JP2010141151A - Luminous flux-splitting element, illumination optical system, exposure device, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination optical system capable of stably actualizing a variety of lighting conditions using a pair of spatial optical modulators while securing relatively simple and compact constitution. <P>SOLUTION: The illumination optical system includes a luminous flux-splitting element (2) configured to split incident luminous flux into two pieces of luminous flux and emit them. The luminous flux-splitting element has: a plurality of first incident-side deflecting surfaces (21a) provided in a first incident region (IR1) in an incident region (IR); and a plurality of second incident-side deflecting surfaces (21b) provided in a second incident region (IR2). Further, the luminous flux-splitting element has: a plurality of first emission-side deflecting surfaces (22a), provided in a first emission region (ER1) corresponding to the first incident region, corresponding to the plurality of first incident-side deflecting surfaces; and a plurality of second emission-side deflecting surfaces (22b), provided in a second emission region (ER2) corresponding to the second incident region, corresponding to the plurality of second incident-side deflecting surfaces. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  In a typical exposure apparatus of this type, a light beam emitted from a light source is passed through a fly-eye lens as an optical integrator, and a secondary light source (generally an illumination pupil) as a substantial surface light source composed of a number of light sources. 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 beam from the secondary light source is condensed 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 highly integrated, and it is indispensable to obtain a uniform illumination distribution on the wafer in order to accurately transfer the fine pattern onto the wafer.

  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 movable multi-mirror is used, the degree of freedom in changing the shape and size of the pupil intensity distribution is high, but the movable multi-mirror as a spatial light modulator is used alone. Therefore, the energy per unit area of the light incident on the reflecting surface of the mirror element becomes relatively large. As a result, the reflectivity of the mirror element tends to decrease with time due to light irradiation, and as a result, it becomes difficult for the spatial light modulator to stably perform a required function over a required period.

  On the other hand, if the cross section of the incident light beam to the spatial light modulator is increased in order to reduce the energy per unit area of the light incident on the reflecting surface of the mirror element, the reflection occupied by a large number of two-dimensionally arranged mirror elements The total area of the region increases, and the spatial light modulator increases in size. The increase in the size of the spatial light modulator leads to an increase in the size of the optical member arranged on the incident side and the emission side of the spatial light modulator, and consequently the size of the illumination optical system. Here, it may be possible to simplify and compact the illumination optical system using a plurality of spatial light modulators, but in order to improve the controllability of the pupil intensity distribution formed by the spatial light modulator, It is desirable to improve the uniformity of the intensity distribution of light incident on each spatial light modulator.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a light beam splitting element capable of supplying a light beam having a uniform intensity distribution to a plurality of spatial light modulators. It is another object of the present invention to provide an illumination optical system capable of stably realizing a variety of illumination conditions using a plurality of spatial light modulators while ensuring a relatively simple and compact configuration. To do. In addition, the present invention uses an illumination optical system that stably realizes a wide variety of illumination conditions, and performs 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 be used.

In order to solve the above problems, in the first embodiment of the present invention, in the light beam splitting element that divides an incident light beam into a plurality of light beams and emits the light beam,
A plurality of first incident-side deflection surfaces provided in a first incident area of the incident areas of the light flux to the light beam splitting element;
A plurality of second incident side deflection surfaces provided in a second incident region of the incident regions;
A plurality of first exit-side deflection surfaces provided corresponding to the plurality of first entrance-side deflection surfaces in a first exit region corresponding to the first entrance region in the exit region of the light flux from the beam splitting element; ,
A plurality of second exit-side deflection surfaces provided corresponding to the plurality of second entrance-side deflection surfaces in a second exit region corresponding to the second entrance region in the exit region;
One first incident side deflection surface and another one first incident side deflection surface of the plurality of first incident side deflection surfaces are an optical path of a light flux through the one first incident side deflection surface. The optical path of the light beam passing through the other first incident side deflection surface is configured to intersect inside the light beam splitting element, and one second of the plurality of second incident side deflection surfaces. The incident-side deflecting surface and another second incident-side deflecting surface include an optical path of a light beam passing through the one second incident-side deflecting surface and an optical path of a light beam passing through the other second incident-side deflecting surface. Is provided so as to intersect inside the light beam splitting element.

In the second embodiment of the present invention, in the illumination optical system that illuminates the illuminated surface based on the light from the light source,
Provided is an illumination optical system comprising a light beam splitting element of a first form arranged in an optical path between the light source and the irradiated surface.

  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 light beam splitting element according to an aspect of the present invention, the incident light beam from the light source is split into a plurality of emitted light beams using the first incident side deflection surface and the second incident side deflection surface. At this time, since the light beams passing through the plurality of incident-side deflection surfaces intersect inside the light beam splitting element, the intensity distribution of the emitted light beam can be made uniform. The light beam split by the action of the light beam splitting element having a relatively simple and compact configuration is guided to a plurality of spatial light modulators via, for example, a deflection member. As a result, the optical member disposed on the incident side and the optical member disposed on the exit side of the plurality of spatial light modulators are not increased in size, and the increase in size of the illumination optical system can be avoided.

