JP5327715B2 - Illumination optical system, exposure apparatus, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination optical system forming a pupil intensity distribution in a highly continuous circumferentially polarized state. <P>SOLUTION: The illumination optical system (2-10) illuminating a face (M) to be illuminated with light from a light source (1) includes: a distribution-forming optical system (2-4) which forms a pupil intensity distribution in the illumination pupil of the distribution forming optical system based on light from the light source, and causes a plurality of light fluxes having polarized states different from one another to enter each of a plurality of pupil regions of the pupil intensity distribution; and a first optical element (5) disposed at or near the illumination pupil and having a plurality of divided regions corresponding to the plurality of pupil regions. Two adjoining divided regions out of the plurality of divided regions have polarization conversion characteristics different from each other. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to 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 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 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.

  In recent years, in order to realize an illumination condition suitable for faithfully transferring a fine pattern in an arbitrary direction, an annular secondary light source is formed on the rear focal plane of the fly-eye lens or in the vicinity of the illumination pupil. A technique has been proposed in which a light beam passing through a ring-shaped secondary light source is set so as to be in a linear polarization state whose polarization direction is the circumferential direction (hereinafter referred to as “circumferential polarization state” for short) (for example, (See Patent Document 1).

Japanese Patent No. 3246615

  In the illumination optical system described in Patent Document 1, the circumferential direction of so-called relatively low continuity is set by setting the polarization state of a light beam passing through each of the arc-shaped divided regions divided into four to eight in the circumferential direction. A polarization state is realized. However, in order to satisfactorily exert the effect of circumferential polarization, it is desired to realize a circumferential polarization state with high continuity based on, for example, a division finer than eight divisions.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an illumination optical system capable of forming a pupil intensity distribution in a circumferential polarization state with high continuity. In addition, the present invention can accurately transfer a fine pattern to a photosensitive substrate under appropriate illumination conditions using an illumination optical system that forms a pupil intensity distribution with a highly continuous circumferential polarization state. An object of the present invention is to provide an exposure apparatus and a device manufacturing method.

In order to solve the above problems, in the first embodiment of the present invention, in the illumination optical system that illuminates the illuminated surface with light from the light source,
Forming a pupil intensity distribution on the illumination pupil of the illumination optical system based on the light from the light source, and forming a distribution in which a plurality of light beams having different polarization states are incident on each of the plurality of pupil regions of the pupil intensity distribution Optical system,
The illumination pupil has a plurality of divided regions corresponding to the plurality of pupil regions, and two adjacent divided regions of the plurality of divided regions have different polarization conversion characteristics. There is provided an illumination optical system characterized by comprising one optical element.

In the second embodiment of the present invention, in the illumination optical system that illuminates the illuminated surface with the light from the light source,
A first polarization conversion member that divides the light from the light source into a plurality of light beams having different polarization states;
A second polarization conversion member comprising a plurality of divided regions in which two adjacent divided regions have different polarization conversion characteristics;
An illumination optical system, wherein the plurality of light beams having different polarization states from the first polarization conversion member are guided to one of the plurality of divided regions of the second polarization conversion member. To do.

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

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

  In the illumination optical system according to one aspect of the present invention, the distribution forming optical system that forms an annular pupil intensity distribution in the illumination pupil based on the light from the light source converts the incident light beam into four light beams having different polarization states. A first polarization conversion member having four optical rotation members for making the four light beams incident on each of the eight pupil regions of the annular pupil intensity distribution. The second polarization conversion member arranged at or near the illumination pupil has eight optical rotation members corresponding to the eight pupil regions, and the two adjacent optical rotation members have different polarization conversion characteristics.

  As a result, a pair consisting of 32 combinations of one optical rotation member of the four optical rotation members in the first polarization conversion member and one optical rotation member of the eight optical rotation members in the second polarization conversion member. As a result of the combined optical rotation of the optical rotatory member, an annular light intensity distribution is formed in the illumination pupil immediately after the second polarization conversion member in a substantially continuous circumferential polarization state of the 32-split type. That is, in the illumination optical system according to the present invention, a highly continuous pupil intensity distribution in the circumferential polarization state can be formed. In the exposure apparatus of the present invention, a fine pattern is accurately transferred to a photosensitive substrate under appropriate illumination conditions using an illumination optical system that forms a pupil intensity distribution having a highly continuous circumferential polarization state. And thus good devices can be manufactured.

It is a figure which shows schematically the structure of the exposure apparatus concerning embodiment of this invention. It is a figure which shows schematically the internal structure of the spatial light modulation unit of FIG. It is a figure which shows schematically the structure of the 1st polarization conversion member 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 structure of the 2nd polarization conversion member of FIG. 1, and the annular | circular shaped light intensity distribution formed in the entrance plane. It is a figure which shows annular | circular shaped light intensity distribution in the substantially continuous circumferential direction polarization | polarized-light state formed in the illumination pupil immediately after a 2nd polarization conversion member. It is a figure which shows an annular | circular shaped light intensity distribution in the substantially continuous radial direction polarization | polarized-light state formed in the illumination pupil immediately after a 2nd polarization conversion member. It is a figure which shows schematically the internal structure of the spatial light modulation unit containing the 1st polarization conversion member concerning a modification. 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 along the normal direction of the transfer surface (exposure surface) of the wafer W, which is a photosensitive substrate, and the Y axis in the direction parallel to the paper surface of FIG. In the W 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. Each of the spatial light modulators 31 and 32 has a plurality of mirror elements that are two-dimensionally arranged and individually controlled. A first polarization conversion member 33 is disposed on the most light source side in the optical path on the light source side (left side in FIG. 2) with respect to the pair of spatial light modulators 31 and 32. A deflection member 34 is disposed in the optical path between the first polarization conversion member 33 and the pair of spatial light modulators 31 and 32. A deflection member 35 is disposed in the optical path between the pair of spatial light modulators 31 and 32 and the relay optical system 4.

