JP2006196715A - Luminous-flux converting element, illuminating optical apparatus, exposure apparatus, and exposure method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form an annular illuminating pupil distribution having circumferential polarization states, while suppressing the loss of a luminous energy favorably. <P>SOLUTION: A luminous-flux converting element for forming a predetermined luminous intensity distribution in a predetermined plane based on an incident luminous flux has first constructive double-refraction regions, each of which converts the incident luminous flux having a predetermined polarization state into an exit luminous flux having a first polarization state; has second constructive double-refraction regions each of which converts the incident luminous flux having the predetermined polarization state into an exit luminous flux having a second polarization state different from the first polarization state; has first means each of which is so provided correspondingly to each first constructive double-refraction region as to guide the incident luminous flux to a first region present on the predetermined plane; and has second means each of which is so provided correspondingly to each second constructive double-refraction region as to guide the incident luminous flux to a second region present on the predetermined plane. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light beam conversion element, an illumination optical apparatus, an exposure apparatus, and an exposure method, and in particular, when a microdevice such as a semiconductor element, an imaging element, or a thin film magnetic head, or a display device such as a liquid crystal display element is manufactured in a lithography process. The present invention relates to an illumination optical apparatus suitable for an exposure apparatus used in the above.

  In a typical exposure apparatus of this type, a light beam emitted from a light source forms a secondary light source as a substantial surface light source including a large number of light sources via a fly-eye lens as an optical integrator. The light flux from the secondary light source (generally, the illumination pupil distribution formed in or near the illumination pupil of the illumination optical device) is limited through an aperture stop disposed in the vicinity of the rear focal plane of the fly-eye lens. After that, it enters the condenser lens.

  The light beam condensed by the condenser lens illuminates the mask on which a predetermined pattern is formed in a superimposed manner. The light transmitted through the mask pattern forms an image on the wafer via the projection optical system. Thus, the mask pattern is projected and exposed (transferred) onto the wafer. The pattern formed on the mask is highly integrated, and it is essential to obtain a uniform illuminance distribution on the wafer in order to accurately transfer this fine pattern onto the wafer.

For example, in Japanese Patent No. 3246615 relating to the application of the present applicant, in order to realize an illumination condition suitable for faithfully transferring a fine pattern in an arbitrary direction, an annular zone is formed on the rear focal plane of the fly-eye lens. A technology for forming a secondary light source and setting the light beam passing through the annular secondary light source to be in a linear polarization state (hereinafter referred to as “circumferential polarization state” for short) with the circumferential direction as the polarization direction. Is disclosed.
Japanese Patent No. 3246615

  However, in the prior art disclosed in the above publication, the annular light source is limited by restricting the circular light beam formed through the fly-eye lens through an aperture stop having an annular opening. Forming. As a result, the prior art has a disadvantage in that a large light loss occurs in the aperture stop, which in turn reduces the throughput of the exposure apparatus.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to form a ring-shaped illumination pupil distribution in a circumferentially polarized state while favorably suppressing a light amount loss. In addition, the present invention forms a ring-shaped illumination pupil distribution in the circumferentially polarized state while suppressing loss of light quantity, and faithfully transfers a fine pattern in an arbitrary direction with high throughput under appropriate illumination conditions. It is an object of the present invention to provide an exposure apparatus and an exposure method that can be used.

In order to achieve the above object, a light beam conversion element according to the present invention is a light beam conversion element for forming a predetermined light intensity distribution on a predetermined surface based on an incident light beam,
A first structural birefringence region that converts an incident light beam having a predetermined polarization state into an outgoing light beam having a first polarization state;
A second structural birefringence region that converts an incident light beam having a predetermined polarization state into an exit light beam having a second polarization state different from the first polarization state;
A first means provided corresponding to the first structural birefringence region and guiding the incident light flux to the first region on the predetermined surface;
And a second means provided corresponding to the second structural birefringence region and guiding the incident light beam to the second region on the predetermined surface.

In order to achieve the above object, an illumination optical apparatus according to the present invention is an illumination optical apparatus that illuminates an illuminated surface based on a light beam from a light source,
The light beam conversion element described above is provided for converting a light beam from the light source in order to form an illumination pupil distribution at or near the illumination pupil of the illumination optical device.

  In order to achieve the above object, an exposure apparatus according to the present invention includes the above-described illumination optical device for illuminating a predetermined pattern, and exposes the predetermined pattern onto a photosensitive substrate. And

  In order to achieve the above object, an exposure apparatus method according to the present invention includes an illumination process for illuminating a mask using the illumination optical apparatus described above, and an exposure process for exposing a pattern of the mask onto a photosensitive substrate. It is characterized by including.

  In the illumination optical device of the present invention, unlike the prior art in which a large amount of light loss occurs in the aperture stop, the light amount loss is substantially generated by using the phase shift action and the light deflection action of the structural birefringence region. In other words, an annular or multipolar illumination pupil distribution in the circumferential polarization state can be formed. That is, in the illumination optical apparatus of the present invention, it is possible to form an annular or multipolar illumination pupil distribution in a circumferentially polarized state while favorably suppressing light loss.

Further, in the exposure apparatus and exposure method using the illumination optical apparatus of the present invention, an illumination optical apparatus capable of forming an annular or multipolar illumination pupil distribution in a circumferentially polarized state while favorably suppressing a light amount loss is used. Therefore, a fine pattern in an arbitrary direction can be faithfully transferred with high throughput under appropriate illumination conditions, and as a result, a good device can be manufactured with high throughput.

  Hereinafter, an outline of an embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram schematically illustrating a configuration of a light beam conversion element according to an embodiment of the present invention, and FIG. 1A is a plan view of the light beam conversion element according to the present embodiment as viewed from the incident side of the light beam. FIG. 1B is a plan view of the light beam conversion element according to the present embodiment as viewed from the light exit side, and FIG. 1C is a side view of the light beam conversion element according to the present embodiment.

  As shown in FIG. 1A, the light beam conversion element 100 according to this embodiment includes a plurality of structural birefringent regions 110 arranged in a two-dimensional matrix on the incident side. As shown in FIG. 1B, the light beam conversion element 100 according to this embodiment includes a plurality of structural birefringent regions 110 provided on the incident side in a one-to-one correspondence with each other. The diffraction region 120 is provided. The plurality of diffraction regions 120 are also arranged in a two-dimensional matrix. In addition, as shown in FIG. 1C, the plurality of structural birefringence regions 110 and the plurality of diffraction regions 120 are provided on both surfaces of the substrate 130 of the light beam conversion element 100.

