JP2014146718A - Illumination optical device, exposure device, and method of manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination optical device which can adjust the pupil intensity distribution at each point on an irradiated surface to a required distribution, respectively.SOLUTION: An illumination optical device illuminating the irradiated surface with light from a light source includes an optical integrator having a plurality of wavefront splitting elements arranged parallelly on the first surface crossing the optical path of the illumination optical device, and a variable member for changing the direction of light incident to the first surface depending on the position in the first surface. The wavefront splitting element of the optical integrator is imparted with a required aberration so that the illumination distribution, formed on the irradiated surface by the light passed through the wavefront splitting element, changes depending on the change in the direction of the incident light.

Description

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

  In an exposure apparatus used for manufacturing a device such as a semiconductor element, a light source emitted from a light source is a secondary light source (generally a surface light source consisting of a number of light sources via a fly-eye lens as an optical integrator). Form a predetermined light intensity distribution in the illumination pupil. 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 miniaturized, and it is indispensable to obtain a uniform illuminance 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 accurately 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 accurately transferred onto the wafer.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an illumination optical device that can adjust the pupil intensity distribution at each point on the irradiated surface to a required distribution. . The present invention also provides an exposure that can perform good exposure under appropriate illumination conditions by using an illumination optical device that adjusts the pupil intensity distribution at each point on the irradiated surface to a required distribution. An object is to provide an apparatus.

In order to solve the above problems, in the first embodiment, in an illumination optical device that illuminates a surface to be irradiated with light from a light source,
An optical integrator having a plurality of wavefront splitting elements arranged in parallel on a first surface crossing the optical path of the illumination optical device;
A variable member that changes a direction of light incident on the first surface according to a position in the first surface;
The wavefront splitting element of the optical integrator is given a required aberration so that the illuminance distribution formed on the irradiated surface by the light passing through the wavefront splitting element changes according to the change in the direction of incident light. An illumination optical device is provided.

In the second embodiment, in the illumination optical device that illuminates the irradiated surface with light from the light source,
An optical integrator having a plurality of wavefront splitting elements arranged in parallel;
A condenser optical system that superimposes a plurality of light fluxes wave-divided by the optical integrator on the irradiated surface;
A variable member that is arranged on the incident side of the optical integrator and changes the illuminance distribution formed on the irradiated surface by changing the position where the light beam passes on the optical surface of the wavefront splitting element. An illumination optical device is provided.

  In the third mode, the illumination optical device according to the first mode or the second mode for illuminating a predetermined pattern installed on the irradiated surface is provided, and the predetermined pattern is exposed on the substrate. Providing equipment.

In the fourth embodiment, using the exposure apparatus of the third embodiment, exposing the predetermined pattern onto the substrate;
Developing the 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 substrate;
And processing the surface of the substrate through the mask layer. A device manufacturing method is provided.

  In the illumination optical apparatus of the present invention, the pupil intensity distribution at each point on the irradiated surface can be adjusted to a required distribution. In the exposure apparatus and the device manufacturing method of the present invention, an exposure optical apparatus that adjusts the pupil intensity distribution at each point on the surface to be irradiated to a required distribution, respectively, can perform good exposure under appropriate illumination conditions. It can be carried out.

It is a figure which shows schematically the structure of the illumination optical apparatus concerning embodiment. It is a figure which shows a mode that the partial light beam which passed through the several micro lens of a micro fly's eye lens is superimposed on an irradiated surface. It is a figure which shows the correspondence of the light ray between an illumination pupil and an illumination area. It is a figure explaining the pupil intensity distribution regarding each point on an illumination area. It is a figure which shows a mode that the partial light beam which passed through the micro lens on an optical axis forms an illumination field on a to-be-irradiated surface. It is a figure which shows a mode that the partial light beam which passed through the micro lens most distant from the optical axis forms an illumination field on a to-be-irradiated surface. It is a figure which shows roughly the modification using a pair of cylindrical lens as a variable magnification optical system. It is a figure which shows roughly the modification using a pair of optical member which has a curved-surface optical surface as a variable magnification optical system. It is a figure which shows roughly the modification which has a pair of optical element in which each wavefront division | segmentation element of an optical integrator was arrange | positioned at intervals. It is a figure which shows schematically the structure of the exposure apparatus provided with the illumination optical apparatus concerning embodiment. 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.

  Hereinafter, embodiments will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically illustrating a configuration of an illumination optical apparatus according to the embodiment. In FIG. 1, the Z axis along the normal direction (the direction of the optical axis AX) of the irradiated surface 16, the X axis in the direction parallel to the paper surface of FIG. In the 16 planes, the Y-axis is set in the direction perpendicular to the plane of FIG.

  Referring to FIG. 1, in the illumination optical device 1 according to the present embodiment, light emitted from a light source 11 is converted into a parallel light beam by a collimator lens 12, and a micro fly eye as an optical integrator is passed through a variable magnification optical system 13. The light enters the lens (or fly-eye lens) 14. The variable magnification optical system 13 includes a negative lens (or negative lens group) 13a fixed along the optical axis AX, and a positive lens (or positive lens group) disposed on the rear side and movable along the optical axis AX. 13b. The operation of the variable magnification optical system 13 will be described later.

  The micro fly's eye lens 14 is an optical element composed of, for example, a large number of micro lenses (wavefront dividing elements) 14a having positive refracting power that are arranged vertically and horizontally and densely. It is configured by forming a group. 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.