  As will be described later, the first polarization conversion member 33 converts (divides) the light beam from the light source 1 into four light beams having different polarization states. The deflection member 34 guides the first light beam and the second light beam to the first spatial light modulator 31 among the four light beams generated through the first polarization conversion member 33, and converts the third light beam and the fourth light beam to the second light beam. Guide to the spatial light modulator 32. The deflecting member 35 guides the light that has passed through the pair of 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.

  The light emitted from the spatial light modulation unit 3 enters the second polarization conversion member 5 through the relay optical system 4. The second polarization conversion member 5 includes eight divided regions in which two adjacent divided regions have different polarization conversion characteristics, and the configuration and operation thereof will be described later. The relay optical system 4 has its front focal position substantially coincident with the position of the array surface of the plurality of mirror elements of each of the spatial light modulators 31 and 32 and its rear focal position substantially coincides with the position of the second polarization conversion member 5. It is set to be. As will be described later, the light that has passed through the spatial light modulators 31 and 32 variably forms a light intensity distribution corresponding to the postures of the plurality of mirror elements at the position of the second polarization conversion member 5.

  The light having the light intensity distribution formed at the position of the second polarization conversion member 5 enters the micro fly's eye lens (or fly eye lens) 7 through the relay optical system 6. The relay optical system 6 optically conjugates the position of the second polarization conversion member 5 and the incident surface of the micro fly's eye lens 7. Therefore, the light passing through the spatial light modulation unit 3 forms a light intensity distribution having the same outer shape as the light intensity distribution formed at the position of the second polarization conversion member 5 on the incident surface of the micro fly's eye lens 7.

  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 controller CR that controls the spatial light modulators 31 and 32 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 incident surface of the micro fly's eye lens 7 and a position optically conjugate with the incident surface, that is, the light intensity distribution immediately after the second polarization conversion member 5 can also be referred to as a pupil intensity distribution. In the configuration of FIG. 1, the beam transmission unit 2, the spatial light modulation unit 3, and the relay optical system 4 form a pupil intensity distribution on the illumination pupil immediately after the second polarization conversion member 5 based on the light from the light source 1. The distribution forming optical system is configured.

  Next, the internal configuration and operation of the spatial light modulation unit 3 will be specifically described. As shown in FIG. 3, the first polarization conversion member 33 has four parallel plane plate-shaped optical rotation members 33a, 33b, 33c, and 33d having different thicknesses. Each of the optical rotation members 33a to 33d is formed of a crystal material that is an optical material having optical activity, for example, quartz. In a state where the first polarization conversion member 33 is positioned in the optical path, the incident surfaces (and thus the exit surfaces) of the optical rotation members 33a to 33d are orthogonal to the optical axis AX, and the crystal optical axis is in the direction of the optical axis AX. Almost coincident (that is, almost coincident with the Y direction as the traveling direction of the incident light).

  The four optical rotation members 33a to 33d are divided so that the four light beams F11, F12, F13, and F14 obtained by dividing the incident light beam F10 from the light source 1 into four equal parts by the line segment extending in the X direction pass through. Yes. The first optical rotation member 33a through which the first light flux F11 passes is +11.25 degrees in the Z direction (that is, 11.1 in the counterclockwise direction in FIG. 3) when Z direction linearly polarized light having a polarization direction in the Z direction is incident. The thickness is set so that linearly polarized light having a polarization direction in the rotated direction is emitted. The second optical rotation member 33b through which the second light beam F12 passes is configured to emit linearly polarized light having a polarization direction in a direction rotated by +22.5 degrees in the Z direction when the Z direction linearly polarized light is incident. The thickness is set.

  The third optical rotation member 33c through which the third light flux F13 passes is a direction obtained by rotating the Z direction by −11.25 degrees (that is, 11.25 degrees clockwise in FIG. 3) when the light of the Z direction linearly polarized light is incident. The thickness is set so as to emit linearly polarized light having a polarization direction. The fourth optical rotation member 33d through which the fourth light flux F14 passes is the Z direction without changing the polarization direction (that is, by rotating the polarization direction by 0 degree or +180 degrees) when the light of the Z direction linearly polarized light enters. The thickness is set so as to emit linearly polarized light. As described above, the first polarization conversion member 33 divides the incident light beam F10 from the light source 1 into four equal parts, and sets the four equalized light beams F11 to F14 to different polarization states. In the following description, it is assumed that Z-direction linearly polarized light is incident on the first polarization conversion member 33.

