JP2007027240A - Illumination optical device, exposure apparatus, and exposure method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust the ratio of light intensity in a central region to that in a peripheral region of a pupil light intensity distribution, for example, in three-pole or five-pole (deformed illumination, based on the three-pole or the five-pole secondary light source). <P>SOLUTION: The illumination optical device (1-12) forms the pupil light intensity distribution on an illumination pupil plane, based on the flux of light from a light source (1), and illuminates an illuminated plane (M) by using the flux of light which has passed through the plane of illumination pupil. The illumination optical device includes an adjustment means (6a, 6b) for adjusting the ratio of the light intensity in the central region to that in the peripheral region of the pupil light intensity distribution which is located on the illumination pupil plane to or near the same, or on a plane that is optically conjugate with the illumination pupil plane or near the same. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an illumination optical apparatus, an exposure apparatus, and an exposure method, and more particularly to an illumination optical apparatus suitable for an exposure apparatus for manufacturing a microdevice such as a semiconductor element, an imaging element, a liquid crystal display element, and a thin film magnetic head in a lithography process. Is.

  In a typical exposure apparatus of this type, a light beam emitted from a light source passes through a fly-eye lens (or micro fly-eye lens) as an optical integrator, and is used as a substantial surface light source composed of a number of light sources. A next light source (generally, a predetermined light intensity distribution on the illumination pupil plane) is formed. The light beam from the secondary light source is limited through an aperture stop disposed in the vicinity of the rear focal plane of the fly-eye lens, and then 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.

  In recent years, a circular secondary light source is formed on the rear focal plane of a fly-eye lens, and its size is changed to change the illumination coherency σ (σ value = aperture aperture diameter / pupil diameter of the projection optical system, or σ Attention has been focused on a technique of changing the value = the exit numerical aperture of the illumination optical system / the incident numerical aperture of the projection optical system. Further, a technique for forming a ring-shaped or quadrupolar secondary light source on the rear focal plane of the fly-eye lens to improve the depth of focus and resolution of the projection optical system has attracted attention (for example, see Patent Document 1). .

JP 2002-231619 A

  As described above, in the conventional exposure apparatus, normal circular illumination based on a circular secondary light source is performed according to the pattern characteristics of the mask, or a secondary light source having a ring shape, a bipolar shape, or a quadrupole shape is used. Based on the modified illumination (annular illumination, dipole illumination, quadrupole illumination). In connection with this technique, the applicant of the present application is, for example, in the international application PCT / JP2004 / 014323, as an appropriate illumination condition for faithfully transferring a mask pattern in which two types of patterns having different characteristics are mixed. Proposed modified illumination (tripolar illumination or pentapolar illumination) based on a polar or pentapolar secondary light source.

  A tripolar (pentapolar) secondary light source (pupil light intensity distribution) in tripolar illumination (pentode illumination) is, for example, a unipolar light intensity distribution formed in a central region centered on the optical axis. , And two (four) peripheral regions that are substantially symmetrical with respect to the optical axis. In this case, in order to realize an appropriate illumination condition, for example, the light intensity in the central region and the peripheral region are set so as to substantially match the required values in the design, or to obtain a desired value according to the characteristics of the mask pattern. It is required to adjust the ratio with the light intensity.

  The present invention has been made in view of the above-described problems. For example, in tripolar illumination or pentapolar illumination, the ratio of the light intensity of the central region of the pupil light intensity distribution to the light intensity of the peripheral region is adjusted. An object of the present invention is to provide an illuminating optical device that can be used. In addition, the present invention has different characteristics by using an illumination optical device that can adjust the ratio of the light intensity in the central region and the light intensity in the peripheral region of the pupil light intensity distribution, for example, in tripolar illumination or pentode illumination. An object of the present invention is to provide an exposure apparatus and an exposure method capable of faithfully transferring various fine patterns including a mask pattern in which two kinds of patterns are mixed.

In order to solve the above problems, in the first embodiment of the present invention, a pupil light intensity distribution is formed on the illumination pupil plane based on the light flux from the light source, and the illuminated surface is used using the light flux that has passed through the illumination pupil plane. In an illumination optical device that illuminates
The light intensity in the central area of the pupil light intensity distribution and the light in the peripheral area of the pupil light intensity distribution are arranged on or near the illumination pupil plane, or on a plane optically conjugate with the illumination pupil plane or in the vicinity thereof. Provided is an illumination optical device comprising an adjusting means for adjusting a ratio to intensity.

In the second aspect of the present invention, in the illumination optical apparatus that forms a pupil light intensity distribution on the illumination pupil plane based on the light flux from the light source and illuminates the illuminated surface using the light flux that has passed through the illumination pupil plane,
The light intensity in the central area of the pupil light intensity distribution and the light in the peripheral area of the pupil light intensity distribution are arranged on or near the illumination pupil plane, or on a plane optically conjugate with the illumination pupil plane or in the vicinity thereof. Provided is an illumination optical device characterized by comprising adjusting means for adjusting the intensity independently of each other.

  In the third embodiment of the present invention, the illumination optical device of the first or second embodiment for illuminating a predetermined pattern, and a projection optical system for forming an image of the predetermined pattern on a photosensitive substrate are provided. An exposure apparatus is provided.

  According to a fourth aspect of the present invention, a predetermined pattern is illuminated via the illumination optical device according to the first or second aspect, and the illuminated pattern is exposed onto a photosensitive substrate by a projection optical system. An exposure method is provided.

  In an illumination optical apparatus according to a typical embodiment of the present invention, for example, a first correction filter and a second correction filter which are disposed on or near a surface optically conjugate with the illumination pupil plane and have the same transmittance distribution are provided. By rotating each around the optical axis, the light intensity in the central region in the tripolar or pentole pupil light intensity distribution is kept constant, while the light intensity in the peripheral region is relatively decreased or increased. be able to. That is, the light intensity in the central region is adjusted so as to substantially match the required value in the design by the action of the pair of correction filters, or in the case of an exposure apparatus, to a desired value according to the characteristics of the mask pattern. And the ratio of the light intensity in the peripheral region can be adjusted.

  Thus, in the illumination optical device according to the present invention, for example, in tripolar illumination or pentapole illumination, the ratio of the light intensity in the central region to the light intensity in the peripheral region of the pupil light intensity distribution can be adjusted. The condition can be realized. In the exposure apparatus and the exposure method of the present invention, for example, an illumination optical apparatus capable of adjusting the ratio of the light intensity in the central region to the light intensity in the peripheral region of the pupil light intensity distribution in tripolar illumination or quinpole illumination. It is possible to faithfully transfer various fine patterns including a mask pattern in which two types of patterns having different characteristics are mixed, and as a result, a good microdevice can be manufactured with high accuracy.