  As the micro fly's eye lens 14, for example, a cylindrical micro fly's eye lens can be used. The configuration and operation of the cylindrical micro fly's eye lens are disclosed in, for example, US Pat. No. 6,913,373. In FIG. 1, for the sake of clarity, the number of microlenses 14a constituting the micro fly's eye lens 14 is displayed much smaller than actual. This also applies to FIG. 2, FIG. 3, FIG. 7, and FIG.

  On the incident surface 14b of the micro fly's eye lens 14, for example, a circular illumination field centered on the optical axis AX is formed. The incident side surface (that is, the unit wavefront dividing surface) of each microlens 14a in the micro fly's eye lens 14 has, for example, a rectangular shape having long sides along the X direction and short sides along the Y direction. The rectangular shape is similar to the shape of the illumination region 16a to be formed on the irradiated surface 16.

  The light beam incident on the micro fly's eye lens 14 is split two-dimensionally, and is formed on the incident side surface 14b of the micro fly's eye lens 14 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 that of the illumination field, that is, a circular secondary light source centered on the optical axis AX (substantial surface light source consisting of many small light sources: pupil intensity distribution) is formed. . The light from the secondary light source formed on the illumination pupil immediately after the micro fly's eye lens 14 illuminates the illuminated surface 16 in a superimposed manner via the condenser optical system 15. In this way, an elongated rectangular illumination region 16a is formed on the irradiated surface 16 along the X direction.

  The illumination optical apparatus 1 of the present embodiment includes a drive unit 17 that moves the positive lens 13b of the variable magnification optical system 13 along the optical axis AX, and an exit pupil plane (immediately after the micro fly's eye lens 14) of the illumination optical apparatus 1. A pupil intensity distribution measurement unit 18 that measures the pupil intensity distribution on the illumination pupil plane 14c) and a control system CR that controls the drive unit 17 based on the measurement result of the pupil intensity distribution measurement unit 18 are provided. The pupil intensity distribution measuring unit 18 includes an imaging unit having a photoelectric conversion surface arranged at a position optically conjugate with the exit pupil position of the illumination optical device 1, for example, and the pupil intensity distribution regarding each point on the irradiated surface 16. (Pupil intensity distribution formed at the exit pupil position of the illumination optical apparatus 1 by light incident on each point) is measured.

  When the illumination optical apparatus 1 according to this embodiment is applied to a scanning exposure apparatus, a stationary exposure having a rectangular shape elongated along the X direction, for example, as an area optically conjugate with the illumination area 16a on the irradiated surface 16 The region is formed on the wafer (photosensitive substrate) through the projection optical system. When the pupil intensity distribution formed on the illumination pupil (for example, the pupil of the projection optical system) by the light incident on one point in the still exposure region is greatly different depending on the position of the incident point, the pattern line for each position on the wafer The width varies and the fine pattern of the mask cannot be accurately transferred onto the wafer with a desired line width over the entire exposure region.

  In the static exposure region, the uniformity of the illuminance distribution along the scanning orthogonal direction, that is, the X direction perpendicular to the scanning direction is more important than the uniformity of the illuminance distribution along the Y direction, which is the scanning direction (scan direction). is there. In addition, the uniformity of the pupil intensity distribution at each point along the X direction is more important than the uniformity of the pupil intensity distribution at each point along the Y direction in the still exposure region. This is because the influence of uneven illuminance along the Y direction and variation in pupil intensity distribution at each point along the Y direction in the still exposure region is averaged by scanning exposure along the Y direction.

  Accordingly, when the illumination optical apparatus 1 of the present embodiment is applied to an exposure apparatus, particularly a scanning exposure apparatus, the illuminance distribution uniformity along the X direction in the illumination area 16a and the X direction in the illumination area 16a. It is important to ensure the uniformity of the pupil intensity distribution at each point along. In the present embodiment, as will be described later, the pupil intensity distribution at each point along the X direction in the illumination region 16a is adjusted by the cooperative action of the variable magnification optical system 13 and the micro fly's eye lens 14.

  In the variable magnification optical system 13, as described above, the interval between the negative lens 13a and the positive lens 13b is configured to be variable. Therefore, the parallel light beam incident on the variable magnification optical system 13 is converted into a divergent light beam or a convergent light beam having a variable angle corresponding to the variable distance between the negative lens 13a and the positive lens 13b. That is, the variable magnification optical system 13 constitutes a variable member that converts a light beam incident on the incident side surface 14b of the micro fly's eye lens 14 into a divergent light beam or a convergent light beam having a desired variable angle. According to another expression, the variable magnification optical system 13 is a variable member that changes the direction of light incident on the incident side surface 14b of the micro fly's eye lens 14 in accordance with the position in the incident side surface 14b. Is configured.

  FIG. 2 shows a state in which partial light beams that have passed through the plurality of microlenses 14 a of the micro fly's eye lens 14 are superimposed on the irradiated surface 16. In FIG. 2, when a light beam is incident on the incident-side surface 14b of the micro fly's eye lens 14, the incident light beam is divided into wavefronts by a plurality of microlenses 14a, and one small light source is formed immediately after each microlens 14a. . Light beams from each small light source formed two-dimensionally along the illumination pupil plane 14 c immediately after the micro fly's eye lens 14 are superimposed on the irradiated surface 16 via the condenser optical system 15.

  When the micro fly's eye lens 14 and the condenser optical system 15 are in an ideal state with no aberration and a parallel light beam having a uniform light intensity distribution is incident on the incident side surface 14b of the micro fly's eye lens 14, it is on the irradiated surface 16. A plurality of light intensity distributions having the same properties (that is, a plurality of uniform light intensity distributions) are superimposed at a predetermined position, and an illumination region 16 a having a uniform illuminance distribution 16 b is formed on the irradiated surface 16.

