JP5700272B2 - Illumination optical system, exposure apparatus, and device manufacturing method - Google Patents

Description

  The present invention relates to a spatial light modulation unit, an illumination optical system, an exposure apparatus, and a device manufacturing method. More specifically, the present invention relates to a spatial light modulation unit suitable for an exposure apparatus for manufacturing devices such as a semiconductor element, an image sensor, 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 collected by the condenser optical system 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.

  Conventionally, there has been proposed an illumination optical system capable of continuously changing the pupil intensity distribution (and thus the illumination condition) without using a zoom optical system (see Patent Document 1). In the illumination optical system disclosed in Patent Document 1, an incident light beam is generated using a movable multi-mirror configured by a large number of minute mirror elements that are arranged in an array and whose tilt angle and tilt direction are individually driven and controlled. By dividing and deflecting into minute units for each reflecting surface, the cross section of the light beam is converted into a desired shape or a desired size, and thus a desired pupil intensity distribution is realized.

JP 2002-353105 A

  In the illumination optical system described in Patent Document 1, since a spatial light modulator having a large number of mirror elements whose postures are individually controlled is used, the degree of freedom in changing the shape and size of the pupil intensity distribution is high. . However, for example, in the case of a spatial light modulator that controls the tilt angle of the mirror element by applying a voltage, the tilt angle of the mirror element does not change linearly with respect to the applied voltage, but also the applied voltage and tilt. Since the non-linearity with the corner tends to vary from mirror element to mirror element and change with time, it is difficult to accurately form a desired pupil intensity distribution.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a spatial light modulation unit capable of accurately forming a desired pupil intensity distribution. It is another object of the present invention to provide an illumination optical system that can illuminate an illuminated surface under a desired illumination condition using a spatial light modulation unit that accurately forms a desired pupil intensity distribution. In addition, the present invention uses an illumination optical system that accurately forms a desired pupil intensity distribution to perform good exposure under appropriate illumination conditions realized according to the characteristics of the pattern to be transferred. An object of the present invention is to provide an exposure apparatus that can perform this.

In order to solve the above problems, in the first embodiment of the present invention, in the spatial light modulation unit used in the illumination optical system that illuminates the irradiated surface with light from the light source,
A spatial light modulator having a plurality of mirror elements that are two-dimensionally arranged and individually controlled;
There is provided a spatial light modulation unit comprising a changing device that changes the direction of the array plane of the plurality of mirror elements.

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 spatial light modulation unit of the first form;
A distribution forming optical system that forms a predetermined light intensity distribution in an illumination pupil of the illumination optical system based on light that has passed through the spatial light modulator;
Provided is an illumination optical system comprising: a control unit that controls the spatial light modulation device and the changing device according to an outer shape of a light intensity distribution to be formed on the illumination pupil.

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

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

  In the spatial light modulation unit according to one aspect of the present invention, a desired pupil intensity distribution can be accurately formed. In the illumination optical system of the present invention, the illuminated surface can be illuminated under a desired illumination condition using a spatial light modulation unit that accurately forms a desired pupil intensity distribution. Further, the exposure apparatus of the present invention uses the illumination optical system that accurately forms a desired pupil intensity distribution to perform good exposure under appropriate illumination conditions realized according to the characteristics of the pattern to be transferred. Which can be done and thus a good device can be produced.

It is a figure which shows schematically the structure of the exposure apparatus concerning embodiment of this invention. It is a figure which shows schematically the internal structure of the spatial light modulation unit of FIG. It is a figure explaining the effect | action of the spatial light modulator in a spatial light modulation unit. It is a fragmentary perspective view of the principal part of a spatial light modulator. It is a figure which shows the dipolar light intensity distribution formed in the entrance plane and back focal plane of a micro fly's eye lens. It is a 1st figure explaining the inconvenience in a prior art. It is a 1st figure explaining the effect of this embodiment. It is a figure which shows the light intensity distribution of 4 pole shape formed in the entrance plane and back side focal plane of a micro fly's eye lens. It is a 2nd figure explaining the inconvenience in a prior art. It is a 2nd figure explaining the effect of this 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.

  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. FIG. 2 is a diagram schematically showing the internal configuration of the spatial light modulation unit of FIG. In FIG. 1, the Z-axis is along the normal direction of the transfer surface (exposure surface) of the wafer W, which is a photosensitive substrate, and the Y-axis is in the direction parallel to the paper surface of FIG. In the W transfer surface, the X axis is set in a direction perpendicular to the paper surface of FIG.

  Referring to FIG. 1, in the exposure apparatus of the present embodiment, exposure light (illumination light) is supplied from a light source 1. As the light source 1, for example, an ArF excimer laser light source that supplies light with a wavelength of 193 nm, a KrF excimer laser light source that supplies light with a wavelength of 248 nm, or the like can be used. The light emitted from the light source 1 enters the relay optical system 4 via the beam transmitter 2 and the spatial light modulation unit 3. The beam transmitter 2 guides the incident light beam from the light source 1 to the spatial light modulation unit 3 while converting the incident light beam into a light beam having an appropriate size and shape, and changes the position of the light beam incident on the spatial light modulation unit 3. And a function of actively correcting the angular variation.