  In addition, since a plurality of spatial light modulators are provided, the energy per unit area of the light incident on the optical surface of the optical element can be kept small compared to the case where the spatial light modulator is used alone. Specifically, when a plurality of spatial light modulators having a plurality of mirror elements are used, the energy per unit area of light incident on the reflecting surface of the mirror element can be suppressed to a small value. As a result, in the plurality of spatial light modulators, the reflectance of the mirror element is unlikely to be lowered even when irradiated with light over a long period of time, and a required function can be stably exhibited over a required period.

  That is, in the illumination optical system of the present invention, it is possible to stably realize a wide variety of illumination conditions using a plurality of spatial light modulators while ensuring a relatively simple and compact configuration. In the exposure apparatus of the present invention, an illumination optical system that stably realizes a wide variety of illumination conditions is used, and is good under appropriate illumination conditions realized according to the characteristics of the pattern to be transferred. Exposure can be performed, and as a result, a good device can be manufactured.

  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 LS. As the light source LS, 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. Light emitted from the light source LS is incident on the spatial light modulation unit 3 via the beam transmitter 1 and the beam splitter 2.

  The beam transmitter 1 guides the incident light beam from the light source LS to the light beam splitting element 2 (and thus the spatial light modulation unit 3) while converting the incident light beam into a light beam having a cross section of an appropriate size and shape. It has a function of actively correcting positional fluctuations and angular fluctuations of incident light beams. The light beam splitting element 2 has a function of dividing a parallel light beam incident along the optical axis AX into two parallel light beams and emitting them along two optical paths parallel to the optical axis AX. A specific configuration and operation of the light beam splitting element 2 will be described later.

  As shown in FIG. 2, the spatial light modulation unit 3 includes, in order from the light incident side, a first deflection member 3c, a pair of spatial light modulators 3a and 3b, and a second deflection member 3d. The spatial light modulators 3a and 3b have a plurality of mirror elements that are two-dimensionally arranged and individually controlled. The first deflecting member 3c guides one of the two light beams split through the light beam splitting element 2 to the first spatial light modulator 3a, and guides the other light beam to the second spatial light modulator 3b. The second deflecting member 3d guides the first light flux that has passed through the first spatial light modulator 3a and the second light flux that has passed through the second spatial light modulator 3b 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 is set so that the front focal position thereof substantially coincides with the positions of the plurality of mirror elements of the spatial light modulators 3a and 3b and the rear focal position substantially coincides with the position of the predetermined plane 5. ing. As will be described later, the light that has passed through the spatial light modulators 3 a and 3 b 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 a secondary beam having substantially the same light intensity distribution as the illumination field formed by the incident light beam on or near the rear focal plane. A light source is formed. A light beam from a secondary light source (that is, pupil intensity distribution) formed on the rear focal plane of the micro fly's eye lens 7 or in the vicinity of the illumination pupil 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 modulators 3a and 3b in the spatial light modulation unit 3. 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 are behind the micro fly's eye lens 7 based on the light that has passed through the spatial light modulators 3 a and 3 b in the spatial light modulation unit 3. A distribution forming optical system for forming a pupil intensity distribution on the illumination pupil is constructed.

  Next, prior to the description of the specific configuration and operation of the light beam splitting element 2, the internal configuration and operation of the spatial light modulation unit 3 will be described. Referring to FIG. 2, the deflecting members 3c and 3d in the spatial light modulation unit 3 have, for example, a triangular prism prism mirror shape extending in the X direction. The light that has entered the spatial light modulation unit 3 along the first optical path parallel to the optical axis AX via the light beam splitting element 2 is reflected by the first reflecting surface 3ca of the first deflecting member 3c, and then the first spatial light. The light enters the modulator 3a. The light modulated by the first spatial light modulator 3 a is reflected by the first reflecting surface 3 da of the second deflecting member 3 d and guided to the relay optical system 4.

  On the other hand, the light incident on the spatial light modulation unit 3 along the second optical path parallel to the optical axis AX via the light beam splitting element 2 is reflected by the second reflecting surface 3cb of the first deflecting member 3c, and then second The light enters the spatial light modulator 3b. The light modulated by the second spatial light modulator 3b is reflected by the second reflecting surface 3db of the second deflecting member 3d and guided to the relay optical system 4.

  Hereinafter, in order to simplify the description, the first spatial light modulator 3a and the second spatial light modulator 3b have the same configuration and are arranged symmetrically with respect to a plane including the optical axis AX and parallel to the XY plane. It is assumed that Therefore, the description which overlaps with the 1st spatial light modulator 3a about the 2nd spatial light modulator 3b is abbreviate | omitted, paying attention to the 1st spatial light modulator 3a, the spatial light modulators 3a and 3b in the spatial light modulation unit 3 The configuration and operation of the will be described.

