WO2004011967A1

WO2004011967A1 - Diffractive optics, illumiinating optical system, exposure system and exposure method

Info

Publication number: WO2004011967A1
Application number: PCT/JP2003/009352
Authority: WO
Inventors: Akihiro Goto; Naonori Kita
Original assignee: Nikon Corporation
Priority date: 2002-07-26
Filing date: 2003-07-23
Publication date: 2004-02-05
Also published as: TW200405426A; AU2003252250A1

Abstract

An illuminating optical system capable of a good four-pole illumination with a restricted loss in light quantity by using a diffractive optics for forming a substantially uniform four-pole-form illumination distribution on an illumination pupil plane. An illumination optical system for illuminating surfaces to be illuminated (13, 15). A diffractive optics (61) is provided for converting an incident light flux into four light fluxes in order to form a secondary light source having a four-pole-form light intensity distribution on an illumination pupil plane. The diffractive optics comprises a first basic diffractive optics, a second basic diffractive optics, a first complementary diffractive optics, and a second complementary diffractive optics that are densely arranged, all in equal numbers.

Description

Description Diffractive optical element, illumination optical device, exposure apparatus and exposure method

The present invention relates to a diffractive optical element, an illumination optical device, an exposure device, and an exposure method, and more particularly to an exposure device for manufacturing microdevices such as semiconductor devices, imaging devices, liquid crystal display devices, and thin-film magnetic heads in a single step. The present invention relates to a suitable illumination optical device. Background art

In a typical exposure apparatus of this type, a light beam emitted from a light source is incident on a fly-eye lens, and then forms a secondary light source composed of a number of light source images on a side focal plane. The luminous flux from the secondary light source is restricted via an aperture stop arranged near the rear focal plane of the fly-eye lens, and then enters the condenser lens. The aperture stop restricts the shape or size of the secondary light source to a desired shape or size according to a desired illumination condition (exposure condition).

The light beam condensed by the condenser lens illuminates the mask on which the predetermined pattern is formed in a superimposed manner. 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. Since the patterns formed on the mask are highly integrated, it is indispensable to obtain a uniform illuminance distribution on the wafer in order to accurately transfer this fine pattern onto the wafer.

In recent years, the size of the secondary light source formed by the fly-eye lens has been changed by changing the size of the aperture (light transmitting portion) of the aperture stop arranged on the exit side of the fly-eye lens. Attention is focused on technologies that change the illumination coherency σ (σ value = aperture stop diameter / pupil diameter of the projection optical system, or hi value = the exit side numerical aperture of the illumination optical system and the entrance side numerical aperture of the projection optical system). Have been. In addition, the shape of the aperture of the aperture stop arranged on the exit side of the fly-eye lens has a ring shape or a four-hole shape (ie, Attention has been focused on a technology that limits the shape of the secondary light source formed by the fly-eye lens to a ring shape or quadrupole shape by setting the shape to (polar), thereby improving the depth of focus and resolution of the projection optical system. ing.

As described above, in the prior art, the secondary light source was formed by a fly-eye lens in order to perform deformed illumination (eg, annular illumination or quadrupole illumination) by limiting the shape of the secondary light source to an annular or quadrupolar shape. The luminous flux from the relatively large secondary light source is limited by an aperture stop having a ring-shaped or quadrupole-shaped opening. In other words, in the annular illumination and quadrupole illumination in the related art, a substantial part of the light flux from the secondary light source is blocked by the aperture stop, and does not contribute to illumination (exposure). As a result, the illuminance on the mask and the wafer was reduced due to the loss of light amount at the aperture stop, and the throughput as an exposure apparatus was also reduced.