  The deflecting members 34 and 35 have, for example, the form of a triangular prism prism mirror extending in the X direction. The deflecting member 34 has a pair of reflecting surfaces 34a and 34b facing the light source, and the ridge line between the reflecting surfaces 34a and 34b extends in the X direction through the optical axis AX. The deflecting member 35 has a pair of reflecting surfaces 35a and 35b facing the mask, and the ridge line between the reflecting surfaces 35a and 35b extends in the X direction through the optical axis AX. The deflecting members 34 and 35 are 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 or an optical material such as quartz. You can also Alternatively, the deflection members 34 and 35 can be formed as mirrors, respectively.

  The Z-direction linearly polarized light beam incident on the spatial light modulation unit 3 along the optical axis AX is converted into four light beams F11 to F14 having different polarization states via the first polarization conversion member 33, and then deflected. Incident on the member 34. The first light beam F11 and the second light beam F12 reflected by the first reflecting surface 34a of the deflecting member 34 enter the first spatial light modulator 31, and the third light beam F13 and the fourth light beam reflected by the second reflecting surface 34b. The light beam F <b> 14 enters the second spatial light modulator 32. The light modulated by the first spatial light modulator 31 is reflected by the first reflecting surface 35 a of the deflecting member 35 and guided to the relay optical system 4. The light modulated by the second spatial light modulator 32 is reflected by the second reflecting surface 35 b of the deflecting member 35 and guided to the relay optical system 4.

  Hereinafter, in order to simplify the description, the pair of spatial light modulators 31 and 32 have the same configuration, and the array surface of the plurality of mirror elements of the first spatial light modulator 31 and the second spatial light modulator. It is assumed that the arrangement surface of the plurality of 32 mirror elements is arranged symmetrically with respect to a plane including the optical axis AX and parallel to the XY plane. That is, each of the spatial light modulators 31 and 32 is arranged such that the array surface of the plurality of mirror elements is parallel to the optical axis AX. Further, the first reflecting surface 34a and the second reflecting surface 34b of the deflecting member 34, and the first reflecting surface 35a and the second reflecting surface 35b of the deflecting member 35 are related to surfaces parallel to the XY plane including the optical axis AX. Assume that they are arranged symmetrically.

  Therefore, the description which overlaps with the 1st spatial light modulator 31 about the 2nd spatial light modulator 32 is abbreviate | omitted, paying attention to the 1st spatial light modulator 31, and a pair of spatial light modulator 31 in the spatial light modulation unit 3 , 32 will be described. As shown in FIG. 4, the spatial light modulator 31 is connected to a plurality of mirror elements 31a arranged two-dimensionally along the XY plane, a base 31b holding the plurality of mirror elements 31a, and a 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).

  As shown in FIG. 5, 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. 4 and 5 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).

  Referring to FIG. 4, a group of rays (that are incident on the first reflecting surface 34 a of the deflecting member 34 (not shown in FIG. 4) along the direction parallel to the optical axis AX and reflected toward the spatial light modulator 31 ( (Corresponding to the first light flux F11 and the second light flux F12), 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 a reference state in which the reflecting surfaces of all the mirror elements 31a are set along one plane (XY plane), the light beam incident on the reflecting surface 34a along the direction parallel to the optical axis AX. Is reflected by the first reflecting surface 35a of the deflecting member 35 (not shown in FIG. 4) in a direction substantially parallel to the optical axis AX after being reflected by the spatial light modulator 31. . 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 is incident on the incident surface 5a of the second polarization conversion member 5 (and thus immediately after the second polarization conversion member 5). Predetermined light intensity distributions SP1 to SP4 are formed on the illumination pupil 5b), and light intensity distributions corresponding to the light intensity distributions SP1 to SP4 are formed on the incident surface of the micro fly's eye lens 7. That is, the relay optical system 4 uses the second polarization conversion that is the far field region (Fraunhofer diffraction region) of the spatial light modulator 31 to change the angle that the plurality of mirror elements SEa to SEd of the spatial light modulator 31 gives to the emitted light. The position of the member 5 is converted.

  Similarly, the light modulated by the second spatial light modulator 32 (corresponding to the third light beam F13 and the fourth light beam F14) is subjected to the second polarization conversion with the light intensity distribution corresponding to the posture of the plurality of mirror elements 32a. It is formed on the incident surface 5a (and the illumination pupil 5b immediately after) of the member 5, and eventually on the incident surface of the micro fly's eye lens 7. Thus, 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 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 second spatial light modulator 32 and the relay optical systems 4 and 6. .

  As shown in FIG. 5, 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 the 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 discretely, a rotation angle is a several state (For example, ..., -2.5 degree, -2.0 degree, ... 0 degree, +0. It is better to perform switching control at 5 degrees... +2.5 degrees,. Although FIG. 5 shows a mirror element 31a having a square outer shape, the outer shape of the mirror element 31a 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 31a is reduced (a shape that can be closely packed). Further, from the viewpoint of light utilization efficiency, the interval between two adjacent mirror elements 31a can be minimized.

  In the present embodiment, as the spatial light modulator 31, for example, a spatial light modulator that continuously changes the directions of a plurality of mirror elements 31a 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 arranged two-dimensionally may be controlled so as to have a plurality of discrete stages.

