WO2005036619A1

WO2005036619A1 - Illumination optical device, and exposure device and method

Info

Publication number: WO2005036619A1
Application number: PCT/JP2004/014323
Authority: WO
Inventors: Mitsunori Toyoda
Original assignee: Nikon Corporation
Priority date: 2003-10-09
Filing date: 2004-09-30
Publication date: 2005-04-21
Also published as: JPWO2005036619A1

Abstract

An illumination optical device that realizes, when mounted for example on an exposure device, an illumination condition suitable for a mask pattern where two kinds of patterns having different characteristics are mixed. The illumination optical device has a first light flux conversion element (7) for converting light flux from a light source section (1) to light flux having a first cross-sectional shape corresponding to a first region on an illumination pupil surface, a second light flux conversion element (8) for converting the light flux from the light source section to light flux having a second cross-sectional shape corresponding to a second region on the illumination pupil surface, a beam splitter (5) for splitting the light flux from the light source section and guiding each of the split light flux to the first light flux conversion element and the second light flux conversion element, and intensity changing means (2, 3, 5) for changing the ratio between the intensity of light reaching the first region through the first light flux conversion element and the intensity of light reaching the second region through the second light flux conversion element.

Description

Specification

Illumination optical device, exposure apparatus, and exposure method

Technical field

The present invention relates to an illumination optical device, an exposure device, and an exposure method, and more particularly, to an exposure device for manufacturing a micro device such as a semiconductor device, an imaging device, a liquid crystal display device, and a thin-film magnetic head by a lithography process.

Background art

[0002] In a typical exposure apparatus of this type, a secondary light source (generally, a predetermined light intensity distribution on an illumination pupil plane) is used as a substantial surface light source that also has a light source power, an emitted light flux power, and an optical light source power. Form. The luminous flux of the secondary light source enters the condenser lens after being restricted via the aperture stop located near the rear focal plane of the fly-eye lens.

[0003] 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) on 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.

[0004] Therefore, a circular secondary light source is formed on the rear focal plane of the fly-eye lens, and the size of the secondary light source is changed to change the illumination coherency σ (σ value = aperture stop diameter 瞳 pupil diameter of the projection optical system. Or a technique that changes the σ value = numerical aperture on the exit side of the illumination optical system Ζ numerical aperture on the incident side of the projection optical system. Attention has also been focused on a technology that forms an annular 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.

Disclosure of the invention

Problems the invention is trying to solve [0005] In the conventional exposure apparatus as described above, ordinary circular illumination based on a circular secondary light source is performed, or an annular, dipole, or quadrupole secondary illumination is performed in accordance with the pattern characteristics of the mask. They perform deformed illumination based on the light source (eg, annular illumination, dipole illumination, or quadrupole illumination). However, it was not possible to achieve appropriate illumination conditions necessary to faithfully transfer a mask pattern in which two types of patterns with different characteristics were mixed, while suppressing loss of light.

[0006] The present invention has been made in view of the above-described problems. For example, when mounted on an exposure apparatus, an illumination condition suitable for a mask pattern in which two types of patterns having different characteristics coexist is set to a light amount. An object is to provide an illumination optical device that can be realized while suppressing loss. Further, the present invention uses an illumination optical device capable of realizing illumination conditions suitable for a mask pattern in which, for example, two types of patterns having different characteristics are mixed, by using an appropriate optical mask realized in accordance with the pattern characteristics of the mask. An object of the present invention is to provide an exposure apparatus and an exposure method capable of performing good exposure under a variety of illumination conditions.

Means for solving the problem

[0007] In order to solve the above-described problems, according to a first embodiment of the present invention, there is provided an illumination optical device that illuminates a surface to be irradiated based on a light beam from a light source unit.

A first light beam conversion element that is arranged in the light path of the light beam from the light source unit and converts the light beam into a light beam having a first cross-sectional shape;

A second luminous flux conversion element disposed in the optical path of the luminous flux from the light source unit, for converting the luminous flux into a luminous flux having a second cross-sectional shape;

The luminous flux having the first cross-sectional shape is arranged in the optical path between the luminous flux having the first cross-sectional shape from the first luminous flux conversion element and the luminous flux having the second cross-sectional shape from the second luminous flux converting element. A condensing optical system that guides a light beam having the second cross-sectional shape to a second area different from the first area on the illumination pupil plane, while guiding the light flux to the first area on the illumination pupil plane of the illumination optical device; A polarization state changer arranged in an optical path between a light source unit and the illumination pupil plane to change the polarization state of the light flux reaching the first area and the polarization state of the light flux reaching the second area independently. There is provided an illumination optical device characterized by comprising means.

According to a second embodiment of the present invention, there is provided an illumination optical device for illuminating a surface to be illuminated,

The polarization state of the first region on the illumination pupil plane and the polarization state of the second region on the illumination pupil plane There is provided an illumination optical device including a polarization state control means for independently controlling.

According to a third embodiment of the present invention, there is provided an illumination optical device for illuminating an irradiated surface,

A first light beam conversion element for converting a light beam from the light source unit into a light beam having a first cross-sectional shape corresponding to a first region on the illumination pupil plane;

A second light beam conversion element for converting a light beam from the light source unit into a light beam having a second cross-sectional shape corresponding to a second region on the illumination pupil plane;

A beam splitter for splitting a light beam from the light source unit and guiding the light beam to the first light beam conversion element and the second light beam conversion element, respectively;

Intensity changing means for changing the ratio of the intensity of light reaching the first region via the first light beam conversion device and the intensity of light reaching the second region via the second light beam conversion device. And an illumination optical device characterized by comprising:

According to a fourth embodiment of the present invention, there is provided an illumination optical device for illuminating a surface to be irradiated,

An illumination optical device is provided, wherein the first light beam conversion element and the second light beam conversion element are configured to be exchangeable with respect to an illumination light path.

According to a fifth aspect of the present invention, there is provided an illumination optical apparatus for illuminating a surface to be illuminated based on a light flux of a light source unit,

A polarization fluctuation eliminating unit disposed between the light source unit and the irradiated surface to prevent a change in the polarization state of a light beam from the light source unit;

The polarization fluctuation eliminating means includes: a polarization beam splitter that divides a light beam from the light source unit according to a polarization state; a polarization adjustment member that aligns the polarization state of the light beam divided by the polarization beam splitter; And a light beam combining optical system for combining the light beams split by the beam splitter.

According to a sixth aspect of the present invention, there is provided an illumination optical apparatus according to the first to fifth aspects for illuminating a mask. An exposure device, comprising: exposing a pattern of the mask onto a photosensitive substrate.

[0013] In a seventh aspect of the present invention, an illumination step of illuminating a mask via the illumination optical device according to the first to fifth aspects, and exposing a pattern formed on the illuminated mask to a photosensitive substrate. A light exposure step.

The invention's effect

In the illumination optical device according to the present invention, for example, the polarization state of the first region and the polarization state of the second region on the illumination pupil plane are obtained by the action of two or more light beam conversion elements, the condensing optical system, and the polarization state changing means. State can be controlled independently. In addition, the light reaching the first area on the illumination pupil plane is formed by the action of the polarizing beam splitter, the two or more light beam converting elements, and the polarization state adjusting means for adjusting the polarization state of the light incident on the polarizing beam splitter. It is possible to change the ratio between the intensity of the light and the intensity of the light reaching the second region.

