposing the predetermined pattern to the photosensitive substrate;
Developing the photosensitive substrate to which the predetermined pattern is transferred, and forming a mask layer having a shape corresponding to the predetermined pattern on the surface of the photosensitive substrate;
And a processing step of processing the surface of the photosensitive substrate through the mask layer.

  In the illumination optical system of the present invention, the light attenuation rate characteristic in which the light attenuation rate increases between adjacent refractive surfaces of the optical integrator as the position of the light reaching the irradiated surface moves away from the center along a predetermined direction. The light reduction part which has is provided. Therefore, the pupil intensity distribution for each point on the irradiated surface can be adjusted independently by the action of the light reducing unit of the optical integrator, and consequently the pupil intensity distribution for each point can be adjusted to distributions having substantially the same properties. Is possible.

  As a result, in the illumination optical system of the present invention, for example, a density filter that uniformly adjusts the pupil intensity distribution at each point on the irradiated surface and a reduction in optical integrator that independently adjusts the pupil intensity distribution for each point. The pupil intensity distribution at each point on the irradiated surface can be adjusted substantially uniformly by the cooperative action with the light part. Thus, the exposure apparatus of the present invention can perform good exposure under appropriate illumination conditions using the illumination optical system that adjusts the pupil intensity distribution at each point on the irradiated surface almost uniformly. And by extension, a good device can be manufactured.

It is a figure which shows schematically the structure of the exposure apparatus concerning embodiment of this invention. It is a perspective view which shows schematically the structure of the cylindrical micro fly's eye lens of FIG. It is a figure which shows the quadrupole secondary light source formed in an illumination pupil. It is a figure which shows the rectangular-shaped static exposure area | region formed on a wafer. It is a figure explaining the property of the quadrupole pupil intensity distribution which the light which injects into the center point P1 in a still exposure area | region forms. It is a figure explaining the property of the quadrupole pupil intensity distribution which the light which injects into the peripheral points P2 and P3 in a still exposure area | region forms. (A) is a light intensity distribution along the Z direction of the pupil intensity distribution with respect to the center point P1, and (b) is a diagram schematically showing the light intensity distribution along the Z direction of the pupil intensity distribution with respect to the peripheral points P2 and P3. It is. It is a figure explaining the structure and effect | action of the light reduction part provided in the cylindrical micro fly's eye lens of FIG. It is a figure which shows a mode that the V-shaped cutting surface as a light reduction part is formed in the area | region corresponding to a pair of surface light source spaced apart by the X direction in quadrupole pupil intensity distribution. (A) shows a state in which a light beam group reaching the center point P1 forms a small light source of the original size, and (b) shows a light beam group reaching the peripheral points P2 and P3 and a small light source of the original size. It is a figure which shows typically a mode that a small small light source is formed. It is a 1st figure explaining the effect | action of the light reduction part of this embodiment. It is a 2nd figure explaining the effect | action of the light reduction part of this embodiment. It is a perspective view which shows roughly the structure of the cylindrical micro fly's eye lens which has another form from FIG. It is a figure which shows schematically the structure of the light reduction part provided in the cylindrical micro fly's eye lens of FIG. It is a figure which shows a mode that the V-shaped cutting surface as a light reduction part is formed only in the area | region corresponding to a pair of surface light source spaced in the X direction in a pentapolar pupil intensity distribution. It is a flowchart which shows the manufacturing process of a semiconductor device. It is a flowchart which shows the manufacturing process of liquid crystal devices, such as a liquid crystal display element.

  Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a drawing schematically showing a configuration of an exposure apparatus according to an embodiment of the present invention. In FIG. 1, the Z axis along the normal direction of the exposure surface (transfer surface) of the wafer W, which is a photosensitive substrate, and the Y axis in the direction parallel to the paper surface of FIG. In the W exposure plane, the X axis is set in a direction perpendicular to the paper surface of FIG.

  Referring to FIG. 1, in the exposure apparatus of the present embodiment, exposure light (illumination light) is supplied from a light source 1. As the light source 1, for example, an ArF excimer laser light source that supplies light with a wavelength of 193 nm, a KrF excimer laser light source that supplies light with a wavelength of 248 nm, or the like can be used. The light emitted from the light source 1 is converted into a light beam having a required cross-sectional shape by the shaping optical system 2 and then enters the afocal lens 4 via, for example, a diffractive optical element 3 for annular illumination.

  The afocal lens 4 is set so that the front focal position thereof and the position of the diffractive optical element 3 substantially coincide with each other, and the rear focal position thereof substantially coincides with the position of the predetermined surface 5 indicated by a broken line in the drawing. System (non-focal optical system). The diffractive optical element 3 is formed by forming a step having a pitch of about the wavelength of exposure light (illumination light) on the substrate, and has a function of diffracting an incident beam to a desired angle. Specifically, the diffractive optical element 3 for annular illumination has a function of forming an annular light intensity distribution in the far field (or Fraunhofer diffraction region) when a parallel light beam having a rectangular cross section is incident. Have

  Therefore, the substantially parallel light beam incident on the diffractive optical element 3 is emitted from the afocal lens 4 with a ring-shaped angular distribution after forming a ring-shaped light intensity distribution on the pupil plane of the afocal lens 4. In the optical path between the front lens group 4a and the rear lens group 4b of the afocal lens 4, a density filter 6 is disposed at or near the pupil position. The density filter 6 has the form of a plane parallel plate, and a dense pattern of light-shielding dots made of chromium, chromium oxide or the like is formed on the optical surface thereof. That is, the density filter 6 has a transmittance distribution with different transmittances depending on the incident position of light. The specific operation of the density filter 6 will be described later.

  The light passing through the afocal lens 4 passes through a zoom lens 7 for varying the σ value (σ value = mask-side numerical aperture of the illumination optical system / mask-side numerical aperture of the projection optical system), and a cylindrical micro as an optical integrator. The light enters the fly eye lens 9. As shown in FIG. 2, the cylindrical micro fly's eye lens 9 includes a first fly eye member (first optical member) 9a disposed on the light source side and a second fly eye member (second optical member) disposed on the mask side. ) 9b.