  FIG. 3 shows the correspondence of light rays between the illumination pupil plane 14 c immediately after the micro fly's eye lens 14 and the illumination area 16 a on the illuminated surface 16. The light beam L1 perpendicularly incident on the center point P1 of the illumination area 16a is emitted in the direction of the optical axis AX (Z direction) from the small light source K1 formed through the micro lens 14a on the optical axis AX of the micro fly's eye lens 14. Corresponds to the light beam L1. Light rays L2 and L3 incident at a maximum angle along the XZ plane with respect to the center point P1 are transmitted in the optical axis AX direction from the small light sources K2 and K3 formed through the minute lens 14a farthest from the optical axis AX in the X direction. Corresponds to the rays L2 and L3 emitted.

  Light rays L4 and L5 perpendicularly incident on a peripheral point P2 furthest away in the + X direction from the optical axis AX and a peripheral point P3 furthest away in the −X direction in the illumination area 16a are transmitted from the small light sources K1 to XZ on the optical axis AX. It corresponds to the light beams L4 and L5 emitted at the maximum angle with respect to the optical axis AX along the plane. Rays L6, L7 and L8, L9 incident at the maximum angle along the XZ plane with respect to the peripheral points P2 and P3 are along the XZ plane from the small light sources K2, K3 that are farthest from the optical axis AX in the X direction. It corresponds to the light beams L6, L7 and L8, L9 emitted at the maximum angle with respect to the optical axis AX.

  Thus, the positional information on the illumination pupil plane 14c where the small light sources K1 to K3 are formed is converted into angle information on the illumination region 16a (ie, the irradiated surface 16) by the Fourier transform action of the condenser optical system 15. Conversely, the angle information on the illumination pupil plane 14 c is converted into position information on the illumination region 16 a by the Fourier transform action of the condenser optical system 15. Therefore, although not shown in the figure, the correspondence of light rays between the illumination pupil plane 14c and the illumination region 16a in the YZ plane is the same as the correspondence relationship of light rays in the XZ plane shown in FIG.

  FIG. 4 is a diagram for explaining pupil intensity distributions H1, H2, and H3 related to the points P1, P2, and P3 on the illumination area 16a. As described with reference to FIG. 3, the light beam L1 perpendicularly incident on the center point P1 of the illumination area 16a corresponds to the light beam L1 emitted in the optical axis AX direction from the micro lens 14a on the optical axis AX. . Light rays (L2, L3, etc.) incident on the center point P1 at the maximum angle correspond to light rays emitted in the direction of the optical axis AX from the minute lens 14a farthest from the optical axis AX.

  Therefore, the distribution of the central region (for example, a circular region) of the pupil intensity distribution H1 with respect to the center point P1 is the optical axis AX from the plurality of microlenses 14a in the central region around the optical axis AX in the micro fly's eye lens 14. Is formed by a light beam emitted at a relatively small angle, that is, a light beam that reaches a central region on the illumination region 16a via a plurality of microlenses 14a in the central region. As a result, the distribution of the central region in the pupil intensity distribution H1 reflects the light intensity distribution in the central region of each illumination field formed on the irradiated surface 16 by the plurality of microlenses 14a in the central region.

  The distribution of the peripheral region of the pupil intensity distribution H1 (for example, an annular region) is a relatively small angle with respect to the optical axis AX from the plurality of microlenses 14a in the peripheral region away from the optical axis AX in the micro fly's eye lens 14. , That is, a light beam that reaches the central region on the illumination region 16a via a plurality of microlenses 14a in the peripheral region. As a result, the distribution of the peripheral region in the pupil intensity distribution H1 reflects the light intensity distribution in the central region of each illumination field formed on the irradiated surface 16 by the plurality of microlenses 14a in the peripheral region.

  In addition, as described with reference to FIG. 3, light rays (L4, L5, etc.) perpendicularly incident on the peripheral points P2, P3 on the illumination area 16a are transferred from the micro lens 14a on the optical axis AX to the optical axis AX. It corresponds to the light beams L4 and L5 emitted at the maximum angle. Light rays (L6 to L9, etc.) incident on the peripheral points P2 and P3 at the maximum angle correspond to light rays emitted at the maximum angle with respect to the optical axis AX from the minute lens 14a farthest from the optical axis AX. .

  Accordingly, the distribution of the central area of the pupil intensity distributions H2 and H3 with respect to the peripheral points P2 and P3 is a light beam emitted from the plurality of microlenses 14a in the central area at a relatively large angle with respect to the optical axis AX, that is, the central area. It is formed by light rays that reach a peripheral region on the illumination region 16a via a plurality of microlenses 14a in the region. As a result, the distribution of the central region in the pupil intensity distributions H2 and H3 reflects the light intensity distribution in the peripheral region of each illumination field formed on the irradiated surface 16 by the plurality of microlenses 14a in the central region.

  The distribution of the peripheral areas of the pupil intensity distributions H2 and H3 is such that light beams emitted from the plurality of microlenses 14a in the peripheral areas at a relatively large angle with respect to the optical axis AX, that is, the plurality of microlenses 14a in the peripheral areas. It is formed by light rays that reach the peripheral area on the illumination area 16a. As a result, the distribution of the peripheral regions in the pupil intensity distributions H2 and H3 reflects the light intensity distribution in the peripheral region of each illumination field formed on the irradiated surface 16 by the plurality of microlenses 14a in the peripheral region.