[0015] Therefore, for example, when the illumination optical device of the present invention is mounted on an exposure apparatus, it is possible to realize illumination conditions suitable for a mask pattern in which two types of patterns having different characteristics are mixed while suppressing loss of light amount. it can. Further, in the exposure apparatus and the exposure method using the illumination optical device of the present invention, it is possible to realize illumination conditions suitable for a mask pattern in which two types of patterns having different characteristics are mixed. Good exposure can be performed under appropriate lighting conditions realized by the above, and thus a good device can be manufactured with high throughput.

In the exposure apparatus and the exposure method using the illumination optical device of the present invention, the polarization states of the vertically or horizontally polarized light and the 45 or 135 degree polarized light can be separately adjusted. Exposure can be performed while favorably correcting polarization state collapse caused by an optical path bending mirror disposed in an optical path or a projection optical path.

Brief Description of Drawings

FIG. 1 is a diagram schematically showing a configuration of an exposure apparatus provided with an illumination optical device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an annular tripolar secondary light source formed on an illumination pupil plane in the first embodiment. FIG. 3 is a diagram showing a pentapole secondary light source and a deformed annular shape formed on an illumination pupil plane in the first embodiment.

{4} is a view schematically showing a configuration of a main part of an exposure apparatus provided with an illumination optical device according to a second embodiment of the present invention.

FIG. 5 is a diagram schematically showing a main configuration of an exposure apparatus including an illumination optical device according to a modification of the first embodiment.

FIG. 6 is a diagram schematically showing a main configuration of an exposure apparatus including an illumination optical device according to a modification of the second embodiment.

FIG. 7 is a diagram schematically showing a main configuration of an exposure apparatus including an illumination optical device according to a modification of the first or second embodiment.

8 is a diagram schematically showing a configuration of a main part of an exposure apparatus provided with an illumination optical device according to a modification shown in FIG. 7.

9 is a view showing an octupole secondary light source formed on an illumination pupil plane in the modification shown in FIG. 7.

FIG. 10 is a flowchart of a method for obtaining a semiconductor device as a micro device.

FIG. 11 is a flowchart of a method for obtaining a liquid crystal display element as a micro device. BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a view schematically showing a configuration of an exposure apparatus provided with an illumination optical device according to a first embodiment of the present invention. In FIG. 1, the Z axis is along the normal direction of the wafer W as the photosensitive substrate, the Y axis is in the plane of the wafer W, and the Y axis is in the direction parallel to the plane of FIG. Set the X-axis in the direction perpendicular to the page 1! /

The exposure apparatus according to the first embodiment includes a light source 1 for supplying exposure light (illumination light). As the light source 1, for example, a KrF excimer laser light source that supplies light having a wavelength of 248 nm or an ArF excimer laser light source that supplies light having a wavelength of 193 nm can be used. The almost parallel light flux emitted from the light source 1 along the Z direction is reflected by the folding mirror in the Y direction. After being deflected to the first prism assembly 2 and the second prism assembly 3, the light enters the beam matching unit 4.

[0020] The first prism assembly 2 is integrally formed by a wedge-shaped first quartz prism 2a and a wedge-shaped first quartz prism 2b having a shape complementary to the first quartz prism 2a. Have been. Similarly, the second prism assembly 3 is integrally formed by a wedge-shaped second quartz prism 3a and a wedge-shaped second quartz prism 3b having a shape complementary to the second quartz prism 3a. I have. The first prism assembly 2 and the second prism assembly 3 are each configured to be rotatable about an optical axis AX. The operation of the first prism assembly 2 and the second prism assembly 3 will be described later.

On the other hand, the beam matching unit 4 includes a beam shaping unit for shaping the parallel beam supplied from the light source 1 into a parallel beam having a predetermined sectional shape, and an optical axis AX of the parallel beam supplied from the light source 1 Beam angle adjusting means for adjusting the angle with respect to the laser beam, beam parallel moving means for parallel moving the parallel beam supplied from the light source 1 with respect to the optical axis AX, and the like. That is, the beam matching unit 4 converts the incident light beam into a light beam having a cross section of an appropriate size and shape, guides the light beam to the polarization beam splitter 5 at the subsequent stage, and changes the position and angle of the light beam incident on the polarization beam splitter 5. It has a function to actively correct the degree fluctuation.

[0022] The prism type polarizing beam splitter 5 subsequent to the beam matching unit 4 is provided with a right-angle prism 6 as reflecting means. The right-angle prism 6 is positioned so as to reflect the reflected light from the polarizing beam splitter 5 and to guide the reflected light along the optical path parallel to the optical path of the transmitted light of the polarizing beam splitter 5. Therefore, of the light incident on the polarization beam splitter 15, the S-polarized light reflected on the polarization splitting surface is reflected on the reflection surface of the right-angle prism 6 and then incident on the first diffractive optical element 7. On the other hand, of the light incident on the polarization beam splitter 5, the P-polarized light transmitted through the polarization splitting surface is incident on the second diffractive optical element 8.

In general, a diffractive optical element is formed by forming a step having a pitch of about the wavelength of exposure light (illumination light) on a substrate, and has an action of diffracting an incident beam to a desired angle. Specifically, the first diffractive optical element 7 receives a parallel light beam having a rectangular cross section. In this case, it has the function of forming a circular light intensity distribution in the far field (or Fraunhofer diffraction region). In addition, the second diffractive optical element 8 has a function of forming a dipole-like light intensity distribution spaced along the X direction in the far field when a parallel light beam having a rectangular cross section is incident. .

[0024] The first diffractive optical element 7 and the second diffractive optical element 8 are configured to be detachable from the illumination optical path, and can be exchanged for other first and second diffractive optical elements having different characteristics. Is configured. The light beam passing through the first diffractive optical element 7 and the second diffractive optical element 8 passes through a zoom lens 9 to a microlens array (or fly-eye lens) 10 having an incident surface located near the rear focal plane. Each is incident. That is, the zoom lens 9 arranges the first diffractive optical element 7 and the second diffractive optical element 8 and the entrance surface of the microlens array 10 substantially in a Fourier transform relationship.

[0025] The microlens array 10 is an optical element composed of a large number of microlenses having a positive refractive power arranged vertically and horizontally and densely. In general, a microlens array is formed by, for example, performing etching on a parallel flat plate to form a group of microlenses. Here, each micro lens constituting the micro lens array is smaller than each lens element constituting the fly-eye lens. Also, unlike a fly-eye lens composed of lens elements isolated from each other, the microlens array has a large number of microlenses (microrefractive surfaces) formed integrally without being isolated from each other. A microlens array is a wavefront splitting optical integrator similar to a fly-eye lens in that lens elements having positive refracting power are arranged vertically and horizontally.

[0026] Thus, the light beam passing through the first diffractive optical element 7 is transmitted to the rear focal plane of the zoom lens 9 (and thus to the incident surface of the microlens array 10), for example, in a circular shape centered on the optical axis AX. The territory is formed. Similarly, the luminous flux passing through the second diffractive optical element 8 is spaced at the rear focal plane of the zoom lens 9 (and, consequently, at the entrance plane of the microlens array 10), for example, along the optical axis AX in the X direction. It forms a dipole illumination field in the X direction that also has two separate circular illumination field forces.

The light beam incident on the microlens array 10 is two-dimensionally split, and the rear focal plane of the microlens array 10 has an illumination formed by the incident light beam, as shown in FIG. Field and A secondary light source having the same light intensity distribution, that is, a circular surface light source 3 la centered on the optical axis AX, and two circular light sources spaced apart along the X direction around the optical axis AX A three-pole secondary light source (31a, 31b) in the X direction consisting of a substantial surface light source of 3 lb is formed.