  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. In FIG. 1, 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 plane of FIG. 1 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. Referring to FIG. 1, 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 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. A substantially parallel light beam emitted from the light source 1 is expanded by the beam expander 2 and shaped into a light beam having a predetermined rectangular cross section. A substantially parallel light beam via a beam expander 2 as a shaping optical system is incident on an afocal lens 4 via a diffractive optical element 3 for annular illumination, for example. The afocal lens 4 is set so that the front focal position thereof and the position of the diffractive optical element 3 substantially coincide with each other, and the rear focal position thereof substantially coincides with the position of the predetermined surface 5 indicated by a broken line in the drawing. System (non-focal optical system).

  In general, a diffractive optical element is formed by forming a step having a pitch of the wavelength of exposure light (illumination light) on a substrate, and has a function of diffracting an incident beam to a desired angle. Specifically, the diffractive optical element 3 for annular illumination forms an annular light intensity distribution in the far field (or Fraunhofer diffraction region) when a parallel light beam having a rectangular cross section is incident. It has a function. Therefore, a substantially parallel light beam incident on the diffractive optical element 3 as a light beam conversion element forms an annular light intensity distribution on the pupil plane of the afocal lens 4 and then exits from the afocal lens 4 with an annular angle distribution. Is done.

  The diffractive optical element 3 is configured to be detachable with respect to the illumination optical path, and is configured to be exchangeable with another diffractive optical element that forms a different light intensity distribution in the far field. The replacement of the diffractive optical element 3 is performed by a drive unit 21 that operates based on a command from the control unit 20. In the optical path between the front lens group 4a and the rear lens group 4b of the afocal lens 4, a pair of correction filters 6 (6a, 6b) and a conical axicon system 7 are disposed on or near the pupil plane. ing. Control of the pair of correction filters 6 and control of the conical axicon system 7 are performed by drive units 22 and 23 that operate based on commands from the control unit 20. The configuration and operation of the pair of correction filters 6 and the conical axicon system 7 will be described later.

  The light beam that has passed through the afocal lens 4 passes through a zoom lens 8 for varying the σ value (σ value = mask-side numerical aperture of the illumination optical apparatus / mask-side numerical aperture of the projection optical system), and is used as a micro fly as an optical integrator. The light enters the eye lens (or fly eye lens) 9. The micro fly's eye lens 9 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. For example, the micro fly's eye lens 9 is formed by subjecting a plane-parallel plate to an etching process to form a micro lens group. It is configured.

  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 5 is disposed at or near the front focal position of the zoom lens 8, and the incident surface of the micro fly's eye lens 9 is disposed at or near the rear focal position of the zoom lens 8. In other words, the zoom lens 8 arranges the predetermined surface 5 and the incident surface of the micro fly's eye lens 9 substantially in a Fourier transform relationship, and consequently the pupil surface of the afocal lens 4 and the incident surface of the micro fly's eye lens 9. Are arranged almost conjugate optically. Accordingly, on the incident surface of the micro fly's eye lens 9, for example, a ring-shaped illumination field centered on the optical axis AX is formed in the same manner as the pupil surface of the afocal lens 4.

  The entire shape of the annular illumination field changes in a similar manner depending on the focal length of the zoom lens 8. The change in the focal length of the zoom lens 8 is performed by the drive unit 24 that operates based on a command from the control unit 20. The light beam incident on the micro fly's eye lens 9 is two-dimensionally divided, and the illumination formed by the incident light beam is formed on the rear focal plane or in the vicinity thereof (and thus the illumination pupil plane) as shown in FIG. A secondary light source (pupil light intensity distribution) having substantially the same light intensity distribution as the field, that is, a secondary light source composed of a ring-shaped substantial surface light source centered 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 9 or in the vicinity thereof is disposed at a position optically conjugate with the mask M (and thus the wafer W) via the condenser optical system 10. The mask blind 11 is illuminated in a superimposed manner. Thus, a rectangular illumination field is formed in the mask blind 11 as an illumination field stop. The light beam that has passed through the rectangular opening (light transmitting portion) of the mask blind 11 is subjected to a light condensing action of the imaging optical system 12 including, for example, the front lens group 12a and the rear lens group 12b. The mask M on which the pattern is formed is illuminated in a superimposed manner.

  Thus, the imaging optical system 12 forms an image of the rectangular opening of the mask blind 11 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. . 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 of this embodiment is provided with a light intensity distribution measuring device 13 as a measuring means for measuring the light intensity distribution on the pupil plane (actually equivalent to the pupil plane) of the projection optical system PL. Yes. For details regarding the light intensity distribution measuring device 13, for example, International Publication WO99 / 36832, Japanese Patent Application Laid-Open No. 11-317349, Japanese Patent Application Laid-Open No. 2000-19012, Japanese Patent Application Laid-Open No. 2002-110540, and the like can be referred to. . Information on the light intensity distribution (corresponding to the pupil light intensity distribution on the illumination pupil plane) in a plane equivalent to the pupil plane of the projection optical system PL measured by the light intensity distribution measuring device 13 is supplied to the control unit 20.

  In place of the diffractive optical element 3 for annular illumination, a diffractive optical element (not shown) for dipole illumination (or for quadrupole illumination) is set in the illumination optical path, thereby dipole illumination (or quadrupole illumination). )It can be performed. A diffractive optical element for dipole illumination (or for quadrupole illumination) forms a dipole (or quadrupole) light intensity distribution in the far field when a parallel light beam having a rectangular cross section is incident. It has the function to do. Therefore, the light beam that has passed through the diffractive optical element for dipole illumination (or for quadrupole illumination) is, for example, two (or four) circular shapes that are symmetric about the optical axis AX on the incident surface of the micro fly's eye lens 9. A dipolar (or quadrupolar) illumination field is formed. As a result, as shown in FIG. 2B (or FIG. 2C), at the rear focal plane of the micro fly's eye lens 9 or in the vicinity thereof, the same dipole as the illumination field formed on the incident plane is provided. (Or quadrupole) secondary light source is formed.

  Further, instead of the diffractive optical element 3 for annular illumination, a diffractive optical element (not shown) for tripolar illumination (or for pentode illumination) is set in the illumination optical path to thereby provide tripolar illumination (or 5). Polar lighting). In tripolar illumination (or pentode illumination), for example, one circular illumination field centered on the optical axis AX and two symmetrical with respect to the optical axis AX (or 4) are formed on the incident surface of the micro fly's eye lens 9. A three-pole (or five-pole) illumination field. As a result, as shown in FIG. 2D (or FIG. 2E), at the rear focal plane of the micro fly's eye lens 9 or in the vicinity thereof, the same three poles as the illumination field formed on the incident surface thereof (Or pentapole) secondary light source is formed.

  Moreover, instead of the diffractive optical element 3 for annular illumination, a normal circular illumination can be performed by setting a diffractive optical element (not shown) for circular illumination in the illumination optical path. The diffractive optical element for circular illumination has a function of forming a circular light intensity distribution in the far field when a parallel light beam having a rectangular cross section is incident. Therefore, the light beam that has passed through the diffractive optical element for circular illumination forms, for example, a circular illumination field around the optical axis AX on the incident surface of the micro fly's eye lens 9. As a result, as shown in FIG. 2F, a secondary light source having the same circular shape as the illumination field formed on the incident surface is formed at or near the rear focal plane of the micro fly's eye lens 9. .