  Hereinafter, to simplify the description, it is assumed that a divergent light beam having a variable angle formed through the variable magnification optical system 13 is incident on the incident-side surface 14b of the micro fly's eye lens 14. FIG. 5 shows a state in which the partial light flux that has passed through the micro lens 31 on the optical axis AX of the micro fly's eye lens 14 forms an illumination field 41 on the irradiated surface 16. FIG. 6 shows how the partial light flux that has passed through the microlens 32 that is farthest from the optical axis AX in the + X direction in the micro fly's eye lens 14 forms an illumination field 42 on the irradiated surface 16.

  When a divergent light beam enters the micro fly's eye lens 14, as shown in FIG. 5, a substantially parallel light beam is directed in the direction along the optical axis AX on the incident-side surface 31a of the minute lens 31 on the optical axis AX. Incident. The light propagating through the inside of the microlens 31 due to the refraction action of the incident side surface 31a passes through the central area 31ba on the exit surface 31b, and as a result is condensed by the refraction action of the central area 31ba, and the optical axis AX. A small light source K1 is formed thereon. The light forming the small light source K1 forms an illumination field 41 having the same outer shape as the illumination region 16a on the irradiated surface 16 via the condenser optical system 15.

  On the other hand, as shown in FIG. 6, on the incident side surface 32a of the minute lens 32 furthest away from the optical axis AX in the + X direction, a substantially parallel light beam is inclined to the optical axis AX by a variable angle θ. Incident. The light propagating through the inside of the microlens 32 due to the refraction action of the incident side surface 32a passes through a region 32ba closer to the periphery on the exit surface 32b, which is different in position from the central region 31ba shown in FIG. The small light source K2 is formed at a position shifted in the + X direction from the element optical axis AXe of the microlens 32 by focusing by the refraction action of the region 32ba closer to the periphery. The light that has formed the small light source K2 forms, via the condenser optical system 15, an illumination field 42 having the same outer shape as that of the illumination region 16a, and thus the same outer shape as that of the illumination field 41, on the irradiated surface 16.

  When the micro fly's eye lens 14 composed of a plurality of microlenses 14a is in an ideal state without aberration, for example, when the incident side surface and the exit surface of each microlens 14a are formed in a desired surface shape, the optical axis AX When a parallel light flux having a uniform light intensity distribution is incident on the upper microlens 31 in a direction along the optical axis AX, the illuminance distribution of the illumination field 41 formed on the irradiated surface 16 is indicated by a broken line in FIG. Evenly distributed. Similarly, even if a parallel light beam having a uniform light intensity distribution is incident on the minute lens 32 farthest from the optical axis AX in a direction inclined with respect to the optical axis AX, the illumination field formed on the irradiated surface 16 The illuminance distribution 42 is uniform as shown by the broken line in FIG.

  In the present embodiment, the illuminance distribution formed on the irradiated surface 16 by the light passing through the exit surface of the exit surface of each microlens 14a of the micro fly's eye lens 14 changes according to the change of the region through which the light passes. Are formed in the required aspherical shape. In other words, each micro lens 14a of the micro fly's eye lens 14 is required so that the illuminance distribution formed on the irradiated surface 16 by the light passing through the micro lens 14a changes according to the change in the direction of incident light. (For example, distortion aberration) is added.

  Therefore, the illuminance distribution of the illumination field 41 formed on the irradiated surface 16 by the partial light flux that has passed through the central region 31ba on the exit surface 31b of the microlens 31 located on the optical axis AX is positive for each microlens 14a. Due to the influence of the applied aberration, for example, as shown by a solid line in FIG. 5, the distribution is a convex distribution 41a in which the intensity is greatest at the center and monotonously decreases toward the periphery along the X direction.

  On the other hand, the illuminance distribution of the illumination field 42 formed on the irradiated surface 16 by the partial light beam passing through the peripheral region 32ba on the exit surface 32b of the micro lens 32 farthest from the optical axis AX in the + X direction is the light beam passage region. Since 32ba is different from the light flux passage region 31ba in the microlens 31, the distribution is different from the illuminance distribution 41a of the illumination field 41 due to the influence of the aberration positively given to each microlens 14a, for example, a solid line in FIG. Thus, the concave distribution 42a is obtained such that the intensity is the smallest at the center and the intensity monotonously increases toward the periphery along the X direction.

  Although not shown, the illumination distribution of the illumination field 43 formed on the irradiated surface 16 by the partial light flux that has passed through the peripheral region 33ba on the exit surface 33b of the minute lens 33 farthest from the optical axis AX in the −X direction is as follows. Since the light flux passage area 33ba is different from the light flux passage area 31ba in the micro lens 31, the distribution 43a is different from the illuminance distribution 41a of the illumination field 41 due to the influence of the aberration positively given to each micro lens 14a. . As an example, the illuminance distribution 43 a of the illumination field 43 is a concave distribution similar to the illumination distribution 42 a of the illumination field 42 formed by the microlenses 32.

  In this case, the distribution of the central region of the pupil intensity distribution H1 related to the center point P1 on the illumination region 16a is that each illumination field formed on the irradiated surface 16 by a plurality of microlenses 14a (such as the microlenses 31) in the central region. Since the light intensity distribution in the central region (such as the illumination field 41) is reflected, the light intensity becomes relatively large. The distribution of the peripheral region of the pupil intensity distribution H1 is the center of each illumination field (such as illumination fields 42 and 43) formed on the irradiated surface 16 by a plurality of minute lenses 14a (such as minute lenses 32 and 33) in the peripheral region. Since the light intensity distribution in the region is reflected, the light intensity is relatively small.