The luminous flux from the secondary light source in the X direction formed on the rear focal plane (illumination pupil plane) of the microlens array 10 is subjected to the condensing operation of the condenser optical system 11 and then is subjected to mask brightening. The lamp 12 is illuminated in a superimposed manner. Thus, a rectangular illumination field corresponding to the shape and the focal length of each microlens constituting the microlens array 10 is formed on the mask blind 12 as the illumination field stop. The light flux passing through the rectangular opening (light transmitting portion) of the mask blind 12 irradiates the mask M on which a predetermined pattern is formed in a superimposed manner after receiving the light-condensing action of the imaging optical system 13.

Thus, the imaging optical system 13 forms an image of the rectangular opening of the mask blind 12 on the mask M. The light flux transmitted through the pattern of the mask M forms an image of the mask pattern on the wafer W as a photosensitive substrate via the projection optical system PL. In this way, by performing batch exposure or scan exposure while 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 area of the wafer W The pattern of the mask M is sequentially exposed. In the first embodiment, when the focal length of the zoom lens 9 changes, the entire secondary light source is similarly enlarged or reduced.

As described above, the second diffractive optical element 8 is a diffractive optical element for dipole illumination in the X direction that forms a dipole secondary light source spaced along the X direction about the optical axis AX. The element is configured. Note that, instead of the second diffractive optical element 8 for X-direction dipole illumination, a second diffractive optical element 8a (not shown) for Z-direction dipole illumination is set in the illumination optical path, so that the Z-direction tripole illumination can be performed. It can be performed. The second diffractive optical element 8a for dipole illumination in the Z direction has a function of forming a dipole-like light intensity distribution spaced along the Z direction in the far field when a parallel light beam enters. .

Accordingly, the light beam passing through the second diffractive optical element 8a forms a dipole-shaped illumination field on the incident surface of the microlens array 10, for example, spaced along the optical axis AX in the Z direction. To achieve. As a result, as shown in FIG. 2 (b), the rear focal plane of the microlens array 10 has a substantially circular light source 31a centered on the optical axis AX and a Z-axis centered on the optical axis AX. direction , And a secondary light source (31a, 31c) having three poles in the Z direction is formed, which is composed of two substantially circular surface light sources 31c spaced apart from each other.

Further, by setting the second diffractive optical element 8b (not shown) for quadrupole illumination in the illumination optical path, pentapole illumination can be performed. The second diffractive optical element 8b for quadrupole illumination has a function of forming a quadrupolar light intensity distribution in the far field when a parallel light beam enters. Therefore, the light beam passing through the second diffractive optical element 8b forms, for example, a quadrupole illumination field centered on the optical axis AX on the incident surface of the microlens array 10. As a result, as shown in FIG. 3 (a), the rear focal plane of the microphone-aperture lens array 10 has a substantially circular circular surface light source 31a centered on the optical axis AX, and a circular centered light source 31a A five-pole secondary light source (31a, 31d) consisting of four circular substantially surface light sources 31d arranged at the vertices of a square or rectangle having one side along the X direction is formed. Is done.

Further, by setting a second diffractive optical element 8c (not shown) for annular illumination in the illumination optical path, modified annular illumination can be performed. The second diffractive optical element 8c for annular illumination has a function of forming an annular (annular) light intensity distribution in the far field when a parallel light beam enters. Therefore, the light beam passing through the second diffractive optical element 8c forms, for example, an annular illumination field around the optical axis AX on the incident surface of the micro lens array 10. As a result, as shown in FIG. 3 (b), the rear focal plane of the microlens array 10 has a substantially circular surface light source 31a centered on the optical axis AX and a circular surface light source 31a centered on the optical axis AX. A deformed annular secondary light source (31a, 31e) including the annular annular surface light source 31e is formed.

Further, a second diffractive optical element 8 for dipole illumination in the X direction, a second diffractive optical element 8a for dipole illumination in the Z direction, a second diffractive optical element 8b for quadrupole illumination, and an annular illumination By setting a second diffractive optical element having other characteristics in the illumination optical path instead of the second diffractive optical element 8c, the number and arrangement of the surface light sources formed apart from the optical axis AX , And the shape and size of each surface light source can be changed.

Further, as described above, the first diffractive optical element 7 forms a relatively small circular substantially surface light source around the optical axis AX to perform circular illumination with a relatively small σ value. , Ie, a diffractive optical element for small σ illumination. In addition, instead of the first diffractive optical element 7 for small σ illumination, a first diffractive optical element having other characteristics is used in the illumination optical path. By setting to the middle, the shape and size of the relatively small surface light source centered on the optical axis AX can be changed.

In the first embodiment, the light that reaches the surface light source (31a) formed around the optical axis AX is S-polarized light, and each of the surface light sources (31b-31e) formed away from the optical axis AX. The light reaching) is P-polarized. However, the first diffractive optical element 7 is arranged in the optical path between the polarizing beam splitter 5 and the zoom lens 9, and the second diffractive optical element 8 is arranged in the optical path between the right-angle prism 6 and the zoom lens 9. As a result, the light reaching the surface light source formed around the optical axis AX becomes P-polarized light, and the light reaching each surface light source formed away from the optical axis AX becomes S-polarized light.

As described above, the first diffractive optical element 7 converts the light beam from the light source 1 into a light beam having the first cross-sectional shape corresponding to the first region on the illumination pupil plane, specifically, the region including the optical axis. It constitutes a first light beam conversion element for conversion. The second diffractive optical element 8 converts the light beam from the light source 1 into a second area on the illumination pupil plane, more specifically, a second sectional shape corresponding to an annular or multiple pole area away from the optical axis. And a second light beam conversion element for converting the light beam into a second light beam. Further, the polarizing beam splitter 5 splits the light beam from the light source 1 to a first diffractive optical element 7 as a first light beam converting element and a second diffractive optical element 8 as a second light beam converting element, respectively. It constitutes a beam splitter for guiding.

Next, the operation of the first prism assembly 2 and the second prism assembly 3 will be described.

In the first prism assembly 2, the vertex direction of the first quartz prism 2a and the vertex direction of the first quartz prism 2b are set in opposite directions, and the deflective action of the first quartz prism 2a is reduced by the first quartz prism 2b. It is configured to compensate (correct). Similarly, in the second prism assembly 3, the vertex direction of the second quartz prism 3a and the vertex direction of the second quartz prism 3b are set in opposite directions, and the eccentric effect of the second quartz prism 3a is reduced by the second quartz prism. 3b is configured to compensate (correct).

When a KrF excimer laser light source or an ArF excimer laser light source is used as the light source 1, substantially linearly polarized light supplied from the light source 1 is incident on the first prism assembly 2. In this case, as disclosed in Japanese Patent Application Laid-Open No. 2000-114157, only the first prism assembly 2 is rotated about the optical axis AX while the second prism assembly 3 is fixed. Accordingly, the intensity ratio between the P-polarized light component and the S-polarized light component included in the light emitted from the second prism assembly 3 can be continuously changed.

[0040] Further, as proposed in the specification and drawings of Japanese Patent Application No. 2003-336869, the crystal optical axis of the first crystal prism 2a and the crystal optical axis of the second crystal prism 3a form an angle of 45 degrees. With such a setting, the light emitted from the second prism assembly 3 can be converted into substantially unpolarized light regardless of the polarization state of the light incident on the first prism assembly 2. . As described above, the first quartz prism 2a and the second prism assembly 3 constitute a polarization state adjusting means for adjusting the polarization state of the light incident on the polarization beam splitter 5.