  On the light source side (incident side) surface of the first fly's eye member 9a and the light source side surface of the second fly's eye member 9b, a plurality of cylindrical refractive surfaces (cylindrical lens groups) arranged side by side in the X direction. 9aa and 9ba are formed with a pitch px. A plurality of cylindrical refractive surfaces (cylindrical lens groups) arranged side by side in the Z direction on the mask side (exit side) surface of the first fly eye member 9a and the mask side surface of the second fly eye member 9b. ) 9ab and 9bb are each formed with a pitch pz (pz> px).

  Focusing on the refraction action in the X direction of the cylindrical micro fly's eye lens 9 (that is, the refraction action in the XY plane), a group of parallel light beams incident along the optical axis AX are formed on the light source side of the first fly eye member 9a. Corresponding in the group of refracting surfaces 9ba formed on the light source side of the second fly's eye member 9b after being wavefront divided along the X direction by the refracting surface 9aa with a pitch px and receiving the condensing action on the refracting surface. The light is focused on the refracting surface to be focused on the rear focal plane of the cylindrical micro fly's eye lens 9.

  Focusing on the refractive action in the Z direction of the cylindrical micro fly's eye lens 9 (ie, the refractive action in the YZ plane), a group of parallel light beams incident along the optical axis AX are formed on the mask side of the first fly's eye member 9a. Corresponding in the group of refracting surfaces 9bb formed on the mask side of the second fly's eye member 9b after the wavefront is divided by the refracting surface 9ab with the pitch pz along the Z direction The light is focused on the refracting surface to be focused on the rear focal plane of the cylindrical micro fly's eye lens 9.

  As described above, the cylindrical micro fly's eye lens 9 is composed of the first fly eye member 9a and the second fly eye member 9b in which the cylindrical lens groups are arranged on both side surfaces, but the size of px is set in the X direction. It has the same optical function as a micro fly's eye lens in which a large number of rectangular minute refracting surfaces (unit wavefront dividing surfaces) having a size of pz in the Z direction are integrally formed vertically and horizontally. In the cylindrical micro fly's eye lens 9, a change in distortion due to variations in the surface shape of the micro-refractive surface is suppressed, and for example, manufacturing errors of a large number of micro-refractive surfaces formed integrally by etching process give the illuminance distribution. The influence can be kept small.

  The position of the predetermined surface 5 is disposed at or near the front focal position of the zoom lens 7, and the incident surface of the cylindrical micro fly's eye lens 9 (that is, the incident surface of the first fly's eye member 9 a) is the rear focal position of the zoom lens 7. Or it is arrange | positioned in the vicinity. In other words, the zoom lens 7 arranges the predetermined surface 5 and the incident surface of the cylindrical micro fly's eye lens 9 substantially in a Fourier transform relationship, and consequently the pupil surface of the afocal lens 4 and the cylindrical micro fly's eye lens 9. The incident surface is optically substantially conjugate.

  Accordingly, on the incident surface of the cylindrical micro fly's eye lens 9, for example, an annular illumination field centered on the optical axis AX is formed in the same manner as the pupil surface of the afocal lens 4. The overall shape of the annular illumination field changes in a similar manner depending on the focal length of the zoom lens 7. As described above, each unit wavefront dividing surface of the cylindrical micro fly's eye lens 9 has a rectangular shape having a long side along the Z direction and a short side along the X direction, and is formed on the mask M. It has a rectangular shape similar to the shape of the illumination area to be formed (and thus the shape of the exposure area to be formed on the wafer W).

  The light beam incident on the cylindrical micro fly's eye lens 9 is split two-dimensionally, and is formed on the incident surface of the cylindrical micro fly's eye lens 9 at the rear focal plane or in the vicinity thereof (and thus the position of the illumination pupil). A secondary light source having substantially the same light intensity distribution as the illumination field, that is, a secondary light source (pupil intensity distribution) composed of a ring-shaped substantial surface light source centered on the optical axis AX is formed.

  An illumination aperture stop (not shown) having an annular opening (light transmitting portion) corresponding to an annular secondary light source on the rear focal plane of the cylindrical micro fly's eye lens 9 or in the vicinity thereof, if necessary. Is arranged. The illumination aperture stop is configured to be detachable with respect to the illumination optical path, and is configured to be switchable with a plurality of aperture stops having apertures having different sizes and shapes. As an aperture stop switching method, for example, a well-known turret method or slide method can be used. The illumination aperture stop is disposed at a position optically conjugate with an entrance pupil plane of the projection optical system PL described later, and defines a range that contributes to illumination of the secondary light source.

  The light that has passed through the cylindrical micro fly's eye lens 9 illuminates the mask blind 11 in a superimposed manner via the condenser optical system 10. Thus, a rectangular illumination field corresponding to the shape and focal length of the unit wavefront dividing surface of the cylindrical micro fly's eye lens 9 is formed on the mask blind 11 as an illumination field stop. The light that has passed through the rectangular opening (light transmission portion) of the mask blind 11 passes through the imaging optical system 12 including the front lens group 12a and the rear lens group 12b, and the mask M on which a predetermined pattern is formed. Are illuminated in a superimposed manner. That is, the imaging optical system 12 forms an image of the rectangular opening of the mask blind 11 on the mask M.

  A pattern to be transferred is formed on the mask M held on the mask stage MS, and a rectangular shape having a long side along the Y direction and a short side along the X direction in the entire pattern region ( The pattern area of the slit shape is illuminated. The light transmitted through the pattern area of the mask M forms an image of the mask pattern on the wafer (photosensitive substrate) W held on the wafer stage WS via the projection optical system PL. That is, a rectangular stationary image having a long side along the Y direction and a short side along the X direction on the wafer W so as to optically correspond to the rectangular illumination area on the mask M. A pattern image is formed in the exposure area (effective exposure area).

  Thus, according to the so-called step-and-scan method, the mask stage MS and the wafer stage WS along the X direction (scanning direction) in the plane (XY plane) orthogonal to the optical axis AX of the projection optical system PL, As a result, by moving (scanning) the mask M and the wafer W synchronously, the wafer W has a width equal to the dimension in the Y direction of the static exposure region and corresponds to the scanning amount (movement amount) of the wafer W. A mask pattern is scanned and exposed to a shot area (exposure area) having a length.