  As shown in FIG. 2, the spatial light modulation unit 3 includes a pair of spatial light modulators 31 and 32 arranged in parallel in the illumination optical path. The spatial light modulators 31 and 32 have a plurality of mirror elements that are two-dimensionally arranged and individually controlled. A deflection member 35 is disposed in the optical path between the beam transmitter 2 and the spatial light modulators 31 and 32, and the deflection member 36 is disposed in the optical path between the spatial light modulators 31 and 32 and the relay optical system 4. Is arranged. The deflecting member 35 divides the light beam from the light source 1 into two, guides the first light beam to the first spatial light modulator 31, and guides the second light beam to the second spatial light modulator 32. The deflecting member 36 guides the light that has passed through the spatial light modulators 31 and 32 to the relay optical system 4. The specific configuration and operation of the spatial light modulation unit 3 will be described later.

  Light emitted from the spatial light modulation unit 3 enters the predetermined surface 5 via the relay optical system 4. The relay optical system 4 has a front focal position that substantially coincides with the position of the array surface of the plurality of mirror elements of the spatial light modulators 31 and 32 and a rear focal position that substantially coincides with the position of the predetermined plane 5. Is set. As will be described later, the light that has passed through the spatial light modulators 31 and 32 variably forms a light intensity distribution on the predetermined surface 5 in accordance with the postures of the plurality of mirror elements.

  The light having the light intensity distribution formed on the predetermined surface 5 enters the micro fly's eye lens (or fly eye lens) 7 via the relay optical system 6. The relay optical system 6 sets the predetermined surface 5 and the incident surface of the micro fly's eye lens 7 optically conjugate. Therefore, the light that has passed through the spatial light modulation unit 3 has the same outer shape as the light intensity distribution formed on the predetermined surface 5 on the incident surface of the micro fly's eye lens 7 that is optically conjugate with the predetermined surface 5. The light intensity distribution is formed.

  The micro fly's eye lens 7 is an optical element made up of a large number of micro lenses having positive refractive power, which are arranged vertically and horizontally and densely. The micro fly's eye lens 7 is configured by forming a micro lens group by etching a plane parallel plate. Has been. In a micro fly's eye lens, unlike a fly eye lens composed of lens elements isolated from each other, a large number of micro lenses (micro refractive surfaces) are integrally formed without being isolated from each other. However, the micro fly's eye lens is the same wavefront division type optical integrator as the fly's eye lens in that the lens elements are arranged vertically and horizontally.

  A rectangular minute refracting surface as a unit wavefront dividing surface in the micro fly's eye lens 7 is a rectangular shape similar to the shape of the illumination field to be formed on the mask M (and the shape of the exposure region to be formed on the wafer W). It is. For example, a cylindrical micro fly's eye lens can be used as the micro fly's eye lens 7. The configuration and action of the cylindrical micro fly's eye lens are disclosed in, for example, US Pat. No. 6,913,373.

  The light beam incident on the micro fly's eye lens 7 is two-dimensionally divided by a large number of microlenses, and the light intensity distribution on the rear focal plane or in the vicinity of the illumination pupil is almost the same as the light intensity distribution formed on the incident plane. A secondary light source (substantially surface light source consisting of a large number of small light sources: pupil intensity distribution) is formed. The light beam from the secondary light source formed on the illumination pupil immediately after the micro fly's eye lens 7 enters an illumination aperture stop (not shown). The illumination aperture stop is disposed at the rear focal plane of the micro fly's eye lens 7 or in the vicinity thereof, and has an opening (light transmission portion) having a shape corresponding to the secondary light source.

  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 a method for switching the illumination aperture stop, for example, a 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 installation of the illumination aperture stop can also be omitted.

  The light from the secondary light source limited by the illumination aperture stop illuminates the mask blind 9 in a superimposed manner via the condenser optical system 8. Thus, a rectangular illumination field corresponding to the shape and focal length of the rectangular micro-refractive surface of the micro fly's eye lens 7 is formed on the mask blind 9 as an illumination field stop. The light beam that has passed through the rectangular opening (light transmitting portion) of the mask blind 9 receives the light condensing action of the imaging optical system 10 and then illuminates the mask M on which a predetermined pattern is formed in a superimposed manner. That is, the imaging optical system 10 forms an image of the rectangular opening of the mask blind 9 on the mask M.

  The light beam transmitted through the mask M held on the mask stage MS forms an image of a mask pattern on the wafer (photosensitive substrate) W held on the wafer stage WS via the projection optical system PL. In this way, batch exposure or scan 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. As a result, the pattern of the mask M is sequentially exposed in each exposure region of the wafer W.

  The exposure apparatus according to the present embodiment includes a pupil intensity distribution measurement unit DT that measures the pupil intensity distribution on the pupil plane of the projection optical system PL based on light via the projection optical system PL, and a measurement result of the pupil intensity distribution measurement unit DT. And a control unit CR for controlling the spatial light modulation unit 3 based on the above. The pupil intensity distribution measurement unit DT includes, for example, a CCD image pickup unit having an image pickup 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 at the pupil position 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 unit DT, reference can be made to, for example, US Patent Publication No. 2008/0030707.

  In this embodiment, the secondary light source formed by the micro fly's eye lens 7 is used as a light source, and the mask M (and thus the wafer W) disposed on the irradiated surface of the illumination optical system 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 can be called the illumination pupil plane of the illumination optical system. 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 or a plane optically conjugate with the illumination pupil plane.