  Furthermore, by replacing the diffractive optical element 3 for annular illumination with another diffractive optical element (not shown) for multi-pole illumination in the illumination optical path, various multi-pole illumination (8-pole illumination, 9 Polar lighting etc.). Similarly, various forms of modified illumination can be performed by setting a diffractive optical element (not shown) having appropriate characteristics in the illumination optical path instead of the diffractive optical element 3 for annular illumination.

  The conical axicon system 7 includes, in order from the light source side, a first prism member 7a having a flat surface facing the light source side and a concave conical refractive surface facing the mask side, and a convex conical shape facing the plane toward the mask side and the light source side. And a second prism member 7b facing the refractive surface. The concave conical refracting surface of the first prism member 7a and the convex conical refracting surface of the second prism member 7b are complementarily formed so as to be in contact with each other. Further, at least one of the first prism member 7a and the second prism member 7b is configured to be movable along the optical axis AX, and the concave conical refracting surface of the first prism member 7a and the second prism member 7b. The distance from the convex conical refracting surface is variable. Hereinafter, the operation of the conical axicon system 7 and the operation of the zoom lens 8 will be described by paying attention to the secondary light source having a ring shape, a dipole shape or a quadrupole shape.

  In a state where the concave conical refracting surface of the first prism member 7a and the convex conical refracting surface of the second prism member 7b are in contact with each other, the conical axicon system 7 functions as a parallel flat plate, and is formed in an annular shape. There is no effect on a dipolar or quadrupolar secondary light source. However, when the concave conical refracting surface of the first prism member 7a and the convex conical refracting surface of the second prism member 7b are separated from each other, the width of the secondary light source having the annular shape, the dipolar shape, or the quadrupolar shape (the annular shape). 1/2 of the difference between the outer diameter and inner diameter of the secondary light source: the difference between the diameter of the circle circumscribed by the secondary or quadrupolar secondary light source (outer diameter) and the diameter of the inscribed circle (inner diameter) The outer diameter (inner diameter) of the secondary light source in the annular, dipolar or quadrupolar shape changes. That is, the annular ratio (inner diameter / outer diameter) and size (outer diameter) of the annular or quadrupolar secondary light source change.

  The zoom lens 8 has a function of similarly enlarging or reducing the entire shape of the annular light source having a ring shape, a dipole shape, or a quadrupole shape. For example, by expanding the focal length of the zoom lens 8 from a minimum value to a predetermined value, the entire shape of the annular light source having a ring shape, a dipole shape, or a quadrupole shape is similarly enlarged. In other words, due to the action of the zoom lens 8, the width and size (outer diameter) of both the annular, dipolar and quadrupolar secondary light sources change without changing. As described above, by the action of the conical axicon system 7 and the zoom lens 8, the annular ratio and the size (outer diameter) of the annular, dipolar, or quadrupolar secondary light source can be controlled.

  For example, in the case of a circular, tripolar or pentapolar secondary light source having a monopolar light intensity distribution in the central region including the optical axis AX, the conical axicon system 7 functions as a parallel flat plate. Thus, the state where the concave conical refracting surface of the first prism member 7a and the convex conical refracting surface of the second prism member 7b are in contact with each other is maintained. Regardless of the form of the light intensity distribution, the circular, tripolar or pentapolar secondary light source is also used in the zoom lens 8 as in the case of the annular, dipolar or quadrupolar secondary light source. As a result, the entire shape is enlarged or reduced in a similar manner.

  In the present embodiment, for example, in order to faithfully transfer a mask pattern in which two types of patterns having different characteristics are mixed, tripolar illumination based on a tripolar or pentapolar secondary light source (pupil light intensity distribution). And 5 pole lighting. As shown in FIG. 2D (FIG. 2E), the tripolar (pentapolar) pupil light intensity distribution has a monopolar shape formed in the central region 30c centered on the optical axis AX. The light intensity distribution and a light intensity distribution having a bipolar shape (four-pole shape) formed in two (four) peripheral regions 30p that are substantially symmetrical with respect to the optical axis AX.

  Here, the optical system is designed so that the ratio between the light intensity of the central region 30c and the light intensity of the peripheral region 30p becomes a predetermined value. However, in practice, the ratio of the light intensity of the central region 30c and the light intensity of the peripheral region 30p in the pupil light intensity distribution formed on the illumination pupil plane is related to the diffractive optical element as the light beam conversion element and other related elements. Due to the manufacturing error of the optical member, it may differ from the required value in the design. Therefore, in the present embodiment, for example, a pair of correction filters (6a, 6b, etc.) is used to adjust the ratio between the light intensity in the central region and the light intensity in the peripheral region of the pupil light intensity distribution in tripolar illumination or pentapolar illumination. ) Is provided.

  FIG. 3 is a diagram schematically showing a configuration of a pair of correction filters used for tripolar illumination. As shown in FIG. 1, the pair of correction filters 6 a and 6 b as adjustment means for tripolar illumination are arranged close to each other along the optical axis AX on or near the pupil plane of the afocal lens 4. . In other words, the pair of correction filters 6a and 6b are surfaces that are optically conjugate with the illumination pupil plane (the rear focal plane of the micro fly's eye lens 9 or a plane in the vicinity thereof) of the illumination optical apparatus (1-12) or It is arranged in the vicinity.

  Further, the first correction filter 6a and the second correction filter 6b have the same transmittance distribution, and are configured to be rotatable about the optical axis AX. Referring to FIG. 3, each of the correction filters 6 a and 6 b includes a circular central region 31 centered on the optical axis AX and a plurality of arc-shaped regions arranged so as to surround the central region 31, that is, the optical axis AX. It is composed of four arcuate regions 32a, 32b, 32c, and 32d obtained by dividing an annular region at the center into four equal parts in the circumferential direction.

Here, the central region 31 has a constant transmittance T1. On the other hand, among the four arc-shaped regions 32a to 32d, the first pair of arc-shaped regions 32a and 32c facing each other with the optical axis AX interposed therebetween have a transmittance T2 of almost 100%, and sandwich the optical axis AX. in arc-shaped regions 32b and 32d of the second pair of opposing both have a transmissivity T1 ^2. Hereinafter, in order to simplify the description, it is assumed that the transmittance T1 of the central region 31 is 0.975, and the transmittance T2 of the arc-shaped regions 32b and 32d is 1. That is, the transmittance T2 of the first pair of arcuate regions 32a and 32c is larger than the transmittance T1 of the central region 31, and the transmittance T1 ² (T1 ² ≈0) of the second pair of arcuate regions 32b and 32d. .95) is smaller than the transmittance T1 of the central region 31.