  In the present embodiment, as described above, the secondary light source formed by the cylindrical micro fly's eye lens 9 is used as the light source, and the mask M arranged on the irradiated surface of the illumination optical system (2 to 12) is Koehler illuminated. For this reason, the position where the secondary light source is formed is optically conjugate with the position of the aperture stop AS of the projection optical system PL, and the formation surface of the secondary light source is the illumination pupil plane of the illumination optical system (2 to 12). Can be called. Typically, the irradiated surface (the surface on which the mask M is disposed or the surface on which the wafer W is disposed when the illumination optical system including the projection optical system PL is considered) is optical with respect to the illumination pupil plane. A Fourier transform plane.

  The pupil intensity distribution is a light intensity distribution (luminance distribution) on the illumination pupil plane of the illumination optical system (2 to 12) or a plane optically conjugate with the illumination pupil plane. When the number of wavefront divisions by the cylindrical micro fly's eye lens 9 is relatively large, the global light intensity distribution formed on the incident surface of the cylindrical micro fly's eye lens 9 and the global light intensity distribution of the entire secondary light source (pupil) Intensity distribution). For this reason, the light intensity distribution on the incident surface of the cylindrical micro fly's eye lens 9 and a surface optically conjugate with the incident surface can also be referred to as a pupil intensity distribution. In the configuration of FIG. 1, the diffractive optical element 3, the afocal lens 4, the zoom lens 7, and the cylindrical micro fly's eye lens 9 are distributions that form a pupil intensity distribution in the illumination pupil behind the cylindrical micro fly's eye lens 9. The forming optical system is configured.

  In place of the diffractive optical element 3 for annular illumination, a plurality of diffractive optical elements (not shown) for multipole illumination (two-pole illumination, four-pole illumination, octupole illumination, etc.) are set in the illumination optical path. Polar lighting can be performed. A diffractive optical element for multipole illumination forms a light intensity distribution of multiple poles (bipolar, quadrupole, octupole, etc.) in the far field when a parallel light beam having a rectangular cross section is incident. It has the function to do. Therefore, the light flux that has passed through the diffractive optical element for multipole illumination is irradiated on the incident surface of the cylindrical micro fly's eye lens 9 with, for example, an illumination field having a plurality of predetermined shapes (arc shape, circular shape, etc.) centered on the optical axis AX. A multipolar illumination field consisting of As a result, the same multipolar secondary light source as the illumination field formed on the incident surface is formed on the rear focal plane of the cylindrical micro fly's eye lens 9 or in the vicinity thereof.

  Moreover, instead of the diffractive optical element 3 for annular illumination, a normal circular illumination can be performed by setting a diffractive optical element (not shown) for circular illumination in the illumination optical path. The diffractive optical element for circular illumination has a function of forming a circular light intensity distribution in the far field when a parallel light beam having a rectangular cross section is incident. Therefore, the light beam that has passed through the diffractive optical element for circular illumination forms, for example, a circular illumination field around the optical axis AX on the incident surface of the cylindrical micro fly's eye lens 9. As a result, a secondary light source having the same circular shape as the illumination field formed on the incident surface is also formed on or near the rear focal plane of the cylindrical micro fly's eye lens 9. Also, instead of the diffractive optical element 3 for annular illumination, various forms of modified illumination can be performed by setting a diffractive optical element (not shown) having appropriate characteristics in the illumination optical path. As a switching method of the diffractive optical element 3, for example, a known turret method or slide method can be used.

  In the following description, in order to facilitate understanding of the effects of the present embodiment, the rear focal plane of the cylindrical micro fly's eye lens 9 or the illumination pupil in the vicinity thereof has four arcs as shown in FIG. It is assumed that a quadrupole pupil intensity distribution (secondary light source) 20 composed of a substantial surface light source (hereinafter simply referred to as “surface light source”) 20a, 20b, 20c and 20d is formed. In the following description, the term “illumination pupil” simply refers to the illumination pupil in the rear focal plane of the cylindrical micro fly's eye lens 9 or in the vicinity thereof.

  Referring to FIG. 3, the quadrupole pupil intensity distribution 20 formed in the illumination pupil includes the surface light sources 20a and 20b spaced in the X direction with the optical axis AX interposed therebetween, and the Z direction with the optical axis AX interposed therebetween. And a pair of arcuate substantial surface light sources 20c and 20d spaced apart from each other. The X direction in the illumination pupil is the short side direction of the rectangular unit wavefront dividing surface of the cylindrical micro fly's eye lens 9 and corresponds to the scanning direction of the wafer W. Further, the Z direction in the illumination pupil is the long side direction of the rectangular unit wavefront dividing surface of the cylindrical micro fly's eye lens 9, and the scanning orthogonal direction perpendicular to the scanning direction of the wafer W (Y direction on the wafer W). It corresponds to.

  As shown in FIG. 4, a rectangular still exposure region ER having a long side along the Y direction and a short side along the X direction is formed on the wafer W. Correspondingly, a rectangular illumination area (not shown) is formed on the mask M. Here, the quadrupole pupil intensity distribution formed on the illumination pupil by light incident on one point in the still exposure region ER has substantially the same shape without depending on the position of the incident point. However, the light intensity of each surface light source constituting the quadrupole pupil intensity distribution tends to differ depending on the position of the incident point.

  Specifically, as shown in FIG. 5, in the case of a quadrupole pupil intensity distribution 21 formed by light incident on the center point P1 in the static exposure region ER, the surface light source 21c and the surface light source 21c spaced apart in the Z direction and The light intensity of 21d tends to be higher than the light intensity of the surface light sources 21a and 21b spaced apart in the X direction. On the other hand, as shown in FIG. 6, in the case of a quadrupole pupil intensity distribution 22 formed by light incident on peripheral points P2 and P3 spaced from the center point P1 in the still exposure region ER in the Y direction, The light intensities of the surface light sources 22c and 22d spaced in the Z direction tend to be smaller than the light intensities of the surface light sources 22a and 22b spaced in the X direction.

