JP2010225954A - Correction unit, lighting optical system, exposure device, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust a difference in light intensity between a pair of regions spaced apart from each other in a predetermined direction across an optical axis in pupil intensity distributions associated with respective points on a surface to be irradiated. <P>SOLUTION: A lighting optical system includes a correction unit (8) which corrects pupil intensity distributions (20a, 20b, 20c, and 20d) formed at a lighting pupil. A correction unit has a first filter (81) disposed nearby an incident surface of an optical integrator (9) and a second filter (82) disposed right behind it. Each of the filters has at least one unit region having an external shape and a transmissivity distribution corresponding to a unit wavefront division surface of the optical integrator. At least one of the first filter and second filter is configured to move in a direction (Z direction) crossing the optical axis (AX). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a correction unit, 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

  Regardless of the shape of the pupil intensity distribution formed on the illumination pupil, light in a pair of regions spaced in a predetermined direction across the optical axis in the pupil intensity distribution for each point on the wafer as the final irradiated surface If the difference in intensity is too large, the pattern may be displaced from the desired position and burned.

  An object of the present invention is to provide an illumination optical system capable of adjusting a light intensity difference between a pair of regions spaced in a predetermined direction across an optical axis in a pupil intensity distribution related to each point on an irradiated surface. And Further, the present invention provides an appropriate illumination using an illumination optical system that adjusts the light intensity difference between a pair of regions spaced in a predetermined direction across the optical axis in the pupil intensity distribution for each point on the irradiated surface. An object of the present invention is to provide an exposure apparatus capable of performing good exposure under conditions.

In order to solve the above-described problem, in the first embodiment of the present invention, a wavefront division type optical integrator disposed in an optical path of an illumination optical system for illuminating a surface to be irradiated is used in combination with the front side of the optical integrator. Is a correction unit that corrects a pupil intensity distribution formed on the illumination pupil located behind the optical integrator,
A first filter disposed at a position near the incident surface of the optical integrator, or at a position optically conjugate with the incident surface, or a position near the first filter;
A second filter disposed at a position immediately after the first filter, or immediately after or near a position optically conjugate with the position of the first filter;
The first filter has at least one first unit region having an outer shape corresponding to a unit wavefront division plane of the optical integrator and a first transmittance distribution;
The second filter has at least one second unit region having an outer shape corresponding to the unit wavefront dividing plane and a second transmittance distribution;
At least one of the first filter and the second filter is configured to be movable in a direction crossing the optical axis of the illumination optical system.

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,
A wavefront division type optical integrator disposed in the optical path of the illumination optical system;
An illumination optical system comprising: a correction unit according to a first form used in combination with the optical integrator is provided.

  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.

  The illumination optical system of the present invention includes a correction unit that is arranged in front of the wavefront division type optical integrator and corrects the pupil intensity distribution formed on the illumination pupil. The correction unit has a first filter having at least one first unit region having a first transmittance distribution corresponding to the unit wavefront dividing plane and a second transmittance distribution corresponding to the unit wavefront dividing plane. A second filter having at least one second unit region, and the first filter and the second filter are configured to be capable of relative movement in a direction across the optical axis.

  As a result, as will be described later, the correction unit determines the pupil according to the relative movement between the first filter and the second filter, the form of the first and second transmittance distributions, the arrangement of the first and second unit regions, and the like. Exhibits various adjustments to the intensity distribution. Therefore, in the illumination optical system of the present invention, a pair of regions spaced in a predetermined direction across the optical axis in the pupil intensity distribution for each point on the irradiated surface by various adjustment operations on the pupil intensity distribution of the correction unit. Can be adjusted. Further, in the exposure apparatus of the present invention, using an illumination optical system that adjusts the light intensity difference between a pair of regions spaced in a predetermined direction across the optical axis in the pupil intensity distribution for each point on the irradiated surface, Good exposure can be performed under appropriate illumination conditions, and thus 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 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. Explain the principle of adjustment by the correction unit It is a figure which shows the structure of a correction | amendment unit roughly. It is a 1st figure explaining the basic effect | action of a correction | amendment unit. It is a 2nd figure explaining the basic effect | action of a correction | amendment unit. It is a 3rd figure explaining the basic effect | action of a correction | amendment unit. It is a 4th figure explaining the basic effect | action of a correction | amendment unit. It is a figure which shows typically a mode that the pupil intensity distribution regarding the center point P1 is adjusted by the correction unit. It is a figure which shows typically a mode that the pupil intensity distribution regarding the peripheral points P2, P3 is adjusted by the correction unit. 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 beam 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 the diffractive optical element 3 for annular illumination, for example.

  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. The light passing through the afocal lens 4 passes through an optical integrator via a zoom lens 7 and a correction unit 8 for varying σ value (σ value = mask-side numerical aperture of illumination optical system / mask-side numerical aperture of projection optical system). Is incident on a micro fly's eye lens (or fly eye lens) 9. The correction unit 8 is disposed in the vicinity of the incident surface of the micro fly's eye lens 9. The configuration and operation of the correction unit 8 will be described later.