  Next, the operation of the plurality of diffraction regions 120 provided on the exit side of the light beam conversion element 100 will be described with reference to FIG. In the following description, the operation of the structural birefringence region 110 is ignored for the sake of simplicity. In FIG. 2, an incident beam 140 to the light beam conversion element 100 is preferably a substantially collimated light beam (substantially parallel light beam), and irradiates the entire plurality of diffraction regions 120. Each diffraction region 120 forms an irradiation region having a predetermined shape (rectangular shape in FIG. 2) on a predetermined surface 150 located in the far field (or Fraunhofer diffraction region) in a superimposed manner. Due to the superimposition of the light beams, the light intensity distribution in the irradiation area formed on the predetermined surface 150 becomes substantially uniform. In FIG. 2, the shape of the irradiation region formed on the predetermined surface 150 is a rectangular shape, but may be a ring shape, a multipolar shape, or a circular shape as necessary. Details of such a diffraction region are disclosed in, for example, US Pat. No. 5,850,300 (and corresponding JP-A-8-94839 and JP-A-2001-507139), US Pat. No. 6,075, No. 627 (and corresponding special table 2003-529784) can be referred to. As described above, the plurality of diffraction regions 120 of the present embodiment have the same functions as those of the wavefront division type optical integrator.

  Next, the operation of the structural birefringence region 110 will be described with reference to FIGS. Here, FIG. 3 is a principle diagram for explaining the principle of structural birefringence, and FIG. 4 is a schematic diagram for explaining the operation of the structural birefringence region 110.

  In the light beam conversion element 100 of the present embodiment, a phase shift action is given to incident light by structural birefringence. FIG. 3 is a diagram schematically showing a part of the structural birefringence region 110 on the light beam conversion element 100. The structural birefringence region 110 includes a phase type diffraction grating 111 formed on a substrate 130. The phase type diffraction grating 111 has a period P, a depth d, and a substrate portion on which the fine grating is formed has a width a. At this time, the duty ratio of the diffraction grating 111 is defined by a / P.

  In FIG. 3, a light beam having a wavelength λ incident on the phase-type diffraction grating 111 is referred to as an incident light beam 141, and a light beam emitted from the phase-type diffraction grating 111 is referred to as an emitted light beam 144. Here, the incident light beam 141 can be decomposed into a polarization component 142 in a direction parallel to the groove of the phase type diffraction grating 111 and a polarization component 143 in a direction orthogonal to the groove of the phase type diffraction grating. The emitted light beam 144 can be decomposed into a polarization component 145 in a direction parallel to the grooves of the phase type diffraction grating 111 and a polarization component 146 in a direction orthogonal to the grooves of the phase type diffraction grating.

Note that the pitch P of the phase-type diffraction grating 111 is set to be equal to or less than the wavelength λ so that diffracted light other than the 0th order is not generated as the emitted light beam 144.
In FIG. 3, the incident light 141 having no phase difference between the polarization component 142 and the polarization component 143 passes through the phase-type diffraction grating 111, so that the polarization component 145 and the polarization component 146 are changed. This indicates that a phase difference ψ has occurred. Therefore, if the incident light beam 141 is linearly polarized light, it can be understood that the emitted light beam 144 is converted to elliptically polarized light. Such a phenomenon is called structural birefringence.

In other words, in a phase-type diffraction grating having a pitch equal to or less than the operating wavelength, the effective refractive index differs between the pitch direction of the diffraction grating and the direction perpendicular to the pitch (groove direction).
The refractive index n _II of the diffraction grating for the polarization component 142 (polarization component having a vibration plane parallel to the groove of the diffraction grating) and the diffraction grating for the polarization component 143 (polarization component having a vibration plane parallel to the pitch direction of the diffraction grating) the refractive index n _⊥,

It is represented by Where P is the pitch of the diffraction grating, a / P is the duty ratio, n1 is the refractive index of the material forming the diffraction grating, and n2 is the refractive index of the incident side medium of the diffraction grating.
When the depth of the groove of the diffraction grating is d and the wavelength used is λ, the phase difference ψ that appears between the polarization component 145 and the polarization component 146 is

Given in.
Thus, the phase difference ψ can be set to an arbitrary value using the pitch P (<λ) of the diffraction grating, the duty ratio, and the groove depth as parameters. That is, the phase shift action of one structural birefringence region 110 is required with the pitch direction (groove direction) of the diffraction grating, the pitch P (<λ) of the diffraction grating, the duty ratio, and the groove depth as parameters. Can do.

Here, assuming that the wavelength λ used is 193 nm, when quartz is used as the substrate 130, the refractive index is n = 1.56 at a wavelength of 193 nm. At this time, assuming that the duty ratio of the diffraction grating in the structural birefringence region 110 is 1: 1 (= 0.5), the refractive index n _{の in} the pitch direction of the diffraction grating is n _＝= 1.19, and the pitch orthogonal direction The refractive index n _II is n _II = 1.31. For example, in order for the structural birefringent region 110 to provide the phase difference λ / 2, the groove depth d of the diffraction grating may be d≈0.804 μm.

  FIG. 4 is a diagram schematically showing the operation of the light beam conversion element 100 according to the present embodiment. FIG. 4A illustrates the action of a specific structural birefringence region 110b2 and the diffraction region 120b2 corresponding to the structural birefringence region 110b2 among the plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. FIG. 4B shows a diffraction corresponding to another structural birefringence region 110c2 and the structural birefringence region 110c2 among the plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. It is a figure which shows the effect | action of the area | region 120c2.

  In FIG. 4A, the structural birefringence region 110b2 gives a phase difference of 0λ to the incident light beam. The light flux to which the phase difference is given is guided to two illumination areas 161 and 162 on the predetermined surface 150 with the optical axis AX sandwiched between them by the diffraction area 120b2 corresponding to the structural birefringence area 110b2. Here, when linearly polarized light that oscillates in the X direction in the figure is incident on the structural birefringence region 110b2, the light beams that reach the two illumination areas 161 and 162 on the predetermined plane oscillate in the X direction in the figure. It becomes linearly polarized light.

  In FIG. 4B, the structural birefringence region 110c2 gives a phase difference of λ / 2 to the incident light beam. The light flux to which the phase difference is given is guided to two illumination areas 163 and 164 sandwiching the optical axis AX on the predetermined surface 150 by the diffraction area 120c2 corresponding to the structural birefringence area 110c2. Here, when linearly polarized light oscillating in the X direction in the drawing is incident on the structural birefringence region 110c2, the light beams reaching the two illumination regions 163 and 164 on the predetermined plane oscillate in the Y direction in the drawing. It becomes linearly polarized light.

  As described above, the light beam conversion element 100 shown in FIG. 4 is composed of two sets of structural birefringence regions and diffraction regions, and linearly polarized light having a vibration (polarization) direction in the circumferential direction around the optical axis AX. The quadrupole illumination areas 161 to 164 are formed on the predetermined surface 150.

  In the example of FIG. 4, the quadrupole illumination areas 161 to 164 are formed on a predetermined surface, but a multipolar illumination area such as a hexapole or octupole or a multipole is formed by a similar method. It is possible to form a ring-shaped illumination area formed by connecting the shaped illumination areas.

  In the example shown in FIG. 4, a linearly polarized light component having a vibration (polarization) direction in the circumferential direction around the optical axis AX is formed on at least a part of the annular zone centering on the optical axis on the predetermined surface. Although the multipolar illumination areas 161 to 164 are formed, it is also possible to form an illumination area in a substantially non-polarized state on a predetermined plane.