  In general, regardless of the outer shape of the pupil intensity distribution formed on the illumination pupil, the pupil intensity distribution related to the center point P1 in the still exposure region ER on the wafer W (the pupil formed on the illumination pupil by the light incident on the center point P1). As shown in FIG. 7A, the light intensity distribution along the Z direction of the intensity distribution has a concave curve distribution that is smallest at the center and increases toward the periphery. On the other hand, the light intensity distribution along the Z direction of the pupil intensity distribution related to the peripheral points P2 and P3 in the static exposure region ER on the wafer W is the largest at the center and toward the periphery as shown in FIG. It has a decreasing convex curve distribution.

  The light intensity distribution along the Z direction of the pupil intensity distribution does not depend much on the position of the incident point along the X direction (scanning direction) in the still exposure region ER, but the Y direction in the still exposure region ER. There is a tendency to change depending on the position of the incident point along the (scanning orthogonal direction). As described above, when the pupil intensity distribution (pupil intensity distribution formed on the illumination pupil by the light incident on each point) on each point in the still exposure region ER on the wafer W is not substantially uniform, for each position on the wafer W. Further, the line width of the pattern varies, and the fine pattern of the mask M cannot be faithfully transferred onto the wafer W with a desired line width over the entire exposure region.

  In the present embodiment, as described above, the density filter 6 having a transmittance distribution with different transmittance according to the incident position of light is disposed at or near the pupil position of the afocal lens 4. The pupil position of the afocal lens 4 is optically conjugate with the incident surface of the cylindrical micro fly's eye lens 9 by the rear lens group 4b and the zoom lens 7. Therefore, the light intensity distribution formed on the incident surface of the cylindrical micro fly's eye lens 9 is adjusted (corrected) by the action of the density filter 6, and as a result, the rear focal plane of the cylindrical micro fly's eye lens 9 or the illumination pupil in the vicinity thereof. The pupil intensity distribution formed at the same time is also adjusted.

  However, the density filter 6 uniformly adjusts the pupil intensity distribution for each point in the still exposure region ER on the wafer W without depending on the position of each point. As a result, by the action of the density filter 6, for example, adjustment is made so that the quadrupole pupil intensity distribution 21 with respect to the center point P <b> 1 becomes substantially uniform, so that the light intensities of the surface light sources 21 a to 21 d become substantially equal to each other. In this case, however, the difference in light intensity between the surface light sources 22a and 22b and the surface light sources 22c and 22d in the quadrupole pupil intensity distribution 22 with respect to the peripheral points P2 and P3 becomes larger.

  That is, in order to adjust the pupil intensity distribution for each point in the static exposure region ER on the wafer W almost uniformly by the action of the density filter 6, the pupil intensity for each point can be adjusted by means other than the density filter 6. It is necessary to adjust the distribution to distributions having the same properties. Specifically, for example, in the pupil intensity distribution 21 related to the center point P1 and the pupil intensity distribution 22 related to the peripheral points P2 and P3, the magnitude relationship between the light intensities of the surface light sources 21a and 21b and the surface light sources 21c and 21d and the surface light sources 22a and 22a. It is necessary to match the magnitude relationship of the light intensity between 22b and the surface light sources 22c and 22d at substantially the same ratio.

  In the present embodiment, in order to make the properties of the pupil intensity distribution related to the center point P1 and the properties of the pupil intensity distribution related to the peripheral points P2 and P3 substantially coincide, specifically, in the pupil intensity distribution 22 related to the peripheral points P2 and P3, In order to adjust the light intensities of the light sources 22a and 22b to be smaller than the light intensities of the surface light sources 22c and 22d, the cylindrical micro fly's eye lens 9 is provided with a dimming portion having a required dimming characteristic. . FIG. 8 is a diagram for explaining the configuration and operation of the dimming unit provided in the cylindrical micro fly's eye lens.

  Referring to FIG. 8, of the pair of fly eye members 9a and 9b constituting the cylindrical micro fly's eye lens 9, two adjacent in the Z direction on the exit side of the second fly eye member 9b on the rear side (mask side). A V-shaped cutting surface 9c extending linearly along the X direction is provided between the two refracting surfaces 9bb. As schematically shown in FIG. 9, the V-shaped cutting surface 9 c is formed in a region corresponding to the pair of surface light sources 20 a and 20 b spaced apart in the X direction in the quadrupole pupil intensity distribution 20. A required number (five examples in FIG. 9) is formed along the line.

  As a result, in the quadrupole pupil intensity distribution 20, the light that forms the surface light sources 20 a and 20 b spaced in the X direction passes through the cylindrical micro fly's eye lens 9, and then reaches the V-shaped cutting surface 9 c. The light that forms the surface light sources 20c and 20d spaced apart in the Z direction is not affected by the V-shaped cutting surface 9c. Hereinafter, with reference to FIG. 8, attention is paid to a light beam group forming one small light source 20aa (or 20ba) among a large number of small light sources constituting the surface light source 20a (or 20b) via one refractive surface 9bb. Then, the operation of the V-shaped cutting surface 9c as the light reducing portion will be described.

  The light beam group L1 reaching the center point P1 in the static exposure region ER on the wafer W passes through the central region along the Z direction of the refractive surface 9bb. Therefore, the light beam group L1 receives the refraction action of the refraction surface 9bb without receiving the action of the V-shaped cutting surface 9c, and forms a small light source having the original size (light quantity) in the illumination pupil. That is, the light ray group L1 forms one small light source with the original light amount among the many small light sources constituting the surface light source 21a (or 21b) of the pupil intensity distribution 21 with respect to the center point P1.

  On the other hand, the light ray group L2 reaching the peripheral point P2 in the static exposure region ER is a region away from the central region along the Z direction of the refractive surface 9bb, that is, one cutting surface 9ca of the V-shaped cutting surface 9c. And passes through the refractive surface 9bb. In other words, a part of the light beam group L2 is incident on the cutting surface 9ca, and the remaining part of the light beam group L2 is incident on the refractive surface 9bb. The light incident and reflected by the cutting surface 9ca and the light incident and refracted by the cutting surface 9ca are led to the outside of the illumination optical path, for example, without contributing to the formation of the pupil intensity distribution.