  As shown in FIG. 3, the first spatial light modulator 3a includes a plurality of mirror elements 3aa arranged two-dimensionally, a base 3ab holding the plurality of mirror elements 3aa, and a cable ( And a drive unit 3ac that individually controls and drives the postures of the plurality of mirror elements 3aa via a not-shown). In FIG. 3, for the sake of clarity, the incident angle of light on the surface (XY plane) on which the plurality of mirror elements 3aa are arranged is set to be relatively large.

  As shown in FIG. 4, the spatial light modulator 3a includes a plurality of minute mirror elements (optical elements) 3aa arranged two-dimensionally. And variably imparting a proper modulation. For ease of explanation and illustration, FIG. 3 and FIG. 4 show a configuration example in which the spatial light modulator 3a includes 4 × 4 = 16 mirror elements 3aa. Are provided with a number of mirror elements 3aa.

  Referring to FIG. 3, a light beam incident on the first reflecting surface 3ca of the first deflecting member 3c (not shown in FIG. 3) along the direction parallel to the optical axis AX and reflected toward the spatial light modulator 3a. In the group, the light beam L1 is incident on the mirror element SEa of the plurality of mirror elements 3aa, 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 3a, in a reference state (hereinafter referred to as “reference state”) in which the reflecting surfaces of all the mirror elements 3aa are set along one plane, the spatial light modulator 3a is arranged in the direction parallel to the optical axis AX. After the light beam incident on the first reflecting surface 3ca is reflected by the spatial light modulator 3a, it is directed in a direction substantially parallel to the optical axis AX by the first reflecting surface 3da of the second deflecting member 3d (not shown in FIG. 3). It is configured to be reflected. The array surface of the plurality of mirror elements 3aa of the spatial light modulator 3a is positioned at the front focal position of the relay optical system 4 or in the vicinity thereof.

  Accordingly, the light reflected by the plurality of mirror elements SEa to SEd of the spatial light modulator 3a 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 3a gives to the emitted light on the predetermined surface 5 that is the far field region (Fraunhofer diffraction region) of the spatial light modulator 3a. Convert to position at.

  Similarly, the light that is reflected by the plurality of mirror elements of the second spatial light modulator 3 b and given a predetermined angular distribution also forms a predetermined light intensity distribution on the incident surface of the micro fly's eye lens 7. In this way, the light intensity distribution (pupil intensity distribution) of the secondary light source formed by the micro fly's eye lens 7 is formed on the incident surface of the micro fly's eye lens 7 by the first spatial light modulator 3a and the relay optical systems 4 and 6. The distribution corresponds to the 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 second spatial light modulator 3b and the relay optical systems 4 and 6.

  As shown in FIG. 4, the spatial light modulator 3a (3b) has a large number of minute reflections regularly and two-dimensionally arranged along one plane with the planar reflecting surface as the upper surface. This is a movable multi-mirror including a mirror element 3aa (3ba) as an element. Each mirror element 3aa (3ba) is movable, and the inclination of the reflection surface, that is, the inclination angle and the inclination direction of the reflection surface are independently determined by the action of the drive unit 3ac (3bc) that operates according to a command from the control unit CR. Be controlled. Each mirror element 3aa (3ba) rotates continuously or discretely by a desired rotation angle, with two directions parallel to the reflecting surface and orthogonal to each other (for example, the X direction and the Y direction) as rotation axes. can do. That is, it is possible to two-dimensionally control the inclination of the reflecting surface of each mirror element 3aa (3ba).

  In addition, when rotating the reflective surface of each mirror element 3aa (3ba) discretely, a rotation angle is a several state (for example, ..., -2.5 degree, -2.0 degree, ... 0 degree). , +0.5 degrees,... +2.5 degrees,. Although FIG. 4 shows a mirror element 3aa (3ba) having a square outer shape, the outer shape of the mirror element 3aa (3ba) is not limited to a square. However, from the viewpoint of light utilization efficiency, it is possible to provide a shape that can be arranged so that the gap between the mirror elements 3aa (3ba) 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 3aa (3ba) can be minimized.

  In the present embodiment, as the spatial light modulators 3a and 3b, for example, spatial light modulators that continuously change the directions of a plurality of mirror elements 3aa (3ba) arranged two-dimensionally are 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. 2006-5243a9 and US Pat. No. 7,095,546 corresponding thereto, and Japanese Patent Application Laid-Open No. 2006-113a37 can be used. Note that the directions of the plurality of mirror elements 3aa (3ba) arranged two-dimensionally may be controlled so as to have a plurality of discrete stages.