  When the number of wavefront divisions by the micro fly's eye lens 7 is relatively large, the overall light intensity distribution formed on the incident surface of the micro fly's eye lens 7 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 7 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 relay optical systems 4 and 6 and the micro fly's eye lens 7 illuminate immediately after the micro fly's eye lens 7 based on the light beam that has passed through the spatial light modulators 31 and 32 in the spatial light modulation unit 3. A distribution forming optical system that forms a pupil intensity distribution on the pupil is configured.

  Next, the internal configuration and operation of the spatial light modulation unit 3 will be specifically described. The deflecting members 35 and 36 are formed of an optical material such as fluorite or quartz, and have a triangular prism-like prism mirror shape extending in the X direction. The deflecting member 35 has a pair of reflecting surfaces 35a and 35b facing the light source, and the ridge line between the reflecting surfaces 35a and 35b extends in the X direction through the optical axis AX. The deflecting member 36 has a pair of reflecting surfaces 36a and 36b facing the mask side, and the ridge line between the reflecting surfaces 36a and 36b extends in the X direction through the optical axis AX. The deflecting members 35 and 36 can also be formed by providing a reflective film made of aluminum, silver, or the like on the side surface of a triangular prism-shaped member formed of a non-optical material such as metal. Alternatively, the deflection members 35 and 36 can be formed as mirrors, respectively.

  The light beam incident on the spatial light modulation unit 3 along the optical axis AX is divided into two by the two reflecting surfaces 35 a and 35 b of the deflecting member 35. The light beam reflected by the reflection surface 35 a enters the spatial light modulator 31, and the light beam reflected by the reflection surface 35 b enters the spatial light modulator 32. The light modulated by the spatial light modulator 31 is reflected by the reflecting surface 36 a of the deflecting member 36 and guided to the relay optical system 4. The light modulated by the spatial light modulator 32 is reflected by the reflecting surface 36 b of the deflecting member 36 and guided to the relay optical system 4.

  Hereinafter, in order to simplify the description, it is assumed that the spatial light modulators 31 and 32 have the same configuration. Therefore, common points regarding the configuration and operation of the spatial light modulators 31 and 32 will be described by focusing on one of the spatial light modulators 31. Further, the reflecting surface 35a and the reflecting surface 35b of the deflecting member 35, and the reflecting surface 36a and the reflecting surface 36b of the deflecting member 36 are arranged symmetrically with respect to a plane parallel to the XY plane including the optical axis AX. To do.

  As shown in FIG. 3, the spatial light modulator 31 is connected to a plurality of mirror elements 31a arranged two-dimensionally along a predetermined plane, a base 31b holding the plurality of mirror elements 31a, and the base 31b. And a drive unit 31c that individually controls and drives the postures of the plurality of mirror elements 31a via cables (not shown). The base 31 b of the spatial light modulator 31 is held by a tiltable stage 33. The stage 33 is configured to rotate by a desired angle based on, for example, the X direction and the Y direction as rotation axes based on a control signal from the control unit CR.

  Therefore, the direction of the array surface of the plurality of mirror elements of the spatial light modulator 31 is changed by the action of the stage 33 that can tilt while holding the base 31b. Similarly, the base 32b of the spatial light modulator 32 is held by a tiltable stage 34. Similarly to the stage 33, the stage 34 is configured to rotate by a desired angle, for example, with the X direction and the Y direction as rotation axes based on a control signal from the control unit CR. Therefore, the direction of the array plane of the plurality of mirror elements 32a of the spatial light modulator 32 is changed by the action of the stage 34 that can tilt while holding the base 32b.

  As shown in FIG. 4, the spatial light modulator 31 (32) includes a plurality of minute mirror elements 31 a (32 a) arranged two-dimensionally, and according to the incident position of incident light. Ejecting with spatial modulation variably applied. For ease of explanation and illustration, FIGS. 3 and 4 show a configuration example in which the spatial light modulator 31 (32) includes 4 × 4 = 16 mirror elements 31a (32a). Comprises much more than 16 mirror elements 31a (32a).

  Hereinafter, in order to facilitate understanding of the description of the basic operation of the spatial light modulation unit 3, the arrangement surface of the multiple mirror elements 31 a of the spatial light modulator 31 and the multiple mirror elements 32 a of the spatial light modulator 32 are described. Are arranged so as to be symmetric with respect to a plane including the optical axis AX and parallel to the XY plane.

  Referring to FIG. 3, among the light ray groups incident on the reflection surface 35 a of the deflecting member 35 (not shown in FIG. 3) and reflected toward the spatial light modulator 31 along the direction parallel to the optical axis AX, The light beam L1 is incident on the mirror element SEa of the plurality of mirror elements 31a, and the light beam L2 is incident on the mirror element SEb different from the mirror element SEa. Similarly, the light beam L3 is incident on a mirror element SEc different from the mirror elements SEa and SEb, and the light beam L4 is incident on a mirror element SEd different from the mirror elements SEa to SEc. The mirror elements SEa to SEd give spatial modulations set according to their positions to the lights L1 to L4.