The present invention has been made in view of the above-described problems, and is used for, for example, an illumination optical device, and is capable of forming a substantially uniform quadrupole illuminance distribution or the like on an illumination pupil plane. It is intended to provide an element. Further, the present invention provides a good multipole illumination such as a quadrupole illumination while suppressing a light quantity loss by using a diffractive optical element which forms a substantially uniform quadrupole illuminance distribution or the like on an illumination pupil plane. It is an object of the present invention to provide an illumination optical device capable of performing the following. Furthermore, the present invention uses an illumination optical device capable of performing good multi-pole illumination such as quadrupole illumination while suppressing light quantity loss, and using a light-sensitive substrate under a lighting condition optimal for a mask. An object of the present invention is to provide an exposure apparatus and an exposure method capable of faithfully transferring a mask pattern. Disclosure of the invention

In order to solve the above problems, in a first invention of the present invention, a first basic diffractive optical element having a linear grid pattern along a first direction;

A second basic diffractive optical element having a linear grating pattern along a second direction different from the first direction,

A first complementary diffractive optical element having a pattern for generating a light amplitude having a first phase difference with respect to the light amplitude generated by the first basic diffractive optical element; A second complementary diffractive optical element having a pattern for generating a light amplitude having a second phase difference with respect to the light amplitude generated by the second basic diffractive optical element,

A diffractive optical element, wherein the first basic diffractive optical element, the second basic diffractive optical element, the first complementary diffractive optical element, and the second complementary diffractive optical element are substantially densely arranged. provide.

In the second invention of the present invention, a first basic diffractive optical element having a linear lattice pattern along the first direction,

With a simple transmission part having substantially no deflection effect,

A diffractive optical element is provided, wherein the first basic diffractive optical element, the second basic diffractive optical element, and the simple transmission portion are arranged substantially densely.

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

An illumination device comprising the diffractive optical element of the first invention for converting an incident light beam into four light beams in order to form a secondary light source having a quadrupolar light intensity distribution on an illumination pupil plane. An optical device is provided.

In a fourth aspect of the present invention, a light source means for supplying a light beam;

Angle light beam forming means for converting the light beam from the light source means into light beams having various angle components with respect to the optical axis, and causing the light beam to enter a first predetermined surface;

An illumination field forming means including a diffractive optical element for forming a quadrupole illumination field on the second predetermined surface based on the light beams having the various angle components incident on the first predetermined surface;

A quadrupole secondary light source having substantially the same light intensity distribution as the quadrupole illumination field is formed based on the light flux from the quadrupole illumination field formed on the second predetermined surface. Optical integrators to perform

A light guiding optical system for guiding a light beam from the optical integrator to the irradiated surface,

The diffractive optical element has a plurality of first gratings each having a linear lattice pattern along a first direction. A first basic diffractive optical element, and a plurality of second basic diffractive optical elements having a linear lattice pattern along a second direction different from the first direction. An illumination optical device is provided, wherein the plurality of second basic diffractive optical elements are arranged substantially densely.

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

In order to form a secondary light source having a dipole-like light intensity distribution on the illumination pupil plane, a diffractive optical element for converting the incident light beam into two light beams is provided.

The diffractive optical element includes: a plurality of basic diffractive optical elements having a linear grating pattern along a certain direction; and a light amplitude having a predetermined phase difference with respect to a light amplitude generated by the basic diffractive optical element. An illumination optical device, comprising: a plurality of complementary diffractive optical elements each having a pattern to be formed; wherein the plurality of basic diffractive optical elements and the plurality of complementary diffractive optical elements are arranged substantially densely. .

According to a sixth aspect of the present invention, in the illumination optical device for illuminating the irradiated surface,

The diffractive optical element includes: a plurality of basic diffractive optical elements having a linear grating pattern along a certain direction; and a plurality of simple transmission portions having substantially no deflecting action. There is provided an illumination optical device, wherein the plurality of simple transmission portions are arranged almost densely.

According to a seventh aspect of the present invention, in the illumination optical device for illuminating the surface to be illuminated,

In order to form a secondary light source having an 8-pole light intensity distribution on the illumination pupil plane, a diffractive optical element for converting the incident light beam into eight light beams is provided.