  In the spatial light modulators 31 and 32, the postures of the plurality of mirror elements 31a and 32a are changed by the action of the drive units 31c and 32c (32c is not shown) that operate according to the control signal from the control unit CR. Each mirror element 31a, 32a is set in a predetermined direction. As shown in FIG. 6, the light reflected by the plurality of mirror elements 31a and 32a of the spatial light modulators 31 and 32, respectively, on the incident surface 5a of the second polarization conversion member 5, for example, the optical axis AX. An annular light intensity distribution (hatched portion in FIG. 6) 20 is formed.

  As shown in FIG. 6, the second polarization conversion member 5 includes eight parallel plane plate-shaped optical rotation members 51, 52, 53, 54, 55 arranged along the circumferential direction of a circle centered on the optical axis AX. , 56, 57, 58. Each of the optical rotation members 51 to 58 is formed of a crystal material that is an optical material having optical activity, for example, quartz. In a state where the second polarization conversion member 5 is positioned in the optical path, the incident surface (and thus the exit surface) of each of the optical rotation members 51 to 58 is orthogonal to the optical axis AX, and its crystal optical axis is in the direction of the optical axis AX. Almost coincident (that is, almost coincident with the Y direction as the traveling direction of the incident light).

  The eight optical rotation members 51 to 58 constituting the second polarization conversion member 5 occupy eight divided regions obtained by dividing an annular region around the optical axis AX into eight equal parts along the circumferential direction. . In other words, the eight optical rotation members 51 to 58 are divided so that eight arc-shaped light beams obtained by dividing the incident ring-shaped light beam 20 into eight equal parts along the circumferential direction respectively pass. Of the eight optical rotation members 51 to 58, a pair of optical rotation members facing each other across the optical axis AX have the same thickness and thus the same polarization conversion characteristics. Or although a pair of optical rotation member which opposes on both sides of optical axis AX has a mutually different thickness, it has the mutually same polarization conversion characteristic.

  Specifically, the pair of optical rotation members 51 and 55 is configured such that when Z-direction linearly polarized light is incident thereon, the polarization direction is not changed (that is, the polarization direction is rotated by 0 degrees or 180 degrees). The thickness is set so as to emit polarized light. The pair of optical rotation members 52 and 56, when the light of the Z-direction linearly polarized light is incident, changes the polarization direction in the direction rotated by +45 degrees (or -135 degrees, that is, 45 degrees counterclockwise in FIG. 6). The thickness is set so as to emit linearly polarized light.

  The pair of optical rotation members 53 and 57 are thick so as to emit linearly polarized light having a polarization direction in a direction obtained by rotating the Z direction by +90 degrees (or -90 degrees) when Z direction linearly polarized light is incident. Is set. The pair of optical rotation members 54 and 58 has a polarization direction in a direction obtained by rotating the Z direction by −45 degrees (or +135 degrees, that is, 45 degrees clockwise in FIG. 6) when light of Z-direction linearly polarized light is incident. The thickness is set so as to emit linearly polarized light. Thus, the 2nd polarization conversion member 5 arrange | positioned in the illumination pupil or its vicinity has the optical rotation members (split area | regions) 51-58 corresponding to eight pupil areas, These eight optical rotation members 51-58. Of the two adjacent optical rotatory members have different polarization conversion characteristics.

  In the present embodiment, four light beams F11 to F14 having different polarization states from the first polarization conversion member 33 are guided to the eight optical rotation members 51 to 58 constituting the second polarization conversion member 5, respectively. Specifically, paying attention to the incident light beam on the optical rotation member 51, the four light beams F11 to F14 are arranged in the order of the light beams F12, F11, F14, and F13 in the clockwise direction in FIG. To do. Here, the region occupied by each of the light beams F11 to F14 corresponds to a region obtained by dividing an arc-shaped light beam region into four equal parts in the circumferential direction. Although not shown, the arrangement of the four light beams F11 to F14 is the same as that of the optical rotation member 51 for the other optical rotation members 52 to 58.

  In other words, in the present embodiment, the light flux F12 generated through the optical rotation member 33b of the first polarization conversion member 33 is modulated by the first spatial light modulator 31, and then becomes eight light fluxes F12 to become the optical rotation members 51 to 51. One light is incident on the light 58, and an octupole-shaped light intensity distribution is formed on the light incident surface 5a of the second polarization conversion member 5. The light flux F11 generated through the optical rotation member 33a of the first polarization conversion member 33 is modulated by the first spatial light modulator 31, and then becomes eight light fluxes F11 to enter the optical rotation members 51 to 58 one by one. Then, an octupole-shaped light intensity distribution is formed on the incident surface 5a of the second polarization conversion member 5. The octupole light intensity distribution formed by the light flux F11 is adjacent to the octupole light intensity distribution formed by the light flux F12 along the clockwise circumferential direction in FIG.

  Similarly, the light fluxes F13 and F14 generated through the optical rotation members 33c and 33d of the first polarization conversion member 33 are modulated by the second spatial light modulator 32, and then become eight light fluxes F13 and F14. One incident light is incident on each of the light beams 51 to 58, and an octupole-shaped light intensity distribution is formed on the incident surface 5 a of the second polarization conversion member 5. The octupole light intensity distribution formed by the light flux F14 is adjacent to the octupole light intensity distribution formed by the light flux F11 along the clockwise circumferential direction in FIG. The light intensity distribution is adjacent to the octupole-shaped light intensity distribution formed by the light beam F14 along the clockwise circumferential direction in FIG.