  In the spatial light modulator 31, in the aligned state in which the reflection surfaces of all the mirror elements 31a are aligned along the arrangement surface, light beams incident on the reflection surface 36a along the direction parallel to the optical axis AX are converted into the spatial light modulator. After being reflected at 31, the reflection surface 36a of the deflection member 36 (not shown in FIG. 3) is reflected in a direction parallel to the optical axis AX. Further, the array surface of the plurality of mirror elements 31a of the spatial light modulator 31 is positioned at or near the front focal position of the relay optical system 4 as described above.

  Therefore, the light reflected by the plurality of mirror elements SEa to SEd of the spatial light modulator 31 and given a predetermined angular distribution forms the predetermined light intensity distributions SP1 to SP4 on the predetermined surface 5, and thus the micro fly's eye A light intensity distribution corresponding to the light intensity distributions SP1 to SP4 is formed on the incident surface of the lens 7. In other words, the relay optical system 4 determines the angle that the plurality of mirror elements SEa to SEd of the spatial light modulator 31 gives to the emitted light on the predetermined surface 5 that is the far field region (Fraunhofer diffraction region) of the spatial light modulator 31. Convert to position at.

  Similarly, the light having passed through the spatial light modulator 32 forms a light intensity distribution corresponding to the applied spatial light modulation on the predetermined surface 5, and hence on the incident surface of the micro fly's eye lens 7. Thus, the light intensity distribution (pupil intensity distribution) formed on the illumination pupil immediately after the micro fly's eye lens 7 is formed on the incident surface of the micro fly's eye lens 7 by the spatial light modulator 31 and the relay optical systems 4 and 6. The distribution corresponds to a combined distribution of the first light intensity distribution and the second light intensity distribution formed on the incident surface of the micro fly's eye lens 7 by the spatial light modulator 32 and the relay optical systems 4 and 6.

  As shown in FIG. 4, the spatial light modulator 31 is a large number of minute reflective elements that are regularly and two-dimensionally arranged along one plane with a planar reflective surface as an upper surface. A movable multi-mirror including a mirror element 31a. Each mirror element 31a is movable, and the inclination of the reflection surface, that is, the inclination angle and the inclination direction of the reflection surface are independently controlled by the action of the drive unit 31c that operates according to a command from the control unit CR. Each mirror element 31a can rotate continuously or discretely by a desired rotation angle about two directions (for example, X direction and Y direction) parallel to the reflecting surface and orthogonal to each other. it can. That is, it is possible to two-dimensionally control the inclination of the reflecting surface of each mirror element 31a.

  In addition, when rotating the reflective surface of each mirror element 31a (32a) discretely, a rotation angle is made into several states (for example, ..., -2.5 degree, -2.0 degree, ... 0 degree). , +0.5 degrees,... +2.5 degrees,. Although FIG. 4 shows a mirror element 31a (32a) having a square outer shape, the outer shape of the mirror element 31a (32a) is not limited to a square. However, from the viewpoint of light utilization efficiency, it is possible to have a shape that can be arranged so that the gap between the mirror elements 31a (32a) is small (a shape that can be packed most closely). Further, from the viewpoint of light utilization efficiency, the interval between two adjacent mirror elements 31a (32a) can be minimized.

  In the present embodiment, as the spatial light modulator 31 (32), for example, a spatial light modulator that continuously changes the directions of a plurality of mirror elements 31a (32a) arranged two-dimensionally is used. As such a spatial light modulator, for example, Japanese Patent Laid-Open No. 10-503300 and European Patent Publication No. 779530 corresponding thereto, Japanese Patent Application Laid-Open No. 2004-78136 and corresponding US Pat. No. 6,900, The spatial light modulator disclosed in Japanese Patent No. 915, Japanese National Publication No. 2006-524349 and US Pat. No. 7,095,546 corresponding thereto and Japanese Patent Application Laid-Open No. 2006-113437 can be used. Note that the directions of the plurality of mirror elements 31a (32a) arranged two-dimensionally may be controlled so as to have a plurality of discrete stages.

  In the spatial light modulator 31 (32), the posture of the plurality of mirror elements 31a (32a) is changed by the action of the drive unit 31c (32c) that operates according to the control signal from the control unit CR, and each mirror element 31a (32a) is set in a predetermined direction. As an example, the light reflected at a predetermined angle by each of the plurality of mirror elements 31a of the spatial light modulator 31 is X with the optical axis AX sandwiched between the incident surface of the micro fly's eye lens 7 as shown in FIG. Among the pair of circular light intensity distributions 20a and 20b arranged symmetrically in the direction, a light intensity distribution 20a on the −X direction side is formed. The light that has passed through the second spatial light modulator 32 forms a light intensity distribution 20 b on the + X direction side on the incident surface of the micro fly's eye lens 7.

  Thus, the light passing through the pair of spatial light modulators 31 and 32 corresponds to the dipole light intensity distribution 20 (20a, 20b) on the rear focal plane of the micro fly's eye lens 7 or the illumination pupil in the vicinity thereof. Bipolar light intensity distribution 21 (21a, 21b) is formed. Furthermore, the position of another illumination pupil optically conjugate with the illumination pupil immediately after the micro fly's eye lens 7, that is, the pupil position of the imaging optical system 10 and the pupil position of the projection optical system PL (the aperture stop AS is disposed). A bipolar light intensity distribution corresponding to the bipolar light intensity distribution 20 is also formed.