  The micro fly's eye lens 9 is, for example, an optical element composed of a large number of micro lenses having positive refractive power arranged vertically and horizontally and densely, by performing etching treatment on a plane-parallel plate to form a micro lens group. It is configured. Each micro lens constituting the micro fly's eye lens is smaller than each lens element constituting the fly eye lens. Further, unlike a fly-eye lens composed of lens elements isolated from each other, a micro fly-eye lens is formed integrally with a large number of micro lenses (micro refractive surfaces) without being isolated from each other. However, the micro fly's eye lens is the same wavefront division type optical integrator as the fly eye lens in that lens elements having positive refractive power are arranged vertically and horizontally. For example, a cylindrical micro fly's eye lens can be used as the micro fly's eye lens 9. The configuration and action of the cylindrical micro fly's eye lens are disclosed in, for example, US Pat. No. 6,913,373.

  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 micro fly's eye lens 9 is disposed at or near the rear focal position of the zoom lens 7. In other words, the zoom lens 7 arranges the predetermined surface 5 and the incident surface of the micro fly's eye lens 9 substantially in a Fourier transform relationship, and consequently the pupil surface of the afocal lens 4 and the incident surface of the micro fly's eye lens 9. Are arranged almost conjugate optically. Accordingly, on the incident surface of the micro fly's eye lens 9, for example, a ring-shaped 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.

  The incident surface (that is, the unit wavefront dividing surface) of each microlens in the micro fly's eye lens 9 is, for example, a rectangular shape having a long side along the Z direction and a short side along the X direction. It has a rectangular shape similar to the shape of the illumination area to be formed above (and thus the shape of the exposure area to be formed on the wafer W). The light beam incident on the micro fly's eye lens 9 is two-dimensionally divided, and an illumination field formed on the incident surface of the micro fly's eye lens 9 at the rear focal plane or in the vicinity thereof (and hence the position of the illumination pupil). A secondary light source having substantially the same light intensity distribution as the light source, that is, a secondary light source (pupil intensity distribution) composed of a ring-shaped substantial surface light source centered on the optical axis AX.

  On the rear focal plane of the micro fly's eye lens 9 or in the vicinity thereof, an illumination aperture stop (not shown) having an annular opening (light transmission part) corresponding to the annular secondary light source is provided if necessary. Has been placed. 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 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 microlens of the 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 micro fly's eye lens 9 is used as a 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 micro fly's eye lens 9 is relatively large, the overall light intensity distribution formed on the incident surface of the micro fly's eye lens 9 and the overall light intensity distribution (pupil intensity distribution) of the entire secondary light source. ) And a high correlation. For this reason, the light intensity distribution on the incident surface of the 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 micro fly's eye lens 9 form a distribution forming optical that forms a pupil intensity distribution in the illumination pupil behind the micro fly's eye lens 9. The 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. Accordingly, the light beam that has passed through the diffractive optical element for multipole illumination is incident on the incident surface of the micro fly's eye lens 9 from, for example, an illumination field having a plurality of predetermined shapes (arc shape, circular shape, etc.) centered on the optical axis AX. To form a multipolar illuminator. As a result, a secondary light source having the same multipolar shape as the illumination field formed on the incident surface is also formed on or near the rear focal plane of the micro fly's eye lens 9.

  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 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 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 operational effects of the correction unit 8 according to the present embodiment, the rear focal plane of the micro fly's eye lens 9 or the illumination pupil in the vicinity thereof is as shown in FIG. It is assumed that a quadrupole pupil intensity distribution (secondary light source) 20 is formed. In the following description, the term “illumination pupil” simply refers to the rear focal plane of the micro fly's eye lens 9 or an illumination pupil in the vicinity thereof.

  Referring to FIG. 2, a quadrupole pupil intensity distribution 20 formed on the illumination pupil includes a pair of arcuate substantial surface light sources 20a and 20b spaced apart in the Z direction across the optical axis AX, and A pair of arcuate substantial surface light sources (hereinafter simply referred to as “surface light sources”) 20c and 20d spaced apart in the X direction across the optical axis AX. The X direction in the illumination pupil is the short side direction of the rectangular microlens of the micro fly's eye lens 9 and corresponds to the scanning direction of the wafer W. The Z direction in the illumination pupil is the long side direction of the rectangular microlens of the micro fly's eye lens 9 and corresponds to the scanning orthogonal direction (Y direction on the wafer W) orthogonal to the scanning direction of the wafer W. ing.

  On the wafer W, as shown in FIG. 3, a rectangular still exposure region ER having a long side along the Y direction and a short side along the X direction is formed. 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 may differ depending on the position of the incident point.

  As a relatively simple example, the light incident on the central point P1 in the still exposure region ER forms a quadrupole pupil intensity distribution schematically shown in FIG. 4 in the illumination pupil, and the peripheral points P2 and P3. Consider a case where incident light forms a quadrupole pupil intensity distribution schematically shown in FIG. 5 in the illumination pupil. That is, in the quadrupole pupil intensity distribution 21 formed by the light incident on the center point P1 in the still exposure region ER, the light intensities of the surface light sources 21b, 21c and 21d are substantially equal to each other as shown in FIG. It is assumed that the light intensity of the surface light source 21a is higher than the light intensity of the other surface light sources 21b to 21d.

  In the quadrupole pupil intensity distribution 22 formed by the light incident on the peripheral point P2 spaced from the central point P1 in the still exposure region ER in the + Y direction, as shown in FIG. 5, the surface light sources 22b and 22c. And the light intensity of the surface light source 22a is greater than the light intensity of the other surface light sources 22b to 22d. The light intensity of the surface light source 22a is larger than that of the surface light source 21a related to the center point P1, and the light intensity of the surface light sources 22b to 22d is substantially equal to the light intensity of the surface light sources 21b to 21d related to the center point P1.