When the polarization state of the light incident on the polarization beam splitter 5 changes due to the operation of the polarization state adjusting means (2, 3), the S-polarized light component reflected by the polarization beam splitter 5 and the polarization beam splitter 5 are separated. The intensity ratio with the transmitted P-polarized component changes. As a result, the intensity of light reaching the surface light source (31a) formed so as to include the optical axis AX on the illumination pupil plane via the first diffractive optical element 7 and the illumination via the second diffractive optical element 8 The ratio with the intensity of light reaching the surface light source (31b-31e) formed on the pupil plane away from the optical axis AX changes.

As described above, the polarization state adjusting means (2, 3) and the polarization beam splitter 5 are connected to the optical axis AX as the first region via the first diffractive optical element 7 as the first light beam conversion element. And reaches the surface light source (31b-31e) distant from the optical axis AX as the second area via the second diffractive optical element 8 as the second light flux conversion element. It constitutes intensity changing means for changing the ratio with the light intensity.

As described above, in the first embodiment, the surface light source (31a) including the optical axis AX is formed on the illumination pupil plane via the first diffractive optical element 7 as the first light beam conversion element. A surface light source (31b-31e) distant from the optical axis AX is formed on the illumination pupil plane via the second diffractive optical element 8 as a two-beam conversion element. Therefore, for example, a pattern suitable for small σ illumination using the first diffractive optical element 7 and a pattern suitable for dipole illumination, quadrupole illumination, or annular illumination using the second diffractive optical element 8 are mixed. Lighting conditions suitable for such mask patterns, that is, appropriate lighting conditions necessary to faithfully transfer a mask pattern in which two types of patterns with different characteristics are mixed, while suppressing loss of light. it can.

In the first embodiment, the first diffractive optical element is actuated by the action of the intensity changing means (2, 3, 5). The intensity of light reaching the surface light source (31a) formed so as to include the optical axis AX on the illumination pupil plane via the element 7 and the optical axis AX on the illumination pupil plane via the second diffractive optical element 8 It is possible to change the ratio with the intensity of light reaching the surface light source (31b-31e) formed away from the light source. Therefore, the ratio of the light intensity in small σ illumination using the first diffractive optical element 7 to the light intensity in dipole illumination, quadrupole illumination, or annular illumination using the second diffractive optical element 8 is appropriately changed. In this way, it is possible to realize various illumination conditions with respect to light intensity.

In the first embodiment, the first diffractive optical element 7 as the first light beam converting element and the second diffractive optical element 8 as the second light beam converting element are configured to be interchangeable with respect to the illumination light path. Have been. Therefore, it is possible to switch between X-direction tripole illumination, Ζ-direction tripole illumination, pentapole illumination, and modified annular illumination, and to determine the number and arrangement of surface light sources formed away from the optical axis 並びに, and By changing the shape and size of each surface light source, and by changing the shape and size of a relatively small surface light source centered on the optical axis ΑΧ, there is a wide variety of secondary light source forms. Lighting conditions can be realized.

FIG. 4 is a diagram schematically showing a main configuration of an exposure apparatus provided with an illumination optical device according to a second embodiment of the present invention. The second embodiment has a configuration similar to that of the first embodiment. However, in the second embodiment, a 1Z2 wavelength plate 14 is provided in the optical path between the right-angle prism 6 and the first diffractive optical element 7, and the optical path between the polarization beam splitter 5 and the second diffractive optical element 8 is provided. The difference from the first embodiment is that a 1Z2 wavelength plate 15 is provided therein, and a prism assembly 16 is provided in the optical path between the first diffractive optical element 7 and the zoom lens 9. Therefore, in FIG. 4, only the configuration from the polarizing beam splitter 5 and the right-angle prism 6 to the micro lens array 10 is illustrated, and other configurations that are the same as those in the first embodiment are omitted. Hereinafter, the second embodiment will be described by focusing on the differences from the first embodiment.

In the second embodiment, in the optical path between the right-angle prism 6 and the first diffractive optical element 7, the 1Z2 wavelength plate 14 in which the crystal optical axis is rotatable around the optical axis AX is arranged. ing. Similarly, in the optical path between the polarizing beam splitter 5 and the second diffractive optical element 8, a 1Z2 wavelength plate 15 having a crystal optical axis rotatable around an optical axis AX is arranged. In the optical path between the first diffractive optical element 7 and the zoom lens 9, a wedge-shaped A prism assembly 16 integrally formed of a quartz prism 16a of this type and a wedge-shaped quartz prism 16b having a shape complementary to the quartz prism 16a is arranged.

[0048] The prism assembly 16 is configured to be rotatable about the optical axis AX. In the prism assembly 16, the apex direction of the quartz prism 16a and the apex direction of the quartz prism 16b are set to be opposite, and the quartz prism 16b compensates (corrects) the deflection effect of the quartz prism 16a. Have been. In the prism assembly 16, by setting the direction of the crystal optic axis of the quartz prism 16a at an angle of 45 degrees with respect to the plane of polarization of the incident linearly polarized light, the light emitted from the prism assembly 16 is substantially reduced. It is converted to light in a non-polarized state. On the other hand, if the direction of the crystal optic axis of the quartz prism 16a is set at an angle of 0 or 90 degrees with respect to the plane of polarization of the incident linearly polarized light, the plane of polarization of the incident linearly polarized light will remain unchanged. Passes through assembly 16.

[0049] Thus, the 1Z2 wavelength plate 14 is provided between the right-angle prism 6 and the first diffractive optical element 7 and thus between the polarizing beam splitter 5 and the first diffractive optical element 7 as the first light beam converting element. The first phase plate is arranged in the optical path between the first and second polarizers to change the direction of the plane of polarization of the incident linearly polarized light (ie, S-polarized light). Further, the 1Z2 wavelength plate 15 is disposed in the optical path between the polarizing beam splitter 5 and the second diffractive optical element 8 as the second light beam converting element, and polarizes incident linearly polarized light (ie, P-polarized light). It constitutes a second phase plate for changing the direction of the plane. Further, the prism assembly 16 is disposed in the optical path between the first diffractive optical element 7 and the zoom lens 9 and, consequently, in the optical path between the 1Z2 wavelength plate 14 as the first phase plate and the zoom lens 9. And a depolarizing element for converting incident linearly polarized light into unpolarized light.

In the second embodiment, the 1Z2 wavelength plate 14 and the prism assembly 16 cooperate to form an optical axis AX on the illumination pupil plane via the first diffraction optical element 7. The polarization state of light reaching the surface light source (31a) can be set to linearly polarized light or non-polarized light having a polarization plane in an arbitrary direction. Further, by the action of the 1Z2 wavelength plate 15, the polarization state of light reaching the surface light source (31b-31e) formed apart from the optical axis AX on the illumination pupil plane via the second diffractive optical element 8 can be changed arbitrarily. Can be set to linearly polarized light having a polarization plane in the direction of. As described above, the polarizing beam splitter 5, the 1Z2 wavelength plate 14, the 1Z2 wavelength plate 15, and the prism assembly 16 form the first region via the first diffractive optical element 7 as the first light beam conversion element. The light reaching the surface light source (31a) including all the optical axes AX and the surface light source (31b-31e) separated from the optical axis AX as the second region via the second diffractive optical element 8 as the second light beam conversion element ) Constitutes a polarization state changing means for changing the polarization state of at least one of the light beams reaching the first and second light beams.