  In the present embodiment, the shape and size of the pupil intensity distribution is freely and quickly changed by the action of the spatial light modulation unit 3 including the spatial light modulators 31 and 32 arranged in parallel, and thus various. Various lighting conditions can be realized. However, in the spatial light modulators 31 and 32, not only the inclination angle of the mirror elements 31a and 32a does not change linearly with respect to the applied voltage, but also the nonlinearity between the applied voltage and the inclination angle varies from mirror element to mirror element. Since there is a tendency to change with time, it is difficult to accurately and stably form a desired pupil intensity distribution.

  The tilt angle error resulting from the non-linearity between the applied voltage and the tilt angle is roughly classified into a non-linear waviness component and a sensitivity variation component. A feature common to these two error components is that the amount of error increases as the applied voltage as the input signal increases. Specifically, the sensitivity fluctuation component tends to increase in almost linear proportion to the applied voltage, and the nonlinear waviness component tends to increase in proportion to almost the square of the applied voltage. Hereinafter, in order to understand the disadvantages in the prior art, it is assumed that the array surface of the plurality of mirror elements 31a and 32a of the spatial light modulators 31 and 32 is fixed in a state parallel to the XY plane.

  In this case, in the aligned state in which the reflecting surfaces of all the mirror elements 31a and 32a are aligned along the arrangement surface, the light passing through the spatial light modulators 31 and 32 is between the incident surface of the micro fly's eye lens 7 and the optical axis AX. Concentrate at the intersection. As described above, the angle that the mirror elements 31 a and 32 a give to the emitted light is converted into a position on the predetermined surface 5, and thus a position on the incident surface of the micro fly's eye lens 7. In other words, the tilt angle from the aligned state of the mirror elements 31a and 32a corresponds to the distance between the position where the light passing through the tilted mirror elements 31a and 32a reaches the incident surface of the micro fly's eye lens 7 and the optical axis AX. ing.

  Therefore, as shown in FIG. 6, in order to form the dipolar light intensity distribution 20 on the incident surface of the micro fly's eye lens 7, at least one of the mirror elements 31a and 32a of the spatial light modulators 31 and 32 is used. However, it is necessary to incline from the aligned state by an angle θ1 corresponding to the distance D1 on the incident surface of the micro fly's eye lens 7. D1 is the distance from the optical axis AX to the farthest points 41 and 42 of the light intensity distributions 20a and 20b, and is equal to the radius R1 of a circle 43 that circumscribes the light intensity distributions 20a and 20b around the optical axis AX. In other words, the maximum tilt angle θ1 required for the mirror elements 31a and 32a to form the dipolar light intensity distribution 20 in the prior art is a value corresponding to the distance D1 on the incident surface of the micro fly's eye lens 7. is there.

  In general, the spatial light modulators 31 and 32 are designed so that the light passing through the mirror elements 31a and 32a reaches an arbitrary position in the pupil region 44 corresponding to the effective region of the illumination pupil on the incident surface of the micro fly's eye lens 7. Is done. Therefore, the maximum inclination angle θm required for the mirror elements 31 a and 32 a to form an arbitrary pupil intensity distribution is a value corresponding to the radius Rp of the circular pupil region 44.

  On the other hand, in the present embodiment, the stages 33 and 34 that can be tilted based on a command from the control unit CR change the orientation of the array surface of the plurality of mirror elements 31a and 32a of the spatial light modulators 31 and 32. It constitutes the change part. In other words, the direction of the arrangement surface of the plurality of mirror elements 31a and 32a of the spatial light modulators 31 and 32 can be variably set by the action of the stages 33 and 34 as the changing units. ing.

  In the present embodiment, as shown in FIG. 7, when the dipole light intensity distribution 20 is formed, the light passing through the spatial light modulator 31 in the aligned state of the mirror elements 31a is the center 20ac of the circular light intensity distribution 20a. The control unit CR sets the orientation of the array surface of the mirror elements 31 a of the spatial light modulator 31 via the stage 33 so that the light is condensed. Similarly, in the aligned state of the mirror elements 32a, the controller CR via the stage 34 causes the controller CR to focus the light that has passed through the spatial light modulator 32 on the center 20bc of the circular light intensity distribution 20b. The orientation of the array surface of the mirror elements 32a is set. In this embodiment, after the orientation of the array surface of the mirror elements 31a is set via the stage 33, the posture of each mirror element 31a can be controlled. In the present embodiment, after the orientations of the array planes of all the mirror elements 32a are set via the stage 34, the posture of each mirror element 32a can be controlled.

  When the dipolar light intensity distribution 20 is formed, the maximum inclination angle θ2 required for the mirror elements 31a and 32a is a value corresponding to the distance D2 on the incident surface of the micro fly's eye lens 7. The distance D2 is equal to the radius of the circular light intensity distributions 20a and 20b, and is considerably smaller than the distance D1 from the optical axis AX to the points 41 and 42. This means that the required maximum inclination angle θ2 from the alignment state of the mirror elements 31a and 32a required for the formation of the dipolar light intensity distribution 20 in this embodiment is the required maximum inclination angle θ1 in the prior art. It means that it is quite small.