  A quadrupole pupil intensity distribution 23 formed by light incident on a peripheral point P3 spaced from the central point P1 in the still exposure region ER in the −Y direction is substantially the same as the pupil intensity distribution 22 related to the peripheral point P2. Suppose that That is, the light intensity of the surface light sources 23b, 23c and 23d is substantially equal to each other, and the light intensity of the surface light source 23a is greater than the light intensity of the other surface light sources 23b to 23d. The light intensity of the surface light source 23a is substantially equal to the surface light source 22a related to the peripheral point P2, and the light intensity of the surface light sources 23b to 23d is the light intensity of the surface light sources 21b to 21d related to the center point P1 and the surface light sources 22b to 22b related to the peripheral point P2. It is assumed that the light intensity is approximately equal to 22d.

  As described above, in the pupil intensity distribution regarding each point on the wafer W, the light of a pair of regions spaced apart in the Z direction (direction corresponding to the scanning orthogonal direction (Y direction on the wafer W)) across the optical axis AX. If the difference in intensity is too large, the pattern printed on the shot area (the peripheral positions corresponding to the peripheral points P2 and P3 in the example shown in FIGS. 4 and 5) may be displaced from the desired position. .

  In the present embodiment, between the pair of surface light sources 21a and 21b spaced apart in the Z direction across the optical axis AX in the pupil intensity distributions 21, 22, and 23 for the points P1, P2, and P3, the surface light source 22a A correction unit 8 is provided as an adjusting means for adjusting the difference in light intensity between the light source 22b and the surface light sources 23a and 23b. Prior to the description of the specific configuration and operation of the correction unit 8, the principle of adjustment by the correction unit 8 will be described with reference to FIG.

  In FIG. 6, of the light reaching the center point P1 in the still exposure region ER on the wafer W, that is, the light reaching the center point P1 ′ of the opening of the mask blind 11, one specific minute of the micro fly's eye lens 9 is shown. Attention is focused on the light L1 that contributes to the formation of the surface light source 21a (and hence the formation of the surface light source 20a) via the lens 9aa. Of the light reaching the peripheral points P2 and P3 in the still exposure region ER, that is, the light reaching the peripheral points P2 ′ and P3 ′ of the opening of the mask blind 11, the surface light sources 22a and 23a are passed through the specific microlenses 9aa. Attention is focused on the light L2 and L3 that contribute to the formation of (and consequently the formation of the surface light source 20a).

  In FIG. 6, in order to simplify the description, the peripheral point P2 ′ corresponding to the peripheral point P2 in the still exposure region ER is located on the + Z direction side of the opening of the mask blind 11, and the periphery in the still exposure region ER It is assumed that the peripheral point P3 ′ corresponding to the point P3 is located on the −Z direction side of the opening of the mask blind 11. In FIG. 6, for the sake of clarity, the size of each microlens 9a is greatly exaggerated, and the light from the surface light source 20a is transmitted by light through a plurality of microlenses 9a arranged in three rows along the Z direction. Although the appearance of forming the whole is schematically shown, in general, light that has passed through more microlenses 9a of the micro fly's eye lens 9 generally forms the surface light source 20a.

  As shown in FIG. 6, when the filter 80 is disposed in the vicinity of the incident surface of the micro fly's eye lens 9, a specific micro lens that is one of a plurality of unit wavefront dividing surfaces of the micro fly's eye lens 9. The light that has passed through the rectangular filter region (unit region) 80a corresponding to the incident surface 9aa passes through the specific microlens 9aa and contributes to the formation of a part of the surface light source 20a, and then passes through the condenser optical system 10. Thus, an illumination field is formed at the position of the mask blind 11. At this time, the light L1 reaching the center point P1 'of the opening of the mask blind 11 passes through the center position P1' 'along the Z direction in the filter region 80a.

  The light L2 reaching the peripheral point P2 ′ of the opening of the mask blind 11 passes through the peripheral position P2 ″ on the −Z direction side in the filter region 80a, and the light L3 reaching the peripheral point P3 ′ is + Z in the filter region 80a. It passes the peripheral position P3 ″ on the direction side. The position of the still exposure region ER, the position of the mask blind 11 and the position of the incident surface of the micro fly's eye lens 9 are optically conjugate, and the incident position of the light to the still exposure region ER and the opening of the mask blind 11 The incident position of the light on the unit area and the incident position of the light on the unit area corresponding to the unit wavefront dividing surface of the micro fly's eye lens 9 in the filter 80 disposed near the incident surface of the micro fly's eye lens 9 are mutually One-to-one correspondence.

  Accordingly, when the intensities of the light beams L1, L2, and L3 reaching the points P1 ′, P2 ′, and P3 ′ of the opening of the mask blind 11 are equal to each other in the optical system that does not include the filter 80, the transmission varies along the Z direction. When the filter 80 having the filter region 80a to which the rate distribution is given is attached to the optical system, the intensity of at least one of the lights L1, L2, and L3 incident on the specific microlens 9aa of the micro fly's eye lens 9 changes. As a result, the light intensity of at least one of the surface light sources 21a, 22a, and 23a changes. That is, the light intensity of the surface light sources 21a, 22a and 23a formed on the illumination pupil by the light reaching the points P1 ′, P2 ′ and P3 ′ of the opening of the mask blind 11 contributes to the formation of the surface light source 20a on the illumination pupil. It changes according to the transmittance distribution applied to the unit region 80a of the filter 80 corresponding to the specific microlens 9aa through which light passes.