Further, the polarization state changing means (5, 14, 15, 16), the first diffractive optical element 7, and the second diffractive optical element 8 form an optical axis AX as a first area on the illumination pupil plane. Polarization state control means for independently controlling the polarization state of the surface light source (31a) including the surface light source (31a) and the polarization state of the surface light source (31b-31e) remote from the optical axis AX as the second area on the illumination pupil plane. Is composed. Thus, in the second embodiment, in addition to the operation and effect of the above-described first embodiment, the polarization state of the surface light source formed apart from the optical axis AX and the polarization state of the surface light source including the optical axis AX are independent of each other. It is possible to realize a variety of illumination conditions with respect to the polarization state of the secondary light source by appropriately changing.

In the above-described second embodiment, the 1Z2 wavelength plate 14 as the first phase plate is disposed in the optical path between the rectangular prism 6 and the first diffractive optical element 7. However, the present invention is not limited to this. For example, the 1Z2 wave plate 14 can be arranged in the optical path between the first diffractive optical element 7 and the zoom lens 9. Further, in the above-described second embodiment, the 1Z2 wavelength plate 15 as the second phase plate is disposed in the optical path between the polarization beam splitter 5 and the first diffractive optical element 8. However, the present invention is not limited to this. For example, the 1Z2 wavelength plate 15 can be arranged in the optical path between the second diffractive optical element 8 and the zoom lens 9.

In the above-described second embodiment, the prism assembly 16 as a depolarizing element is arranged in the optical path between the first diffractive optical element 7 and the zoom lens 9. However, the prism assembly 16 can be arranged in the optical path between the 1Z2 wavelength plate 14 as the first phase plate and the first diffractive optical element 7 without being limited to this. Alternatively, the prism assembly 16 is arranged in the optical path between the second diffractive optical element 8 and the zoom lens 9 or in the optical path between the 1Z2 wavelength plate 15 as the second phase plate and the second diffractive optical element 8. You can also. Alternatively, the optical path between the 1Z2 wave plate 14 and the zoom lens 9 and the 1Z2 wave plate 15 and the zoom lens A prism assembly as a depolarizing element can be arranged on both sides of the optical path between the lens 9 and the prism 9.

FIG. 5 is a diagram schematically showing a configuration of a main part of an exposure apparatus including an illumination optical device according to a modification of the first embodiment. 5 is different from the first embodiment in the optical path between the power polarizing beam splitter 5 and the first diffractive optical element 7 having a configuration similar to that of the first embodiment. Hereinafter, a modification of FIG. 6 will be described, focusing on differences from the first embodiment.

In the modified example of FIG. 5, the reflection surface of the right-angle prism 6 is an amplitude division surface (typically a half mirror), and a pair of mirrors 17a and 17b are provided to detour light transmitted through the amplitude division surface. An optical path is formed, and light guided along the bypass optical path is re-entered on the amplitude division plane so as to substantially match light reflected on the amplitude division plane. With this configuration, it is possible to reduce the temporal coherence of the light reflected by the polarization beam splitter 5 (that is, the S-polarized light).

FIG. 6 is a diagram schematically showing a main configuration of an exposure apparatus including an illumination optical device according to a modification of the second embodiment. The modification of FIG. 6 is similar to that of the second embodiment except that the 1Z2 wave plate 14 is provided in the optical path between the right-angle prism 6 and the first diffractive optical element 7, and the 1Z2 This embodiment is different from the second embodiment in that the arrangement of the wave plate 15 and the prism assembly 16 is omitted. Hereinafter, a modification of FIG. 6 will be described, focusing on differences from the second embodiment.

In the modification of FIG. 6, the S-polarized light reflected by the polarization beam splitter 5 is incident on the 1Z2 wavelength plate 14 via the right-angle prism 6. The light converted to P-polarized light via the 1Z2 wavelength plate 14 reaches the incident surface of the microphone lens array 10 in the P-polarized state via the first diffractive optical element 7 and the zoom lens 9. On the other hand, the P-polarized light transmitted through the polarizing beam splitter 5 reaches the incident surface of the microlens array 10 in the P-polarized state via the second diffractive optical element 8 and the zoom lens 9.

As described above, in the modified example of FIG. 6, the incident light is divided by the polarization beam splitter 5 in the polarization direction, and the reflected light of the polarization beam splitter 5 is used by using the 1Z2 wavelength plate 14 as a phase member. After matching the polarization state to the polarization state of the transmitted light of the polarization beam splitter 5, the polarization beam splitter 5 passes through a zoom lens 9 (or a condenser lens) as an optical path combining optical system. The reflected light and transmitted light of one splitter 5 are combined. As a result, for example, the polarization state of the light incident on the polarization beam splitter 5 is changed by the influence of the light transmitting member that is disposed in the optical path upstream of the polarization beam splitter 5 and is formed of birefringent fluorite. Even if it fluctuates over time, the polarization state of the light combined via the zoom lens 9 can always be kept constant.

In the above-described embodiment, a wave plate (phase member) is used as a member for changing the direction of the plane of polarization of the linearly polarized light that enters. As a member for changing the direction of the plane of polarization of the incident linearly polarized light while applying force, an optical rotator not limited to a wave plate may be used. Here, as the optical rotator, for example, an optical rotator formed of quartz can be used. Further, in the second embodiment, for example, a polarizer disclosed in Japanese Patent Application Publication No. 2003-35822 and US Patent Publication No. 2002Z176166A corresponding thereto may be applied instead of the 1Z2 wavelength plate 15. Thereby, the polarization state of light reaching the surface light source (31b-31e) formed apart from the optical axis AX on the illumination pupil plane via the second diffractive optical element 8 is changed to a circumference around the optical axis AX. It can be set to polarized light with a plane of polarization in the direction (tangential polarized light). It is preferable that the tangential polarizer is provided so as to be able to remove the illumination optical path force. Here, U.S. Patent Publication No. 2002Z176166A is incorporated herein by reference.

In the above-described embodiment, it is not preferable that the polarization state of the illumination light to the mask M (and the exposure light to the wafer W) changes with time in various aspects. For this reason, as the optical member disposed closer to the mask M than the polarizing beam splitter 5, only the optical member without changing the polarization state of light is disposed, that is, for example, a light transmitting member formed of fluorite. Is not preferably arranged. Further, in the above embodiment, two light beam conversion elements are used, but the number of light beam conversion elements is not limited to two. When three or more light beam conversion elements are used, the light beam from the light source section may be split into three or more branches.

Further, in the above-described embodiment, a catadioptric projection optical system or a catoptric projection optical system that can be used instead of the refractive projection optical system can be used as the projection optical system PL. For example, FIGS. 7 to 9 show modified examples in which an off-axis catadioptric optical system having an optical path bending mirror for deflecting an optical path is applied as a catadioptric projection optical system. FIG. 7A shows a first intermediate image of an object as an off-axis catadioptric optical system having a field region or a projection region (image forming region) in a region off the optical axis. Refraction-type first imaging optical system G1, reflection-refraction-type second imaging optical system G2 that forms a second intermediate image (secondary image) as the first intermediate image, and second intermediate image FIG. 3 is a diagram schematically illustrating a part of an exposure apparatus including a projection optical system PL including a refraction-type third imaging optical system G3 that forms a third image on the image surface as a final image (a tertiary image). is there. FIG. 7 (a) shows the illumination optical device from the microlens array 10 as an optical integrator to the imaging optical system 13 for imaging the image of the mask blind 12. The illumination optical device of the modification shown in FIG. 7A is different from the illumination optical devices of the above embodiments in that the optical axis of the illumination optical device and the optical axis of the projection optical system PL are coaxial. The point that the optical axis of the illumination optical device is located almost at the center of the field of view of the projection optical system PL.