  In the first spatial light modulator 3a, the attitude of the plurality of mirror elements 3aa is changed by the action of the drive unit 3ac that operates according to the control signal from the control unit CR, and each mirror element 3aa is in a predetermined direction. Is set. The light reflected at a predetermined angle by each of the plurality of mirror elements 3aa of the first spatial light modulator 3a is incident on the incident surface of the micro fly's eye lens 7 as shown in FIG. Two arc-shaped light intensity distributions 20a and 20b spaced apart in the direction are formed.

  Similarly, in the second spatial light modulator 3b, the posture of the plurality of mirror elements 3ba is changed by the action of the drive unit 3bc that operates according to the control signal from the control unit CR, and each mirror element 3ba is predetermined. The direction is set. As shown in FIG. 5, the light reflected at a predetermined angle by the plurality of mirror elements 3ba of the second spatial light modulator 3b is incident on the incident surface of the micro fly's eye lens 7 on the optical axis AX, for example. Two arc-shaped light intensity distributions 20c and 20d spaced apart in the direction are formed.

  Thus, quadrupolar light intensity distributions 21a to 21d corresponding to the quadrupolar light intensity distributions 20a to 20d are formed on the rear focal plane of the micro fly's eye lens 7 or in the vicinity of the illumination pupil. Further, the position of another illumination pupil that is optically conjugate with the illumination pupil at or near the rear focal plane of the micro fly's eye lens 7, that is, the pupil position of the imaging optical system 10 and the pupil position (aperture) of the projection optical system PL. A quadrupole light intensity distribution corresponding to the quadrupole light intensity distributions 20a to 20d is also formed at the position where the aperture stop AS is disposed.

  Next, a specific configuration and operation of the light beam splitting element 2 of the present embodiment will be described with reference to FIG. In the present embodiment, the present invention is applied to a light beam splitting element that splits an incident parallel light beam into two parallel light beams and emits the split light beam. Specifically, the light beam splitting element 2 of the present embodiment splits a parallel light beam incident along the optical axis AX (Y direction) into two parallel light beams, and the two split parallel light beams are parallel to the optical axis AX ( That is, the light is emitted along two light emission paths that are parallel to the incident light path and spaced from each other.

  The beam splitting element 2 includes a plurality of first incident-side deflection surfaces 21a provided in the first incident region IR1 in the incident region IR of the light beam from the beam transmitting unit 1, and a second incident in the incident region IR. And a plurality of second incident side deflection surfaces 21b provided in the region IR2. The beam splitting element 2 includes a plurality of first exit-side deflection surfaces 22a provided in the first exit region ER1 corresponding to the first entrance region IR1 corresponding to the plurality of first entrance-side deflection surfaces 21a, The second exit region ER2 corresponding to the second entrance region IR2 has a plurality of second exit side deflection surfaces 22b provided corresponding to the plurality of second entrance side deflection surfaces 21b.

  The incident region IR of the light beam to the light beam splitting element 2 is a rectangular region having a short side along the Z direction and a long side along the X direction with the optical axis AX as the center. The first incident region IR1 and the second incident region IR2 are rectangular regions obtained by equally dividing the incident region IR by the XY plane including the optical axis AX. That is, the first incident region IR1 and the second incident region IR2 do not overlap with each other in the incident region IR, and are not separated from each other in the incident region IR.

  Hereinafter, in order to facilitate understanding of the description, the first incident region IR1 is provided with four first incident side deflection surfaces 21aa, 21ab, 21ac, and 21ad arranged in the Z direction, and the second incident region IR2 includes It is assumed that four first incident side deflection surfaces 21ba, 21bb, 21bc, and 21bd are provided side by side in the Z direction. Correspondingly, four first exit-side deflection surfaces 22aa, 22ab, 22ac, 22ad are provided in the first exit region ER1 in the Z direction, and the second exit region ER2 is provided in the Z direction. It is assumed that four second exit side deflection surfaces 22ba, 22bb, 22bc, and 22bd are provided side by side.

  Further, it is assumed that the four first incident-side deflection surfaces 21aa to 21ad and the four second incident-side deflection surfaces 21ba to 21bd are arranged adjacent to each other when viewed from the optical axis AX direction. Further, when viewed from the optical axis AX direction, the four first exit-side deflection surfaces 22aa to 22ad are arranged so as to be adjacent to each other, and the four second exit-side deflection surfaces 22ba to 22bd are arranged to be adjacent to each other. It shall be. However, when viewed from the optical axis AX direction, the four first exit-side deflection surfaces 22aa to 22ad and the four second exit-side deflection surfaces 22ba to 22bd are separated from each other.

  In the actual beam splitting element 2, the number of incident side deflection surfaces 21a and 21b provided side by side in the Z direction is more than four, and the incident side deflection surfaces 21a and 21b are two-dimensionally arranged as necessary. . Each deflection surface 21a, 21b, 22a, 22b is a planar refractive optical surface formed on the surface of a light-transmitting substrate. The light beam splitting element 2 is manufactured by subjecting the surface of a plane-parallel plate formed of an optical material such as quartz or fluorite to etching or polishing.