  This is because a required transmittance distribution is given to the unit region of the filter 80 corresponding to at least one microlens 9a among the plurality of microlenses 9a through which light contributing to the formation of the surface light source 20a passes. The light intensity of the surface light sources 21a, 22a, 23a with respect to the points P1 ′, P2 ′, P3 ′ of the opening of the mask blind 11 is adjusted, and consequently the surface light sources 21a, 22a with respect to the points P1, P2, P3 in the still exposure region ER. , 23a can be adjusted. More generally, the light intensity of at least a partial region of the pupil intensity distribution for each point in the still exposure region ER is provided by providing a required transmittance distribution to one or more unit regions of the filter 80, respectively. Can be adjusted.

  As shown in FIG. 7, the correction unit 8 of the present embodiment includes a pair of filters 81 and 82 arranged along the optical axis AX (corresponding to the Y direction). Each filter 81, 82 has a form of a plane parallel plate formed of an optical material such as quartz or fluorite. The first filter 81 is disposed in the vicinity of the incident surface 9 b of the micro fly's eye lens 9, and the second filter 82 is disposed immediately after the first filter 81.

  The first filter 81 is configured to be movable along the Z direction while maintaining a posture in which the incident surface 81a is orthogonal to the optical axis AX. The second filter 82 is also configured to be movable along the Z direction while maintaining a posture in which the incident surface 82a is orthogonal to the optical axis AX. In other words, the first filter 81 and the second filter 82 are configured to be movable along the Z direction, which is the long side direction of the rectangular unit wavefront dividing surface of the micro fly's eye lens 9. In the correction unit 8, the first filter 81 and the second filter 82 individually move along the Z direction based on a command from the drive control system 89.

  The correction unit 8 acts on the light reaching one surface light source 20a of the pair of surface light sources 20a and 20b spaced in the Z direction across the optical axis AX in the quadrupole pupil intensity distribution 20. It is configured. Specifically, on the exit surface 81b (or the incident surface 81a) of the first filter 81, a unit corresponding to at least one microlens 9a among the plurality of microlenses 9a through which light contributing to the formation of the surface light source 20a passes. In the region 81c, a light-reducible thin film (for example, a thin film made of chromium or chromium oxide) whose thickness changes according to the position in the Z direction is formed.

  Similarly, on the incident surface 82a (or exit surface 82b) of the second filter 82, a unit region corresponding to at least one minute lens 9a among the plurality of minute lenses 9a through which light contributing to the formation of the surface light source 20a passes. Also on 82c, a light-reducing thin film whose thickness changes according to the position in the Z direction is formed. That is, each of the filters 81 and 82 includes at least one unit region 81c and 82c having a transmittance distribution with different transmittances depending on the incident position of light. As described above, the unit regions 81c and 82c are regions having an outer shape corresponding to the unit wavefront dividing surface of the micro fly's eye lens 9 in the filters 81 and 82, that is, one side along the X direction and one side along the Z direction. Is a rectangular region defined by

  Hereinafter, in order to facilitate understanding of the description, it is assumed that the plurality of unit regions 81c and 82c corresponding to all the microlenses 9a through which the light contributing to the formation of the surface light source 20a passes have the same transmittance distribution. . Further, the unit region 81c is provided on the exit surface 81b of the first filter 81, and the unit region 82c is provided on the entrance surface 82a of the second filter 82. Further, as shown by reference numerals 31a and 31b in FIG. 8, the unit areas 81c and 82c have the highest transmittance at the center positions 81ca and 82ca along the Z direction of the unit areas 81c and 82c. It is assumed that a transmittance distribution in which the transmittance linearly decreases from 82 ca to the peripheral positions 81 cb and 81 cc; 82 cb and 82 cc along the Z direction is formed.

  In FIG. 8, the vertical axis indicates the normalized transmittance when the maximum transmittance at the center positions 81ca and 82ca is 1, and the horizontal axis indicates the Z-direction position in the unit regions 81c and 82c. In FIG. 8, in order to facilitate understanding of the operation of the correction unit 8, a similar transmittance distribution is also formed in part of the unit regions on both sides along the Z direction of one unit region 81c, 82c. It shows a state. As a specific numerical example, the same transmittance distributions 31a and 31b are symmetrical with respect to the center positions 81ca and 82ca, the transmittance at the center positions 81ca and 82ca is 1, and the peripheral positions 81cb and 82cb; The transmittance at 82 cc is 0.95. The notation in FIG. 8 is the same in FIGS. 9 to 11 related thereto.

  In the reference state of the correction unit 8 in which the center position 81ca of the unit region 81c and the center position 82ca of the unit region 82c coincide with each other in the Z direction, one unit region 81c of the first filter 81 and the second filter 82 The light that passes through one corresponding unit region 82c and forms the surface light source 20a is only one unit region (corresponding to the filter region 80a in FIG. 6) having the combined transmittance distribution indicated by reference numeral 32 in FIG. It is optically equivalent to the light that passes through and forms the surface light source 20a. Here, the combined transmittance distribution 32 is a distribution obtained by simply adding the transmittance distribution 31b in the unit region 82c to the transmittance distribution 31a in the unit region 81c according to the position in the Z direction.