  In this embodiment, after setting the orientation of the array surface of the mirror elements 31a and 32a via the stages 33 and 34, the posture of each of the mirror elements 31a and 32a can be controlled. The maximum tilt angle θ2 required for each mirror element 31a, 32a to form the intensity distribution 20 is suppressed to be smaller than that of the prior art, and as a result, nonlinearity between the applied voltage and the tilt angle of each mirror element 31a, 32a. The occurrence of the tilt angle error due to the is suppressed to a small level. As a result, even if the non-linearity between the applied voltage and the tilt angle varies for each mirror element 31a and 32a and tends to vary with time, the effect of the non-linearity between the applied voltage and the tilt angle is suppressed to a desired level. The bipolar light intensity distribution 20 (21) can be formed accurately and stably.

  As described above, in this embodiment, the outer shape of the light intensity distribution 21 to be formed on the illumination pupil immediately after the micro fly's eye lens 7 by the action of the stages 33 and 34 that can be tilted based on the command from the controller CR. Depending on the shape, it is possible to variably set the orientation of the array surface of the plurality of mirror elements 31a, 32a of the spatial light modulators 31, 32. As a result, the required maximum inclination angle θ2 from the alignment state of the mirror elements 31a and 32a required for forming the dipole light intensity distribution 20 is suppressed to be smaller than the required maximum inclination angle θ1 in the prior art. It is done.

  Thus, in the illumination optical system (2 to 10) of the present embodiment, the influence of the nonlinearity between the applied voltage and the tilt angle of the mirror element is suppressed to be small, and the desired dipolar light intensity distribution 20 is eventually obtained. The pupil intensity distribution can be formed accurately and stably. In the exposure apparatus (2 to WS) of this embodiment, the pattern characteristics of the mask M to be transferred using the illumination optical system (2 to 10) that accurately and stably forms a desired pupil intensity distribution. Good exposure can be performed under appropriate illumination conditions realized according to the above.

  In the above-described embodiment, when the bipolar light intensity distribution 20 is formed, the light that has passed through the aligned spatial light modulators 31 and 32 is collected at the centers 20ac and 20bc of the light intensity distributions 20a and 20b. Further, the orientation of the array surface of the mirror elements 31a and 32a of the spatial light modulators 31 and 32 is set. However, the present invention is not limited to this. For example, the orientation of the array surface is set so that the light that has passed through the aligned spatial light modulators 31 and 32 is condensed at an arbitrary position in the region of the light intensity distributions 20a and 20b. Even in this case, the same effect as the above-described embodiment can be obtained.

  Further, in the above-described embodiment, the function and effect of the present invention are described by taking as an example a dipole illumination in which a dipole pupil intensity distribution 21 is formed on the illumination pupil. However, the present invention is not limited to dipole illumination. For example, multipolar illumination or annular pupil in which a pupil intensity distribution other than dipole (eg, tripolar, quadrupole, quinpole) is formed. It is obvious that the same effect can be obtained by applying the present invention to annular illumination in which an intensity distribution is formed, circular illumination in which a circular pupil intensity distribution is formed, and the like.

  As an example, consider the application of this embodiment to quadrupole illumination. Referring to FIG. 8, the light reflected at a predetermined angle by each of the plurality of mirror elements 31a of the spatial light modulator 31 is incident on the incident surface of the micro fly's eye lens 7 in the X direction and the Z direction with the optical axis AX interposed therebetween. The light intensity distribution 50a on the −X direction side and the light intensity distribution 50a on the + Z direction side are formed among the four circular light intensity distributions 50a and 50b arranged symmetrically. The light that has passed through the second spatial light modulator 32 forms a light intensity distribution 50 b on the + X direction side and a light intensity distribution 50 b on the −Z direction side on the incident surface of the micro fly's eye lens 7.

  Thus, the light passing through the pair of spatial light modulators 31 and 32 corresponds to the quadrupole light intensity distribution 50 (50a, 50b) on the rear focal plane of the micro fly's eye lens 7 or the illumination pupil in the vicinity thereof. A quadrupolar light intensity distribution 51 (51a, 51b) is formed. Further, a quadrupole light is also applied to the position of another illumination pupil optically conjugate with the illumination pupil immediately after the micro fly's eye lens 7, that is, the pupil position of the imaging optical system 10 and the pupil position of the projection optical system PL. A quadrupole light intensity distribution corresponding to the intensity distribution 50 is formed.

  In the prior art in which the array surface of the plurality of mirror elements 31a and 32a is fixed in a state parallel to the XY plane, as shown in FIG. 9, in order to form a quadrupole light intensity distribution 50, the mirror elements 31a, At least one of 32a needs to be inclined from the aligned state by an angle θ3 corresponding to the distance R3 on the incident surface of the micro fly's eye lens 7. The distance R3 is equal to the radius of a circle 45 that circumscribes the light intensity distributions 50a and 50b with the optical axis AX as the center. That is, the maximum inclination angle θ3 required for the mirror elements 31a and 32a to form the quadrupole light intensity distribution 50 in the prior art is a value corresponding to the distance R3 on the incident surface of the micro fly's eye lens 7. is there.