  In the light beam splitting element 2, light rays incident on the first incident region IR1 along the optical axis AX are three first incident side deflection surfaces 21aa, 21ab, 21ad and three first emission side deflection surfaces 22aa, 22ab, 22ad. And then exit from the first exit region ER1 of the light beam splitting element 2. However, the light beam incident on the first incident side deflection surface 21ac along the optical axis AX passes through the light beam splitting element 2 without being deflected by the first incident side deflection surface 21ac and the first emission side deflection surface 22ac. To do. As a result, the light beam having a rectangular solid cross section incident on the first incident region IR1 of the light beam splitting element 2 is emitted from the first emission region ER1 as a light beam having a rectangular solid cross section.

  Similarly, the light beam incident on the second incident region IR2 along the optical axis AX is deflected by the three second incident side deflection surfaces 21ba, 21bb, 21bd and the three second emission side deflection surfaces 22ba, 22bb, 22bd. Is emitted from the second emission region ER2 of the light beam splitting element 2. However, the light beam incident on the second incident side deflection surface 21bc along the optical axis AX passes through the light beam splitting element 2 without being deflected by the second incident side deflection surface 21bc and the second emission side deflection surface 22bc. To do. As a result, the light beam having a rectangular solid cross section incident on the second incident region IR2 of the light beam splitting element 2 is emitted from the second emission region ER2 as a light beam having a rectangular solid cross section.

  In the light beam splitting element 2, one of the first incident-side deflection surfaces 21 aa to 21 ad and another deflection surface are an optical path of the light beam passing through the one deflection surface and another deflection surface. The optical path of the light beam passing through the light beam splitting element 2 is configured to intersect inside the light beam splitting element 2. Similarly, one of the second incident-side deflection surfaces 21ba to 21bd and another deflection surface are the light path of the light beam through one deflection surface and the light beam through another deflection surface. Are configured to intersect with each other inside the light beam splitting element 2. This means that there is at least one set of two deflection surfaces such that the optical paths of the luminous flux intersect, and that the optical paths of the luminous flux intersect for two arbitrarily selected deflection surfaces. Not in.

  In the light beam splitting element 2, in order to intersect the optical path of the light beam through one deflection surface and the optical path of the light beam through another deflection surface, one deflection is made on the first incident side deflection surfaces 21aa to 21ad. The angle formed between the normal line of the surface and the optical axis AX is different from the angle formed between the normal line of another deflection surface and the optical axis AX. Similarly, in the second incident side deflection surfaces 21ba to 21bd, the angle formed between the normal line of one deflection surface and the optical axis AX and the angle formed between the normal line of another deflection surface and the optical axis AX are mutually different. Is different. This means that there is at least one set of two deflection surfaces in which the angle formed between the normal line of the deflection surface and the optical axis AX is different from each other, and the normal line for two arbitrarily selected deflection surfaces. It does not mean that the angles formed by the optical axis AX are different from each other.

  The light beam splitting element 2 is configured to divide a light beam incident along the + Y direction into two light beams and emit these two light beams along the + Y direction. In other words, the deflection angle at the first incident side deflection surfaces 21aa to 21ad and the deflection angle at the first emission side deflection surfaces 22aa to 22ad are the traveling direction (+ Y direction) of the light beam incident on the light beam splitting element 2. It is stipulated to maintain. The deflection angle at the second incident side deflection surfaces 21ba to 21bd and the deflection angle at the second emission side deflection surfaces 22ba to 22bd are determined so as to maintain the traveling direction of the light beam incident on the light beam splitting element 2. ing.

  In the light beam splitting element 2 of the present embodiment, the incident light beam is wavefront divided by the plurality of first incident side deflection surfaces 21a and the plurality of second incident side deflection surfaces 21b. At least a part of the plurality of light beams divided by the plurality of first incident-side deflecting surfaces 21a is deflected by the incident-side deflecting surface 21a and the corresponding exit-side deflecting surface 22a, and the incident position when viewed from the optical axis AX direction. Are ejected from different positions. At least some of the plurality of light beams divided by the plurality of second incident-side deflection surfaces 21b are deflected by the incident-side deflection surface 21b and the corresponding emission-side deflection surface 22b, and the incident position as viewed from the optical axis AX direction. Are ejected from different positions.

  As a result, in the light beam splitting element 2 of the present embodiment, the light intensity distribution of the emitted light beam can be smoothed and relatively uniform as an averaging effect by the wavefront splitting of the plurality of incident side deflection surfaces 21a and 21b. It is possible to guide a light beam having a light intensity distribution to the spatial light modulators 3a and 3b. This is because the light intensity distribution of the light beam incident on each mirror element SE of the spatial light modulators 3a and 3b is smoothed, and the spatial light modulators 3a and 3b stably perform a required function over a required period. It means you can do that.