  As a result, a part of the light beam L2 is subjected to the dimming action of the V-shaped cutting surface 9c and the remaining part is subjected to the refracting action of the refracting surface 9bb to form a small light source smaller than the original size in the illumination pupil. To do. That is, the light beam group L2 forms one small light source among a large number of small light sources constituting the surface light source 22a (or 22b) of the pupil intensity distribution 22 with respect to the peripheral point P2 as a small light source having a light amount smaller than the original. .

  A part of the light beam L3 reaching the peripheral point P3 in the still exposure region ER also enters the cutting surface 9ca, and the remaining part enters the refracting surface 9bb. As a result, similarly to the light beam group L2, the light beam group L3 receives a dimming action of the V-shaped cutting surface 9c, and the remaining light beam receives a refraction action of the refracting surface 9bb. Form on the illumination pupil. That is, the light ray group L3 forms one small light source among a large number of small light sources constituting the surface light source 22a (or 22b) of the pupil intensity distribution 22 related to the peripheral point P3 as a small light source having a light amount smaller than the original. .

  In this way, the ray group L1 reaching the center point P1 in the still exposure region ER has an original size as shown schematically in FIG. 10A in the surface light sources 21a and 21b of the quadrupole pupil intensity distribution 21. The small light sources 31 having the same length (that is, the original light amount) are formed in a matrix. On the other hand, ray groups L2 and L3 reaching the peripheral points P2 and P3 in the still exposure region ER are schematically shown in FIG. 10B in the surface light sources 22a and 22b of the quadrupole pupil intensity distribution 22. As described above, the small light source 32a having the original size (original light amount) and the small light source 32b smaller than the original (smaller light amount than the original) are formed in a matrix.

  Actually, unlike the schematic diagram shown in FIG. 10B, the small light source 32b corresponds to the position along the Z direction and the number n of the V-shaped cutting surface 9c, and n along the Z direction. It is formed side by side along the X direction at each position. Therefore, in the surface light sources 22a and 22b of the pupil intensity distribution 22 related to the peripheral points P2 and P3, the light sources L2 and L3 are subjected to the dimming action of the V-shaped cutting surface 9c, and the small light source 32b having a smaller light amount than the original. Depending on the proportion of the total number of small light sources, the overall light intensity decreases.

  Here, the proportion of the small light source 32b depends on the number n of the V-shaped cutting surfaces 9c acting on the surface light sources 22a and 22b. Further, the degree to which the light beam groups L2 and L3 are subjected to the dimming action of the V-shaped cutting surface 9c, that is, the light reduction rate, depends on the cross-sectional shape along the XY plane of the V-shaped cutting surface 9c. Generally, as the point at which the light ray group reaches the still exposure region ER is further away from the central point P1 along the Y direction, the light ray group passes through a region away from the central region along the Z direction of the refractive surface 9bb. In other words, the ratio of the light incident on the cutting surface 9ca is larger than the ratio of the light incident on the refracting surface 9bb.

  In other words, the degree to which the light ray group reaching one point in the still exposure region ER is subjected to the dimming action of the V-shaped cutting surface 9c is from the center point P1 of the still exposure region ER to the point where the light ray group reaches. It increases as the distance along the Y direction (scanning orthogonal direction) increases. In other words, the V-shaped cutting surface 9c as the light reducing portion has a light attenuation rate as the position of the light beam reaching the still exposure region ER as the irradiated surface moves away from the center of the still exposure region ER along the Y direction. The light attenuation rate characteristic increases.

  Thus, in the pupil intensity distribution 21 related to the center point P1, the light forming the surface light sources 21a and 21b is not affected by the dimming action of the V-shaped cutting surface 9c, so that the light intensity of the surface light sources 21a and 21b is the original. Maintained in size. Since the light that forms the surface light sources 21c and 21d is not affected by the dimming action of the V-shaped cutting surface 9c, the light intensity of the surface light sources 21c and 21d is maintained at its original size. As a result, as shown in FIG. 11, the pupil intensity distribution 21 related to the center point P1 remains the original distribution without receiving the dimming action of the V-shaped cutting surface 9c. That is, the property that the light intensity of the surface light sources 21c and 21d spaced in the Z direction is larger than the light intensity of the surface light sources 21a and 21b spaced in the X direction is maintained as it is.

  On the other hand, in the pupil intensity distribution 22 related to the peripheral points P2 and P3, part of the light from the surface light sources 22a and 22b is subjected to the dimming action of the V-shaped cutting surface 9c. The light intensity decreases. Since the light from the surface light sources 22c and 22d is not affected by the dimming action of the V-shaped cutting surface 9c, the light intensity of the surface light sources 22c and 22d is maintained at the original size. As a result, the pupil intensity distribution 22 relating to the peripheral points P2 and P3 is changed to a pupil intensity distribution 22 ′ having a property different from the original distribution 22 due to the dimming action of the V-shaped cutting surface 9c, as shown in FIG. Adjusted. That is, in the adjusted pupil intensity distribution 22 ′, the light intensity of the surface light sources 22c and 22d spaced in the Z direction is larger than the light intensity of the surface light sources 22a ′ and 22b ′ spaced in the X direction. It changes to properties.

  As described above, the action of the V-shaped cutting surface 9c adjusts the pupil intensity distribution 22 relating to the peripheral points P2 and P3 to a distribution 22 'having substantially the same property as the pupil intensity distribution 21 relating to the center point P1. Similarly, the pupil intensity distribution for each point arranged along the Y direction between the center point P1 and the peripheral points P2 and P3, and hence the pupil intensity distribution for each point in the still exposure region ER on the wafer W is also the center. It is adjusted to a distribution having substantially the same property as the pupil intensity distribution 21 related to the point P1. In other words, the pupil intensity distribution regarding each point in the still exposure region ER on the wafer W is adjusted to distributions having substantially the same properties by the action of the V-shaped cutting surface 9c.