Hereinafter, with reference to FIGS. 5 to 7, a description will be given of a case where an illumination region that is substantially non-polarized is formed on a predetermined surface.
Here, FIG. 5A shows a specific structural birefringence region 110a1 and a diffraction region 120a1 corresponding to the structural birefringence region 110a1 among the plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. FIG. 5B corresponds to the specific structural birefringence region 110b1 and the structural birefringence region 110b1 among the plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. FIG. 5C is a diagram illustrating the operation of the diffraction region 120b1, and FIG. 5C illustrates a specific structural birefringence region 110c1 and its structural birefringence region among the plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. It is a figure which shows the effect | action of the diffraction area | region 120c1 corresponding to 110c1.

  FIG. 6A shows the action of a specific structural birefringence region 110d1 and the diffraction region 120d1 corresponding to the structural birefringence region 110d1 among the plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. FIG. 6B illustrates a specific structural birefringence region 110e1 and a diffraction region 120e1 corresponding to the structural birefringence region 110e1 among the plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. FIG. 6C corresponds to a specific structural birefringence region 110f1 and the structural birefringence region 110f1 among the plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. It is a figure which shows the effect | action of the diffraction area | region 120f1 to do.

  FIG. 7A shows the operation of a specific structural birefringence region 110g1 and the diffraction region 120g1 corresponding to the structural birefringence region 110g1 among the plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. FIG. 7B illustrates a specific structural birefringence region 110h1 and a diffraction region 120h1 corresponding to the structural birefringence region 110h1 among the plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. It is a figure which shows the effect | action of.

  In the description of FIGS. 5A to 7B, the light beam conversion element 100 has a light beam on the XY plane (a surface orthogonal to the optical axis and a surface orthogonal to the light beam traveling direction) in the drawing. A straight line having a vibration plane (polarization plane) in the −45 ° (+ 135 °) direction from the X axis when viewed from the exit side (a vibration plane (polarization) in the + 45 ° (+ 225 °) direction from the X axis as viewed from the incident side of the polarized light beam). It is assumed that linearly polarized light) having a plane) is incident. In the following description of the polarization state of the light beam, it will be described in the case of viewing from the light beam exit side.

  In FIG. 5A, the structural birefringence region 110a1 gives a phase difference of 0λ to the incident light flux of 45 ° direction linearly polarized light. Then, the light flux to which the phase difference is given is guided to the substantially circular illumination area 171 centered on the optical axis AX on the predetermined surface 150 by the diffraction area 120a1 corresponding to the structural birefringence area 110a1. Here, the light beam reaching the substantially circular illumination region 171 becomes 45 ° -direction linearly polarized light.

  In FIG. 5B, the structural birefringence region 110b1 gives a phase difference of λ / 8 with respect to an incident light beam of 45 ° direction linearly polarized light. The light flux to which the phase difference of λ / 8 is given is guided to the substantially circular illumination region 172 centered on the optical axis AX on the predetermined surface 150 by the diffraction region 120b1 corresponding to the structural birefringence region 110b1. . Here, the light beam reaching the substantially circular illumination region 172 becomes clockwise elliptically polarized light having a major axis in the 45 ° direction. The substantially circular illumination region 172 and the illumination region 171 shown in FIG. 5A have substantially the same shape and size.

  In FIG. 5C, the structural birefringence region 110c1 provides a phase difference of λ / 4 with respect to an incident light beam of 45 ° direction linearly polarized light. Then, the light flux to which the phase difference of λ / 4 is given is guided to the substantially circular illumination region 173 centered on the optical axis AX on the predetermined surface 150 by the diffraction region 120c1 corresponding to the structural birefringence region 110c1. . Here, the light beam reaching the substantially circular illumination region 173 becomes clockwise circularly polarized light. The substantially circular illumination region 173 and the illumination region 171 shown in FIG. 5A have substantially the same shape and size.

  In FIG. 6A, the structural birefringence region 110d1 gives a phase difference of 3λ / 8 to the incident light flux of 45 ° direction linearly polarized light. Then, the light flux given the phase difference of 3λ / 8 is guided to the substantially circular illumination region 174 centered on the optical axis AX on the predetermined surface 150 by the diffraction region 120d1 corresponding to the structural birefringence region 110d1. . Here, the light beam reaching the substantially circular illumination region 174 becomes clockwise elliptically polarized light having a major axis in the −45 ° direction. The substantially circular illumination region 174 and the illumination region 171 shown in FIG. 5A have substantially the same shape and size.

  In FIG. 6B, the structural birefringent region 110e1 gives a phase difference of λ / 2 to the incident light flux of 45 ° direction linearly polarized light. The light flux to which the phase difference of λ / 2 is given is guided to the substantially circular illumination region 175 centered on the optical axis AX on the predetermined surface 150 by the diffraction region 120e1 corresponding to the structural birefringence region 110e1. . Here, the light beam reaching the substantially circular illumination region 175 becomes linearly polarized light in the −45 ° direction. Note that the substantially circular illumination area 175 and the illumination area 171 shown in FIG. 5A have substantially the same shape and size.

  In FIG. 6C, the structural birefringence region 110f1 gives a phase difference of 5λ / 8 to the incident light flux of 45 ° direction linearly polarized light. The light beam having a phase difference of 5λ / 8 is guided to the substantially circular illumination region 176 centered on the optical axis AX on the predetermined surface 150 by the diffraction region 120f1 corresponding to the structural birefringence region 110f1. . Here, the light beam reaching the substantially circular illumination region 176 becomes counterclockwise elliptically polarized light having a major axis in the −45 ° direction. Note that the substantially circular illumination area 176 and the illumination area 171 shown in FIG. 5A have substantially the same shape and size.

  In FIG. 7A, the structural birefringence region 110g1 gives a phase difference of 3λ / 4 to the incident light flux of 45 ° direction linearly polarized light. The light beam having a phase difference of 3λ / 4 is guided to the substantially circular illumination region 177 centered on the optical axis AX on the predetermined surface 150 by the diffraction region 120g1 corresponding to the structural birefringence region 110g1. . Here, the light beam reaching the substantially circular illumination region 177 becomes counterclockwise circularly polarized light. Note that the substantially circular illumination region 177 and the illumination region 171 shown in FIG. 5A have substantially the same shape and size.

  In FIG. 7B, the structural birefringence region 110h1 gives a phase difference of 7λ / 8 to the incident light flux of 45 ° direction linearly polarized light. Then, the light flux to which the phase difference of 7λ / 8 is given is guided to the substantially circular illumination region 178 centered on the optical axis AX on the predetermined surface 150 by the diffraction region 120h1 corresponding to the structural birefringence region 110h1. . Here, the light beam reaching the substantially circular illumination region 178 becomes counterclockwise elliptically polarized light having a major axis in the −45 ° direction. Note that the substantially circular illumination region 178 and the illumination region 171 shown in FIG. 5A have substantially the same shape and size.

  Since the light beams having these various polarization states are superimposed on each other on the predetermined surface 150 (since the illumination regions 171 to 178 are superimposed), a substantially non-polarized illumination region can be obtained.