  As a result, an annular light intensity distribution 21 centered on the optical axis AX is formed on the illumination pupil immediately after the second polarization conversion member 5, as shown in FIG. A highly continuous circumferential polarization state is realized in which the polarization state of the light beam passing through each divided region equally divided into 32 (= 4 × 8) in the circumferential direction is set in the circumferential direction. However, in FIG. 7, for the sake of clarity of the drawing, each divided region divided into 32 equal parts is not illustrated and is divided into eight equal parts corresponding to the eight optical rotation members 51 to 58 of the second polarization conversion member 5. Only the boundary lines of the arc-shaped divided areas are indicated by broken lines.

  Here, focusing on the arc-shaped light beam 21a that has passed through the optical rotation member 51 of the second polarization conversion member 5, the light beam portion corresponding to the light beam F12 generated through the optical rotation member 33b of the first polarization conversion member 33 is the Z direction. Is linearly polarized light having a polarization direction in a direction rotated +22.5 degrees (22.5 degrees counterclockwise in FIG. 7). Here, the combined rotation angle of the optical rotation members 51 and 33b, +22.5 degrees, is the sum of 0 degree, which is the rotation angle of the optical rotation member 51, and +22.5 degrees, which is the rotation angle of the optical rotation member 33b. Don't be.

  Similarly, a light beam portion corresponding to the light beam F11 generated through the optical rotation member 33a becomes linearly polarized light having a polarization direction in a direction rotated by +11.25 degrees (= 0 + 11.25) in the Z direction, and the optical rotation member 33d is changed. The portion of the light beam corresponding to the light beam F14 generated through the rotation becomes linearly polarized light having a polarization direction in the direction rotated by 0 degrees (= 0 + 0) in the Z direction (that is, Z direction linearly polarized light), and is generated through the optical rotation member 33c. The light beam portion corresponding to the light beam F13 becomes linearly polarized light having a polarization direction in a direction rotated by −11.25 degrees (= 0-11.25: 11.25 degrees clockwise in FIG. 7) in the Z direction.

  Focusing on the arc-shaped light beam 21b having passed through the optical rotation member 52 of the second polarization conversion member 5, the light beam portion corresponding to the light beam F12 generated through the optical rotation member 33b of the first polarization conversion member 33 has a Z direction. It becomes linearly polarized light having a polarization direction in a direction rotated by +67.5 degrees. Here, the combined rotation angle of the optical rotation members 52 and 33b, +67.5 degrees, is obtained as the sum of +45 degrees, which is the rotation angle of the optical rotation member 52, and +22.5 degrees, which is the rotation angle of the optical rotation member 33b. It is done.

  Similarly, the light beam portion corresponding to the light beam F11 generated through the optical rotation member 33a becomes linearly polarized light having a polarization direction in the direction obtained by rotating the Z direction by +56.25 degrees (= + 45 + 11.25), and the optical rotation member 33d A light beam portion corresponding to the light beam F14 generated through the optical rotation member 33c becomes linearly polarized light having a polarization direction in the direction rotated by +45 degrees (= + 45 + 0) in the Z direction, and the light beam portion corresponding to the light beam F13 generated through the optical rotation member 33c. Becomes linearly polarized light having a polarization direction in a direction obtained by rotating the Z direction by +33.75 degrees (= + 45-11.25).

  Further, focusing on the arc-shaped light beam 21h that has passed through the optical rotation member 58 of the second polarization conversion member 5, the light beam portion corresponding to the light beam F12 generated through the optical rotation member 33b of the first polarization conversion member 33 has a Z direction. It becomes linearly polarized light having a polarization direction in a direction rotated by −22.5 degrees. Here, the combined optical rotation angle of the optical rotation members 58 and 33b, −22.5 degrees, is the sum of −45 degrees, which is the optical rotation angle of the optical rotation member 58, and +22.5 degrees, which is the optical rotation angle of the optical rotation member 33b. As obtained.

  Similarly, a light beam portion corresponding to the light beam F11 generated through the optical rotation member 33a becomes linearly polarized light having a polarization direction in a direction obtained by rotating the Z direction by −33.75 degrees (= −45 + 11.25). The light beam portion corresponding to the light beam F14 generated through 33d becomes linearly polarized light having the polarization direction in the direction rotated by −45 degrees (= −45 + 0) in the Z direction, and becomes the light beam F13 generated through the optical rotation member 33c. The corresponding light beam portion becomes linearly polarized light having a polarization direction in a direction obtained by rotating the Z direction by −56.25 degrees (= −45−11.25).

  Thus, the description of the arc-shaped light beams 21c to 21g that have passed through the other optical rotatory members 53 to 57 is omitted, but the illumination pupil immediately after the second polarization conversion member 5 has a high continuity of the 32 equal type. An annular light intensity distribution 21 is formed in the direction polarization state. In the circumferential polarization state, the light beam passing through the annular light intensity distribution 21 becomes a linear polarization state having a polarization direction in a tangential direction of a circle with the optical axis AX as the center. As a result, an annular light intensity distribution is formed in the illumination pupil immediately after the micro fly's eye lens 7 in a substantially continuous circumferential polarization state corresponding to the annular light intensity distribution 21. 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). ), An annular light intensity distribution is formed in a substantially continuous circumferential polarization state corresponding to the annular light intensity distribution 21.