  In other words, the V-shaped cutting surface 9c as a light reducing portion provided in the cylindrical micro fly's eye lens 9 adjusts the pupil intensity distribution for each point to a distribution having substantially the same property. Necessary required dimming rate characteristics, that is, required dimming rate characteristics in which the dimming rate increases as the position of light reaching the still exposure region ER as the irradiated surface moves away from the center point P1 along the Y direction. Have. As described above, the required light attenuation rate characteristic of the light reduction portion is realized by appropriately setting the number of V-shaped cutting surfaces 9c, the cross-sectional shape of the V-shaped cutting surface 9c, and the like.

  As described above, the cylindrical micro fly's eye lens 9 as the wavefront division type optical integrator according to the present embodiment includes the V-shaped cutting surface 9c provided between the refractive surfaces 9bb adjacent in the Z direction. Yes. The V-shaped cutting surface 9c as the light reducing portion has a required reduction in which the light attenuation rate increases as the position of the light reaching the stationary exposure region ER that is the irradiated surface moves away from the center point P1 along the Y direction. It has light rate characteristics. Accordingly, the pupil intensity distribution for each point on the irradiated surface is independently adjusted by the action of the dimming portion obtained by appropriately setting the formation position, number, cross-sectional shape, etc. of the V-shaped cutting surface 9c. As a result, the pupil intensity distribution for each point can be adjusted to distributions having substantially the same properties.

  In the illumination optical system (2 to 12) of the present embodiment, the dimming unit of the cylindrical micro fly's eye lens 9 that independently adjusts the pupil intensity distribution for each point in the still exposure region ER on the wafer W; The pupil intensity distribution for each point is substantially uniform by the cooperative action with the density filter 6 that has a required transmittance characteristic that changes according to the incident position of light and uniformly adjusts the pupil intensity distribution for each point. Can be adjusted. Therefore, the exposure apparatus (1 to WS) of the present embodiment uses the illumination optical system (2 to 12) that adjusts the pupil intensity distribution at each point in the static exposure region ER on the wafer W almost uniformly. Therefore, it is possible to perform good exposure under appropriate illumination conditions according to the fine pattern of the mask M. As a result, the fine pattern of the mask M is faithfully applied on the wafer W with a desired line width over the entire exposure region. Can be transferred to.

  In the present embodiment, it is conceivable that the light amount distribution on the wafer (irradiated surface) W is affected by, for example, the adjusting action of the dimming part of the cylindrical micro fly's eye lens 9. In this case, the exposure amount is changed by changing the illuminance distribution in the still exposure region ER or changing the shape of the still exposure region (illumination region) ER as required by the action of the light amount distribution adjusting unit having a known configuration. Distribution can be changed. Specifically, as the light amount distribution adjusting unit for changing the illuminance distribution, configurations described in Japanese Patent Application Laid-Open Nos. 2001-313250 and 2002-1000056 (and US Pat. Nos. 6,771,350 and 6927836 corresponding thereto). And techniques can be used. Further, as the light amount distribution adjusting unit for changing the shape of the illumination area, the configuration and method described in the pamphlet of International Patent Publication No. WO2005 / 048326 (and the corresponding US Patent Publication No. 2007/0014112) are used. Can do.

  In the above description, the cylindrical micro fly's eye lens 9 having the form shown in FIG. 2 is used as the wavefront division type optical integrator. However, without being limited thereto, for example, a cylindrical micro fly's eye lens 19 having another form as shown in FIG. 13 may be used. As shown in FIG. 13, the cylindrical micro fly's eye lens 19 includes a first fly eye member 19a disposed on the light source side and a second fly eye member 19b disposed on the mask side.

  A plurality of cylindrical refracting surfaces (cylindrical lens groups) 19aa and 19ab arranged side by side in the X direction are formed at a pitch p1 on the light source side surface and the mask side surface of the first fly-eye member 19a. ing. A plurality of cylindrical refracting surfaces (cylindrical lens groups) 19ba and 19bb arranged side by side in the Z direction are respectively formed on the light source side surface and the mask side surface of the second fly-eye member 19b at a pitch p2 (p2>). p1).

  Focusing on the refractive action in the X direction of the cylindrical micro fly's eye lens 19 (that is, the refractive action in the XY plane), a group of parallel light beams incident along the optical axis AX are formed on the light source side of the first fly's eye member 19a. Corresponding in the group of refracting surfaces 19ab formed on the mask side of the first fly's eye member 19a after the wavefront is divided at the pitch p1 along the X direction by the refracting surfaces 19aa The light is focused on the refracting surface to be focused on the rear focal plane of the cylindrical micro fly's eye lens 19.

  Focusing on the refractive action in the Z direction of the cylindrical micro fly's eye lens 19 (that is, the refractive action in the YZ plane), a group of parallel beams incident along the optical axis AX are formed on the light source side of the second fly's eye member 19b. Corresponding in the group of refracting surfaces 19bb formed on the mask side of the second fly's eye member 19b after the wave front is divided at the pitch p2 along the Z direction by the refracting surfaces 19ba of the second fly-eye member 19b. The light is focused on the refracting surface to be focused on the rear focal plane of the cylindrical micro fly's eye lens 19.

  As described above, the cylindrical micro fly's eye lens 19 is composed of the first fly eye member 19a and the second fly eye member 19b in which the cylindrical lens groups are arranged on both side surfaces, and has a size of p1 in the X direction. It has a large number of rectangular microscopic refracting surfaces (unit wavefront dividing surfaces) having a size of p2 in the direction. That is, the cylindrical micro fly's eye lens 19 has a rectangular unit wavefront dividing surface having a long side along the Z direction and a short side along the X direction.

  Even when the cylindrical micro fly's eye lens 19 is used, the same effect as that of the above-described embodiment can be obtained by providing a dimming portion made of, for example, a V-shaped cutting surface, similarly to the cylindrical micro fly's eye lens 9 of FIG. It can be demonstrated. Specifically, as shown in FIG. 14, two refractive surfaces adjacent to each other in the Z direction on the exit side of the second fly eye member 19b on the rear side (mask side) of the pair of fly eye members 19a and 19b. A V-shaped cutting surface 19c extending linearly along the X direction is provided between 19bb. The V-shaped cutting surface 19c is composed of a pair of cutting surfaces 19ca.