  On the other hand, in the distribution of the central region of the pupil intensity distributions H2 and H3 related to the peripheral points P2 and P3 on the illumination region 16a, a plurality of microlenses 14a (microlenses 31 and the like) in the central region are formed on the irradiated surface 16. Since the light intensity distribution in the peripheral region of each of the illuminated fields (such as the illuminated field 41) is reflected, the light intensity is relatively small. The distribution of the peripheral areas of the pupil intensity distributions H2 and H3 is as follows: each illumination field (such as illumination fields 42 and 43) formed on the irradiated surface 16 by a plurality of minute lenses 14a (such as minute lenses 32 and 33) in the surrounding area. Since the light intensity distribution in the peripheral area of is reflected, the light intensity becomes relatively large.

  This is because when the angle of the divergent light beam (generally divergent light beam or convergent light beam) incident on the micro fly's eye lens 14 is changed by the action of the variable magnification optical system 13, that is, the direction of the light incident on each micro lens 14a. Means that the pupil intensity distribution H1 related to the center point P1 and the pupil intensity distributions H2 and H3 related to the peripheral points P2 and P3 change according to different modes in accordance with the change in the direction of the incident light. ing. In other words, the drive unit 17 moves the positive lens 13b along the optical axis AX according to a command from the control system CR, so that the pupil at each point along the X direction in the illumination region 16a according to the amount of movement. The intensity distribution can be adjusted.

  In the present embodiment, the pupil intensity distribution measuring unit 18 measures the pupil intensity distribution on the exit pupil plane of the illumination optical apparatus 1 (the illumination pupil plane 14c immediately after the micro fly's eye lens 14). The control system CR controls the drive unit 17 based on the measurement result of the pupil intensity distribution measurement unit 18. That is, the drive unit 17 uses the output from the pupil intensity distribution measurement unit 18 to move the positive lens 13b of the variable magnification optical system 13 along the optical axis AX, and consequently the pupil at each point on the irradiated surface 16. Adjust the intensity distribution to the required distribution.

  Thus, in the illumination optical device 1, the pupil intensity distribution at each point on the irradiated surface 16 can be adjusted to a required distribution by the cooperative action of the variable magnification optical system 13 and the micro fly's eye lens 14. . That is, the variable magnification optical system 13 is arranged on the incident side of the micro fly's eye lens 14 and changes the passage position of the light beam on the exit surface (generally an optical surface) of the micro lens 14a that is the wavefront splitting element. A variable member that changes the illuminance distribution formed by the light beam on the irradiated surface 16 is formed.

  In the above-described embodiment, in the variable magnification optical system 13, the negative lens 13a is fixed along the optical axis AX, and the positive lens 13b is configured to be movable along the optical axis AX. However, without being limited thereto, a specific configuration of the variable magnification optical system that converts a light beam incident on the incident-side surface 14b of the micro fly's eye lens 14 into a divergent light beam or a convergent light beam having a desired variable angle, Various forms are possible. For example, in the configuration of FIG. 1, a variable power optical system that exhibits the same effect as the variable power optical system 13 by setting at least one of the negative lens 13 a and the positive lens 13 b to be movable along the optical axis AX. Is obtained.

  Further, as shown in FIG. 7, a modification using a pair of cylindrical lenses 13c and 13d as a variable power optical system is also possible. A variable magnification optical system 13A according to the modification of FIG. 7 is disposed on the rear side of a negative cylindrical lens (or negative cylindrical lens group) 13c fixed along the optical axis AX, and is movable along the optical axis AX. And a positive cylindrical lens (or a positive cylindrical lens group) 13d.

  The negative cylindrical lens 13c has a negative refractive power in the X direction (in the XZ plane) and has no refractive power in the Y direction (in the YZ plane). The positive cylindrical lens 13d has a positive refractive power in the X direction and no refractive power in the Y direction. The drive unit 17A moves the positive cylindrical lens 13d along the optical axis AX in accordance with a command from the control system CR.

  In this case, the parallel light beam incident on the variable magnification optical system 13A is converted into a divergent light beam or a convergent light beam having a variable angle corresponding to the variable interval between the negative cylindrical lens 13c and the positive cylindrical lens 13d on the XZ plane. That is, the variable magnification optical system 13A determines the direction along the XZ plane of light incident on the incident side surface 14b of the micro fly's eye lens 14 according to the position along the X direction in the incident side surface 14b. Change. In the modification of FIG. 7, at least one of the negative cylindrical lens 13 c and the positive cylindrical lens 13 d can be set to be movable along the optical axis AX.

  Further, as shown in FIG. 8, a modification using a pair of optical members 13e and 13f having a curved optical surface as a variable power optical system is also possible. A variable power optical system 13B according to the modification of FIG. 8 includes a first optical member 13e having a planar incident-side surface orthogonal to the optical axis AX and a cubic curved exit surface along the X direction. A planar surface that is arranged on the rear side and has an incident-side surface that is complementary to the exit surface of the first optical member 13e (ie, a cubic curved surface along the X direction) and that is orthogonal to the optical axis AX. And a second optical member 13f having an exit surface.

  The first optical member 13e and the second optical member 13f are configured to be relatively movable along the X direction. The drive unit 17B relatively moves the first optical member 13e and the second optical member 13f along the X direction in accordance with a command from the control system CR. In this case, the parallel light beam incident on the variable magnification optical system 13B is converted into a divergent light beam or a convergent light beam having a variable angle corresponding to the relative movement between the first optical member 13e and the second optical member 13f on the XZ plane. That is, the variable magnification optical system 13B has a direction along the XZ plane of light incident on the incident side surface 14b of the micro fly's eye lens 14 as in the case of the variable magnification optical system 13A of the modified example of FIG. It changes according to the position along the X direction in the incident side surface 14b.