  On the other hand, in the present embodiment in which the orientation of the array plane of the plurality of mirror elements 31a and 32a can be variably set, as shown in FIG. 10, the mirror element 31a is formed when the quadrupolar light intensity distribution 50 is formed. In the aligned state, the control unit CR causes the mirror element of the spatial light modulator 31 via the stage 33 so that the light that has passed through the spatial light modulator 31 is collected at an intermediate position 50am of the center 50ac of the pair of light intensity distributions 50a. The direction of the arrangement surface 31a is set. Similarly, in the aligned state of the mirror elements 32a, the controller CR passes the stage 34 through the stage 34 so that the light having passed through the spatial light modulator 32 is condensed at an intermediate position 50bm between the centers 50bc of the pair of light intensity distributions 50b. The orientation of the array surface of the mirror elements 32a of the modulator 32 is set. In this embodiment, after the orientation of the array surface of the mirror elements 31a is set via the stage 33, the posture of each mirror element 31a can be controlled. In the present embodiment, after the orientations of the array planes of all the mirror elements 32a are set via the stage 34, the posture of each mirror element 32a can be controlled.

  When the quadrupole light intensity distribution 50 is formed, the maximum inclination angle θ4 required for the mirror elements 31a and 32a is a value corresponding to the distance D3 on the incident surface of the micro fly's eye lens 7. The distance D3 is equal to the sum of the distance between the intermediate positions 50am, 50bm and the centers 50ac, 50bc and the radius of the circular light intensity distribution 50b, and is smaller than the radius D3 of the circumscribed circle 45 centered on the optical axis AX. . Therefore, the required maximum inclination angle θ4 from the alignment state of the mirror elements 31a and 32a required for forming the quadrupole light intensity distribution 50 in this embodiment is larger than the required maximum inclination angle θ3 in the prior art. Small.

  In this embodiment, after setting the orientation of the array surface of the mirror elements 31a and 32a via the stages 33 and 34, the posture of each of the mirror elements 31a and 32a can be controlled. The maximum inclination angle θ4 required for the mirror elements 31a and 32a to form the intensity distribution 50 is suppressed to be smaller than that of the prior art, and as a result, is caused by nonlinearity between the applied voltage and the inclination angles of the mirror elements 31a and 32a. The occurrence of tilt angle error is suppressed to a small level. As a result, even if the non-linearity between the applied voltage and the tilt angle varies for each mirror element 31a and 32a and tends to vary with time, the effect of the non-linearity between the applied voltage and the tilt angle is suppressed to a desired level. The quadrupolar light intensity distribution 50 (51) can be formed accurately and stably.

  In the above description regarding the quadrupole illumination, the spatial light modulator is arranged so that the light that has passed through the aligned spatial light modulators 31 and 32 is collected at the intermediate positions 50am and 50bm of the pair of light intensity distributions 50a and 50b. The orientation of the arrangement surface of the mirror elements 31a and 32a of 31 and 32 is set. However, for example, four spatial light modulators are arranged in parallel, and the light that has passed through each of the aligned spatial light modulators is centered in the light intensity distributions 50a and 50b (or any region within the region of the light intensity distributions 50a and 50b). By setting the orientation of the arrangement surface so that the light is condensed at the position), the maximum inclination angle θ4 can be further reduced, and the occurrence of the inclination angle error can be further reduced.

  In this embodiment, the orientation of the array surface of the plurality of mirror elements 31a and 32a in the spatial light modulators 31 and 32 is changed by the inclination of the stages 33 and 34 holding the bases 31b and 32b. It is not limited. For example, the bases 31 b and 32 b are tiltably attached to the stages 33 and 34, and the bases 31 b and 32 b are tilted with respect to the stages 33 and 34, thereby changing the orientation of the array surface of the plurality of mirror elements 31 a and 32 a. It may be changed.

  In the above description, as the spatial light modulator having a plurality of mirror elements that are two-dimensionally arranged and individually controlled, the orientations (angle: inclination) of the plurality of two-dimensionally arranged reflecting surfaces are individually set. A controllable spatial light modulator is used. However, the present invention is not limited to this. For example, a spatial light modulator that can individually control the height (position) of a plurality of two-dimensionally arranged reflecting surfaces can be used. As such a spatial light modulator, for example, Japanese Patent Application Laid-Open No. 6-281869 and US Pat. No. 5,312,513 corresponding thereto, and Japanese Patent Laid-Open No. 2004-520618 and US Patent corresponding thereto are disclosed. The spatial light modulator disclosed in FIG. 1d of Japanese Patent No. 6,885,493 can be used. In these spatial light modulators, by forming a two-dimensional height distribution, an action similar to that of the diffractive surface can be given to incident light. Note that the spatial light modulator having a plurality of two-dimensionally arranged reflection surfaces described above is disclosed in, for example, Japanese Patent Laid-Open No. 2006-513442 and US Pat. No. 6,891,655 corresponding thereto, or a special table. You may deform | transform according to the indication of 2005-524112 gazette and the US Patent Publication 2005/0095749 corresponding to this.

  In the above-described embodiment, the micro fly's eye lens 7 is used as the optical integrator, but instead, an internal reflection type optical integrator (typically a rod type integrator) may be used. In this case, a condensing optical system that condenses light from the predetermined surface 5 is disposed instead of the relay optical system 6. Then, instead of the micro fly's eye lens 7 and the condenser optical system 8, a rod type is used so that the incident end is positioned at or near the rear focal position of the condensing optical system that condenses the light from the predetermined surface 5. Place the integrator. At this time, the injection end of the rod-type integrator is positioned at the mask blind 9. When a rod type integrator is used, a position optically conjugate with the position of the aperture stop AS of the projection optical system PL in the imaging optical system 10 downstream of the rod type integrator can be called an illumination pupil plane. In addition, since a virtual image of the secondary light source of the illumination pupil plane is formed at the position of the entrance surface of the rod integrator, this position and a position optically conjugate with this position are also called the illumination pupil plane. Can do. Here, the condensing optical system, the imaging optical system, and the rod integrator can be regarded as a distribution forming optical system.