The difference between the transmittance T2 of the first pair of arcuate regions 32a and 32c and the transmittance T1 of the center region 31 is the same as the transmittance T1 ² and the center region 31 of the second pair of arcuate regions 32b and 32d. Is substantially equal to the difference from the transmittance T1. Further, the four arc-shaped regions 32a to 32d have a transmittance distribution that is rotationally symmetrical twice with respect to the center (that is, AX) of each of the correction filters 6a and 6b. Each of the correction filters 6a and 6b is configured by forming a predetermined light shielding rate distribution expressed by the denseness of minute dot patterns such as chromium on a quartz glass substrate, for example.

FIG. 4 is a diagram for explaining the operation of the correction filter pair of FIG. 3 in tripolar illumination. In the standard state shown in FIG. 4A, the first arcuate region 32a located diagonally to the left of the first correction filter 6a and the fourth arcuate region 32d of the second correction filter 6b are in the optical axis AX direction. Are overlapping. As a result, the synthetic transmittance of the first correction filter 6a and the second correction filter 6b becomes T1 ² over the entire region, 3 dipolar light intensity and the peripheral region 30p of the central area 30c of the pupil intensity distribution of The ratio to the light intensity is not adjusted by the pair of correction filters (6a, 6b).

In the state shown in FIG. 4B, from the standard state shown in FIG. 4A, the first correction filter 6a is −45 degrees around the optical axis AX (the counterclockwise direction in the figure is negative and the clockwise direction is positive). The second correction filter 6b is rotated +45 degrees around the optical axis AX. In this state, the first arcuate region 32a located on the left of the first correction filter 6a in the drawing and the first arcuate region 32a of the second correction filter 6b overlap in the optical axis AX direction. As a result, the combined transmittance of the first correction filter 6a and the second correction filter 6b is T1 ⁴ ≈0.90 in the upper and lower arc-shaped regions in the drawing, and T2 = 1 in the left and right arc-shaped regions in the drawing. Become. Therefore, in the state shown in FIG. 4B, the light intensity of the central region 30c of the tripolar pupil light intensity distribution is unchanged compared to the standard state shown in FIG. 4A, but the peripheral region 30p. The light intensity decreases by about 5%.

In the state shown in FIG. 4C, from the standard state shown in FIG. 4A, the first correction filter 6a is rotated +45 degrees around the optical axis AX, and the second correction filter 6b is −45 around the optical axis AX. It is rotating. In this state, the first arcuate region 32a located on the upper side of the first correction filter 6a in the drawing and the third arcuate region 32c of the second correction filter 6b overlap in the direction of the optical axis AX. As a result, the combined transmittance of the first correction filter 6a and the second correction filter 6b is T2 = 1 in the upper and lower arc-shaped regions in the drawing, and T1 ⁴ ≈0.90 in the left and right arc-shaped regions in the drawing. Become. Therefore, in the state shown in FIG. 4C, the light intensity of the central region 30c of the tripolar pupil light intensity distribution is unchanged compared to the standard state shown in FIG. 4A, but the peripheral region 30p. The light intensity increases by about 5%.

In the state shown in FIG. 4D, from the standard state shown in FIG. 4A, the first correction filter 6a rotates about -5 degrees around the optical axis AX, and the second correction filter 6b moves around the optical axis AX. It has rotated about +5 degrees. In this case, the combined transmittance of the first correction filter 6a and the second correction filter 6b is T2 = 1 in a small area on the left and right in the figure (area where the azimuth angle range from the optical axis AX is about 10 degrees), In the upper and lower small regions in the figure (region where the azimuth angle range from the optical axis AX is about 10 degrees), T1 ⁴ ≈0.90.

  Therefore, in the state shown in FIG. 4D, the light intensity of the central region 30c of the tripolar pupil light intensity distribution is unchanged compared to the standard state shown in FIG. The light intensity at the central portion is reduced by about 5%, and the light intensity at both sides of the peripheral region 30p is unchanged. That is, the light intensity in the peripheral region 30p is effectively reduced by 2% to 3%, for example. In FIG. 4D, the pair of peripheral regions 30p are arranged vertically in the figure. However, in the case of a tripolar pupil light intensity distribution in which the pair of peripheral regions 30p are arranged side by side in the figure, The light intensity of the central region 30c is unchanged, and the light intensity of the peripheral region 30p is effectively increased by 2% to 3%, for example.

  In this embodiment, in the case of tripolar illumination, the diffractive optical element for tripolar illumination is set in the illumination optical path by the drive unit 21 that has received a command from the control unit 20, and the drive unit that has received the command from the control unit 20 22 sets a pair of correction filters (6a, 6b) for tripolar illumination in the illumination optical path. Then, the control unit 20 is based on the information on the light intensity distribution (corresponding to the pupil light intensity distribution on the illumination pupil plane) on the plane equivalent to the pupil plane of the projection optical system PL measured by the light intensity distribution measuring device 13. The pair of correction filters (6a, 6b) are controlled.

  Specifically, the control unit 20 rotates the first correction filter 6a and the second correction filter 6b having the same transmittance distribution in the opposite directions around the optical axis AX through the driving unit 22 in the opposite directions. By doing so, only the light intensity of the peripheral region 30p is relatively lowered or increased without changing the light intensity of the central region 30c in the tripolar pupil light intensity distribution. Thus, by the action of the pair of correction filters (6a, 6b), for example, the light intensity of the central region 30c and the light intensity of the peripheral region 30p of the tripolar pupil light intensity distribution so as to substantially match the required values in the design. The ratio with the above can be adjusted, so that appropriate illumination conditions can be realized. Alternatively, even if the ratio of the light intensity of the central region 30c and the light intensity of the peripheral region 30p substantially matches the required value in the design, the three poles are set so as to have a desired value according to the characteristics of the mask pattern. The ratio of the light intensity of the central region 30c and the light intensity of the peripheral region 30p of the pupil-shaped light intensity distribution can be positively adjusted by the action of the pair of correction filters (6a, 6b), and thus the optimal illumination conditions Can be achieved.

  FIG. 5 is a diagram schematically showing a configuration of a pair of correction filters used for pentapolar illumination. A pair of correction filters 60a and 60b as adjustment means for pentapole illumination are arranged on the optical axis AX on or near the pupil plane of the afocal lens 4 instead of the correction filter pair (6a, 6b) for tripolar illumination. Arranged close to each other. The first correction filter 60a and the second correction filter 60b have the same transmittance distribution and are configured to be rotatable about the optical axis AX.

Referring to FIG. 5, each of the correction filters 60 a and 60 b includes a circular central region 31 centered on the optical axis AX and a plurality of arc-shaped regions arranged so as to surround the central region 31, that is, the optical axis AX. It is constituted by eight arcuate regions 33a to 33h obtained by dividing an annular region as a center into eight equal parts in the circumferential direction. Here, the central region 31 has a constant transmittance T1. On the other hand, of the eight arcuate regions 33a to 33h, the first pair of arcuate regions 33a and 33e and the third pair of arcuate regions 33c and 33g facing each other across the optical axis AX are almost 100%. has a transmittance T2, the arc-shaped regions 33b and 33f as well as arcuate regions 33d and 33h of the fourth pair of second pair of opposite sides of the optical axis AX together with the transmittance T1 ^2.