  In the reference state of the correction unit 8, the surface light source 21a is formed and the intensity of light reaching the center point P1 in the still exposure region ER is not reduced, but the surface light sources 22a and 23a are formed and the periphery in the still exposure region ER is formed. The intensity of light reaching points P2 and P3 is reduced by 10%. That is, in the reference state of the correction unit 8, the light intensity of the surface light source 21a of the pupil intensity distribution 21 with respect to the center point P1 does not decrease, but the light of the surface light sources 22a and 23a of the pupil intensity distributions 22 and 23 with respect to the peripheral points P2 and P3. The strength is reduced by 10%. As a result, the difference between the light intensity decrease rate of the surface light source 21a and the light intensity decrease rates of the surface light sources 22a and 23a is 10%.

  From the reference state of the correction unit 8 described above, the first filter 81 is moved in the + Z direction (or -Z) by a distance of 1/16 of the Z direction dimension (corresponding to the longitudinal dimension of the unit wavefront dividing surface) of the unit regions 81c and 82c. In the first movement state in which the second filter 82 is moved in the −Z direction (or + Z direction) by the same distance, the transmittance distributions 31a and 31b that are displaced from each other in the Z direction are added. A composite transmittance distribution 33 as shown in FIG. 9 is obtained. In the first movement state in which the first filter 81 and the second filter 82 are relatively moved from the reference state in the Z direction by a distance of 1/8 of the dimension in the Z direction of the unit regions 81c and 82c, the surface light source 21a is formed to be the center. The intensity of light reaching the point P1 is reduced by about 1.1%, and the intensity of light reaching the peripheral points P2 and P3 by forming the surface light sources 22a and 23a is reduced by about 8.9%.

  That is, in the first movement state of the correction unit 8, the light intensity of the surface light source 21a of the pupil intensity distribution 21 related to the center point P1 is reduced by about 1.1%, and the surfaces of the pupil intensity distributions 22 and 23 related to the peripheral points P2 and P3. The light intensity of the light sources 22a and 23a is reduced by about 8.9%. As a result, the difference between the decrease rate of the light intensity of the surface light source 21a and the decrease rate of the light intensity of the surface light sources 22a and 23a is about 7.7%.

  From the reference state of the correction unit 8, the first filter 81 is moved in the + Z direction (or −Z direction) by a distance of 1/8 of the Z direction dimension of the unit regions 81 c and 82 c, and the second filter 82 is moved by the same distance − In the second movement state moved in the Z direction (or + Z direction), the transmittance distributions 31a and 31b shifted in the Z direction are added to obtain a combined transmittance distribution 34 as shown in FIG. In the second movement state in which the first filter 81 and the second filter 82 are relatively moved from the reference state in the Z direction by a distance of 1/4 of the dimension in the Z direction of the unit areas 81c and 82c, the surface light source 21a is formed to be the center. The intensity of light reaching the point P1 is reduced by about 2.7%, and the intensity of light reaching the peripheral points P2, P3 by forming the surface light sources 22a and 23a is reduced by about 7.3%.

  That is, in the second movement state of the correction unit 8, the light intensity of the surface light source 21a of the pupil intensity distribution 21 related to the center point P1 is reduced by about 2.7%, and the surfaces of the pupil intensity distributions 22 and 23 related to the peripheral points P2 and P3. The light intensity of the light sources 22a and 23a is reduced by about 7.3%. As a result, the difference between the light intensity decrease rate of the surface light source 21a and the light intensity decrease rates of the surface light sources 22a and 23a is about 4.6%.

  From the reference state of the correction unit 8, the first filter 81 is moved in the + Z direction (or −Z direction) by a distance that is ¼ of the Z direction dimension of the unit regions 81 c and 82 c, and the second filter 82 is moved by the same distance by −. In the third movement state moved in the Z direction (or + Z direction), the transmittance distributions 31a and 31b that are displaced from each other in the Z direction are added to obtain a combined transmittance distribution 35 as shown in FIG. In the third movement state in which the first filter 81 and the second filter 82 are relatively moved from the reference state in the Z direction by a distance of ½ of the dimension in the Z direction of the unit regions 81c and 82c, the surface light sources 21a, 22a, and 23a The intensity of light that contributes to the formation and reaches the points P1, P2, P3 is reduced by about 5%.

  That is, in the third movement state of the correction unit 8, the light intensity of the surface light source 21a of the pupil intensity distribution 21 related to the center point P1 is reduced by about 5%, and the surface light sources 22a of the pupil intensity distributions 22 and 23 related to the peripheral points P2 and P3. , 23a is also reduced by about 5%. As a result, the difference between the light intensity reduction rate of the surface light source 21a and the light intensity reduction rates of the surface light sources 22a and 23a is eliminated.

  According to the above numerical example, the relative position along the Z direction of the first filter 81 and the second filter 82 changes between the reference state and the third movement state, so that the light intensity of the surface light source 21a is changed. The difference between the decrease rate and the decrease rate of the light intensity of the surface light sources 22a and 23a continuously changes between 0% and 10%. In the above numerical example, the transmittance distribution 31a of the unit region 81c and the transmittance distribution 31b of the unit region 82c are the same, and the transmittance changes symmetrically and linearly with respect to the center positions 81ca and 82ca. Yes. The same transmittance distribution is given to the group of unit regions 81c and 82c corresponding to all the microlenses 9a through which the light contributing to the formation of the surface light source 20a passes.