  In general, in the circumferential polarization illumination based on the annular intensity distribution in the circumferential polarization state or a multipolar (bipolar, quadrupole, octupole, etc.) pupil intensity distribution, the wafer W as the final irradiated surface is formed. The irradiated light becomes a polarization state mainly composed of S-polarized light. Here, the S-polarized light is linearly polarized light having a polarization direction in a direction perpendicular to the incident surface (polarized light having an electric vector oscillating in a direction perpendicular to the incident surface). However, the incident surface is defined as a surface including the normal of the boundary surface at that point and the incident direction of light when the light reaches the boundary surface of the medium (surface to be irradiated: the surface of the wafer W). The As a result, in the circumferential polarization illumination, the optical performance (such as depth of focus) of the projection optical system can be improved, and a mask pattern image with high contrast can be obtained on the wafer (photosensitive substrate).

  In the illumination optical systems (2 to 10) of this embodiment, the distribution forming optical systems (2 to 4) that form an annular pupil intensity distribution based on the light from the light source 1 change the incident light flux F10 into different polarization states. The first polarization conversion member 33 having four optical rotation members 33a to 33d for converting the four light fluxes F11 to F14 into eight arc-shaped pupil intensity distributions of these four light fluxes F11 to F14. Are incident on each of the pupil regions. The second polarization conversion member 5 arranged at or near the illumination pupil has eight optical rotation members (divided regions) 51 to 58 corresponding to eight arcuate pupil regions, and the two adjacent optical rotation members are Different polarization conversion characteristics.

  Thus, one optical rotation member among the four optical rotation members 33 a to 33 d in the first polarization conversion member 33 and one optical rotation member among the eight optical rotation members 51 to 58 in the second polarization conversion member 5. The illumination pupil immediately after the second polarization conversion member 5 has a substantially continuous circumferential polarization state of 32 equally-divided type (generally 32 split type) by the combined optical rotation action of a pair of optical rotation members composed of 32 combinations. An annular light intensity distribution 21 is formed. That is, in the illumination optical system (2 to 10) of the present embodiment, the pupil intensity distribution 21 in the circumferential polarization state with high continuity can be formed. Further, in the exposure apparatus (2 to WS) of the present embodiment, the pattern of the mask M to be transferred using the illumination optical system (2 to 10) that forms the pupil intensity distribution 21 in the circumferential polarization state with high continuity. The fine pattern can be accurately transferred onto the wafer W by exerting the effect of circumferentially polarized light satisfactorily under appropriate illumination conditions realized in accordance with the above characteristics.

  By the way, using a single polarization conversion member having a configuration like the second polarization conversion member 5, the annular light intensity distribution 21 is formed in a substantially continuous circumferential polarization state of a 32-split type. It is necessary to arrange 32 optical rotators having slightly different polarization conversion characteristics between the two optical rotators in the circumferential direction. However, it is much more difficult to manufacture the 32 split type polarization conversion member than to manufacture the 8 split type second polarization conversion member 5. As described above, this embodiment is advantageous in that the polarization conversion member is relatively easy to manufacture even though the number of circumferentially polarized states is relatively large.

  In the above-described embodiment, the Z-direction linearly polarized light is incident on the first polarization conversion member 33. However, when the X-direction linearly polarized light is incident on the first polarization conversion member 33, FIG. As described above, an annular light intensity distribution 22 (22a to 22h) is formed in the illumination pupil immediately after the second polarization conversion member 5 in a radially-polarized state with a high continuity of 32 equal types. In the radial polarization state, the light beam passing through the annular light intensity distribution 22 is in a linear polarization state having a polarization direction in the radial direction of the circle with the optical axis AX as the center.

  In general, in radial polarization illumination based on an annular or multipolar pupil intensity distribution in the radial polarization state, the light irradiated on the wafer W as the final irradiated surface is a polarization state in which P-polarized light is the main component. become. Here, the P-polarized light is linearly polarized light having a polarization direction in a direction parallel to the incident surface defined as described above (polarized light whose electric vector is oscillating in a direction parallel to the incident surface). is there. As a result, in the radial polarization illumination, a good mask pattern image can be obtained on the wafer (photosensitive substrate) while suppressing the reflectance of light in the resist applied to the wafer W to be small.

  In the above-described embodiment, the present invention is described based on the spatial light modulation unit 3 having the specific configuration shown in FIG. 2, but various configurations are possible for the configuration of the spatial light modulation unit. Specifically, in the above-described embodiment, a pair of reflective spatial light modulators 31 and 32 arranged in parallel in the optical path is used as a spatial light modulation element that emits by applying spatial modulation to incident light, A first polarization conversion member 33 is disposed on the light source side. However, the present invention is not limited to this, and various forms are possible with respect to the type and number of spatial light modulation elements, the positional relationship between the spatial light modulation elements and the first polarization conversion member, and the like.