  In the modification of FIG. 8, the first optical member 13e has a flat incident-side surface and a cubic curved exit surface, and the second optical member 13f has a cubic curved incident-side surface and flat surface. Shaped injection surface. However, the present invention is not limited to this, and the first optical member 13e has a cubic curved surface on the incident side and a planar exit surface, or the second optical member 13f has a planar surface on the incident side. It may have a cubic curved surface.

  In the above-described embodiment and modification, the variable member changes the direction of light incident on the incident-side surface 14b of the micro fly's eye lens 14 that is an optical integrator according to the position in the incident-side surface 14b. The variable magnification optical systems 13, 13A, 13B are used. However, the present invention is not limited to this. Examples of the variable member include a prism array having a plurality of individually controlled prism elements, a mirror array having a plurality of individually controlled mirror elements, and a deformable flexible member. A mirror having a reflective surface can also be used.

  Further, in the above-described embodiment, each microlens 14a that is a wavefront dividing element of the micro fly's eye lens 14 is configured as a single element, and the exit surface of each microlens 14a corresponds to a change in the light passage region. The light passing through the emission surface is formed in a required aspherical shape so that the illuminance distribution formed on the irradiated surface 16 changes. However, the present invention is not limited to this, and a modification using an optical integrator obtained by arranging wavefront splitting elements 35 having a pair of optical elements 35a and 35b in parallel as shown in FIG. 9 is also possible.

  Specifically, each wavefront splitting element 35 of the optical integrator includes a first optical element 35a and a second optical element 35b disposed on the rear side at a distance from the first optical element 35a. In addition, in FIG. 9, the wavefront division | segmentation element 35 located on the optical axis AX is illustrated. In this case, at least one of the incident-side surface 35ba and the exit surface 35bb of the second optical element 35b is formed on the irradiated surface 16 by the light that has passed through the second optical element 35b according to the change of the light passage region. What is necessary is just to form in required aspherical form so that the illumination distribution 45 may change.

  FIG. 10 is a view schematically showing a configuration of an exposure apparatus including the illumination optical apparatus according to the embodiment. In FIG. 10, the Z axis along the normal direction of the transfer surface (exposure surface) of the wafer W, which is a photosensitive substrate, and the X axis in the direction parallel to the paper surface of FIG. In the W transfer surface, the Y axis is set in the direction perpendicular to the paper surface of FIG. The exposure apparatus shown in FIG. 10 includes the illumination optical apparatus 1 according to the embodiment of FIG. 1 (or illumination optical apparatuses 1A and 1B according to the modifications of FIGS. 7 and 8).

  When the illumination optical apparatus 1 (1A, 1B) is applied to an exposure apparatus, as a light source for supplying exposure light (illumination light), for example, an ArF excimer laser light source for supplying pulsed light with a wavelength of 193 nm or a wavelength of 248 nm A KrF excimer laser light source or the like that supplies the pulsed light can be used. In this case, the installation of the collimating lens 12 is omitted, and in the optical path between the light source and the variable magnification optical system 13 (13A, 13B), in order from the light incident side, a beam transmitting unit, a spatial light modulator, and a relay An optical system or the like can be attached. Further, in the optical path between the condenser optical system 15 and the irradiated surface 16, a mask blind, an imaging optical system, and the like can be attached in order from the light incident side.

  Here, the spatial light modulator includes a plurality of mirror elements arranged in a predetermined plane and individually controlled, and a plurality of mirrors based on a control signal from a control system CR that comprehensively controls the operation of the exposure apparatus. And a drive unit that individually controls and drives the posture of the element. The beam transmission unit converts the incident light beam from the light source into a light beam having a cross section of an appropriate size and shape and guides it to the spatial light modulator, and also performs positional and angular fluctuations of the light beam incident on the spatial light modulator. It has a function to actively correct.

  In the relay optical system, the front focal position is located in the vicinity of the array surface of the plurality of mirror elements of the spatial light modulator, and the rear focal position is located in the vicinity of the incident surface 14 b of the micro fly's eye lens 14. The arrangement surface of the spatial light modulator and the incident side surface 14b of the micro fly's eye lens 14 are optically set in a Fourier transform relationship. Therefore, the light that has passed through the spatial light modulator and the relay optical system variably distributes the light intensity corresponding to the postures of the plurality of mirror elements on the incident-side surface 14b of the micro fly's eye lens 14.

  A mask blind as an illumination field stop is disposed at or near the rear focal position of the condenser optical system 15. Therefore, the light from the secondary light source formed on the illumination pupil 14 c immediately after the micro fly's eye lens 14 illuminates the mask blind in a superimposed manner via the condenser optical system 15. The light beam that has passed through the rectangular opening (light transmitting portion) of the mask blind is placed at the position of the irradiated surface 16 in the illumination optical device 1 (1A, 1B) under the light collecting action of the imaging optical system. The mask M is illuminated in a superimposed manner to form an elongated rectangular illumination region 16a along the X direction.

  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 X direction and a short side along the Y 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 X direction and a short side along the Y 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 Y direction (scanning direction) in the plane (XY plane) orthogonal to the optical axis AX of the projection optical system PL, As a result, the mask M and the wafer W are moved (scanned) synchronously so that the wafer W has a width equal to the dimension in the X 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. Alternatively, collective exposure is performed while the wafer stage WS is two-dimensionally driven and controlled in a plane (XY plane) orthogonal to the optical axis AX of the projection optical system PL, and thus the wafer W is two-dimensionally driven and controlled. Thus, the pattern of the mask M is sequentially exposed on each exposure region of the wafer W.