  In particular, when the characteristics of the light intensity distribution of the incident light beam are known, the light intensity of the emitted light beam that has passed through the first emission region ER1 through the plurality of first incident side deflection surfaces 21a and the plurality of first emission side deflection surfaces 22a. The distribution can be matched so as to be smoothed as compared with the light intensity distribution of the incident light beam to the first incident region IR1. Similarly, the light intensity distribution of the emitted light beam that has passed through the second emission region ER2 through the plurality of second incident side deflection surfaces 21b and the plurality of second emission side deflection surfaces 22b is light of the incident light beam to the second incident region IR2. Corresponding to be smoothed compared to the intensity distribution.

  Further, in the light beam splitting element 2 of the present embodiment, the incident light beam and the second incident light on the first incident region IR1 are caused by the cooperative deflection action of the incident side deflection surfaces 21a and 21b and the emission side deflection surfaces 22a and 22b. The incident light flux on the region IR2 can be shifted along a predetermined direction when viewed from the optical axis AX direction, and can be emitted along two emission light paths spaced from each other. This means that one light beam emitted from the light beam splitting element 2 is not incident on a dead zone (an area where it is difficult to perform a required deflection function) at the apex angle portion of the first deflection member 3c. This means that the first light can be guided to the first spatial light modulator 3a through the effective reflection region of the first reflection surface 3ca, and the other light beam can be guided to the second spatial light modulator 3b through the effective reflection region of the second reflection surface 3cb. is doing.

  Further, by arranging the incident-side deflection surfaces 21a and 21b and the emission-side deflection surfaces 22a and 22b so as to be adjacent to each other when viewed from the optical axis AX direction, two light beams having a solid cross section incident on the light beam splitting element 2 can be obtained. It can be divided into two and emitted as two light beams having a solid cross section. In addition, the cooperative deflection action of the incident-side deflection surfaces 21a and 21b and the exit-side deflection surfaces 22a and 22b does not substantially increase the divergence angle of the incident light beam (while maintaining the divergence angle substantially). ) Can be injected. This is because the substantially parallel incident light beam having a relatively small divergence angle is divided into two, and the substantially parallel exit light beam having a relatively small divergence angle can be guided to the spatial light modulators 3a and 3b. This means that the control of 3a and 3b can be performed efficiently and easily.

  By the way, with a configuration that uses an ordinary microprism array, axicon system, diffuser plate, diffractive optical element, etc., to split the incident light beam and smooth the light intensity distribution, a split light beam with a solid cross section cannot be obtained or diverged. There is an inconvenience that it is difficult to suppress the increase in corners. Further, in the light beam splitting element 2 of the present embodiment, the first incident region IR1 and the second incident region IR2 do not overlap each other in the incident region IR, so that the deflection angles at the incident side deflection surfaces 21a and 21b are excessively increased. Even if it is not set large, the incident light beam can be divided into two light beams.

  As described above, in the illumination optical system (1 to 10) of the present embodiment that illuminates the mask M as the irradiated surface based on the light from the light source LS, the incident light beam from the light source LS is relatively simple and The light beam splitting element 2 having a compact configuration is split into two light beams. The divided light beams are guided to the pair of spatial light modulators 3a and 3b via the reflecting surfaces 3ca and 3cb of the first deflecting member 3c. As a result, the optical member disposed on the incident side and the optical member disposed on the exit side of the pair of spatial light modulators 3a and 3b are not increased in size, and consequently the illumination optical system (1-10) is large. Can be avoided.

  Further, since the illumination optical system (1 to 10) of the present embodiment includes the pair of spatial light modulators 3a and 3b, the mirror element SE of the mirror element SE is compared with the case where the spatial light modulator is used alone. The energy per unit area of light incident on the reflecting surface is reduced (for example, halved). As a result, in the spatial light modulators 3a and 3b, the reflectance of the mirror element SE is unlikely to decrease even when light irradiation is performed over a long period of time, and a required function can be stably exhibited over a required period. it can.

  That is, in the illumination optical systems (1 to 10) of the present embodiment, a pair of spatial light modulators 3a and 3b that stably exhibit a required function while ensuring a relatively simple and compact configuration are used. It is possible to stably realize a variety of illumination conditions with respect to the shape and size of the pupil intensity distribution. In the exposure apparatus (1 to WS) of this embodiment, the illumination optical system (1 to 10) that stably realizes a wide variety of illumination conditions is used to obtain the pattern characteristics of the mask M to be transferred. Good exposure can be performed under appropriate illumination conditions realized accordingly.

  In the above-described embodiment, the light beam splitting element 2 having the specific configuration shown in FIG. 6, that is, the light beam splitting element 2 having a plurality of deflection surfaces 21a, 21b, 22a, 22b formed as planar refractive optical surfaces. The present invention is described based on the above. However, the present invention is not limited to this, and various forms are possible for the specific configuration of the light beam splitting element. For example, there are various forms such as the number of each deflecting surface constituting the light beam splitting element, the arrangement of each deflecting surface, the form of each deflecting surface, the cross-sectional shape of the incident light beam, the number of split light beams, the cross-sectional shape of each exiting light beam, etc. Is possible.