The diffractive optical element has a first basic diffractive optical element having a linear grating pattern along a first direction, and a second basic diffractive optical element having a linear grating pattern along a second direction substantially orthogonal to the first direction. A basic diffractive optical element, a third basic diffractive optical element having a linear lattice pattern along a third direction substantially 45 degrees with the first direction, and approximately 45 degrees with the first direction. And a fourth basic diffractive optical element having a linear grating pattern along a fourth direction substantially orthogonal to the third direction, An illumination optical device is provided, wherein the first to fourth basic diffractive optical elements are arranged substantially densely.

According to an eighth aspect of the present invention, in the illumination optical device for illuminating the irradiated surface,

A light source unit for supplying a light beam; an angle light beam forming unit for converting the light beam from the light source unit into a light beam having various angle components with respect to an optical axis and causing the light beam to enter a first predetermined surface; An illumination field forming means including a diffractive optical element for forming a multipolar illumination field on a second predetermined surface based on the light beam having the various angle components incident on the first predetermined surface; With

The diffractive optical element is configured by arranging a plurality of basic diffractive optical elements having a predetermined diffractive optical element pattern in a substantially dense manner,

The angle light beam forming means has an optical member composed of a plurality of optical elements,

An illumination characterized in that the diffractive optical element is positioned such that a total of four or more basic diffractive optical elements or complementary diffractive optical elements are included in an element light beam corresponding to each optical element of the optical member. An optical device is provided.

In a ninth aspect of the present invention, a light source means for supplying a light beam;

An illumination field forming means including a diffractive optical element for forming a multipole illumination field on a second predetermined surface based on the light beams having various angle components incident on the first predetermined surface. When,

A multi-pole secondary light source having substantially the same light intensity distribution as the multi-pole illumination field is formed based on the light flux from the multi-pole illumination field formed on the second predetermined surface. Optical Integral evening for

A light guiding optical system for guiding a light beam from the optical integrator to the surface to be irradiated,

The diffractive optical element is constituted by arranging a plurality of basic diffractive optical elements having a substantially square outer shape and having a predetermined diffractive optical element pattern in a substantially dense manner. The diffractive optical element and the optical integrator Having an optical system arranged in the optical path between

The size of each surface light source constituting the multipole secondary light source is defined as, the length of one side of the basic diffractive optical element is defined as L, the center wavelength of the light beam is defined as λ, and the focal length of the optical system is defined as f

L> 2.5 X f Χ λ / φ

An illumination optical device characterized by satisfying the following conditions:

A tenth aspect of the present invention is characterized in that the diffractive optical element of the first or second aspect of the invention or the illumination optical device of the fifth or sixth aspect of the invention generates substantially the same light amplitude as the diffractive optical element. A refractive optical element is provided.

According to the eleventh aspect of the present invention, in the illumination optical device for illuminating the illuminated surface, in order to form a secondary light source having a predetermined light intensity distribution on the illumination pupil surface, the incident light beam is converted into a light beam having a predetermined cross-sectional shape. There is provided an illumination optical device comprising the refractive optical element of the tenth invention for conversion.

According to a twelfth aspect of the present invention, there is provided an illumination optical device according to the third to ninth aspects or the eleventh aspect, and a projection for projecting and exposing a pattern of a mask disposed on the surface to be irradiated onto a photosensitive substrate. An exposure apparatus comprising an optical system.

According to a thirteenth invention of the present invention, the mask is illuminated via the illumination optical device of the third invention to the ninth invention or the eleventh invention, and an image of a pattern formed on the illuminated mask is formed on a photosensitive substrate. There is provided an exposure method characterized by performing projection exposure on the top. BRIEF DESCRIPTION OF THE FIGURES

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

FIG. 2 is a view schematically showing a configuration of a basic diffraction optical element and a complementary diffraction optical element included in a quadrupole illumination diffractive optical element according to the first embodiment.

FIG. 3 is a cross-sectional view of each optical element in FIG.