Hereinafter, in order to simplify the description, it is assumed that the transmittance T1 of the central region 31 is 0.975 and the transmittance T2 of the arc-shaped regions 33a, 33c, 33e, and 32g is 1. That is, the transmittance T2 of the first pair of arcuate regions 33a and 33e and the third pair of arcuate regions 33c and 33g is larger than the transmittance T1 of the central region 31, and the second pair of arcuate regions 33b. And 33f and the fourth pair of arcuate regions 33d and 33h have a transmittance T1 ² (T1 ² ≈0.95) smaller than the transmittance T1 of the central region 31. The difference between the transmittance T2 of the first pair of arc-shaped regions 33a and 33e and the third pair of arc-shaped regions 33c and 33g and the transmittance T1 of the central region 31 is the second pair of arc-shaped regions 33a and 33e. approximately equal to 33b and 33f as well as the difference between the transmittance T1 of the arcuate region 33d and 33h of the transmittance T1 ² and the central region 31 of the fourth pair. Further, the eight arc-shaped regions 33a to 33h have a transmittance distribution that is rotationally symmetric four times via the centers (that is, AX) of the correction filters 60a and 60b.

FIG. 6 is a diagram for explaining the operation of the correction filter pair of FIG. 5 in pentapolar illumination. In the standard state shown in FIG. 6A, the first arcuate region 33a located diagonally to the left of the first correction filter 60a and the eighth arcuate region 33h of the second correction filter 60b are in the optical axis AX direction. Are overlapping. As a result, the synthetic transmittance of the first correction filter 60a and the second correction filter 60b becomes T1 ² over the entire region, four peripheral regions 30p are arranged in FIG cruciform cross 5 dipolar Eye Also in the light intensity distribution, the ratio between the light intensity of the central region 30c and the light intensity of the peripheral region 30p is also obtained in the X-shaped pentapolar pupil light intensity distribution in which the four peripheral regions 30p are arranged in an X shape in the figure. Is not adjusted by the pair of correction filters (60a, 60b).

In the state shown in FIG. 6B, from the standard state shown in FIG. 6A, the first correction filter 60 does not rotate around the optical axis AX, and only the second correction filter 60b +45 around the optical axis AX. Rotating degrees (counterclockwise in the figure is negative and clockwise is positive). In this state, the first arcuate region 33a located diagonally to the left of the first correction filter 60a in the drawing and the first arcuate region 33a of the second correction filter 60b overlap in the optical axis AX direction. As a result, the combined transmittance of the first correction filter 60a and the second correction filter 60b is T1 ⁴ ≈0.90 in the upper, lower, left and right arc-shaped regions in the drawing, and T2 = 1 in the other arc-shaped regions. .

  Therefore, in the state shown in FIG. 6B, the light intensity of the central region 30c in the cross-shaped pentapole pupil light intensity distribution is unchanged compared to the standard state shown in FIG. The light intensity of the four peripheral regions 30p is about 5% lower. On the other hand, the light intensity of the central region 30c in the X-shaped pentapole pupil light intensity distribution remains unchanged, but the light intensity of the four X-shaped peripheral regions 30p increases by about 5%. Since the first correction filter 60a has a transmittance distribution that is rotationally symmetric four times, even if the first correction filter 60a is rotated around the optical axis AX by, for example, ± 90 degrees from the standard state shown in FIG. A state equivalent to the first correction filter 60a in FIG. 6B is obtained.

In the state shown in FIG. 6C, from the standard state shown in FIG. 6A, the first correction filter 60a rotates about −45 degrees around the optical axis AX, and the second correction filter 60b rotates around the optical axis AX. Not done. In this state, the first arcuate region 33a located on the left of the first correction filter 60a in the drawing and the first arcuate region 33a of the second correction filter 60b overlap in the direction of the optical axis AX. As a result, the combined transmittance of the first correction filter 60a and the second correction filter 60b is T2 = 1 in the upper, lower, left and right arc-shaped regions in the figure, and T1 ⁴ ≈0.90 in the other arc-shaped regions. .

  Therefore, in the state shown in FIG. 6C, the light intensity of the central region 30c in the cross-shaped pentapolar pupil light intensity distribution is unchanged compared to the standard state shown in FIG. The light intensity of the four surrounding regions 30p increases by about 5%. On the other hand, the light intensity of the central region 30c in the X-shaped pentapole pupil light intensity distribution is unchanged, but the light intensity of the four X-shaped peripheral regions 30p is reduced by about 5%. Since the second correction filter 60b has a four-fold rotationally symmetric transmittance distribution, even if the second correction filter 60b is rotated around the optical axis AX by, for example, ± 90 degrees from the standard state shown in FIG. A state equivalent to the second correction filter 60b in FIG. 6C is obtained.

  In the present embodiment, the diffractive optical element for pentode illumination is set in the illumination optical path by the drive unit 21 that has received a command from the control unit 20 and the drive unit that has received a command from the control unit 20 in the case of pentode illumination. 22 sets a pair of correction filters (60a, 60b) for pentapole illumination in the illumination optical path. Then, the control unit 20 is based on the information on the light intensity distribution (corresponding to the pupil light intensity distribution on the illumination pupil plane) on the plane equivalent to the pupil plane of the projection optical system PL measured by the light intensity distribution measuring device 13. The pair of correction filters (60a, 60b) are controlled.

  Specifically, the control unit 20 rotates at least one of the first correction filter 60a and the second correction filter 60b having the same transmittance distribution around the optical axis AX via the drive unit 22, Only the light intensity of the peripheral region 30p is relatively lowered or increased without changing the light intensity of the central region 30c in the pentapolar pupil light intensity distribution. In this way, by the action of the pair of correction filters (60a, 60b), for example, pentapolar pupil light so as to substantially match a required value in design or to a desired value according to the characteristics of the mask pattern. The ratio between the light intensity of the central region 30c and the light intensity of the peripheral region 30p in the intensity distribution can be adjusted, so that appropriate illumination conditions can be realized or the illumination conditions can be optimized.

  FIG. 7 is a diagram schematically showing the configuration of another correction filter pair used for pentode illumination. Another correction filter pair 61a and 61b as adjustment means for pentapole illumination is also replaced with, for example, the correction filter pair (6a, 6b) for tripolar illumination, and the optical axis at or near the pupil plane of the afocal lens 4 Arranged close to each other along AX. The first correction filter 61a and the second correction filter 61b have different transmittance distributions and are configured to be rotatable about the optical axis AX.

Referring to FIGS. 7A and 7B, each of the correction filters 61a and 61b has a configuration similar to that of the correction filter (60a and 60b) of FIG. 5, and is adjacent to the correction filter (60a and 60b). The two arc-shaped regions and the two arc-shaped regions facing each other with the optical axis AX sandwiched between these two arc-shaped regions are removed. That is, the first correction filter 61a is an arcuate region 35b having an arcuate region 35a, the transmittance T1 ² adjacent to counterclockwise in the figure in a circular arc-like region 35a having 100% transmittance T2 substantially, an arcuate region 35c having a transmittance T2 opposite the arcuate region 35a across the optical axis AX, an arc-shaped region 35d having a transmittance T1 ² opposite the arcuate area 35b on both sides of the optical axis AX , And the other region having the transmittance T1, that is, the central region 34.