  In the configuration of FIG. 6, most of the deflection surface is provided on the surface of the portion protruding outward. However, the present invention is not limited to this, and for example, as shown in FIG. 7, a modification in which at least a part of the plurality of deflection surfaces is provided on the surface of the recessed portion inside the substrate is possible. Similarly to the light beam splitting element 2 of the above-described embodiment, the light beam splitting element according to this modification is also subjected to etching processing, polishing processing, etc. on the surface of a plane parallel plate formed of an optical material such as quartz or fluorite. Manufactured by applying.

  6 and 7, each deflecting surface has a refractive optical surface formed on the surface of a light-transmitting substrate. However, the present invention is not limited to this. For example, as shown in FIG. 8, at least a part of a plurality of deflecting surfaces is attached to the surface of a light-transmitting substrate (for example, attached to the surface of a prism). Variations having a surface configuration are also possible.

  In the configurations of FIGS. 6 to 8, each deflecting surface has a refractive optical surface. However, the present invention is not limited to this, and a modification having a form of a diffractive optical surface in which at least a part of the plurality of deflection surfaces is formed on the surface of the light-transmitting substrate is also possible.

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

  In the above description, as the spatial light modulator having a plurality of optical elements that are two-dimensionally arranged and individually controlled, the direction (angle: inclination) of the plurality of two-dimensionally arranged reflecting surfaces is set. An individually 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 reflecting surfaces described above is disclosed in, for example, Japanese Patent Publication No. 2006-513a42 and US Pat. 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 description, a reflective spatial light modulator having a plurality of mirror elements is used. However, the present invention is not limited to this. For example, transmission disclosed in US Pat. No. 5,229,872 A type of spatial light modulator may be used.

  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, the present invention is applied to a light beam splitting element that guides a split light beam arranged in the optical path of the illumination optical system to a pair of spatial light modulators. However, the present invention is not limited to this. In general, the present invention can be applied to a light beam splitting element that splits an incident light beam into a plurality of light beams and emits the light beam.

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

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

  Next, a device manufacturing method using the exposure apparatus according to the above-described embodiment will be described. FIG. 9 is a flowchart showing a semiconductor device manufacturing process. As shown in FIG. 9, in the semiconductor device manufacturing process, a metal film is vapor-deposited on the wafer W to be a substrate of the semiconductor device (step S40), and a photoresist, which is a photosensitive material, is applied on the vapor-deposited metal film. (Step S42). Subsequently, using the 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. 10 is a flowchart showing a manufacturing process of a liquid crystal device such as a liquid crystal display element. As shown in FIG. 10, in the manufacturing process of the liquid crystal device, a pattern formation process (step S50), a color filter formation process (step S52), a cell assembly process (step S54), and a module assembly process (step S56) are sequentially performed. In the pattern forming process of step S50, a predetermined pattern such as a circuit pattern and an electrode pattern is formed on the glass substrate coated with a photoresist as the plate P using the 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 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 also be applied. Here, the teachings of US Patent Publication No. 2006/0170901 and US Patent Publication No. 2007/0146676 are incorporated by reference.

  In the above-described embodiment, the present invention is applied to 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.

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 typically 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 figure which shows schematically the structure of the light beam splitting element concerning this embodiment. It is a figure which shows schematically the principal part structure of the light beam splitting element concerning the 1st modification of this embodiment. It is a figure which shows schematically the structure of the light beam splitting element concerning the 2nd modification 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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Beam transmission part 2 Beam splitting element 3 Spatial light modulation unit 3a, 3b Spatial light modulator 3c, 3d Deflection member 4, 6 Relay optical system 7 Micro fly eye lens 8 Condenser optical system 9 Mask blind 10 Imaging optical system DT Pupil intensity distribution measurement unit LS Light source CR Control unit M Mask MS Mask stage PL Projection optical system W Wafer WS Wafer stage

Claims (22)