FIG. 4 is a diagram schematically showing a configuration of four types of blocks included in the diffractive optical element for quadrupole illumination in the first embodiment. FIG. 5 is a diagram schematically showing an entire configuration of a diffractive optical element for quadrupole illumination in the first embodiment.

FIG. 6 is a view for explaining the basic operation of the diffractive optical element for quadrupole illumination in the first embodiment.

FIG. 7 is a view for explaining the principle of forming a quadrupole illumination field on the incidence surface of the microlens array in the first embodiment.

FIG. 8 is a view showing a quadrupole illumination field formed on the entrance surface of the microphone aperture lens array in the first embodiment.

FIG. 9 shows a quadrupole illumination field formed on the incident surface of the microlens array as an optical integrator when the microlens array is used as the divergent light beam forming element in the first embodiment. FIG.

FIG. 10 is a diagram schematically showing a configuration of a basic diffractive optical element and a complementary diffractive optical element included in the quadrupole illumination diffractive optical element in the second embodiment.

FIG. 11 is a diagram schematically showing the configuration of four types of blocks included in the diffractive optical element for quadrupole illumination in the second embodiment.

FIG. 12 is a diagram schematically showing an overall configuration of a diffractive optical element for quadrupole illumination in the second embodiment.

FIG. 13 is a view for explaining a basic operation of the diffractive optical element for quadrupole illumination in the first embodiment.

FIG. 14 is a diagram showing a quadrupole illumination field formed on the entrance surface of the microlens array in the second embodiment.

FIG. 15 shows a quadrupole illumination formed on an entrance surface of a microlens array as an optical integrator when a microlens array is used as a divergent light beam forming element in the second embodiment. It is a figure showing a field.

FIG. 16 is a diagram conceptually showing the configurations of the basic diffractive optical element and the complementary diffractive optical elements (Dl ', D2', El ', E2') in the third embodiment.

FIG. 17 is a diagram conceptually showing the configuration of blocks F 1 ′ to F 4 ′ constituted by optical elements (D 1 ′, D 2 ′, E 1 ′, E 2 ′). FIG. 18 is a conceptual diagram in which synthesized blocks DQ1 to DQ4 are formed by combining blocks C1 to C4 and blocks F1 'to F4'.

FIG. 19 is a diagram conceptually showing the configuration of a diffractive optical element 63 of the third embodiment configured by arranging a large number of synthetic blocks DQ1 to DQ4 densely vertically and horizontally.

FIG. 20 is a view for explaining the basic operation of the diffractive optical element for octupole illumination in the third embodiment.

FIG. 21 is a diagram showing an octupole illumination field formed on the entrance surface of the microphone aperture lens array in the third embodiment.

FIG. 22 shows an octupole pole formed on the incident surface of the microlens array as an optical integrator when the microlens array is used as the divergent light beam forming element in the third embodiment. It is a figure which shows Teruno.

FIG. 23 is a diagram schematically showing a configuration of a basic diffractive optical element and a complementary diffractive optical element included in the dipole optical element for dipole illumination in the fourth embodiment.

FIG. 24 is a diagram schematically showing an overall configuration of a dipole optical element for dipole illumination in the fourth embodiment.

FIG. 25 is a view for explaining the random arrangement of each optical element in the fourth embodiment.

FIG. 26 is a view for explaining the basic operation of the dipole optical element for dipole illumination in the fourth embodiment.

FIG. 27 is a view showing a dipole-shaped illumination field formed on the entrance surface of the microlens array in the fourth embodiment.

FIG. 28 is a diagram showing a dipole-shaped illumination field formed on the entrance surface of the microlens as a divergent light beam forming element in the fourth embodiment.

FIG. 29 is a diagram schematically showing a light intensity profile of each surface light source constituting the multipolar secondary light source.

FIG. 30 is a block diagram of the exposure apparatus shown in FIG. It is a figure which shows schematically the principal part structure at the time of using a de integrator.