  Here, if the example shown in FIG. 4 and the example shown in FIGS. 5 to 7 are provided on one light beam conversion element, the non-polarized light having the illumination area as shown in FIG. 8, that is, the optical axis AX as the center. And a multipolar shape having a linearly polarized light component having a vibration (polarization) direction in the circumferential direction centered on the optical axis AX and disposed in at least a part of the annular region 165 centered on the optical axis AX. The illumination areas 161 to 164 can be formed simultaneously.

  Each of the multipolar illumination regions 161 to 164 shown in FIGS. 4A and 4B is formed of a set of a plurality of structural birefringence regions and diffraction regions, and each of the illumination regions 161 to 161 is formed. It is preferable to improve the uniformity of the light intensity distribution at 164.

  In the light beam conversion element according to the above-described embodiment, the phase shift action and the light deflection action (diffraction action, refraction action, etc.) of the structural birefringence region are used, and the circumferential direction is not substantially generated without causing a light amount loss. It is possible to form an annular or multipolar illumination pupil distribution in a polarization state. In particular, when a plurality of structural birefringent regions are integrally formed on a single substrate, it is not necessary to align each region, so that the manufacturing is easy and the stability of the element can be improved. it can.

  Next, with reference to FIG. 9, an embodiment in which the light beam conversion element according to the above-described embodiment is applied to an illumination optical device will be described. The illumination optical apparatus shown in FIG. 9 is applied to an exposure apparatus that exposes the pattern of the mask M onto the wafer W, which is a photosensitive substrate, and therefore an exposure apparatus to which the illumination optical apparatus is applied will be described. To do.

  9, the Z-axis along the normal direction of the wafer W, which is a photosensitive substrate, the Y-axis in the direction parallel to the paper surface of FIG. 9 in the plane of the wafer W, and the plane of the wafer W in FIG. The X axis is set in the direction perpendicular to the paper surface. The exposure apparatus of this embodiment includes a light source 1 for supplying exposure light (illumination light).

  As the light source 1, for example, an ArF excimer laser light source that supplies light having a wavelength of 193 nm can be used. A substantially parallel light beam emitted from the light source 1 along the Z direction has a rectangular cross section extending along the X direction and is incident on a beam expander 2 including a pair of lenses 2a and 2b. Each lens 2a and 2b has a negative refracting power and a positive refracting power in the plane of FIG. 9 (in the YZ plane), respectively. Accordingly, the light beam incident on the beam expander 2 is enlarged in the plane of FIG. 9 and shaped into a light beam having a predetermined rectangular cross section.

  A substantially parallel light beam through the beam expander 2 as a shaping optical system is converted into a ¼ wavelength plate 4a, a ½ wavelength plate 4b, a depolarizer (non-polarization element) 4c, and the light beam conversion shown in the above embodiment. The light enters the afocal lens 6 through the element 100. Here, the quarter wavelength plate 4a, the half wavelength plate 4b, and the depolarizer 4c constitute a polarization state switching unit 4 as described later. The afocal lens 6 is set so that the front focal position and the position of the diffractive optical element 5 substantially coincide with each other, and the rear focal position and the position of the predetermined surface 7 indicated by a broken line in the drawing substantially coincide with each other. System (non-focal optical system).

  As described above, the light beam conversion element 100 has a predetermined shape (a substantially circular light intensity centered on the optical axis) in its far field (or Fraunhofer diffraction region) when a parallel light beam having a rectangular cross section is incident. And a light intensity distribution having a shape obtained by synthesizing the distribution and a multipolar light intensity distribution arranged in an annular region centered on the optical axis.

  Therefore, the substantially parallel light beam incident on the light beam conversion element 100 forms a light intensity distribution having a predetermined shape on the pupil plane of the afocal lens 6 and then exits from the afocal lens 6 as a substantially parallel light beam. A conical axicon system 8 is disposed on or near the pupil plane in the optical path between the front lens group 6a and the rear lens group 6b of the afocal lens 6. Will be described later. Hereinafter, in order to simplify the description, the basic configuration and operation will be described ignoring the operation of the conical axicon system 8.

  The light beam that has passed through the afocal lens 6 enters a micro fly-eye lens (or fly-eye lens) 11 as an optical integrator through a zoom lens 9 for variable σ value. The micro fly's eye lens 11 is an optical element composed of a large number of microlenses having positive refractive power arranged vertically and horizontally and densely. In general, a micro fly's eye lens is configured by, for example, performing etching on a plane parallel plate to form a micro lens group.

  Here, each micro lens constituting the micro fly's eye lens is smaller than each lens element constituting the fly eye lens. Further, unlike a fly-eye lens composed of lens elements isolated from each other, a micro fly-eye lens is formed integrally with a large number of micro lenses (micro refractive surfaces) without being isolated from each other. However, the micro fly's eye lens is the same wavefront division type optical integrator as the fly eye lens in that lens elements having positive refractive power are arranged vertically and horizontally.

  The position of the predetermined surface 7 is disposed in the vicinity of the front focal position of the zoom lens 9, and the incident surface of the micro fly's eye lens 11 is disposed in the vicinity of the rear focal position of the zoom lens 9. In other words, the zoom lens 9 arranges the predetermined surface 7 and the incident surface of the micro fly's eye lens 11 substantially in a Fourier transform relationship, and consequently the pupil surface of the afocal lens 6 and the incident surface of the micro fly's eye lens 11. Are arranged almost conjugate optically.

  Accordingly, on the incident surface of the micro fly's eye lens 11, similarly to the pupil surface of the afocal lens 6, for example, a predetermined shape centered on the optical axis AX (a substantially circular light intensity distribution and light centered on the optical axis). An illumination field having a shape obtained by synthesizing the multipolar light intensity distribution arranged in the annular zone centered on the axis is formed. The overall shape of the illumination field changes in a similar manner depending on the focal length of the zoom lens 9. Each microlens constituting the micro fly's eye lens 11 has a rectangular cross section similar to the shape of the illumination field to be formed on the mask M (and thus the shape of the exposure region to be formed on the wafer W).

  The light beam incident on the micro fly's eye lens 11 is two-dimensionally divided by a large number of microlenses, and the light intensity substantially the same as the illumination field formed by the incident light beam is formed on the rear focal plane or in the vicinity thereof (and thus the illumination pupil). A secondary light source having a distribution, that is, a secondary light source composed of a substantial surface light source having an annular shape centering on the optical axis AX is formed. The light beam from the secondary light source formed on the rear focal plane of the micro fly's eye lens 11 or in the vicinity thereof illuminates the mask blind 14 in a superimposed manner after passing through the beam splitter 12a and the condenser optical system 13.

  Thus, a rectangular illumination field corresponding to the shape and focal length of each microlens constituting the micro fly's eye lens 11 is formed on the mask blind 14 as an illumination field stop. The light beam that has passed through the rectangular opening (light transmitting portion) of the mask blind 14 is deflected in the Y direction by a deflecting plane mirror (planar reflecting mirror) M21 for bending the optical path, and then enters the imaging optical system 15. The light beam that has received the light condensing action of the imaging optical system 15 is deflected in the Z direction by a deflecting plane mirror M22 for bending the optical path, and then illuminates the mask M on which a predetermined pattern is formed in a superimposed manner.