  However, various forms are possible for the transmittance distribution given to the unit areas 81c and 82c and the arrangement (number and position) of the unit areas 81c and 82c. That is, in the correction unit 8 of the present embodiment, the relative positions of the first filter 81 and the second filter 82 along the Z direction, the form of the transmittance distribution given to the unit regions 81c and 82c (the change in transmittance). Form), a pair of regions (for example, surfaces) spaced apart in the Z direction across the optical axis AX in the pupil intensity distribution for each point in the static exposure region ER of the wafer W according to the arrangement of the unit regions 81c and 82c, etc. The light intensity difference between the light sources 21a, 22a, and 23a and the surface light sources 21b, 22b, and 23b) can be adjusted, and as a result, various adjustment effects can be exerted on the pupil intensity distribution.

  Specifically, as shown in FIG. 12, the light intensity of the surface light source 21a becomes substantially equal to the light intensity of the other surface light sources 21b to 21d in the pupil intensity distribution 21 related to the center point P1 by the action of the correction unit 8. To lower. As a result, in the pupil intensity distribution 21 ′ relating to the center point P1 adjusted by the correction unit 8, the light intensity of the surface light source 21a ′ and the light intensity of the surface light source 21b spaced apart in the Z direction are substantially equal, and X The light intensities of the surface light sources 21c and 21d spaced apart in the direction are also substantially equal. Alternatively, the difference between the light intensity of the surface light source 21a 'and the light intensity of the surface light source 21b is adjusted to a required light intensity difference.

  Further, as shown in FIG. 13, by the action of the correction unit 8, in the pupil intensity distributions 22 and 23 relating to the peripheral points P2 and P3, the light intensity of the surface light sources 22a and 23a is changed to the other surface light sources 22b to 22d; The light intensity is reduced so as to be approximately equal to the light intensity. As a result, in the pupil intensity distributions 22 ′ and 23 ′ relating to the peripheral points P2 and P3 adjusted by the correction unit 8, the light intensities of the surface light sources 22a ′ and 23a ′ spaced in the Z direction and the surface light sources 22b and 23b. The light intensities are substantially equal, and the light intensities of the surface light sources 22c, 22d; 23c, 23d spaced in the X direction are also substantially equal. Alternatively, the difference between the light intensity of the surface light sources 22a 'and 23a' and the light intensity of the surface light sources 22b and 23b is adjusted to a required light intensity difference.

  The operation of adjusting the difference between the light intensity of the surface light sources 21a ′, 22a ′, and 23a ′ and the light intensity of the surface light sources 21b, 22b, and 23b to a required light intensity difference is, for example, light through the projection optical system PL. Based on the measurement result of a pupil intensity distribution measuring device (not shown) that measures the pupil intensity distribution on the pupil plane of the projection optical system PL. The pupil intensity distribution measuring apparatus includes, for example, a CCD imaging unit having an imaging surface disposed at a position optically conjugate with the pupil position of the projection optical system PL, and the pupil intensity relating to each point on the image plane of the projection optical system PL. The distribution (pupil intensity distribution formed on the pupil plane of the projection optical system PL by the light incident on each point) is monitored. For the detailed configuration and operation of the pupil intensity distribution measuring apparatus, reference can be made to US Patent Publication No. 2008/0030707.

  Specifically, the measurement result of the pupil intensity distribution measuring device is supplied to a control unit (not shown). The control unit outputs a command to the drive control system 89 of the correction unit 8 so that the pupil intensity distribution on the pupil plane of the projection optical system PL becomes a desired distribution based on the measurement result of the pupil intensity distribution measuring device. The drive control system 89 controls the position in the Z direction of each filter 81, 82 based on a command from the control unit, and the light intensity of the surface light sources 21a ′, 22a ′, 23a ′ and the light of the surface light sources 21b, 22b, 23b. The difference from the intensity is adjusted to the required light intensity difference.

  As described above, the illumination optical system (2 to 12) of the present embodiment is disposed in front of the micro fly's eye lens 9 which is a wavefront division type optical integrator, and the rear focal position of the micro fly's eye lens 9 Alternatively, a correction unit 8 that corrects the pupil intensity distribution formed on the illumination pupil in the vicinity thereof is provided. The correction unit 8 includes a first filter 81 disposed in the vicinity of the incident surface of the micro fly's eye lens 9 and a second filter 82 disposed immediately after the first filter 81.

  The first filter 81 has at least one unit region 81c having a rectangular outer shape corresponding to the unit wavefront dividing surface of the micro fly's eye lens 9 and the transmittance distribution 31a. The second filter 82 has at least one unit region 82c having a rectangular outer shape corresponding to the unit wavefront dividing plane and the transmittance distribution 31b. The first filter 81 and the second filter 82 are configured to be capable of relative movement in the Z direction across the optical axis AX, that is, the direction corresponding to the long side of the rectangular unit wavefront dividing surface.

  As a result, the correction unit 8 has various pupil intensity distributions depending on the relative movement between the first filter 81 and the second filter 82, the form of the transmittance distributions 31a and 31b, the arrangement of the unit regions 81c and 82c, and the like. It exerts an adjustment effect. Therefore, in the illumination optical system (2 to 12) of the present embodiment, Z is placed across the optical axis AX in the pupil intensity distribution relating to each point in the still exposure region ER by various adjustment effects on the pupil intensity distribution of the correction unit 8. The difference in light intensity between a pair of regions spaced apart in the direction can be adjusted.