FIG. 31A is a cross-sectional view of a blaze-type diffractive optical element cut along a cross section in the periodic direction.

FIG. 31B is a cross-sectional view of a multilevel diffractive optical element cut along a cross section in the periodic direction.

FIG. 31C is a cross-sectional view of the binary diffractive optical element cut along a cross section in the periodic direction.

FIG. 32 is a flowchart of a method for obtaining a semiconductor device as a micro device.

FIG. 33 is a flowchart of a method for obtaining a liquid crystal display element as a micro device.

FIG. 34 is a diagram schematically showing a configuration of a mask used for manufacturing a diffractive optical element by lithography.

FIG. 35 is a diagram showing a diffractive optical element generated on a glass substrate using the mask of FIG.

FIG. 36 is a diagram showing a pentapole illumination field formed on the entrance surface of the microlens array in the fifth embodiment.

FIG. 37 is a view for explaining the basic function of the diffractive optical element for five-pole illumination in the fifth embodiment.

FIG. 38 is a diagram schematically showing an overall configuration of a pentapole illumination diffractive optical element in the fifth embodiment.

FIG. 39 is a view schematically showing a configuration of a block element included in the diffractive optical element for five-pole illumination in the fifth embodiment.

FIG. 40 is a diagram schematically showing a modified example of a block element included in the diffractive optical element for five-pole illumination in the fifth embodiment.

FIG. 41 is a diagram showing a quintuple-shaped illumination field formed on the entrance surface of the microlens array in the sixth embodiment.

FIG. 42 shows the basic operation of the pentapole illumination diffractive optical element in the sixth embodiment. FIG.

FIG. 43 is a diagram schematically showing an overall configuration of a diffractive optical element for quintuple illumination in the sixth embodiment.

FIG. 44 is a diagram schematically showing a configuration of a block element included in the diffractive optical element for quintuple illumination in the sixth embodiment.

FIG. 45 is a drawing schematically showing a modified example of the block element included in the diffractive optical element for five-pole illumination in the sixth embodiment.

FIG. 46 is a diagram showing a tripolar illumination field formed on the entrance surface of the microlens array in the seventh embodiment.

FIG. 47 is a view for explaining the basic operation of the diffractive optical element for tripolar illumination in the seventh embodiment.

FIG. 48 is a diagram schematically showing an overall configuration of a diffractive optical element for tripolar illumination in the seventh embodiment.

FIG. 49 is a diagram schematically showing a configuration of a block element included in the triode illumination diffractive optical element in the seventh embodiment.

FIG. 50 is a diagram showing a nine-pole illumination field formed on the entrance surface of the microlens array in the eighth embodiment.

FIG. 51 is a diagram for explaining the basic operation of the diffractive optical element for nine-pole illumination in the eighth embodiment. 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 including an illumination optical device according to each embodiment of the present invention. In FIG. 1, the Z axis is set along the normal direction of the wafer 15 as a photosensitive substrate, the Y axis is set in a direction parallel to the plane of FIG. The X-axis is set in the direction perpendicular to the plane of the paper in Fig. 1 within the plane of Fig. 1.

The exposure apparatus shown in Fig. 1 is an ArF excimer laser light source (or 248 nm) that supplies 193 nm wavelength light as the light source 1 for supplying exposure light (illumination light). (KrF excimer laser light source) that supplies light of a wavelength. A parallel light beam emitted from the light source 1 along the Z direction has a rectangular cross section elongated in the X direction and enters the shaping optical system 2. The shaping optical system 2 is composed of, for example, a lens having a negative refractive power and a lens having a positive refractive power in the plane of FIG. 1 (within the YZ plane).

The parallel light beam shaped into a light beam having a predetermined rectangular cross section via the shaping optical system 2 is deflected in the Y direction by the bending mirror 3 and then enters the diffractive optical element 4. Generally, a diffractive optical element is formed by forming a step having a pitch of about the wavelength of exposure light (illumination light) on a glass substrate, and has an action of diffracting an incident beam to a desired angle. Specifically, the diffractive optical element 4 is a divergent light beam forming element having a function of diffracting an incident rectangular parallel light beam to form a circular light beam in the far field.