  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. Here, the teachings of US Patent Publication No. 2007/0296936 are incorporated by reference.

  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 the photosensitive substrate, that is, the plate P.

  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 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 method for filling the liquid in the optical path between the projection optical system and the photosensitive substrate, a method 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 Application Laid-Open No. 6-124873 in a liquid bath, or a predetermined depth on a stage as disclosed in Japanese Patent Application Laid-Open No. 10-303114. A technique 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, 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 2 Beam transmission part 3 Spatial light modulation units 31 and 32 Spatial light modulators 33 and 34 Stages 35 and 36 Deflection members 4 and 6 Relay optical system 7 Micro fly-eye lens 8 Condenser optical system 9 Mask blind 10 Imaging optics System DT Pupil intensity distribution measurement unit CR Control unit M Mask MS Mask stage PL Projection optical system W Wafer WS Wafer stage

Claims (19)

In the illumination optical system that illuminates the illuminated surface with light from the light source,
Are two-dimensionally arranged on the first base, a first spatial light modulator having a plurality of mirror elements the position or orientation relative to the first base are individually controlled,
A second spatial light modulator having a plurality of mirror elements that are two-dimensionally arranged on the second base and whose positions or postures with respect to the second base are individually controlled;
A distribution forming optical system that forms a predetermined light intensity distribution on an illumination pupil of the illumination optical system with light that has passed through the first and second spatial light modulators ;
An illumination optical system comprising: a changing device that changes an inclination of the second base with respect to the first base. The illumination optical system according to claim 1, wherein the changing device has a stage that can tilt while holding the second base. It said first and second spatial light modulators, the illumination optical system according to claim 1 or claim 2, characterized in that it has the plurality of the driving unit for individually driving and controlling the position or orientation of the mirror elements, respectively . The illumination optical system according to claim 3, wherein the driving unit continuously or discretely changes the positions or postures of the plurality of mirror elements. 2. A control unit for controlling the first spatial light modulator, the second spatial light modulator, and the changing device according to a light intensity distribution to be formed on the illumination pupil. 5. The illumination optical system according to any one of items 4 to 4. The first spatial light modulator and the second spatial light modulator are arranged in parallel,
The changing device includes a first changing unit that changes an attitude of the first base of the first spatial light modulator, and a second changing unit that changes an attitude of the second base of the second spatial light modulator; Have
The control unit is configured to change the first change so that light that has passed through the first spatial light modulator reaches a first region of the illumination pupil in an aligned state in which reflecting surfaces of the plurality of mirror elements are aligned along an array surface. 6. The second change unit is controlled so that light passing through the second spatial light modulator in the aligned state reaches a second region of the illumination pupil in the aligned state. The illumination optical system according to any one of the above. The illumination optical system according to claim 6, further comprising a light splitter that splits light from the light source and makes the light enter the first spatial light modulator and the second spatial light modulator . The distribution forming optical system forms a multipolar light intensity distribution on the illumination pupil,
The control unit controls the first changing unit so that the first region is located in a region of a first pole of the light intensity distribution having a plurality of poles, and the second region is the plurality of poles. 8. The illumination optical system according to claim 6, wherein the second changing unit is controlled so as to be located in a region of a second pole of the light intensity distribution in a shape . The control unit controls the first changing unit so that the first region is located at the center of the first pole region, and the second region is located at the center of the second pole region. The illumination optical system according to claim 8, wherein the second changing unit is controlled . The distribution forming optical system forms a multipolar light intensity distribution on the illumination pupil,
The control unit controls the first changing unit such that the first region is located between a first pole region and a second pole region of the multipolar light intensity distribution; and The second change unit is controlled so that the second region is positioned between a third pole region and a fourth pole region of the multipolar light intensity distribution. The illumination optical system according to 6 or 7 . The control unit controls the first changing unit so that the first region is located between the center of the first pole region and the center of the second pole region, and the second region is 11. The illumination optical system according to claim 10 , wherein the second changing unit is controlled so as to be positioned between the center of the third pole region and the center of the fourth pole region . The lighting device according to any one of claims 1 to 11, wherein the changing device rotates at least one of the first base and the second base with two axes orthogonal to each other as a rotation axis. Optical system. The illumination optical system according to any one of claims 1 to 12, wherein the plurality of mirror elements are arranged at or near a front focal position of the distribution forming optical system . The illumination optical system according to any one of claims 1 to 13, wherein the distribution forming optical system converts an angle of light from the plurality of mirror elements into a position on the illumination pupil . The illumination optical system according to claim 1, wherein the distribution forming optical system includes a fly's eye optical system including a plurality of optical surfaces that divide incident light two-dimensionally. . 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 1 to 15. 17. An exposure apparatus comprising the illumination optical system according to claim 1 for illuminating a predetermined pattern, and exposing the predetermined pattern onto a photosensitive substrate. The exposure apparatus according to claim 17, further comprising a projection optical system that forms an image of the predetermined pattern on the photosensitive substrate. An exposure process for exposing the predetermined pattern to the photosensitive substrate using the exposure apparatus according to claim 17 or 18,
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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