  In the exposure apparatus (2 to WS) of the present embodiment, the light in a pair of regions spaced apart in the Z direction across the optical axis AX in the pupil intensity distribution for each point in the static exposure region ER on the wafer W. Using the illumination optical system (2 to 12) for adjusting the intensity difference, it is possible to perform good exposure under appropriate illumination conditions according to the fine pattern of the mask M, and thus expose the fine pattern of the mask M. The entire area can be faithfully transferred onto the wafer W with a desired line width at a desired position.

  In the present embodiment, it is conceivable that the light amount distribution on the wafer (irradiated surface) W is affected by, for example, the adjustment function of the correction unit 8. In this case, the illuminance distribution in the still exposure region ER or the shape of the still exposure region (illumination region) ER can be changed as necessary by the action of the light quantity distribution adjusting unit having a known configuration. 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-described embodiment, the correction unit 8 is configured by a pair of filters 81 and 82 having the form of a plane parallel plate arranged perpendicular to the optical axis AX according to the specific form shown in FIG. Yes. However, the present invention is not limited to this, and various configurations are possible for the specific configuration of the correction unit 8. That is, the area on the pupil intensity distribution where the correction unit acts, the form of each filter constituting the correction unit (outer shape, etc.), the posture of each filter, the direction of relative movement of each filter (direction crossing the optical axis), each Various forms are possible with respect to the form of the transmittance distribution formed on the filter, the position of the surface on which the transmittance distribution is formed (incident surface or exit surface), the arrangement position of each filter, and the like. For example, as each filter, a light-transmitting substrate in which at least one surface has a curvature can be used.

  In the above-described embodiment, the first filter 81 is disposed in the vicinity of the incident surface of the micro fly's eye lens 9, and the second filter 82 is disposed immediately after the first filter 81. However, the present invention is not limited to this, and the first filter 81 is located at a position optically conjugate with the incident surface of the micro fly's eye lens 9 or a position in the vicinity thereof (for example, a pupil position of the afocal lens 4 or a position in the vicinity thereof). Or a position optically conjugate with the position of the first filter 81 (for example, a position optically conjugate with the position of the first filter 81 in the optical path of the afocal lens 4) or in the vicinity thereof. A second filter 82 can be arranged.

  In the above-described embodiment, correction is made to light reaching one surface light source 20a of the pair of surface light sources 20a and 20b spaced apart in the Z direction across the optical axis AX in the quadrupole pupil intensity distribution 20. Unit 8 is activated. However, the present invention is not limited to this, and the correction unit can also act on light reaching one or more surface light sources selected from four surface light sources constituting a quadrupole pupil intensity distribution. More generally, the correction unit can act on light reaching an arbitrary region on the pupil intensity distribution having an arbitrary outer shape.

  In the above-described embodiment, the first filter 81 and the second filter 82 are configured to be movable along the Z direction, which is the long side direction of the rectangular unit wavefront dividing surface of the micro fly's eye lens 9. Yes. However, the present invention is not limited to this, and the pair of filters can be configured to be movable along the X direction which is the short side direction of the unit wavefront dividing plane. More generally, at least one of the first filter and the second filter can be configured to be movable in an arbitrary direction across the optical axis.

  Further, in the above-described embodiment, a required transmittance distribution is given to the unit regions 81c and 82c by forming the light-reducing thin film whose thickness varies along the predetermined direction in the unit regions 81c and 82c. Yes. However, the present invention is not limited to this, and a plurality of light-shielding dots (for example, minute light-shielding dots made of chromium or chromium oxide) whose density distribution changes along the direction crossing the optical axis are formed in the unit region. Thus, a required transmittance distribution can be given to the unit region. Further, by forming at least one dimming region (such as a light shielding region, a scattering region, or a diffraction region) in the unit region, a required transmittance distribution can be given to the unit region.

  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.

  In the above-described embodiment, a variable pattern forming apparatus that forms a predetermined pattern based on predetermined electronic data can be used instead of a mask. By using such a variable pattern forming apparatus, the influence on the synchronization accuracy can be minimized even if the pattern surface is placed vertically. As the variable pattern forming apparatus, for example, a DMD (digital micromirror device) including a plurality of reflecting elements driven based on predetermined electronic data can be used. An exposure apparatus using DMD is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-304135, International Patent Publication No. 2006/080285 pamphlet and US Patent Publication No. 2007/0296936 corresponding thereto. In addition to a non-light-emitting reflective spatial light modulator such as DMD, a transmissive spatial light modulator may be used, or a self-luminous image display element may be used. Note that a variable pattern forming apparatus may be used even when the pattern surface is placed horizontally. Here, the teachings of US Patent Publication No. 2007/0296936 are incorporated by reference.

  Further, in the above-described embodiment, in place of or in addition to the diffractive optical element 3, for example, a large number of minute element mirrors arranged in an array and whose tilt angle and tilt direction are individually driven and controlled. A spatial light modulator that converts the cross section of the light beam into a desired shape or a desired size by dividing the incident light beam into minute units for each reflecting surface and deflecting the incident light beam may be used. An illumination optical system using such a spatial light modulator is disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-353105.