Therefore, the light beam diffracted through the diffractive optical element 4 enters the afocal zoom lens 5 as the first variable power optical system, and forms a circular light beam on the pupil plane. The light from the circular light beam is emitted from the afocal zoom lens 5 and enters the diffractive optical element 6 for multipole illumination (dipole illumination, quadrupole illumination, and octupole illumination). The focal zoom lens 5 continuously increases the magnification in a predetermined range while maintaining the diffractive optical element 4 as a divergent light beam forming element and the diffractive optical element 6 for multipole illumination in an optically almost conjugate relationship. It is configured to be able to change. However, as shown in FIG. 1, the diffractive optical element 6 is slightly displaced from the surface optically conjugate with the diffractive optical element 4 toward the light source.

Thus, the light flux enters the diffractive optical element 6 from the oblique direction substantially symmetrically with respect to the optical axis AX. That is, the diffractive optical element 4 and the afocal zoom lens 5 convert the luminous flux from the light source 1 into luminous fluxes having various angle components with respect to the optical axis AX. (A predetermined surface). The diffractive optical element 6 has a function of, when a parallel light beam is made incident, diffracting the light beam to form a multipolar light beam around the optical axis AX in the far field. The detailed configuration and operation of the diffractive optical element 6 will be described later. The light beam passing through the diffractive optical element 6 illuminates a micro lens array (or fly-eye lens) 8 as an optical integrator through a zoom lens 7 as a second variable power optical system. The zoom lens 7 optically couples the diffractive optical element 6 and the rear focal plane of the micro lens array 8 almost optically. In other words, the zoom lens 7 connects the diffractive optical element 6 and the entrance surface of the microlens array 8 substantially in a Fourier transform relationship.

Therefore, the light beam that has passed through the diffractive optical element 6 is distributed on the rear focal plane of the zoom lens 7 (and, consequently, the incident surface of the microlens array 8) by the circular distribution of the diffractive optical element 4 and the multipolar dot by the diffractive optical element 6 itself A light intensity distribution based on the composition with the shape distribution, that is, a multipolar illumination field centered on the optical axis AX is formed. As described above, the diffractive optical element 6 and the zoom lens 7 are arranged such that the optical axis AX is centered on the basis of the light beams having various angle components incident on the incident surface (first predetermined surface) of the diffractive optical element 6. The illumination field forming means for forming the multi-polar illumination field on the incident surface (second predetermined surface) of the microlens array 8 is configured. The width (1/2 of the difference between the outer diameter and the inner diameter) of the multipole illumination field varies depending on the magnification of the afocal zoom lens 5, and the overall size is the focal length of the zoom lens 7. Varies depending on

The microlens array 8 is an optical element composed of a large number of microlenses having a positive refractive power arranged vertically and horizontally and densely. Each of the microlenses constituting the microlens array 8 has a rectangular cross section similar to the shape of the illumination field to be formed on the mask 13 (and, consequently, the shape of the exposure region to be formed on the wafer 15). Generally, a microlens array is formed by, for example, performing etching on a parallel flat glass plate to form a microlens group.

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, which is made up of lens elements that are isolated from each other, a microlens array is formed by integrating a large number of microlenses without being isolated from each other. However, a microlens array is the same as a fly-eye lens in that lens elements having positive refractive power are arranged vertically and horizontally. Note that in FIG. 1 For this reason, the number of microlenses forming the microlens array 8 is shown to be much smaller than the actual number.