  That is, the optical system 15 forms an image of the rectangular opening of the mask blind 14 on the mask M. The light beam that has passed through the pattern of the mask M held on the mask stage MS forms an image of the mask pattern on the wafer (photosensitive substrate) W held on the wafer stage WS via the projection optical system PL. . The internal configuration of the projection optical system PL will be described later. Thus, by performing batch exposure or scan exposure while driving and controlling the wafer W two-dimensionally in a plane (XY plane) orthogonal to the optical axis AX of the projection optical system PL, each exposure region of the wafer W is masked. M patterns are sequentially exposed.

  In the polarization state switching unit 4, the quarter wavelength plate 4a is configured such that the crystal optical axis is rotatable about the optical axis AX, and converts incident elliptically polarized light into linearly polarized light. The half-wave plate 4b is configured such that the crystal optical axis is rotatable about the optical axis AX, and changes the polarization plane of incident linearly polarized light. The depolarizer 4c is composed of a wedge-shaped quartz prism having a complementary shape and a wedge-shaped quartz prism. The quartz prism and the quartz prism are configured to be detachable with respect to the illumination optical path as an integral prism assembly.

  When a KrF excimer laser light source or an ArF excimer laser light source is used as the light source 1, the light emitted from these light sources typically has a polarization degree of 95% or more, and the quarter-wave plate 4a has almost linearly polarized light. Light enters. However, when a right-angle prism as a back reflector is interposed in the optical path between the light source 1 and the polarization state switching unit 4, the polarization plane of the incident linearly polarized light does not coincide with the P-polarization plane or the S-polarization plane. The linearly polarized light is changed to elliptically polarized light by total reflection at the right angle prism.

  In the polarization state switching unit 4, for example, even if elliptically polarized light is incident due to total reflection by a right-angle prism, linearly polarized light converted by the action of the quarter wavelength plate 4 a is a half wavelength plate. 4b. When the crystal optical axis of the half-wave plate 4b is set to make an angle of 0 degrees or 90 degrees with respect to the plane of polarization of the linearly polarized light incident thereon, the linearly polarized light incident on the half-wave plate 4b Passes through without changing the plane of polarization.

  In addition, when the crystal optical axis of the half-wave plate 4b is set to form an angle of 45 degrees with respect to the plane of polarization of the linearly polarized light incident thereon, the linearly polarized light incident on the half-wave plate 4b is It is converted into linearly polarized light whose polarization plane has changed by 90 degrees. Further, when the crystal optical axis of the crystal prism of the depolarizer 4c is set to form an angle of 45 degrees with respect to the plane of polarization of the linearly polarized light incident thereon, the linearly polarized light incident on the crystal prism is unpolarized light. Converted to non-polarized light.

  The polarization state switching unit 4 is configured such that when the depolarizer 4c is positioned in the illumination optical path, the crystal optical axis of the quartz prism forms an angle of 45 degrees with respect to the polarization plane of linearly polarized light that is incident. Incidentally, when the crystal optical axis of the crystal prism is set to make an angle of 0 degrees or 90 degrees with respect to the plane of polarization of the linearly polarized light incident thereon, the plane of polarization of the linearly polarized light incident on the crystal prism changes. It passes without any changes. Further, when the crystal optical axis of the half-wave plate 4b is set to make an angle of 22.5 degrees with respect to the plane of polarization of the linearly polarized light incident thereon, the linearly polarized light incident on the half-wave plate 4b is The light is converted into non-polarized light including a linearly polarized light component that passes through without changing its polarization plane and a linearly polarized light component whose polarization plane changes by 90 degrees.

  As described above, in the polarization state switching unit 4, linearly polarized light is incident on the half-wave plate 4b. However, in order to simplify the following description, the polarization direction (the direction of the electric field) in the Y direction in FIG. ) Linearly polarized light (hereinafter referred to as “Y-direction polarized light”) is incident on the half-wave plate 4b.

  When the depolarizer 4c is retracted from the illumination optical path, if the crystal optical axis of the half-wave plate 4b is set so as to make an angle of 0 degrees or 90 degrees with respect to the polarization plane of the Y-direction polarized light that is incident, 1/2 The Y-direction polarized light incident on the wave plate 4b passes through the Y-direction polarized light without changing the polarization plane, and enters the light beam conversion element in the Y-direction polarization state. Also, if the crystal optical axis of the half-wave plate 4b is set to make an angle of 45 degrees with respect to the polarization plane of the Y-direction polarized light that is incident, the Y-direction polarized light incident on the half-wave plate 4b is The polarization plane changes by 90 degrees to become X-direction polarized light, and enters the light beam conversion element 100 in the X-direction polarization state. If the crystal optical axis of the half-wave plate 4b is set to make an angle of 22.5 degrees with respect to the plane of polarization of the linearly polarized light incident thereon, the Y-direction polarized light incident on the half-wave plate 4b Changes the plane of polarization by 45 degrees to become 45 ° linearly polarized light, and enters the light beam conversion element 100.

  On the other hand, when the depolarizer 4c is positioned in the illumination optical path, an angle of 0 degree or 90 degrees is formed with respect to the polarization plane (polarization direction) of the Y-direction polarization incident on the crystal optical axis of the half-wave plate 4b. When set, the Y-direction polarized light incident on the half-wave plate 4b passes through the Y-polarized light without changing the polarization plane and enters the quartz prism of the depolarizer 4c. Since the crystal optical axis of the quartz prism is set to make an angle of 45 degrees with respect to the polarization plane of the incident Y-direction polarized light, the Y-direction polarized light incident on the quartz prism is converted into unpolarized light. Is done.

  The light that has been depolarized through the quartz prism enters the light beam conversion element 100 in a non-polarized state through the quartz prism as a compensator for compensating the traveling direction of the light. On the other hand, if the crystal optical axis of the half-wave plate 4b is set to make an angle of 45 degrees with respect to the polarization plane of the Y-direction polarization incident, the Y-direction polarization light incident on the half-wave plate 4b is The polarization plane changes by 90 degrees, and becomes linearly polarized light (hereinafter referred to as “X-direction polarized light”) having a polarization direction (electric field direction) in the X direction in FIG. 9 and enters the quartz prism of the depolarizer 4c. . Since the crystal optical axis of the quartz prism is set to make an angle of 45 degrees with respect to the polarization plane of the incident X-direction polarized light, the X-direction polarized light incident on the quartz prism is converted into unpolarized light. The light is converted and enters the light beam conversion element 100 through the quartz prism in a non-polarized state.

  As described above, in the polarization state switching unit 4, non-polarized light can be incident on the light beam conversion element 100 by inserting and positioning the depolarizer 4 c in the illumination optical path. Further, by retracting the depolarizer 4c from the illumination optical path and setting the rotation angle around the optical axis of the crystal optical axis of the half-wave plate 4b, linearly polarized light having a polarization plane (vibration plane) in a desired direction is converted into a light beam. The light can enter the conversion element 100.