  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 may be 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. 14 is a flowchart showing a manufacturing process of a semiconductor device. As shown in FIG. 14, in the semiconductor device manufacturing process, a metal film is vapor-deposited on a wafer W to be a semiconductor device substrate (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. 15 is a flowchart showing a manufacturing process of a liquid crystal device such as a liquid crystal display element. As shown in FIG. 15, in the manufacturing process of the liquid crystal device, 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, a so-called immersion method is applied in which the optical path between the projection optical system and the photosensitive substrate is filled with a medium (typically liquid) having a refractive index larger than 1.1. You may do it. In this case, as a technique for filling the liquid in the optical path between the projection optical system and the photosensitive substrate, a technique for locally filling the liquid as disclosed in International Publication No. WO 99/49504, A method of moving a stage holding a substrate to be exposed as disclosed in Japanese Patent Laid-Open No. 6-124873 in a liquid bath, or a predetermined depth on a stage as disclosed in Japanese Patent Laid-Open No. 10-303114. A method of forming a liquid tank and holding the substrate in the liquid tank can be employed. Here, the teachings of International Publication No. WO99 / 49504, JP-A-6-124873 and JP-A-10-303114 are incorporated by reference.

  In the above-described embodiment, a so-called polarization illumination method disclosed in US Publication Nos. 2006/0170901 and 2007/0146676 can also be applied. Here, the teachings of US Patent Publication No. 2006/0170901 and US Patent Publication No. 2007/0146676 are incorporated by reference.

  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 an object other than the mask (or wafer) is used. The present invention can also be applied to a general illumination optical system that illuminates the irradiation surface.

DESCRIPTION OF SYMBOLS 1 Light source 3 Diffractive optical element 4 Afocal lens 7 Zoom lens 8 Correction unit 81, 82 Each filter 9 Micro fly's eye lens (optical integrator)
DESCRIPTION OF SYMBOLS 10 Condenser optical system 11 Mask blind 12 Imaging optical system M Mask MS Mask stage PL Projection optical system AS Aperture stop W Wafer WS Wafer stage

Claims (20)

Used in combination with a wavefront splitting type optical integrator arranged in the optical path of the illumination optical system that illuminates the illuminated surface, arranged in front of the optical integrator, and formed in the illumination pupil on the rear side of the optical integrator A correction unit for correcting the pupil intensity distribution
A first filter disposed at a position near the incident surface of the optical integrator, or at a position optically conjugate with the incident surface, or a position near the first filter;
A second filter disposed at a position immediately after the first filter, or immediately after or near a position optically conjugate with the position of the first filter;
The first filter has at least one first unit region having an outer shape corresponding to a unit wavefront division plane of the optical integrator and a first transmittance distribution;
The second filter has at least one second unit region having an outer shape corresponding to the unit wavefront dividing plane and a second transmittance distribution;
At least one of the first filter and the second filter is configured to be movable in a direction crossing the optical axis of the illumination optical system. The optical integrator has a rectangular unit wavefront dividing surface,
2. The correction according to claim 1, wherein at least one of the first filter and the second filter is configured to be movable along a direction of one side of the rectangular unit wavefront dividing surface. unit. The correction unit according to claim 2, wherein the first filter and the second filter are configured to be movable along the direction of the one side. The correction unit according to claim 1, wherein the first unit region and the second unit region have the same transmittance distribution. 5. The correction unit according to claim 1, wherein at least one of the first unit region and the second unit region has at least one dimming region. 6. 6. At least one of the first unit area and the second unit area has a plurality of light-shielding dots whose density distribution changes along the transverse direction. The correction unit described in the paragraph. 7. The device according to claim 1, wherein at least one of the first unit region and the second unit region has a thin film whose thickness varies along the transverse direction. Correction unit. The correction unit according to claim 1, wherein the first filter and the second filter have a shape of a plane parallel plate. The correction unit according to claim 8, wherein the first filter and the second filter maintain a state parallel to each other. In the illumination optical system that illuminates the illuminated surface based on the light from the light source,
A wavefront division type optical integrator disposed in the optical path of the illumination optical system;
An illumination optical system comprising: the correction unit according to claim 1, wherein the correction optical unit is used in combination with the optical integrator. The illumination optical system according to claim 10, further comprising a distribution forming optical system that forms a pupil intensity distribution in the illumination pupil on the rear side of the optical integrator. The optical integrator has an elongated rectangular unit wavefront dividing surface along a predetermined direction,
The illumination optical system according to claim 10 or 11, wherein the first filter and the second filter are configured to be movable along the predetermined direction. The correction unit is configured to act on light reaching at least one of a pair of regions spaced in the predetermined direction across the optical axis of the illumination optical system in the illumination pupil. The illumination optical system according to claim 12. 14. The light intensity distribution adjustment unit for changing an illuminance distribution on the irradiated surface or a shape of an illumination area formed on the irradiated surface, further comprising: Lighting optics. The illumination optical system according to claim 14, wherein the light amount distribution adjustment unit corrects an influence on the light amount distribution on the irradiated surface by the correction unit. 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. The illumination optical system according to any one of 10 to 15. 17. An exposure apparatus comprising the illumination optical system according to claim 10 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 17, wherein the pattern is exposed by projection onto the photosensitive substrate. 19. The optical integrator according to claim 17, wherein the optical integrator has an elongated rectangular unit wavefront dividing surface along a predetermined direction, and the predetermined direction corresponds to a direction orthogonal to the scanning direction. Exposure device. An exposure step of exposing the predetermined pattern to the photosensitive substrate using the exposure apparatus according to any one of claims 17 to 19,
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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