  The exposure apparatus of the present embodiment measures the first pupil intensity distribution that measures the pupil intensity distribution on the exit pupil plane of the illumination optical apparatus 1 (1A, 1B) based on the light that has passed through the illumination optical apparatus 1 (1A, 1B). A second pupil intensity distribution measuring unit DTw that measures the pupil intensity distribution on the pupil plane of the projection optical system PL (the exit pupil plane of the projection optical system PL) based on the light through the projection optical system PL, Based on the measurement result of at least one of the first and second pupil intensity distribution measuring units DTr and DTw, the zoom optical system 13 (13A, 13B) and the spatial light modulator are controlled and the operation of the exposure apparatus is integrated. And a control system CR for controlling.

  The first pupil intensity distribution measurement unit DTr is optically conjugate with, for example, the exit pupil position of the illumination optical device 1 (1A, 1B), similarly to the pupil intensity distribution measurement unit 18 in the illumination optical device 1 (1A, 1B). An imaging unit having a photoelectric conversion surface arranged at a position, and pupil intensity distribution (light incident on each point is incident on the illumination optical device 1 (1A) on each surface on the illuminated surface by the illumination optical device 1 (1A, 1B) , 1B) pupil intensity distribution formed at the exit pupil position). In addition, the second pupil intensity distribution measurement unit DTw includes an imaging unit having a photoelectric conversion surface arranged at a position optically conjugate with the pupil position of the projection optical system PL, for example, and includes each image plane of the projection optical system PL. A pupil intensity distribution related to the points (pupil intensity distribution formed by light incident on each point at the pupil position of the projection optical system PL) is measured.

  For the detailed configuration and operation of the pupil intensity distribution measuring unit 18, DTr, DTw, reference can be made to, for example, US Patent Publication No. 2008/0030707. The disclosure of US Patent Publication No. 2010/0020302 can also be referred to as the pupil intensity distribution measuring unit 18, DTr, and DTw.

  In the present embodiment, the secondary light source formed by the micro fly's eye lens 14 is used as a light source, and the mask M (and thus the wafer W) disposed on the irradiated surface 16 of the illumination optical device 1 (1A, 1B) 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 device 1 (1A, 1B). Can be called. Moreover, the image of the formation surface of this secondary light source can be called the exit pupil plane of the illumination optical device 1 (1A, 1B). Typically, the surface to be irradiated (the surface on which the mask M is disposed, or the surface on which the wafer W is disposed when the illumination optical device 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 apparatus 1 (1A, 1B) or a plane optically conjugate with the illumination pupil plane. When the number of wavefront divisions by the micro fly's eye lens 14 is relatively large, the overall light intensity distribution formed on the incident side surface 14b of the micro fly's eye lens 14 and the overall light intensity distribution of the entire secondary light source ( (Pupil intensity distribution). For this reason, the surface 14b on the incident side of the micro fly's eye lens 14 and the surface optically conjugate with the surface 14b on the incident side can also be referred to as illumination pupil planes. The light intensity distribution on these surfaces is also the pupil intensity distribution. It can be called.

  As described above, in the illumination optical device 1 (1A, 1B), the pupil at each point on the irradiated surface 16 is obtained by the cooperative action of the variable magnification optical system 13 (13A, 13B) and the micro fly's eye lens 14. Each intensity distribution can be adjusted to a required distribution. Therefore, in the exposure apparatus of the present embodiment, illumination that adjusts the pupil intensity distribution at each point in the still exposure region on the wafer W disposed at a position optically conjugate with the irradiated surface 16 to a required distribution. Using the optical device 1 (1A, 1B), 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 spread over the entire exposure region. Thus, it can be accurately transferred onto the wafer W with a desired line width.

  In the present embodiment, the operation of adjusting the pupil intensity distribution for each point in the still exposure region to a required distribution is performed based on the measurement results of the pupil intensity distribution measurement units DTr and DTw. Specifically, the measurement results of the pupil intensity distribution measurement units DTr and DTw are supplied to the control system CR. Based on the measurement results of the pupil intensity distribution measuring units DTr, DTw, the control system CR, for example, the illumination optical device 1 (1A, 1B) so that the pupil intensity distribution on the pupil plane of the projection optical system PL becomes a desired distribution. Command is output to the drive unit 17 (17A, 17B). The drive unit 17 (17A, 17B) drives the variable magnification optical system 13 (13A, 13B) based on a command from the control system CR, and requires a pupil intensity distribution for each point in the still exposure region on the wafer W. Adjust to the distribution of.

  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. As the variable pattern forming apparatus, for example, a spatial light modulation element including a plurality of reflection elements driven based on predetermined electronic data can be used. An exposure apparatus using a spatial light modulator is disclosed, for example, in US Patent Publication No. 2007/0296936. In addition to the non-light-emitting reflective spatial light modulator as described above, a transmissive spatial light modulator may be used, or a self-luminous image display element may be used.

  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. 11 is a flowchart showing a manufacturing process of a semiconductor device. As shown in FIG. 11, 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 projection 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 wafer W after the transfer is completed. Development, that is, development of the photoresist to which the pattern has been transferred (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 projection exposure apparatus of the above-described embodiment is generated, and the recess penetrates the photoresist layer. It is. 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 projection exposure apparatus of the above-described embodiment performs pattern transfer using the wafer W coated with the photoresist as a photosensitive substrate.