  In other words, in the polarization state switching unit 4, the polarization state of the incident light to the light beam conversion element 100 is changed by the action of the polarization state switching unit including the quarter wavelength plate 4a, the half wavelength plate 4b, and the depolarizer 4c. Switching between the linear polarization state and the non-polarization state can be performed, and in the case of the linear polarization state, the polarization direction of the linearly polarized light incident on the light beam conversion element 100 can be set to an arbitrary direction.

  Next, the conical axicon system 8 includes, in order from the light source side, a first prism member 8a having a plane facing the light source side and a concave conical refractive surface facing the mask side, and a plane facing the mask side and facing the light source side. And a second prism member 8b having a convex conical refracting surface. The concave conical refracting surface of the first prism member 8a and the convex conical refracting surface of the second prism member 8b are complementarily formed so as to be in contact with each other. Further, at least one of the first prism member 8a and the second prism member 8b is configured to be movable along the optical axis AX, and the concave conical refractive surface of the first prism member 8a and the second prism member 8b. The distance from the convex conical refracting surface is variable.

  Here, in a state where the concave conical refracting surface of the first prism member 8a and the convex conical refracting surface of the second prism member 8b are in contact with each other, the conical axicon system 8 functions and is formed as a parallel plane plate. There is no effect on the secondary light source in the annular zone. However, if the concave conical refracting surface of the first prism member 8a and the convex conical refracting surface of the second prism member 8b are separated, the annular ratio (inner diameter / outer diameter) and size (outer diameter) of the secondary light source ) Will change.

  The zoom lens 9 has a function of enlarging or reducing the overall shape of the secondary light source in a similar manner. For example, by enlarging the focal length of the zoom lens 9 from a minimum value to a predetermined value, the overall shape of the secondary light source is similarly enlarged. In other words, due to the action of the zoom lens 9, the annular zone width and size (outer diameter) both change without changing the annular zone ratio of the secondary light source. In this way, the annular ratio and size (outer diameter) of the secondary light source can be controlled by the action of the conical axicon system 8 and the zoom lens 9.

  Further, the polarization monitor 12 includes a first beam splitter 12a disposed in the optical path between the micro fly's eye lens 11 and the condenser optical system 13, and the polarization state of the incident light to the first beam splitter 12a. It has a function to detect. When the control unit confirms that the illumination light to the mask M (and thus the wafer W) is not in the desired polarization state or non-polarization state based on the detection result of the polarization monitor 12, the polarization state switching unit 4 is turned on. The quarter wavelength plate 4a, the half wavelength plate 4b, and the depolarizer 4c that are configured can be driven and adjusted to adjust the state of illumination light to the mask M to a desired polarization state or non-polarization state.

  In the present embodiment, the depolarizer 4c of the polarization state switching unit 4 is retracted from the illumination light path during circumferential polarization illumination (modified illumination in which the light beam passing through the secondary light source distributed in the annular zone is set in the circumferential polarization state). In addition, by adjusting the angle position of the crystal optical axis of the half-wave plate 4b around the optical axis and causing the 45 ° direction linearly polarized light to be incident on the light beam conversion element 100, it is shown in the illumination pupil plane of the illumination optical device. The light intensity distribution shown in FIG. As a result, a multipolar secondary light source distributed in the annular zone and a secondary light source distributed in the vicinity of the optical axis are formed on or near the rear focal plane of the micro fly's eye lens 11. Here, the light beam passing through the multipolar secondary light source distributed in the annular zone is set in the circumferential polarization state. In the circumferential polarization state, the light beams passing through the ellipse regions 161 to 164 constituting the secondary light source distributed in the annular region are the optical axes at the center positions along the circumferential direction of the respective ellipse regions 161 to 164. A linear polarization state having a polarization direction substantially coincident with the tangential direction of the circle centered on AX is obtained.

  Thus, in the present embodiment, the secondary light source in the circumferential polarization state distributed in the annular zone is formed by the phase shift action and the diffraction action of the light beam conversion element 100 without substantially generating a light amount loss. Can do. In other words, in the illumination optical apparatus according to the present embodiment, it is possible to form the illumination pupil distribution in the circumferential polarization state while suppressing the light amount loss satisfactorily. In the circumferential polarization illumination based on the illumination pupil distribution in the circumferential polarization state, the light irradiated onto the wafer W as the final irradiated surface is in a polarization state mainly composed of S polarization.

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 annular illumination, the optical performance (such as the depth of focus) of the projection optical system can be improved, and a high-contrast mask pattern image can be obtained on the wafer (photosensitive substrate).

  In the light beam conversion element 100 described above, a multipolar light intensity distribution including a pole on the optical axis is formed in the illumination pupil plane (a plane conjugate with the predetermined plane 150) of the illumination optical apparatus. 10 (a), a substantially annular light intensity distribution, a bipolar light intensity distribution as shown in FIGS. 10 (b) and 10 (c), and as shown in FIG. 10 (d). Alternatively, it may be a quadrupole light intensity distribution or an octupole light intensity distribution as shown in FIG. In FIGS. 10A to 10E, the polarization directions of the light beams forming each light intensity distribution are indicated by arrows. Further, as shown in FIG. 10 (f), a substantially circular light intensity distribution including the optical axis may be formed by a non-polarized light beam. Such a plurality of types of light beam conversion elements may be prepared in advance and provided so as to be interchangeable with the light beam conversion element 100 of FIG.

  In the above-described example, the structural birefringence region 110 and the diffraction region 120 are provided on both surfaces of the single substrate 130. However, as shown in FIG. The diffraction region 120 may be formed on one side of the substrate 132 different from the substrate 131. At this time, it is preferable to provide alignment marks 133 and 134 for optically aligning the two substrates 131 and 132, respectively. As a technique for holding the two substrates 131 and 132 at such a narrow interval, for example, the technique disclosed in Japanese Patent Application Laid-Open No. 2004-146792 can be referred to.

  As described above, when the structural birefringence region 110 and the diffraction region 120 are provided separately, the structural birefringence region 110 is located on the incident side of the light beam, and the diffraction region 120 is located on the emission side of the light beam. Is preferred. If this order is reversed, the angular range of the light beam incident on the structural birefringence region 110 becomes too wide, and it is difficult to uniformly impart a desired phase difference to the light beam.

  In addition, as shown in FIG. 12, the diffraction pattern of the diffraction region 120 may be formed of an aggregate of fine patterns having a pitch of a wavelength λ or less. In this case, the diffraction pattern itself of the diffraction region 120 has a function of structural birefringence.

  As a method for creating a diffraction grating in the above-described structural birefringence region 110, after applying a photosensitive material on the substrate 130, EB direct drawing, a two-beam interference exposure method, or an exposure method using near-field light. The diffraction grating pattern is exposed, and the exposed photosensitive material is developed. Thereafter, using the developed photosensitive material as a mask, etching is performed so as to obtain a required groove depth, or the same material as that of the substrate 130 is deposited. Moreover, the processing technique using the gas energy cluster ion currently used for processing to a photonic crystal can also be used.