On the other hand, the second correction filter 61b is an arcuate region 35e having a transmissivity T1 ^2, an arcuate region 35f having a transmissivity T2 adjacent to counterclockwise in the figure in a circular arc region 35e, the optical axis AX An arcuate region 35g having a transmittance T1 ² across the arcuate region 35e across, an arcuate region 35h facing the arcuate region 35f across the optical axis AX and a transmissivity T2, and a transmittance T1 It is comprised by the other area | region which has these, ie, the center area | region 34. Hereinafter, in order to simplify the description, it is assumed that the transmittance T1 of the central region 34 is 0.975, and the transmittance T2 of the arc-shaped regions 35a, 35c, 35f, and 35h is 1.

That is, the transmittance T2 of the first pair of arcuate regions 35a and 35c and the fourth pair of arcuate regions 35f and 35h is larger than the transmittance T1 of the central region 34, and the second pair of arcuate regions 35b. And 35d and the third pair of arcuate regions 35e and 35g have a transmittance T1 ² (T1 ² ≈0.95) smaller than the transmittance T1 of the central region 34. The difference between the transmittance T2 of the first pair of arcuate regions 35a and 35c and the fourth pair of arcuate regions 35f and 35h and the transmittance T1 of the central region 31 is the second pair of arcuate regions approximately equal to 35b and 35d as well as the difference between the transmittance T1 of the third pair of arcuate regions 35e and 35g of the transmittance T1 ² and the central region 34. Further, the four arc-shaped regions (35a to 35d; 35e to 35h) have a transmittance distribution that is rotationally symmetric twice with respect to the center (that is, AX) of each of the correction filters 61a and 61b.

FIG. 8 is a diagram for explaining the operation of the correction filter pair of FIG. In the standard state shown in FIG. 8A, the first arcuate region 35a located diagonally to the left of the first correction filter 61a and the first arcuate region 35e of the second correction filter 61b are in the optical axis AX direction. Are overlapping. As a result, the synthetic transmittance of the first correction filter 61a and the second correction filter 61b becomes T1 ² over the entire area, the light intensity of the central region 30c of the pupil intensity distribution of the cross-shaped 5-polar shape and the peripheral area The ratio to the light intensity of 30p is not adjusted by the pair of correction filters (61a, 61b).

In the state shown in FIG. 8B, the first correction filter 61a is -22.5 degrees around the optical axis AX from the standard state shown in FIG. The second correction filter 61b is rotated +22.5 degrees around the optical axis AX. In this state, the first arc-shaped region 35a located obliquely lower left in the drawing of the first correction filter 61a and the second arc-shaped region 35f of the second correction filter 61b overlap in the optical axis AX direction. As a result, the combined transmittance of the first correction filter 61a and the second correction filter 61b is T1 ³ ≈0.927 in the upper, lower, left and right arc-shaped regions in the drawing. Therefore, in the state shown in FIG. 8B, the light intensity of the central region 30c in the cross-shaped pentapole pupil light intensity distribution is unchanged compared to the standard state shown in FIG. The light intensity of the four peripheral regions 30p is about 2.4% lower.

  In the state shown in FIG. 8C, from the standard state shown in FIG. 8A, the first correction filter 61a is rotated by −67.5 degrees around the optical axis AX, and the second correction filter 61b is turned around the optical axis AX. It is rotated +67.5 degrees. In this state, the second arcuate region 35b located obliquely lower right in the drawing of the first correction filter 61a and the third arcuate region 35g of the second correction filter 61b overlap in the direction of the optical axis AX. As a result, the combined transmittance of the first correction filter 61a and the second correction filter 61b is T1 = 0.975 in the upper, lower, left and right arc-shaped regions in the drawing. Therefore, in the state shown in FIG. 8C, the light intensity of the central region 30c in the cross-shaped pentapole pupil light intensity distribution is unchanged compared to the standard state shown in FIG. The light intensity of the four surrounding regions 30p increases by about 2.6%.

  Thus, in the modified example using the correction filter pair (61a, 61b) in FIG. 7, as in the case of using the pair of correction filters (60a, 60b) shown in FIG. Or the ratio between the light intensity of the central region 30c and the light intensity of the peripheral region 30p in the pentapolar pupil light intensity distribution can be adjusted so as to have a desired value according to the characteristics of the mask pattern. As a result, it is possible to realize an appropriate illumination condition or optimize the illumination condition.

  As described above, in the illumination optical device (1 to 12) of the present embodiment, the pair of correction filters (6a, 6b; 60a, 60b; 61a, 61b) as the adjusting means in the three-pole illumination or the five-pole illumination. By the action, the ratio of the light intensity of the central region 30c and the light intensity of the peripheral region 30p in the pupil light intensity distribution can be adjusted. In the exposure apparatus of the present embodiment, an illumination optical apparatus (1) that can adjust the ratio between the light intensity 30c in the central region and the light intensity in the peripheral region 30p of the pupil light intensity distribution in tripolar illumination or pentapolar illumination. To 12), it is possible to faithfully transfer various fine patterns including a mask pattern in which two types of patterns having different characteristics are mixed.

  In the above description, in the pair of correction filters (6a, 6b; 60a, 60b; 61a, 61b) as the adjusting means, the transmittance inside each arc-shaped region is constant, and two adjacent circles are used. The transmittance changes intermittently between the arcuate regions. However, as shown in FIG. 9, for example, a pair of correction filters (62a, 62b) acting in the same manner as the pair of correction filters (60a, 60b) shown in FIG. 5 is transmitted between two adjacent arc-shaped regions. A configuration in which the rate changes continuously is also possible.

Referring to FIG. 9, the pair of correction filters (62a, 62b) has an overall configuration similar to that of the pair of correction filters (60a, 60b) shown in FIG. 5, but is transmitted between two adjacent arc-shaped regions. the rate is continuously changed from T2 to T1 ² along the arrow in FIG. That is, continuously change 'from the center of the second arc-shaped region 33b' first arcuate region 33a to the center and the center of the eighth circular arc-shaped region 33h 'in, and transmittance along the circumferential direction from T2 to T1 ² is doing.

Similarly, from the center of the third arcuate region 33c ′ to the center of the second arcuate region 33b ′ and the center of the fourth arcuate region 33d ′, the center of the fifth arcuate region 33e ′ extends to the fourth arcuate region 33d. The transmittance is from the center of 'and the center of the sixth arcuate region 33f' to the center of the seventh arcuate region 33g 'to the center of the sixth arcuate region 33f' and the center of the eighth arcuate region 33h '. along the circumferential direction continuously changes from T2 to T1 ^2. Similarly for the pair of correction filters (6a, 6b) shown in FIG. 3 and the pair of correction filters (61a, 61b) shown in FIG. 7, the transmittance is continuous between two adjacent arc-shaped regions. The modification which applied the structure which changes automatically is possible.