In a light beam splitting element that divides an incident light beam into a plurality of light beams and emits it,
A plurality of first incident-side deflection surfaces provided in a first incident area of the incident areas of the light flux to the light beam splitting element;
A plurality of second incident side deflection surfaces provided in a second incident region of the incident regions;
A plurality of first exit-side deflection surfaces provided corresponding to the plurality of first entrance-side deflection surfaces in a first exit region corresponding to the first entrance region in the exit region of the light flux from the beam splitting element; ,
A plurality of second exit-side deflection surfaces provided corresponding to the plurality of second entrance-side deflection surfaces in a second exit region corresponding to the second entrance region in the exit region;
One first incident side deflection surface and another one first incident side deflection surface of the plurality of first incident side deflection surfaces are an optical path of a light flux through the one first incident side deflection surface. The optical path of the light beam passing through the other first incident side deflection surface is configured to intersect inside the light beam splitting element, and one second of the plurality of second incident side deflection surfaces. The incident-side deflecting surface and another second incident-side deflecting surface include an optical path of a light beam passing through the one second incident-side deflecting surface and an optical path of a light beam passing through the other second incident-side deflecting surface. Is configured to intersect inside the light beam splitting element. The first emission light beam that has passed through the first emission region and the second emission light beam that has passed through the second emission region are emitted along a first emission light path and a second emission light path that are parallel to each other at an interval. The light beam splitting element according to claim 1. 3. The light beam splitting element according to claim 2, wherein the first emission light path and the second emission light path are parallel to an incident light path of a light beam to the light beam splitting element. 4. The light beam splitting element according to claim 1, wherein the incident parallel light beam is divided into a plurality of parallel light beams and emitted. The plurality of first incident-side deflection surfaces and the plurality of first emission-side deflection surfaces are such that the light intensity distribution of the first emitted light beam that has passed through the first emission region is the light intensity of the incident light beam to the first incident region. To be smoothed compared to the distribution,
The plurality of second incident side deflection surfaces and the plurality of second emission side deflection surfaces are such that the light intensity distribution of the second emitted light beam that has passed through the second emission region is the light intensity of the incident light beam to the second incident region. 5. The light beam splitting element according to claim 1, wherein the light beam splitting element is associated so as to be smoothed in comparison with the distribution. The deflection angles at the plurality of first incident-side deflection surfaces and the deflection angles at the plurality of first emission-side deflection surfaces are determined so as to maintain the traveling direction of the light beam incident on the light beam dividing element,
The deflection angles at the plurality of second incident side deflection surfaces and the deflection angles at the plurality of second emission side deflection surfaces are determined so as to maintain the traveling direction of the light beam incident on the light beam splitting element. The light beam splitting element according to claim 1, wherein: The light beam splitting element according to any one of claims 1 to 6, wherein the first incident region and the second incident region do not overlap each other in the incident region. The light beam splitting element according to claim 1, wherein at least one of the plurality of deflecting surfaces has a refractive optical surface. The refractive optical surface is a plane;
The angle formed between the normal line of the first incident-side deflection surface and the optical axis is different from the angle formed between the normal line of the other first incident-side deflection surface and the optical axis.
The angle formed between the normal line of the one second incident side deflection surface and the optical axis is different from the angle formed between the normal line of the other second incident side deflection surface and the optical axis. Item 9. A beam splitter according to Item 8. 10. The light beam splitting element according to claim 8, wherein the refractive optical surface is formed on a surface of a light transmissive substrate. 10. The light beam splitting element according to claim 8, wherein the refractive optical surface has an optical surface of a prism attached to a surface of a light transmissive substrate. The light beam splitting element according to claim 1, wherein at least one of the plurality of deflecting surfaces has a diffractive optical surface. 13. The light beam splitting element according to claim 12, wherein the diffractive optical surface is formed on a surface of a light transmissive substrate. In the illumination optical system that illuminates the illuminated surface based on the light from the light source,
An illumination optical system comprising the light beam splitting element according to any one of claims 1 to 13 disposed in an optical path between the light source and the irradiated surface. A first spatial light modulator having a plurality of optical elements that can be arranged in the optical path of the first emitted light beam that has passed through the first emission region and is two-dimensionally arranged and individually controlled;
A second spatial light modulator having a plurality of optical elements that can be arranged in the optical path of the second exit light flux that has passed through the second exit region and that is two-dimensionally arranged and individually controlled;
Distribution formation for forming a pupil intensity distribution in the illumination pupil of the illumination optical system based on at least one of the light flux through the first spatial light modulator and the light flux through the second spatial light modulator The illumination optical system according to claim 14, further comprising an optical system. A deflecting member that deflects at least one of the light beam that has passed through the first spatial light modulator and the light beam that has passed through the second spatial light modulator and guides it to the distribution forming optical system; The illumination optical system according to claim 15, which is characterized by: The spatial light modulator includes a plurality of mirror elements arranged two-dimensionally and a drive unit that individually controls and drives the postures of the plurality of mirror elements. Lighting optics. The illumination optical system according to claim 17, wherein the driving unit continuously or discretely changes directions of the plurality of mirror elements. 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 15 to 18. 20. An exposure apparatus comprising the illumination optical system according to any one of claims 14 to 19 for illuminating a predetermined pattern, and exposing the predetermined pattern onto a photosensitive substrate. 21. The exposure apparatus according to claim 20, further comprising a projection optical system that forms an image of the predetermined pattern on the photosensitive substrate. An exposure step of exposing the predetermined pattern to the photosensitive substrate using the exposure apparatus according to claim 20 or 21,
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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