  For example, as a spatial light modulator, a transmissive spatial light modulator having a plurality of transmissive optical elements that are two-dimensionally arranged and individually controlled, a transmissive diffractive optical element, a reflective diffractive optical element, etc. Can be used. In general, when a reflective spatial light modulator or a reflective diffractive optical element is used as the spatial light modulation element, it is more mechanical between the optical members to dispose the first polarization conversion member on the incident side than on the emission side. Interference can be easily avoided. Further, when a transmissive diffractive optical element or a transmissive spatial light modulator is used as the spatial light modulator, the optical members may be arranged with each other regardless of whether the first polarization conversion member is disposed on the incident side or the exit side. The mechanical interference can be easily avoided.

  Moreover, in the above-mentioned embodiment, although the 1st polarization conversion member 33 is comprised by four parallel plane plate-like optical rotation members 33a-33d, various forms are possible about the structure of a 1st polarization conversion member. . For example, as shown in FIG. 9, instead of the first polarization conversion member 33, a first polarization conversion member 36 having a form in which the thickness continuously changes along a predetermined direction can be used. The first polarization conversion member 36 according to the modification of FIG. 9 is formed of a crystal material that is an optical material having optical activity, for example, quartz, and is a declination prism whose thickness varies linearly along the Z direction. It has a form. On the exit side (or incident side) of the first polarization conversion member 36, a correction member 37 is disposed as a compensator that compensates for the light deflection action (change in the light traveling direction) by the first polarization conversion member 36. .

  As an example, the correction member 37 is a declination prism formed of quartz that is the same optical material as the first polarization conversion member 36 and having a shape complementary to the first polarization conversion member 36. Further, the correction member 37 is arranged so that the crystal optical axis is parallel or perpendicular to the polarization direction of the incident light so as not to change the polarization state of the light passing therethrough. In the modification of FIG. 9, the light beam incident on the spatial light modulators 31 and 32 through the first polarization conversion member 36 includes a linearly polarized light component whose polarization direction continuously changes over a predetermined range. Therefore, the light beam containing linearly polarized light whose polarization direction continuously changes over a required range to each of the optical rotation members 51 to 58 of the second polarization conversion member 5 by the modulation action of the spatial light modulators 31 and 32. Incident.

  Specifically, the optical rotation member 51 is rotated from the direction in which the Z direction is rotated by −16.875 degrees (= (− 11.25-22.5) / 2: 16.875 degrees clockwise in FIG. 7). Includes linearly polarized light whose polarization direction continuously changes to the direction rotated in the Z direction by +28.125 degrees (= (+ 22.5 + 33.75) / 2: 28.125 degrees counterclockwise in FIG. 7) A light beam enters. As a result, in the modification of FIG. 9, a ring-shaped light intensity distribution is formed in a circumferential polarization state that is more continuous than in the above-described embodiment. In the modification of FIG. 9, the correction member 37 can be omitted, and at least one of the deflection members 34 and 35 can be used as a compensator to compensate the light deflection action by the first polarization conversion member 36.

  In the embodiment of FIG. 2 and the modification of FIG. 9, a light beam moving unit (not shown) that emits a light beam incident from the light source 1 in parallel with the Z direction is emitted or emitted from the first polarization conversion members 33 and 36. By attaching to the side, the light incident from the light source 1 can be selectively guided to at least one of the pair of spatial light modulators 31 and 32. The light flux moving unit is configured by using a parallel plane plate (harving) that can be inclined with respect to the optical axis, a pair of mirrors, and the like.

  In the above-described embodiment, the first polarization conversion member 33 is constituted by four rectangular optical rotation members 33a to 33d. However, the present invention is not limited to this, and various forms are possible for the type, shape, number, etc. of the basic elements constituting the first polarization conversion member. In general, a first polarization conversion member is configured using a plurality of wave plates that change incident light into light of a predetermined polarization state, or a plurality of polarizers that select and emit light of a predetermined polarization state from incident light It is possible to constitute the first polarization conversion member using Note that when the first polarization conversion member is configured using a plurality of polarizers, for example, light in a non-polarized state is incident.

  Moreover, in the above-mentioned embodiment, the 2nd polarization conversion member 5 has the annular | circular shaped external shape as a whole, and is comprised by the eight circular arc-shaped optical rotation members 51-58. However, the present invention is not limited to this, and various forms are possible for the overall outer shape of the second polarization conversion member, the type, shape, number, etc. of the basic elements constituting the second polarization conversion member. For example, the second polarization conversion member having a circular outer shape as a whole can be constituted by a plurality of fan-shaped optical rotation members. In addition, the second polarization conversion member can be configured using a plurality of wave plates that change incident light into light having a predetermined polarization state.

  In general, in the present invention, the first polarization conversion member divides the light from the light source into a plurality of light beams having different polarization states, and the second polarization conversion member has two adjacent divided regions having different polarization conversion characteristics. A plurality of divided areas are provided. A plurality of light beams having different polarization states from the first polarization conversion member are guided to one of the plurality of divided regions of the second polarization conversion member. Here, the number and polarization state of light beams (corresponding to the light beams F11 to F14) obtained through the first polarization conversion member, the number of divided regions (corresponding to the optical rotation members 51 to 58) of the second polarization conversion member, and polarization conversion characteristics. The arrangement of the plurality of light beams in each divided region is not limited to the above-described embodiment, and various forms are possible.