  FIG. 12 is a flowchart showing a manufacturing process of a liquid crystal device such as a liquid crystal display element. As shown in FIG. 12, 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 projection exposure apparatus of the above-described embodiment. The pattern forming step includes an exposure step of transferring the pattern to the photoresist layer using the projection exposure apparatus of the above-described embodiment, and development of the plate P on which the pattern is transferred, that is, development of the photoresist layer on the glass substrate. 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 process in 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 suitable pulse lasers are used. A light source, for example, an F ₂ laser light source that supplies laser light with a wavelength of 157 nm, a Kr ₂ laser light source that supplies laser light with a wavelength of 146 nm, an Ar ₂ laser light source that supplies laser light with a wavelength of 126 nm, or the like can be used. It is also possible to use a CW (Continuous Wave) light source such as an ultrahigh pressure mercury lamp that emits bright lines such as g-line (wavelength 436 nm) and i-line (wavelength 365 nm). A harmonic generator of a YAG laser or the like can also be used. In addition, as disclosed in, for example, US Pat. No. 7,023,610, a single wavelength laser beam in an infrared region or a visible region oscillated from a DFB semiconductor laser or a fiber laser is used as vacuum ultraviolet light. For example, a harmonic that is amplified by a fiber amplifier doped with erbium (or both erbium and ytterbium) and wavelength-converted into ultraviolet light using a nonlinear optical crystal may be used.

  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. WO99 / 49504, a special technique, A method of moving a stage holding a substrate to be exposed as disclosed in Kaihei 6-124873 in a liquid bath, or a predetermined stage on a stage as disclosed in JP-A-10-303114. A method of forming a liquid tank having a depth and holding the substrate therein 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 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 the illumination optical apparatus that illuminates the mask (or wafer) in the exposure apparatus. However, the present invention is not limited to this, and the object other than the mask (or wafer) is used. The present invention can also be applied to a general illumination optical device that illuminates the irradiation surface.

1, 1A, 1B Illumination optical device 11 Light source 12 Collimate lens 13, 13A, 13B Variable magnification optical system 14 Micro fly's eye lens (optical integrator)
15 Condenser optical system 16 Irradiated surface 16a Illumination area 17, 17A, 17B Drive unit 18, DTr, DTw Pupil intensity distribution measurement unit CR Control system M Mask MS Mask stage PL Projection optical system W Wafer WS Wafer stage

Claims (15)

In an illumination optical device that illuminates the illuminated surface with light from a light source,
An optical integrator having a plurality of wavefront splitting elements arranged in parallel on a first surface crossing the optical path of the illumination optical device;
A variable member that changes a direction of light incident on the first surface according to a position in the first surface;
The wavefront splitting element of the optical integrator is given a required aberration so that the illuminance distribution formed on the irradiated surface by the light passing through the wavefront splitting element changes according to the change in the direction of incident light. An illumination optical device. The illumination optical apparatus according to claim 1, wherein the variable member includes a variable magnification optical system that converts a light beam incident on the first surface into a divergent light beam or a convergent light beam having a desired variable angle. The illumination optical apparatus according to claim 2, wherein the variable magnification optical system includes a lens movable along the optical axis. The variable power optical system includes a plurality of cylindrical lenses having a refractive power in a first direction and having no refractive power in a second direction orthogonal to the first direction. Illumination optical device. The variable magnification optical system includes a first optical member having a plane-shaped exit surface or entrance surface that is orthogonal to the optical axis and has a third-order curved entrance surface or exit surface along a first direction. A second optical member disposed on the rear side of the first optical member and having a surface shape complementary to that of the first optical member, wherein the first optical member and the second optical member are the first optical member. The illumination optical apparatus according to claim 2, wherein the illumination optical apparatus is configured to be relatively movable along a direction. 6. The illumination optical apparatus according to claim 5, wherein the first optical member has a cubic curved exit surface, and the second optical member has a cubic curved entrance surface. The illumination optical apparatus according to any one of claims 4 to 6, wherein an illumination area formed on the irradiated surface has an elongated rectangular shape along the first direction. Each wavefront splitting element has a single element,
The exit surface of the single element is formed in a required aspherical shape so that the illuminance distribution formed on the irradiated surface by the light passing through the exit surface changes according to the change of the region through which the light passes. The illumination optical device according to claim 1, wherein the illumination optical device is an illumination optical device. Each wavefront splitting element has a first element and a second element arranged on the rear side at a distance from the first element,
At least one of the incident-side surface and the exit surface of the second element is configured such that the illuminance distribution formed on the irradiated surface by the light passing through the second element changes according to the change of the region through which the light passes. The illumination optical device according to claim 1, wherein the illumination optical device is formed in a required aspherical shape. The illumination optical apparatus according to claim 1, further comprising a condenser optical system that superimposes a plurality of light beams that have been wavefront-divided by the optical integrator on the irradiated surface. In an illumination optical device that illuminates the illuminated surface with light from a light source,
An optical integrator having a plurality of wavefront splitting elements arranged in parallel;
A condenser optical system that superimposes a plurality of light fluxes wave-divided by the optical integrator on the irradiated surface;
A variable member that is arranged on the incident side of the optical integrator and changes the illuminance distribution formed on the irradiated surface by changing the position where the light beam passes on the optical surface of the wavefront splitting element. An illumination optical device. The illumination optical apparatus according to claim 11, wherein the variable member includes a variable magnification optical system that converts a light beam incident on the optical integrator into a divergent light beam or a convergent light beam having a desired variable angle. 13. An exposure apparatus comprising: the illumination optical apparatus according to claim 1 for illuminating a predetermined pattern installed on the irradiated surface, wherein the predetermined pattern is exposed on a substrate. apparatus. The exposure apparatus according to claim 13, further comprising a projection optical system that forms an image of the predetermined pattern on the substrate. Using the exposure apparatus according to claim 13 or 14, exposing the predetermined pattern to the substrate;
Developing the 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 substrate;
Processing the surface of the substrate through the mask layer. A device manufacturing method comprising:

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