  In the above example, quartz having a relatively high refractive index at a wavelength of 193 nm is applied as the material of the substrate 130 (131, 132). However, the substrate material may be fluorite. When fluorite is used, it is preferable that the crystal axis {111} or {100} of fluorite be the optical axis direction in order to prevent the influence of intrinsic birefringence of fluorite. Further, as the substrate material, an optical material exhibiting birefringence such as quartz or magnesium fluoride may be used. In this case, since the optical path length of the light passing through the substrate is different when the incident angle of the light beam with respect to the substrate is different, the influence of birefringence by the substrate changes depending on the incident angle. Therefore, the incident angle dependency in the structural birefringence region can be compensated by the incident angle dependency in the substrate. In other words, the incident angle dependency of the phase difference with respect to the substrate can be made constant within a predetermined angle range.

  In the above example, linearly polarized light is incident on the light beam conversion element 100, but circularly polarized light may be incident. At this time, the groove depth of the diffraction grating in the birefringent region 110 of the light beam conversion element 100 can be halved.

  In the above-described embodiment, the diffraction action is used as means for guiding the incident light beam incident on the light beam conversion element 100 to a predetermined region on the predetermined surface 150. For example, a microprism array, a Fresnel lens array, a microlens array is used. It is also possible to use a refraction action such as.

  In the exposure apparatus according to the above-described embodiment, the illumination optical device illuminates the mask (reticle) (illumination process), and the projection optical system is used to expose the transfer pattern formed on the mask onto the photosensitive substrate (exposure). Step), a micro device (semiconductor element, imaging element, liquid crystal display element, thin film magnetic head, etc.) can be manufactured. Hereinafter, refer to the flowchart of FIG. 13 for an example of a method for obtaining a semiconductor device as a micro device by forming a predetermined circuit pattern on a wafer or the like as a photosensitive substrate using the exposure apparatus of the above-described embodiment. To explain.

  First, in step 301 of FIG. 13, a metal film is deposited on one lot of wafers. In the next step 302, a photoresist is applied on the metal film on the one lot of wafers. Thereafter, in step 303, the image of the pattern on the mask is sequentially exposed and transferred to each shot area on the wafer of one lot through the projection optical system using the exposure apparatus of the above-described embodiment. Thereafter, in step 304, the photoresist on the one lot of wafers is developed, and in step 305, the resist pattern is etched on the one lot of wafers to form a pattern on the mask. Corresponding circuit patterns are formed in each shot area on each wafer. Thereafter, a device pattern such as a semiconductor element is manufactured by forming a circuit pattern of an upper layer. According to the semiconductor device manufacturing method described above, a semiconductor device having an extremely fine circuit pattern can be obtained with high throughput.

  In the exposure apparatus of the above-described embodiment, a liquid crystal display element as a display device can be obtained by forming a predetermined pattern (circuit pattern, electrode pattern, etc.) on a plate (glass substrate). Hereinafter, an example of the technique at this time will be described with reference to the flowchart of FIG. In FIG. 14, in the pattern formation process 401, a so-called photolithography process is performed in which the exposure pattern of the above-described embodiment is used to transfer and expose a mask pattern onto a photosensitive substrate (such as a glass substrate coated with a resist). . By this photolithography process, a predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. Thereafter, the exposed substrate undergoes steps such as a developing step, an etching step, and a resist stripping step, whereby a predetermined pattern is formed on the substrate, and the process proceeds to the next color filter forming step 402.

Next, in the color filter forming step 402, a large number of sets of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix or three of R, G, and B A color filter is formed by arranging a plurality of stripe filter sets in the horizontal scanning line direction. Then, after the color filter forming step 402, a cell assembly step 403 is executed. In the cell assembly step 403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern formation step 401, the color filter obtained in the color filter formation step 402, and the like.

  In the cell assembly step 403, for example, liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern formation step 401 and the color filter obtained in the color filter formation step 402, and a liquid crystal panel (liquid crystal cell) is obtained. ). Thereafter, in a module assembling step 404, components such as an electric circuit and a backlight for performing a display operation of the assembled liquid crystal panel (liquid crystal cell) are attached to complete a liquid crystal display element. According to the above-described method for manufacturing a liquid crystal display element, a liquid crystal display element having an extremely fine circuit pattern can be obtained with high throughput.

In the above-described embodiment, ArF excimer laser light (wavelength: 193 nm) is used as exposure light. However, the present invention is not limited to this, and other suitable laser light sources, for example, light having a wavelength of 248 nm are supplied. The present invention can also be applied to a KrF excimer laser light source or an F ₂ laser light source that supplies laser light having a wavelength of 157 nm.

  In the above-described embodiment, a so-called immersion method is applied in which the optical path between the projection optical system and the photosensitive substrate is filled with a medium (typically liquid) having a refractive index larger than 1.1. You may do it. In this case, as a method of filling the liquid in the optical path between the projection optical system and the photosensitive substrate, a method of locally filling the liquid as disclosed in International Publication No. WO99 / 49504, A method of moving a stage holding a substrate to be exposed as disclosed in Japanese Patent Application Laid-Open No. 6-124873 in a liquid bath, or a predetermined depth on a stage as disclosed in Japanese Patent Application Laid-Open No. 10-303114. A technique of forming a liquid tank and holding the substrate in the liquid tank can be employed.

As the liquid, it is preferable to use a liquid that is transmissive to exposure light and has a refractive index as high as possible, and is stable with respect to a photoresist applied to the projection optical system and the substrate surface, for example, KrF excimer laser light. When ArF excimer laser light is used as exposure light, pure water or deionized water can be used as the liquid. When F ₂ laser light is used as exposure light, a fluorine-based liquid such as fluorine oil or perfluorinated polyether (PFPE) that can transmit the F ₂ laser light may be used as the liquid.