FIG. 7B shows a catadioptric first imaging optical system (Gl, G2) that forms a first intermediate image of an object as an off-axis catadioptric optical system. (1) A part of an exposure apparatus including a projection optical system PL including a refraction type second imaging optical system G3 for forming a final image (secondary image) as an intermediate image on an image plane. FIG. Note that, in FIG. 7 (b), the configuration other than the projection optical system PL is the same as that in FIG. 7 (a), so that the description is omitted here.

The off-axis catadioptric projection optical system shown in FIG. 7A is disclosed, for example, in US Patent Publication No. 2003ZOO 11755 and International Publication WO2004Z019128, and FIG. The off-axis catadioptric projection optical system shown in b) is disclosed in, for example, US Pat. No. 5,805,334 and US Pat. No. 2002Z0039175. Here, US Patent Publication No. 2003Z0011755, International Publication WO2004Z019128, US Patent No. 5805334, and US Patent Publication No. 2002Z0039175 are incorporated by reference.

In an exposure apparatus provided with a projection optical system PL provided with such an optical path bending mirror FM, a polarization image, in particular, a linearly polarized light (a circle centered on the optical axis) which becomes S-polarized with respect to the image plane. In the case of forming an image with peripheral polarized light, when illuminating the mask with linearly polarized light that becomes s-polarized light with respect to the mask, due to the characteristics of the optical path bending mirror, V-polarized light (vibrates in the image plane in the X direction in the figure) Linearly polarized light with a plane) or H-polarized light (a straight line with a vibration plane in the Y direction Polarization degree) and the degree of polarization of ± 45 degree polarization (ぉ on the image plane, and linear polarization with a vibration plane in the ± 45 degree direction to the X direction in the figure) or 135 degree polarization (ぉ on the image plane). Therefore, the degree of polarization degree of linearly polarized light having a vibration plane in ± 135 degrees with respect to the X direction in the drawing may be different from each other.

At this time, for example, the light beam from the light source unit is divided into four branches, and four light beam conversion elements are used. Each light beam conversion element converts the light beam into V polarized light, H polarized light, ± 45 degree polarized light, and ± 135 degree polarized light. A corresponding light beam is generated, and the degree of polarization of each light beam may be adjusted so as to be S-polarized with respect to the image plane even after passing through the optical path bending mirror. Hereinafter, with reference to FIGS. 8 and 9, a description will be given of a modification of the polarization state changing unit that can independently change the polarization state of each of V-polarized light, H-polarized light, ± 45-degree polarized light, and ± 135-degree polarized light. I do.

FIG. 8 (a) is a perspective view of a four-part polarization state changing unit, FIG. 8 (b) is a first YZ sectional view, FIG. 8 (c) is an XY sectional view, and FIG. d) is a second YZ sectional view. The polarization state changing means shown in FIG. 8 is, for example, the polarization state changing means (5-6) of the embodiment shown in FIG. 1 or the polarization state changing means (5, 14-16) of the embodiment shown in FIG. ), The description of the light path on the light source side of the polarization state changing means and the description of the light path on the light condensing optical system side of the light flux conversion element will be omitted.

In FIG. 8, the polarization state changing means includes a first polarization beam splitter 17, a second polarization beam splitter 19a, a third polarization beam splitter 19b, a first rectangular prism 20a, The second right-angle prism 20b, the third right-angle prism 23, the 1Z2 wavelength plate 18a as the first phase plate, the 1Z2 wavelength plate 18b as the second phase plate, the 1/2 wavelength plate 21a as the third phase plate, and the fourth A 1Z2 wavelength plate 22a as a phase plate, a 1/2 wavelength plate 21b as a fifth phase plate, and a 1Z2 wavelength plate 22b as a sixth phase plate are provided. Here, the 1Z2 wave plates 18a, 18b, 21a, 21b, 22a, 22b are each rotatable around the Y axis in the figure. In FIG. 8A, the illustration of the first to fourth diffractive optical elements 24a to 25b as the first to fourth light beam conversion elements is omitted.

The light from the polarization state adjusting means (not shown) (the first and second prism assemblies 2 and 3 in FIG. 1) is polarized and separated by the first polarization beam splitter 17, and the first polarization beam is split. P-polarized light transmitted through the beam splitter 17 (with respect to the polarization separation surface of the polarization beam splitter 17). (P-polarized light: linearly polarized light having a vibration plane in the X direction) is incident on a second polarization beam splitter 19a via a 1Z2 wavelength plate 18a as a first phase plate. Of the light polarized and separated by the second polarization beam splitter 19a, the light transmitted through the polarization splitting surface is emitted from the second polarization beam splitter 19a and travels to the 1Z2 wavelength plate 21a as the third phase plate. On the other hand, the light reflected on the polarization splitting surface of the second polarization beam splitter 19a travels to the 1Z2 wavelength plate 22a as the fourth phase plate via the first right-angle prism 20a. At this time, the light amount ratio of the light split into two at the polarization splitting surface of the second polarization beam splitter 19a is appropriately determined by the rotation angle of the 1Z2 wavelength plate 18a as the first phase plate around the optical axis (Y axis). Value is set to

On the other hand, the S-polarized light reflected by the first polarizing beam splitter 17 (S-polarized light with respect to the polarization splitting plane of the polarizing beam splitter 17: linearly polarized light having a vibration plane in the Z direction) is the third orthogonal light. After being reflected by the prism 23, it is incident on a third polarizing beam splitter 19b via a 1Z2 wavelength plate 18b as a second phase plate. Of the light polarized and separated by the third polarization beam splitter 19b, the light transmitted through the polarization splitting surface is emitted by the third polarization beam splitter 19b and travels to the 1Z2 wavelength plate 21b as the fifth phase plate. . On the other hand, the light reflected on the polarization splitting surface of the third polarizing beam splitter 19b travels to the sixth phase plate 1Z2 wavelength plate 22b via the second right-angle prism 20b. At this time, the light intensity ratio of the light split into two at the polarization splitting surface of the third polarization beam splitter 19b is determined by the rotation angle of the 1Z2 wavelength plate 18b as the second phase plate around the optical axis (Y axis). Value is set to

FIG. 9 is a diagram for explaining the light intensity distribution on the illumination pupil plane formed on the rear focal plane of the microlens array 10 as an optical integrator. As shown in FIG. 9, in this modification, octupole illumination is performed as multipole illumination. Here, the light beam from the first diffractive optical element 24a as the first light beam converting element shown in FIG. 8 forms a surface light source 31f, and the light beam from the second diffractive optical element 25a as the second light beam converting element is A light source 31g is formed, a light beam from a third diffractive optical element 24b as a third light beam conversion element forms a surface light source 31h, and a light beam from a fourth diffractive optical element 25b as a fourth light beam conversion element is used as a surface light source 31i. Is formed. In FIG. 9, the polarization direction of light reaching each of the surface light sources 31f-31i is indicated by an arrow. V polarization is used for the surface light source 31f, H polarization is used for the surface light source 31g, and ± 45 degrees for the surface light source 31h. The directional polarization is ± 135 degrees directional polarization in the surface light source 31i. Then, by appropriately setting the rotation angles of the 1Z2 wavelength plates 21a-22b as the third-sixth phase plates shown in FIG. 8 around the optical axis (Y-axis), the first-fourth light flux conversion is performed. The polarization directions incident on the first to fourth diffractive optical elements 24a to 25b as elements can be set independently, and the polarization directions of the light beams from the respective surface light sources 31f-3 can be set independently. Can be. As a result, it is possible to adjust the direction of polarization of the light flux from each surface light source, and thus the state of polarization, so that the light becomes s-polarized with respect to the image plane even after passing through the optical path bending mirror in the projection optical system PL.