  In the above description, the first correction filter (6a, 61a) and the second correction filter in the pair of correction filters (6a, 6b) shown in FIG. 3 and the pair of correction filters (61a, 61b) shown in FIG. (6b, 61b) are rotated in the opposite direction by the same angle (rotation amount). However, in general, various modifications are possible for the rotation direction and the rotation amount of the first correction filter and the second correction filter. When the rotation direction and the rotation amount are different between the first correction filter and the second correction filter, when two orthogonal axis directions are considered on the illumination pupil plane, the illumination pole (pupil light) on one axis line is considered. It is possible to control the intensity ratio between the intensity distribution) and the illumination pole on the other axis, thereby adjusting (correcting) the vertical / horizontal difference in the pattern transfer line width.

  In the above description, the first correction filter (6a, 60a) and the second correction filter in the pair of correction filters (6a, 6b) shown in FIG. 3 and the pair of correction filters (60a, 60b) shown in FIG. (6b, 60b) have a transmittance distribution with each other. However, in general, various modifications of the transmittance distribution of the first correction filter and the second correction filter are possible.

  Further, in the above description, only the light intensity of the peripheral region 30p is relatively lowered or increased without changing the light intensity of the central region 30c in the tripolar or pentapolar pupil light intensity distribution. Thus, the ratio between the light intensity of the central region 30c and the light intensity of the peripheral region 30p is adjusted. Further, in the above description, the present invention is applied to a tripolar or pentapolar pupil light intensity distribution. However, the light intensity in the central area and the light intensity in the peripheral area of the pupil light intensity distribution can be adjusted independently of each other, for example, by appropriately setting the transmittance distribution, rotation direction, rotation amount, etc. of the pair of correction filters. It is also possible to apply the present invention to other appropriate pupil light intensity distributions other than tripolar and pentapolar.

  In the above description, the pair of correction filters (6a, 6b; 60a, 60b; 61a, 61b) as adjusting means are arranged on the pupil surface of the afocal lens 4 or in the vicinity thereof, but the present invention is not limited to this. For example, the micro fly's eye lens 9 as an optical integrator can be arranged near the exit side (illumination pupil plane or the vicinity thereof). Further, for example, a pair of correction filters as adjusting means can be disposed in the vicinity of the incident side of the micro fly's eye lens 9, the pupil plane of the imaging optical system 12, or the vicinity thereof.

  By the way, as described above, the first prism member 7a and the second prism member 7b are kept in contact with each other so that the conical axicon system 7 functions as a plane-parallel plate during tripolar illumination or pentapolar illumination. Is done. However, as shown in FIG. 10A, if the conical axicon system 7 is configured to be exchangeable with another deformed conical axicon system 70, the action of the deformed conical axicon system 70 causes tripolar or pentapolar pupil light. It is possible to change only the position and shape of the peripheral region while maintaining the position and shape of the central region in the intensity distribution.

  As shown in FIG. 10B, the deformed conical axicon system 70 includes, in order from the light source side, a first prism member 70a having a flat surface facing the light source side and a refracting surface having a concave cross section facing the mask side, and a mask side. The second prism member 70b has a flat surface and a refracting surface having a convex cross section facing the light source. The concave refracting surface of the first prism member 70a and the convex refracting surface of the second prism member 70b are complementarily formed so as to be in contact with each other.

  More specifically, the refracting surface of the concave section of the first prism member 70a has a planar central portion 70c orthogonal to the optical axis AX and a peripheral conical portion corresponding to the side surface of the cone centered on the optical axis AX. 70d. Similarly, the refracting surface of the convex section of the second prism member 70b has a planar central portion 70e orthogonal to the optical axis AX, and a peripheral conical portion 70f corresponding to the side surface of the cone centered on the optical axis AX. Have In addition, at least one member of the first prism member 70a and the second prism member 70b is configured to be movable along the optical axis AX, and the concave refractive surface of the first prism member 70a and the second prism member 70b. The interval between the convex cross section and the refractive surface is variable.

  In the deformed conical axicon system 70, as shown in FIG. 10 (b), the central luminous flux 41a that forms the light intensity distribution of the central region 30c centered on the optical axis AX, among the tripolar pupil light intensity distributions, It passes through the central portion 70c of the first prism member 70a and the central portion 70e of the second prism member 70b. On the other hand, of the tripolar pupil light intensity distributions, the two peripheral light beams 41b forming the light intensity distributions of the two peripheral regions 30p facing each other across the optical axis AX are the peripheral conical portions 70d of the first prism member 70a. And the peripheral cone portion 70f of the second prism member 70b.

  Here, in a state where the concave refracting surface of the first prism member 70a and the convex refracting surface of the second prism member 70b are in contact with each other, the deformed conical axicon system 70 with respect to the central light beam 41a and the two peripheral light beams 41b. Functions as a plane parallel plate and has no effect on the tripolar pupil light intensity distribution formed. However, if the concave refracting surface of the first prism member 70a and the convex refracting surface of the second prism member 70b are separated, the deformed conical axicon system 70 does not affect the central light beam 41a, but the two peripheral light beams In contrast to 41b, the deformed cone axicon system 70 functions as a so-called beam expander.

  FIG. 11 is a diagram for explaining the action of the modified cone axicon system on the tripolar pupil light intensity distribution. As shown in FIG. 11, the light intensity distribution of the two circular peripheral regions 30p constituting the tripolar pupil light intensity distribution (secondary light source) has an interval between the deformed cone axicon system 70 from zero to a predetermined value. Is expanded outward along the radial direction of the circle centered on the optical axis AX, and the shape changes from a circular shape to an elliptical shape. That is, a line segment connecting the center point of the light intensity distribution of the circular peripheral region 30p before the change and the center point of the light intensity distribution of the elliptical peripheral region 30p ′ after the change passes through the optical axis AX, and the center point The moving distance depends on the distance between the deformed conical axicon system 70.

  Further, an angle at which the circular peripheral region 30p before the change is viewed from the optical axis AX (an angle formed by a pair of tangent lines from the optical axis AX to the peripheral region 30p) and an elliptical peripheral region 30p ′ after the change are The angle seen from AX is equal. Then, the diameter of the circular peripheral region 30p before the change, that is, the difference between the radius of the circle circumscribing the two peripheral regions 30p as the optical axis AX and the radius of the inscribed circle, and the elliptical shape after the change as the optical axis AX The difference between the radius of the circle circumscribing the peripheral region 30p ′ and the radius of the inscribed circle is equal. As described above, the circular peripheral region 30p changes in the circumferential direction depending on the interval of the deformed conical axicon system 70, but does not change in the radial direction.