FIG. 1 is a diagram schematically showing a configuration of a light beam conversion element according to an embodiment of the present invention. FIG. 1A is a plan view of the light beam conversion element according to the present embodiment as viewed from the incident side of the light beam, and FIG. ) Is a plan view of the light beam conversion element according to the present embodiment as viewed from the light emission side, and FIG. 1C is a side view of the light beam conversion element according to the present embodiment. 6 is a schematic diagram for explaining the operation of a plurality of diffraction regions 120 provided on the exit side of the light beam conversion element 100. FIG. It is a principle figure explaining the principle of structural birefringence. FIG. 5 is a schematic diagram for explaining the operation of a structural birefringence region 110. FIG. 5A is a diagram illustrating the operation of the structural birefringence region and the diffraction region provided in the light beam conversion element 100, and FIG. FIG. 5B is a diagram illustrating the operation of the structural birefringence region 110a1 and the diffraction region 120a1 corresponding to the structural birefringence region 110a1, and FIG. 5B is a diagram illustrating a plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. FIG. 5C is a diagram showing the operation of a specific structural birefringent region 110b1 and the diffraction region 120b1 corresponding to the structural birefringent region 110b1, and FIG. 5C shows a plurality of structural birefringences provided in the light beam conversion element 100. It is a figure which shows the effect | action of the diffraction area 120c1 corresponding to the specific structure birefringence area | region 110c1 and the structure birefringence area | region 110c1 among an area | region and a diffraction area. FIG. 6A is a diagram illustrating the operation of the structural birefringence region and the diffraction region provided in the light beam conversion element 100. FIG. 6A illustrates a specific structure among the plurality of structural birefringence regions and diffraction regions provided in the light beam conversion element 100. FIG. 6B is a diagram illustrating the operation of the structural birefringent region 110d1 and the diffraction region 120d1 corresponding to the structural birefringent region 110d1, and FIG. 6B is a diagram illustrating a plurality of structural birefringent regions and diffraction regions provided in the light beam conversion element 100. FIG. 6C is a diagram showing the operation of a specific structural birefringent region 110e1 and the diffraction region 120e1 corresponding to the structural birefringent region 110e1, and FIG. 6C shows a plurality of structural birefringences provided in the light beam conversion element 100. It is a figure which shows the effect | action of the diffraction structure 120f1 corresponding to the specific structure birefringence area | region 110f1 and its structure birefringence area | region 110f1 among an area | region and a diffraction area. FIG. 7A is a diagram illustrating the operation of the structural birefringence region and the diffraction region provided in the light beam conversion element 100, and FIG. FIG. 7B is a diagram illustrating the operation of the structural birefringent region 110g1 and the diffraction region 120g1 corresponding to the structural birefringent region 110g1, and FIG. It is a figure which shows the effect | action of the diffraction area | region 120h1 corresponding to the specific structure birefringence area | region 110h1 and the structure birefringence area | region 110h1 among these. 3 is a diagram illustrating an example of an illumination area formed by a light beam conversion element 100. FIG. It is a figure which shows schematically the structure of the exposure apparatus concerning embodiment of this invention. 6 is a diagram showing another example of an illumination area formed by the light beam conversion element 100. FIG. It is a figure which shows the modification of the light beam conversion element. 6 is a diagram showing a modification of the structural birefringence region and the diffraction region of the light beam conversion element 100. FIG. It is a flowchart of the method at the time of obtaining the semiconductor device as a microdevice. It is a flowchart of the method at the time of obtaining the liquid crystal display element as a display device.

Explanation of symbols

100 Beam Conversion Element 110 Structural Birefringence Area 120 Diffraction Area 130 Substrate

Claims (20)

In a light beam conversion element for forming a predetermined light intensity distribution on a predetermined surface based on an incident light beam,
A first structural birefringence region that converts an incident light beam having a predetermined polarization state into an outgoing light beam having a first polarization state;
A second structural birefringence region that converts an incident light flux having a predetermined polarization state into an exit light flux having a second polarization state different from the first polarization state;
A first means provided corresponding to the first structural birefringence region and guiding the incident light flux to the first region on the predetermined surface;
And a second means for guiding the incident light beam to the second region on the predetermined surface. The light beam conversion device is provided corresponding to the second structural birefringence region. The first region and the second region are positioned in at least a part of a predetermined ring zone region that is a predetermined ring zone region centered on a predetermined point on the predetermined surface;
The light beam passing through the first region and the second region has a polarization state mainly composed of linearly polarized light whose polarization direction is a circumferential direction of the predetermined ring zone region. The light beam conversion element described in 1. The predetermined light intensity distribution has an outer shape substantially the same shape as the predetermined annular zone region,
The polarization state of the light beam passing through the first region has a linearly polarized component that substantially coincides with the tangential direction of the circle centered on the predetermined point at the center position along the circumferential direction of the first region. ,
The polarization state of the light beam passing through the second region has a linearly polarized component that substantially coincides with the tangential direction of the circle centered on the predetermined point at the center position along the circumferential direction of the second region. The light beam conversion element according to claim 2. The predetermined light intensity distribution is multipolar distributed in the predetermined annular zone region,
The polarization state of the light beam passing through the first region has a linearly polarized component that substantially coincides with the tangential direction of the circle centered on the predetermined point at the center position along the circumferential direction of the first region. ,
The polarization state of the light beam passing through the second region has a linearly polarized component that substantially coincides with the tangential direction of the circle centered on the predetermined point at the center position along the circumferential direction of the second region. The light beam conversion element according to claim 2. 5. The light beam conversion element according to claim 1, wherein the first unit and the second unit include a diffractive optical element or a refractive optical element. The first means and the first structural birefringence region are provided in a one-to-one correspondence, and the second means and the second structural birefringence region are provided in a one-to-one correspondence. The light beam conversion element according to any one of claims 1 to 5. The said 1st and 2nd structural birefringent area | region and the said 1st and 2nd means are formed on another optical member, The Claim 1 characterized by the above-mentioned. Light beam conversion element. 7. The light beam according to claim 1, wherein the first and second structural birefringent regions and the first and second means are formed on the same optical member. Conversion element. 9. The light beam conversion element according to claim 8, wherein the first means is formed in the first structural birefringence region, and the second means is formed in the second structural birefringence region. . The first structural birefringence region and the second structural birefringence region are integrally formed in different regions on the same substrate. The light beam conversion element described. A third structural birefringence region that converts an incident light beam having a predetermined polarization state into an exit light beam having a third polarization state different from the first and second polarization states;
A fourth structural birefringence region that converts an incident light beam having a predetermined polarization state into an exit light beam having a fourth polarization state different from the first to third polarization states;
A third means provided corresponding to the third structural birefringence region and guiding the incident light flux to the third region on the predetermined surface;
11. The apparatus according to claim 1, further comprising a fourth means provided corresponding to the fourth structural birefringence region and guiding the incident light beam to a third region on the predetermined surface. The light beam conversion element according to claim 1. 12. The light beam conversion element according to claim 11, wherein the first to fourth structural birefringence regions are integrally formed in different regions on the same substrate. In the illumination optical device that illuminates the illuminated surface based on the light flux from the light source,
13. The light beam conversion element according to claim 1, which converts a light beam from the light source to form an illumination pupil distribution at or near the illumination pupil of the illumination optical device. An illumination optical device. The illumination optical device according to claim 13, wherein the light beam conversion element is configured to be exchangeable with another light beam conversion element having different characteristics. A wavefront splitting type optical integrator disposed in an optical path between the light flux conversion element and the irradiated surface;
The illumination optical device according to claim 13 or 14, wherein the light beam conversion element forms the predetermined light intensity distribution on an incident surface of the optical integrator based on an incident light beam. The polarization state of the light beam from the light beam conversion element is set so that the light irradiated on the irradiated surface is in a polarization state mainly composed of S-polarized light. The illumination optical apparatus according to Item 1. 17. An exposure apparatus comprising the illumination optical apparatus according to claim 13 for illuminating a predetermined pattern, and exposing the predetermined pattern onto a photosensitive substrate. 18. The exposure apparatus according to claim 17, wherein the polarization state of the light beam from the light beam conversion element is set so that the light applied to the photosensitive substrate is in a polarization state mainly composed of S-polarized light. . An exposure process comprising: an illumination process of illuminating a mask using the illumination optical apparatus according to claim 13; and an exposure process of exposing a pattern of the mask onto a photosensitive substrate. Method. 20. The exposure method according to claim 19, wherein the polarization state of the light beam from the light beam conversion element is set so that the light applied to the photosensitive substrate is in a polarization state mainly composed of S-polarized light. .