  In the above description, the operational effects of the present invention are described by taking, as an example, modified illumination in which an annular pupil intensity distribution is formed on the illumination pupil, that is, annular illumination. However, the present invention is similarly applied to, for example, multipolar illumination in which a multipolar pupil intensity distribution is formed without being limited to annular illumination, and the same operational effects can be obtained. Is clear.

  Further, in the above description, as the spatial light modulator having a plurality of mirror 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 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 the light from the second polarization conversion member 5 is disposed instead of the relay optical system 6. In place of the micro fly's eye lens 7 and the condenser optical system 8, the incident end is positioned at or near the rear focal position of the condensing optical system for condensing the light from the second polarization conversion member 5. A rod-type integrator is placed in 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. 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. 10 is a flowchart showing a manufacturing process of a semiconductor device. As shown in FIG. 10, in the semiconductor device manufacturing process, a metal film is vapor-deposited on a wafer W to be a substrate of the semiconductor device (step S40), and a photoresist, which is a photosensitive material, is applied on the vapor-deposited metal film. (Step S42). Subsequently, using the exposure apparatus of the above-described embodiment, the pattern formed on the mask (reticle) M is transferred to each shot area on the wafer W (step S44: exposure process), and the transfer of the wafer W after the transfer is completed. Development, that is, development of the photoresist to which the pattern has been transferred is performed (step S46: development process).

  Thereafter, using the resist pattern generated on the surface of the wafer W in step S46 as a mask, processing such as etching is performed on the surface of the wafer W (step S48: processing step). Here, the resist pattern is a photoresist layer in which unevenness having a shape corresponding to the pattern transferred by the exposure apparatus of the above-described embodiment is generated, and the recess penetrates the photoresist layer. is there. In step S48, the surface of the wafer W is processed through this resist pattern. The processing performed in step S48 includes, for example, at least one of etching of the surface of the wafer W or film formation of a metal film or the like.

  FIG. 11 is a flowchart showing a manufacturing process of a liquid crystal device such as a liquid crystal display element. As shown in FIG. 11, 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, etc.), micromachine, thin film magnetic head, and 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, 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 modulator 33 1st polarization conversion members 34 and 35 Deflection members 4 and 6 Relay optical system 5 2nd polarization conversion member 7 Micro fly's eye lens 8 Condenser optics System 9 Mask blind 10 Imaging optical 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 (17)

In the illumination optical system that illuminates the illuminated surface with light from the light source,
Forming a pupil intensity distribution on the illumination pupil of the illumination optical system based on the light from the light source, and forming a distribution in which a plurality of light beams having different polarization states are incident on each of the plurality of pupil regions of the pupil intensity distribution Optical system,
The illumination pupil has a plurality of divided regions corresponding to the plurality of pupil regions, and two adjacent divided regions of the plurality of divided regions have different polarization conversion characteristics. An illumination optical system comprising one optical element. The distribution forming optical system includes a spatial light modulation element that emits light after applying spatial modulation to incident light, and a second optical element that converts the incident light beam into a plurality of light beams having different polarization states. The illumination optical system according to claim 1. The spatial light modulator includes a spatial light modulator having a plurality of mirror elements that are two-dimensionally arranged and individually controlled;
The illumination optical system according to claim 2, wherein the second optical element is disposed on an incident side of the spatial light modulator. The spatial light modulator has a diffractive optical element,
The illumination optical system according to claim 2, wherein the second optical element is disposed on an incident side or an emission side of the diffractive optical element. 5. The illumination optical system according to claim 2, wherein the second optical element includes a plurality of parallel plane plate-shaped optical rotation members formed of an optical material having optical activity. 6. The second optical element according to claim 2, wherein the second optical element is formed of an optical material having optical rotation and has a form in which the thickness continuously changes along a predetermined direction. Lighting optics. The illumination optical system according to claim 2, wherein the second optical element has a plurality of wave plates that change incident light into light having a predetermined polarization state. The illumination optical system according to any one of claims 2 to 7, wherein the second optical element includes a plurality of polarizers that select and emit light having a predetermined polarization state from incident light. 9. The illumination optical system according to claim 1, wherein the first optical element has a plurality of divided regions arranged along a circumferential direction of a circle having the optical axis as a center. The illumination optical system according to claim 9, wherein the first optical element has the plurality of divided regions obtained by equally dividing a circular or annular region along a circumferential direction. 11. The illumination optical system according to claim 1, wherein the first optical element has a plurality of parallel plane plate-shaped optical rotation members formed of an optical material having optical activity. The illumination optical system according to any one of claims 1 to 10, wherein the first optical element includes a plurality of wave plates that change incident light into light having a predetermined polarization state. 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 12. In the illumination optical system that illuminates the illuminated surface with light from the light source,
A first polarization conversion member that divides the light from the light source into a plurality of light beams having different polarization states;
A second polarization conversion member comprising a plurality of divided regions in which two adjacent divided regions have different polarization conversion characteristics;
The illumination optical system, wherein the plurality of light beams having different polarization states from the first polarization conversion member are guided to one of the plurality of divided regions of the second polarization conversion member. 15. 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 15, 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 15 or 16,
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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