  More generally, without being limited to a cylindrical micro fly's eye lens, a plurality of first refracting surfaces having a predetermined refractive power in a first direction in a plane orthogonal to the optical axis of the illumination optical system, The present invention is applied to a wavefront division type optical integrator provided with a plurality of second refracting surfaces provided on the rear side so as to correspond to the first refracting surface and having a predetermined refractive power in the first direction. Can do. In this case, at least two adjacent second refracting surfaces have a dimming portion having a dimming rate characteristic in which the dimming rate increases as the position of the light reaching the irradiated surface increases from the center along the first direction. Between.

  In the above description, the cylindrical micro fly's eye lenses 9 and 19 serving as optical integrators are provided with the light-reducing portions including the V-shaped cutting surfaces 9c and 19c. However, the present invention is not limited to this. For example, the light reduction portion may be configured using a reflection film, a light reduction film, a light scattering film, or the like provided so as to correspond to the V-shaped cutting surfaces 9c and 19c. it can.

  Further, in the above description, the operational effects of the present invention are described by taking, as an example, modified illumination in which a quadrupole pupil intensity distribution is formed on the illumination pupil, that is, quadrupole illumination. However, the present invention is not limited to quadrupole illumination. For example, annular illumination in which an annular pupil intensity distribution is formed, multipolar illumination in which a multipolar pupil intensity distribution other than quadrupole is formed, and the like. In contrast, it is apparent that the same effects can be obtained by applying the present invention.

  Further, as shown in FIG. 15, a pair of surface light sources 23 a and a pair of surface light sources 23 a spaced apart in the X direction in the pentapolar pupil intensity distribution 23 using a modified illumination in which a pentapolar pupil intensity distribution is formed on the illumination pupil. Only the light source 23b can be dimmed, and the surface light source 23e located between the pair of surface light sources 23a and 23b and positioned on the optical axis AX can be prevented from being light-damped. In this case, the region corresponding to the pair of surface light sources 23a and 23b, not the entire region along the X direction of the region between the two refractive surfaces 9bb on the exit side of the second fly's eye member 9b of the cylindrical micro fly's eye lens 9 Only a V-shaped cutting surface 9c may be provided.

  The exposure apparatus of the above-described embodiment is manufactured by assembling various subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Is done. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

  Next, a device manufacturing method using the exposure apparatus according to the above-described embodiment will be described. FIG. 16 is a flowchart showing a manufacturing process of a semiconductor device. As shown in FIG. 16, in the semiconductor device manufacturing process, a metal film is vapor-deposited on a wafer W to be a substrate of the semiconductor device (step S40), and a photoresist, which is a photosensitive material, is applied on the vapor-deposited metal film. (Step S42). Subsequently, using the exposure apparatus of the above-described embodiment, the pattern formed on the mask (reticle) M is transferred to each shot area on the wafer W (step S44: exposure process), and the transfer of the wafer W after the transfer is completed. Development, that is, development of the photoresist to which the pattern has been transferred is performed (step S46: development process). Thereafter, using the resist pattern generated on the surface of the wafer W in step S46 as a mask, processing such as etching is performed on the surface of the wafer W (step S48: processing step).

  Here, the resist pattern is a photoresist layer in which unevenness having a shape corresponding to the pattern transferred by the exposure apparatus of the above-described embodiment is generated, and the recess penetrates the photoresist layer. is there. In step S48, the surface of the wafer W is processed through this resist pattern. The processing performed in step S48 includes, for example, at least one of etching of the surface of the wafer W or film formation of a metal film or the like. In step S44, the exposure apparatus of the above-described embodiment performs pattern transfer using the wafer W coated with the photoresist as the photosensitive substrate, that is, the plate P.

  FIG. 17 is a flowchart showing a manufacturing process of a liquid crystal device such as a liquid crystal display element. As shown in FIG. 17, in the liquid crystal device manufacturing process, a pattern formation process (step S50), a color filter formation process (step S52), a cell assembly process (step S54), and a module assembly process (step S56) are sequentially performed.

  In the pattern forming process of step S50, a predetermined pattern such as a circuit pattern and an electrode pattern is formed on the glass substrate coated with a photoresist as the plate P using the exposure apparatus of the above-described embodiment. In this pattern formation process, an exposure process for transferring the pattern to the photoresist layer using the exposure apparatus of the above-described embodiment and development of the plate P to which the pattern is transferred, that is, development of the photoresist layer on the glass substrate are performed. And a developing step for generating a photoresist layer having a shape corresponding to the pattern, and a processing step for processing the surface of the glass substrate through the developed photoresist layer.

  In the color filter forming step of step S52, a large number of sets of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix or three R, G, and B A color filter is formed by arranging a plurality of stripe filter sets in the horizontal scanning direction.

  In the cell assembly process in step S54, a liquid crystal panel (liquid crystal cell) is assembled using the glass substrate on which the predetermined pattern is formed in step S50 and the color filter formed in step S52. Specifically, for example, a liquid crystal panel is formed by injecting liquid crystal between a glass substrate and a color filter. In the module assembling process in step S56, various components such as an electric circuit and a backlight for performing the display operation of the liquid crystal panel are attached to the liquid crystal panel assembled in step S54.

  In addition, the present invention is not limited to application to an exposure apparatus for manufacturing a semiconductor device, for example, an exposure apparatus for a display device such as a liquid crystal display element formed on a square glass plate or a plasma display, It can also be widely applied to an exposure apparatus for manufacturing various devices such as an image sensor (CCD or the like), a micromachine, a thin film magnetic head, and a DNA chip. Furthermore, the present invention can also be applied to an exposure process (exposure apparatus) when manufacturing a mask (photomask, reticle, etc.) on which mask patterns of various devices are formed using a photolithography process.