Note that if a 1Z4 wavelength plate is provided adjacent to the 1Z2 wavelength plates 21a-22b as the third-sixth phase plates so as to be rotatable around the optical axis (Y axis), each of the surface light sources 31f-3 It is also possible to independently adjust the degree of polarization of the luminous flux from the light, and thus the state of polarization. Further, the prism assembly 16 shown in FIG. 4 may be detachably provided in the optical path near the first to fourth diffractive optical elements 24a to 25b.

In the exposure apparatus that is active in the above embodiment, the mask (reticle) is illuminated by the illumination optical device (illumination step), and the transfer pattern formed on the mask is projected onto the photosensitive substrate using the projection optical system. By exposing (exposure step), a micro device (semiconductor element, imaging element, liquid crystal display element, thin film magnetic head, etc.) can be manufactured. Hereinafter, 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 will be described. This will be described with reference to FIG.

First, in step 301 of FIG. 10, 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 wafer. Thereafter, in step 303, using the exposure apparatus of the above-described embodiment, an image of the pattern on the mask is sequentially exposed and transferred to each shot area on the wafer of the lot through the projection optical system. Thereafter, in step 304, the photoresist on the one lot of wafers is developed, and in step 305, etching is performed on the one lot of wafers using the resist pattern as a mask, thereby forming a pattern on the mask. Corresponding circuit pattern forces are formed in each shot area on each wafer. Thereafter, by forming a circuit pattern of a further upper layer, a device such as a semiconductor element is formed. Manufactured. According to the above-described semiconductor device manufacturing method, a semiconductor device having an extremely fine circuit pattern can be obtained with high throughput.

Further, in the exposure apparatus of the above embodiment, a predetermined pattern is formed on a plate (glass substrate).

By forming (a circuit pattern, an electrode pattern, etc.), a liquid crystal display element as a micro device can be obtained. Hereinafter, an example of the technique at this time will be described with reference to the flowchart in FIG. In FIG. 11, in a pattern forming step 401, a so-called photolithography step of transferring and exposing a mask pattern onto a photosensitive substrate (a glass substrate coated with a resist) using the exposure apparatus of the above-described embodiment is executed. . By this photolithography process, a predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. After that, the exposed substrate goes through each process such as a developing process, an etching process, and a resist stripping process, so that a predetermined pattern is formed on the substrate, and the process proceeds to the next color filter forming process 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 R, G, A color filter is formed by arranging a plurality of sets of filters of three stripes B in the horizontal scanning line direction. Then, after the color filter forming step 402, a cell assembling step 403 is performed. In the cell assembling step 403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern forming step 401, the color filter obtained in the color filter forming step 402, and the like.

In the cell assembling step 403, for example, a liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern forming step 401 and the color filter obtained in the color filter forming step 402, Manufacture panels (liquid crystal cells). 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 a high throughput.

In the above-described embodiment, KrF excimer laser light or ArF excimer laser light is used as exposure light. However, the present invention is not limited to this. The present invention can also be applied to an F laser light source that supplies laser light having a wavelength of 157 nm. Furthermore, in the above-described embodiment, the present invention has been described by taking a projection exposure apparatus having 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. It is clear that can be applied.

In the above-described embodiment, a method of filling the optical path between the projection optical system and the photosensitive substrate with a medium (typically, a liquid) having a refractive index larger than 1.1, that is, a so-called immersion method The law may be applied. 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. A method of moving a stage holding a substrate to be exposed in a liquid tank as disclosed in Japanese Patent Application Laid-Open No. 124873, or a method in which a predetermined depth is placed on a stage as disclosed in Japanese Patent Application Laid-Open No. 10-303114. A method of forming a liquid tank and holding the substrate in the liquid tank can be adopted. Here, International Publication No. WO 99Z49504 is incorporated by reference.

As the liquid, it is preferable to use a liquid that has transparency to exposure light and a refractive index as high as possible, and a liquid that is stable to the photoresist applied to the substrate surface. For example, when KrF excimer laser light or ArF excimer laser light is used as the exposure light, pure water or deionized water can be used as the liquid. When F laser light is used as the exposure light, a liquid that can transmit F laser light, such as a fluorine-based perfluoropolyether (PFPE), can be used as the liquid! ,.

Explanation of symbols

[0083] 1 Laser light source

2, 3 prism assembly (polarization state adjusting means)

2a, 3a quartz prism

2b, 3b quartz prism

4 Beam matching unit

5 Polarizing beam splitter

6 Right angle prism

7, 8 Diffractive optical element 9 Zoom lens

10 micro lens array

11 Condenser optics

12 Mask blind

13 Imaging optics

14, 15 1Z2 wave plate

16 Prism assembly (Depolarizing element)

16a quartz prism

16b quartz prism

M mask

PL projection optical system

W wafer

Claims

The scope of the claims

[1] An illumination optical device that illuminates a surface to be irradiated based on a light beam from a light source unit,

The luminous flux having the first cross-sectional shape is arranged in the optical path between the luminous flux having the first cross-sectional shape from the first luminous flux conversion element and the luminous flux having the second cross-sectional shape from the second luminous flux converting element. A condensing optical system that guides a light beam having the second cross-sectional shape to a second area different from the first area on the illumination pupil plane, while guiding the light flux to the first area on the illumination pupil plane of the illumination optical device; A polarization state changer arranged in an optical path between a light source unit and the illumination pupil plane to change the polarization state of the light flux reaching the first area and the polarization state of the light flux reaching the second area independently. An illumination optical device comprising means.

[2] The polarization state changing unit is disposed in an optical path between the light source unit and the first light beam conversion element and in an optical path between the light source unit and the second light beam conversion element. The illumination optical apparatus according to claim 1, further comprising a beam splitter that splits a light beam from the light source unit and guides the light beam to the first light beam conversion element and the second light beam conversion element, respectively. .

[3] The illumination optical device according to claim 2, wherein the beam splitter includes a polarizing beam splitter.

[4] The polarization state changing means is disposed in an optical path between the polarization beam splitter and the first light beam conversion element or in an optical path between the first light beam conversion element and the illumination pupil plane. First polarization plane changing means for changing the direction of the plane of polarization of the linearly polarized light incident thereon,

The direction of the plane of polarization of linearly polarized light that is disposed in the optical path between the polarizing beam splitter and the second light beam converting element or in the optical path between the second light beam converting element and the illumination pupil plane 4. The illumination optical device according to claim 3, further comprising a second polarization plane changing unit for changing the polarization plane.

[5] An intensity change for changing a ratio of an intensity of light reaching the first region via the first light beam conversion device and an intensity of light reaching the second region via the second light beam conversion device. The illumination optical device according to any one of claims 1 to 4, further comprising means.

[6] The intensity changing means is arranged in an optical path between the light source unit and the first light beam conversion element and in an optical path between the light source unit and the second light beam conversion element. A polarizing beam splitter that splits a light beam from the light source unit and guides the light beam to the first light beam conversion element and the second light beam conversion element, respectively;

A polarization state adjusting unit disposed in an optical path between the light source unit and the polarization beam splitter to adjust a polarization state of light incident on the polarization beam splitter. 6. The illumination optical device according to claim 5, wherein:

7. The method according to claim 1, wherein the first light beam conversion element is exchangeable with another light beam conversion element having characteristics different from those of the first light beam conversion element. Illumination optics.