  On the other hand, the light intensity distribution of the circular central region 30c constituting the tripolar pupil light intensity distribution is not affected even when the interval of the deformed cone axicon system 70 is increased from zero to a predetermined value. Therefore, when the interval between the deformed conical axicon system 70 is increased from zero to a predetermined value, the position and size (shape) of the light intensity distribution of the two circular peripheral regions 30p constituting the tripolar pupil light intensity distribution. ) Changes independently of the light intensity distribution of the circular central region 30c. Although not shown, the same effect can be obtained by the action of the deformed conical axicon system 70 even in the quintuple pupil light intensity distribution.

  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. Refer to the flowchart of FIG. 12 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. 12, 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 micro 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. 13, 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) 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, it is also possible to apply the present invention to such an F ₂ laser light source for supplying laser light of wavelength 157 nm.

  In the above-described embodiment, the present invention has been described by taking an exposure apparatus including an illumination optical apparatus as an example. However, the present invention is applied to a general illumination optical apparatus for illuminating an irradiated surface other than a mask. Obviously you can do that.

It is a figure which shows schematically the structure of the exposure apparatus concerning embodiment of this invention. It is a figure which shows various pupil light intensity distribution formed on an illumination pupil surface. It is a figure which shows roughly the structure of a pair of correction filter used in the case of tripolar illumination. It is a figure explaining the effect | action of the correction filter pair of FIG. 3 in tripolar illumination. It is a figure which shows roughly the structure of a pair of correction filter used in the case of 5 pole illumination. It is a figure explaining the effect | action of the correction filter pair of FIG. 5 in pentapolar illumination. It is a figure which shows schematically the structure of another correction | amendment filter pair used in the case of 5 pole illumination. It is a figure explaining the effect | action of the correction filter pair of FIG. 7 in pentapolar illumination. It is a figure which shows roughly the structure of a pair of correction filter which acts similarly to a pair of correction filter shown in FIG. 5 with the form which the transmittance | permeability changes continuously between two adjacent circular arc area | regions. It is a figure which shows schematically the structure of the deformation | transformation cone axicon system provided so that exchange with the cone axicon system was possible. It is a figure explaining the effect | action of a deformation | transformation cone axicon system with respect to tripolar pupil light intensity distribution. 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 microdevice.

Explanation of symbols

1 Light Source 3 Diffractive Optical Element (Flux Conversion Element)
4 afocal lens 6a, 6b correction filter 7 conical axicon system 8 zoom lens 9 micro fly's eye lens 10 condenser optical system 11 mask blind 12 imaging optical system 13 light intensity distribution measuring device 20 control unit 21-24 driving unit M mask PL Projection optical system W wafer

Claims (18)

In an illumination optical device that forms a pupil light intensity distribution on an illumination pupil plane based on a light flux from a light source and illuminates an illuminated surface using the light flux that has passed through the illumination pupil plane.
The light intensity in the central area of the pupil light intensity distribution and the light in the peripheral area of the pupil light intensity distribution are arranged on or near the illumination pupil plane, or on a plane optically conjugate with the illumination pupil plane or in the vicinity thereof. An illumination optical apparatus comprising an adjusting means for adjusting a ratio with intensity. In an illumination optical device that forms a pupil light intensity distribution on an illumination pupil plane based on a light flux from a light source and illuminates an illuminated surface using the light flux that has passed through the illumination pupil plane.
The light intensity in the central area of the pupil light intensity distribution and the light in the peripheral area of the pupil light intensity distribution are arranged on or near the illumination pupil plane, or on a plane optically conjugate with the illumination pupil plane or in the vicinity thereof. An illumination optical apparatus comprising adjustment means for adjusting the intensity independently of each other. The adjusting unit includes a first correction filter having a first transmittance distribution and a second correction filter having a second transmittance distribution. The first correction filter and the second correction filter are light beams. The illumination optical apparatus according to claim 1, wherein the illumination optical apparatus is arranged close to each other along an axis and configured to be rotatable about the optical axis. The first correction filter and the second correction filter have the same transmittance distribution and are configured to rotate in opposite directions by the same angle around the optical axis. The illumination optical apparatus according to any one of 1 to 3. The first correction filter and the second correction filter each include a central region having a constant transmittance and a plurality of peripheral regions arranged so as to surround the central region and having different transmittances. 5. The illumination optical device according to 4. The plurality of peripheral regions have a plurality of arc-shaped regions obtained by dividing an annular region around the optical axis in the circumferential direction, and sandwich the optical axis among the plurality of arc-shaped regions. The opposing first pair of arcuate regions have the same first transmittance, and the opposing second pair of arcuate regions across the optical axis have the same second transmittance. The illumination optical apparatus according to claim 5, wherein The illumination optical device according to claim 6, wherein the plurality of arc-shaped regions included in the plurality of peripheral regions are obtained by equally dividing an annular region centered on the optical axis into four equal parts. The illumination optical device according to claim 6, wherein the plurality of arc-shaped regions included in the plurality of peripheral regions are obtained by dividing an annular region centered on the optical axis into approximately eight equal parts. 9. The device according to claim 6, wherein the first transmittance is larger than the transmittance of the central region, and the second transmittance is smaller than the transmittance of the central region. Illumination optical device. The illumination optical according to claim 9, wherein a difference between the first transmittance and the transmittance of the central region is substantially equal to a difference between the transmittance of the central region and the second transmittance. apparatus. 11. The plurality of peripheral regions have a transmittance distribution that is n times rotationally symmetric with respect to the centers of the first correction filter and the second correction filter, where n is an integer. The illumination optical device according to claim 1. The illumination optical device according to claim 5, wherein the plurality of peripheral regions have a continuous transmittance change. The adjusting means has a plurality of sets of the first correction filter and the second correction filter,
The plurality of sets of the first correction filter and the second correction filter are configured to be switchable with respect to an illumination optical path in accordance with the pupil light intensity distribution. The illumination optical device according to 1. A light beam conversion element for converting the light beam from the light source into a light beam having a predetermined cross section, and an optical integrator disposed in an optical path between the light beam conversion element and the irradiated surface,
The illumination optical apparatus according to claim 1, wherein the adjusting unit is disposed in an optical path between the light beam conversion element and the optical integrator. 15. An illumination optical apparatus according to claim 1, for illuminating a predetermined pattern, and a projection optical system for forming an image of the predetermined pattern on a photosensitive substrate. An exposure apparatus characterized by that. According to the measurement means for measuring the light intensity distribution on the pupil plane of the projection optical system or a plane equivalent to the pupil plane, and the measurement result of the light intensity distribution on the pupil plane or the plane equivalent to the pupil plane 16. The exposure apparatus according to claim 15, further comprising a control means for controlling the adjustment means. 15. An exposure method comprising illuminating a predetermined pattern via the illumination optical apparatus according to claim 1, and exposing the illuminated pattern onto a photosensitive substrate by a projection optical system. A measuring step of measuring a light intensity distribution on a pupil plane of the projection optical system or a plane equivalent to the pupil plane; and the adjusting means according to a measurement result of the light intensity distribution on the pupil plane or a plane equivalent to the pupil plane The exposure method according to claim 17, further comprising a control step of controlling

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