In the above-described embodiment, ArF excimer laser light (wavelength: 193 nm) or KrF excimer laser light (wavelength: 248 nm) is used as the exposure light. However, the present invention is not limited to this, and other appropriate laser light sources are used. For example, the present invention can also be applied to an F ₂ laser light source that supplies laser light having a wavelength of 157 nm.

  In the above-described embodiment, the present invention is applied to a step-and-scan type exposure apparatus that scans and exposes the pattern of the mask M on the shot area of the wafer W. However, the present invention is not limited to this, and the present invention can also be applied to a step-and-repeat type exposure apparatus that repeats the operation of collectively exposing the pattern of the mask M to each exposure region of the wafer W.

  In the above-described embodiment, the present invention is applied to the illumination optical system that illuminates the mask or wafer in the exposure apparatus. However, the present invention is not limited to this, and the irradiated surface other than the mask or wafer is illuminated. The present invention can also be applied to a general illumination optical system.

DESCRIPTION OF SYMBOLS 1 Light source 3 Diffractive optical element 4 Afocal lens 6 Density filter 7 Zoom lens 9, 19 Cylindrical micro fly's eye lens (optical integrator)
10 Condenser optical system 11 Mask blind 12 Imaging optical system M Mask PL Projection optical system AS Aperture stop W Wafer

Claims (18)

In the wavefront division type optical integrator used in the illumination optical system that illuminates the illuminated surface,
A plurality of first refractive surfaces having a predetermined refractive power in a first direction within a plane orthogonal to the optical axis of the illumination optical system;
A plurality of second refracting surfaces provided at a rear side of the plurality of first refracting surfaces so as to correspond to the plurality of first refracting surfaces, and having a predetermined refractive power in the first direction;
A decrease in light attenuation rate which is provided between at least two adjacent second refracting surfaces and increases as the position of light reaching the irradiated surface moves away from the center of the irradiated surface along the first direction. An optical integrator comprising a dimming portion having a light rate characteristic. The plurality of first refracting surfaces have substantially no refracting power in a second direction orthogonal to the first direction in the plane, and the plurality of second refracting surfaces have almost no refracting power in the second direction. The optical integrator according to claim 1, wherein the optical integrator is provided. 3. The optical integrator according to claim 1, wherein the dimming part has a V-shaped cutting surface extending along a second direction orthogonal to the first direction in the plane. 3. The optical integrator according to claim 1, wherein the dimming section includes a reflective film extending along a second direction orthogonal to the first direction in the plane. 3. The optical integrator according to claim 1, wherein the light reduction unit includes a light reduction film extending along a second direction orthogonal to the first direction in the plane. The optical integrator according to claim 1, wherein the dimming unit includes a light scattering film extending along a second direction orthogonal to the first direction in the plane. In order from the light incident side, a first optical member and a second optical member are provided,
On the exit side of the first optical member, the plurality of first refractive surfaces are arranged along the first direction,
7. The optical integrator according to claim 1, wherein the plurality of second refracting surfaces are arranged along the first direction on an emission side of the second optical member. . The plurality of first refracting surfaces have substantially no refractive power in a second direction orthogonal to the first direction in the plane;
The plurality of second refracting surfaces have substantially no refractive power in the second direction;
On the incident side of the first optical member, a plurality of third refractive surfaces having a predetermined refractive power in the second direction and having almost no refractive power in the first direction are arranged along the second direction. ,
On the incident side of the second optical member, a plurality of fourth lenses having a predetermined refractive power in the second direction and substantially non-refracting power in the first direction so as to correspond to the plurality of third refractive surfaces. The optical integrator according to claim 7, wherein refractive surfaces are arranged along the second direction. In order from the light incident side, a first optical member and a second optical member are provided,
The plurality of first refracting surfaces are arranged along the first direction on the incident side of the second optical member,
The optical integrator according to any one of claims 1 to 6, wherein the plurality of second refracting surfaces are arranged along the first direction on an exit side of the second optical member. . The plurality of first refracting surfaces have substantially no refractive power in a second direction orthogonal to the first direction in the plane;
The plurality of second refracting surfaces have substantially no refractive power in the second direction;
On the incident side of the first optical member, a plurality of third refractive surfaces having a predetermined refractive power in the second direction and having almost no refractive power in the first direction are arranged along the second direction. ,
On the exit side of the first optical member, a plurality of fourth lenses having a predetermined refractive power in the second direction and substantially non-refractive power in the first direction so as to correspond to the plurality of third refractive surfaces. The optical integrator according to claim 9, wherein refractive surfaces are arranged along the second direction. 11. The optical integrator according to claim 1, comprising an elongated rectangular unit wavefront dividing surface along the first direction. 11. In the illumination optical system that illuminates the illuminated surface based on the light from the light source,
An illumination optical system comprising the optical integrator according to any one of claims 1 to 11. The illumination optical system according to claim 12, further comprising a distribution forming optical system that forms a pupil intensity distribution in an illumination pupil behind the optical integrator. The projection pupil is used in combination with a projection optical system that forms a surface optically conjugate with the irradiated surface, and the illumination pupil is at a position optically conjugate with an aperture stop of the projection optical system. 14. The illumination optical system according to 12 or 13. 15. An exposure apparatus comprising the illumination optical system according to any one of claims 12 to 14 for illuminating a predetermined pattern, and exposing the predetermined pattern onto a photosensitive substrate. A projection optical system for forming an image of the predetermined pattern on the photosensitive substrate; and moving the predetermined pattern and the photosensitive substrate relative to the projection optical system along a scanning direction to The exposure apparatus according to claim 15, wherein the pattern is exposed by projection onto the photosensitive substrate. The exposure apparatus according to claim 16, wherein the first direction in the optical integrator corresponds to a direction orthogonal to the scanning direction. An exposure step of exposing the predetermined pattern to the photosensitive substrate using the exposure apparatus according to any one of claims 15 to 17,
Developing the photosensitive substrate to which the predetermined pattern is transferred, and forming a mask layer having a shape corresponding to the predetermined pattern on the surface of the photosensitive substrate;
And a processing step of processing the surface of the photosensitive substrate through the mask layer.

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