[8] The illumination optical device according to claim 7, wherein the second light beam conversion element is replaceable with another light beam conversion element having a characteristic different from that of the second light beam conversion element.

9. The illumination device according to claim 1, further comprising an optical integrator disposed in an optical path between the light-collecting optical system and the irradiation surface. Ming optical device.

10. The method according to claim 1, wherein the first area is an area including an optical axis on the illumination pupil plane, and the second area is an area distant from the optical axis on the illumination pupil plane. 10. The illumination optical device according to any one of claims 1 to 9.

[11] In an illumination optical device for illuminating an irradiation surface,

An illumination optical device comprising: a polarization state control unit for independently controlling a polarization state of a first area on an illumination pupil plane and a polarization state of a second area on the illumination pupil plane.

[12] The polarization state control means,

To convert a light beam from the light source unit into a light beam having a first cross-sectional shape corresponding to the first region A first light beam conversion element of

A second light beam conversion element for converting the light beam from the light source unit into a light beam having a second cross-sectional shape corresponding to the second region;

Polarization state changing means for changing the polarization state of at least one of light reaching the first region via the first light beam conversion element and light reaching the second region via the second light beam conversion element 12. The illumination optical device according to claim 11, comprising:

[13] The polarization state changing means,

A polarizing beam splitter as the beam splitter,

The direction of the plane of polarization of linearly polarized light which is incident on the optical path between the polarizing beam splitter and the first light beam converting element or in the optical path between the first light beam converting element and the illumination pupil plane is changed. First polarization plane variable means for changing,

The direction of the plane of polarization of the linearly polarized light incident on the optical path between the polarization beam splitter and the second light beam conversion element or in the light path between the second light beam conversion element and the illumination pupil plane is changed. 13. The illumination optical device according to claim 12, further comprising a second polarization plane changing unit for changing the polarization plane.

[14] The polarization state changing unit is disposed in an optical path between the first polarization plane variable unit and the illumination pupil plane or in an optical path between the second polarization plane variable unit and the illumination pupil plane. 14. The illumination optical device according to claim 13, further comprising a depolarizing element for converting the linearly polarized light to be input into non-polarized light.

15. The illumination optical device according to claim 14, wherein the depolarizing element has a wedge-shaped quartz prism whose crystal optical axis is rotatable about an optical axis.

[16] An intensity change for changing a ratio of an intensity of light reaching the first area via the first light beam conversion element and an intensity of light reaching the second area via the second light beam conversion element. The illumination optical device according to any one of claims 12 to 15, further comprising: means.

[17] The intensity changing unit includes a polarization beam splitter as the beam splitter, and a polarization state adjusting unit for adjusting a polarization state of light incident on the polarization beam splitter. An illumination optical device according to claim 16.

[18] The polarization state adjusting unit is disposed in an optical path between the light source unit and the polarization beam splitter, and has a pair of wedge shapes in which a crystal optical axis is rotatable about an optical axis. 18. The illumination optical device according to claim 17, comprising: a quartz prism.

[19] The illumination according to any one of claims 12 to 18, wherein the first light beam conversion element and the second light beam conversion element are configured to be exchangeable with respect to an illumination light path. Optical device.

20. The method according to claim 1, wherein the first area is an area including an optical axis on the illumination pupil plane, and the second area is an area away from the optical axis on the illumination pupil plane. 20. The illumination optical device according to any one of 1 to 19.

21. The illumination optical device according to claim 11, wherein the second region has an annular shape or a plurality of polarities.

[22] An optical integrator for forming a secondary light source on the illumination pupil plane based on the light beams from the first light beam conversion device and the second light beam conversion device;

22. The illumination optical device according to claim 12, further comprising: a light guiding optical system for guiding a light beam of the optical integrator to the irradiated surface.

[23] In an illumination optical device for illuminating a surface to be irradiated,

Intensity changing means for changing the ratio of the intensity of light reaching the first area via the first light beam conversion element and the intensity of light reaching the second area via the second light beam conversion element. An illumination optical device, comprising: a step;

[24] The intensity changing unit includes a polarization beam splitter as the beam splitter, and a polarization state adjusting unit for adjusting a polarization state of light incident on the polarization beam splitter. An illumination optical device according to claim 23.

[25] The polarization state adjusting unit is disposed in an optical path between the light source unit and the polarization beam splitter, and has a pair of wedges configured such that a crystal optical axis is rotatable about an optical axis. 25. The illumination optical device according to claim 24, further comprising: a quartz prism.

26. The illumination according to claim 23, wherein the first light beam conversion element and the second light beam conversion element are configured to be exchangeable with respect to an illumination light path. Optical device.

27. The method according to claim 2, wherein the first area is an area including an optical axis on the illumination pupil plane, and the second area is an area away from the optical axis on the illumination pupil plane. 27. The illumination optical device according to any one of 3 to 26.

[28] The illumination optical device according to any one of claims 23 to 27, wherein the second region has an annular shape or a plurality of polarities.

[29] An optical integrator for forming a secondary light source on the illumination pupil plane based on the light beams from the first light beam conversion device and the second light beam conversion device;

The illumination optical device according to any one of claims 23 to 28, further comprising: a light guiding optical system for guiding a light flux of the optical integrator to the irradiation surface.

[30] In an illumination optical device for illuminating a surface to be irradiated,

The illumination optical device, wherein the first light beam conversion element and the second light beam conversion element are configured to be exchangeable with respect to an illumination light path.

[31] The light beam from the light source unit is split into the first light beam conversion element and the second light beam conversion device. 31. The illumination optical device according to claim 30, further comprising a beam splitter for guiding each to an element.

32. The method according to claim 3, wherein the first area is an area including an optical axis on the illumination pupil plane, and the second area is an area away from the optical axis on the illumination pupil plane.

32. The illumination optical device according to 0 or 31.

[33] The illumination optical device according to any one of claims 30 to 32, wherein the second region has an annular shape or a plurality of polarities.

[34] An optical integrator for forming a secondary light source on the illumination pupil plane based on the light beams from the first light beam conversion device and the second light beam conversion device;

The illumination optical device according to any one of claims 30 to 33, further comprising: a light guiding optical system for guiding a light beam of the optical integrator to the irradiation surface.

[35] In an illumination optical device that illuminates an irradiated surface based on a light beam from a light source unit,

The polarization fluctuation eliminating means includes: a polarization beam splitter that divides a light beam from the light source unit according to a polarization state; a polarization adjustment member that aligns the polarization state of the light beam divided by the polarization beam splitter; An illumination optical device, comprising: a light beam combining optical system that combines light beams split by a beam splitter.

[36] An exposure apparatus, comprising: the illumination optical device according to any one of claims 1 to 35 for illuminating a mask, and exposing a pattern of the mask onto a photosensitive substrate.

37. The exposure apparatus according to claim 36, further comprising a projection optical system for forming an image of the pattern of the mask on the photosensitive substrate.

38. The exposure apparatus according to claim 37, wherein the projection optical system includes an optical path bending mirror.

[39] An illumination step of illuminating a mask via the illumination optical device according to any one of claims 1 to 35,

Exposure step of exposing a pattern formed on the illuminated mask to a photosensitive substrate An exposure method characterized by comprising:

40. The exposure method according to claim 39, wherein the exposing step includes a projecting step of forming an image of the mask pattern on the photosensitive substrate.

41. The exposure method according to claim 40, wherein the projecting step includes an optical path bending step of bending an optical path.