Therefore, the light beam incident on the microlens array 8 is two-dimensionally divided by a large number of microlenses, and the rear focal plane of the microlens array 8 is illuminated by the light beam incident on the microlens array 8. A secondary light source having substantially the same light intensity distribution as the field, that is, a multipolar secondary light source composed of a plurality of substantially planar light sources centered on the optical axis AX is formed. As described above, the microlens array 8 has the same light intensity as the multi-pole illumination field based on the light flux from the multi-pole illumination field formed on the incident surface (second predetermined surface). It constitutes an optical integrator for forming a multi-pole secondary light source with distribution.

The luminous flux from the multipolar secondary light source formed on the rear focal plane of the microlens array 8 is restricted as necessary through an aperture stop having a multipolar light transmitting portion, and the condenser optical system After receiving the light condensing action of 9, the mask blind 10 as an illumination field stop is illuminated in a superimposed manner. The light beam passing through the rectangular opening (light transmitting portion) of the mask blind 10 receives the light-condensing action of the imaging optical system (11a, lib), and then illuminates the mask 13 in a superimposed manner. I do. Here, the imaging optical system (11a, lib) optically connects the mask blind 10 and the mask 13 almost conjugately, and the imaging optical system (11a , Lib), an image of the rectangular opening of the mask blind 10 is formed.

The mask 13 is supported on a two-dimensionally movable mask stage (not shown). The light flux transmitted through the pattern of the mask 13 forms an image of the mask pattern on the wafer 15 which is a photosensitive substrate via the projection optical system 14. The wafer 15 is supported on a two-dimensionally movable wafer stage (not shown). In this way, by performing batch exposure or scan exposure while driving and controlling the wafer 15 two-dimensionally in a plane (XY plane) perpendicular to the optical axis AX of the projection optical system 14, each wafer 15 The pattern of the mask 13 is sequentially exposed on the exposure area.

In the batch exposure, a mask pattern is collectively exposed to each exposure region of a wafer according to a so-called step-and-repeat method. In this case, The shape of the illumination area on the disc 13 is a rectangular shape close to a square, and the cross-sectional shape of each microlens of the microlens array 8 is also a rectangular shape close to a square. On the other hand, in scan exposure, according to a so-called step-and-scan method, a mask pattern is scanned and exposed on each exposure region of a wafer while moving the mask and the wafer relative to a projection optical system. In this case, the shape of the illumination area on the mask 13 is a rectangular shape with a ratio of the short side to the long side of, for example, 1: 3, and the cross-sectional shape of each microlens of the microlens array 8 is similar to this. It has a rectangular shape.

In each embodiment, the diffractive optical element 6 includes various types of diffractive optical elements 61 to 64 for multipole illumination configured to be exchangeable with respect to the illumination optical path. Also, instead of the diffractive optical element 4 as a divergent light beam forming element, for example, a microlens array (or flywheel) composed of a large number of regular hexagonal microlenses (or lens elements) arranged vertically and horizontally and densely. (Eye lens) can also be used. In this case, on the incident surface of the microlens array 8, a light intensity distribution based on a composition of a regular hexagon and a multipolar dot, that is, a multipolar field centered on the optical axis AX is formed. On the rear focal plane of the array 8, a multi-pole secondary light source composed of a plurality of substantially planar light sources centered on the optical axis AX is formed.

(First Embodiment)

FIG. 2 is a view schematically showing a configuration of a basic diffraction optical element and a complementary diffraction optical element included in a quadrupole illumination diffractive optical element according to the first embodiment. FIG. 3 is a cross-sectional view of each optical element in FIG. FIG. 4 is a diagram schematically showing the configuration of four types of blocks included in the diffractive optical element for quadrupole illumination in the first embodiment. FIG. 5 is a diagram schematically showing an entire configuration of a diffractive optical element for quadrupole illumination in the first embodiment. FIG. 6 is a view for explaining the basic operation of the diffractive optical element for quadrupole illumination in the first embodiment.

Referring to FIG. 2, the diffractive optical element 61 of the first embodiment has a first basic diffractive optical element A 1 having a linear grating pattern along the X direction and a linear grating pattern along the Z direction. A second basic diffractive optical element B1, a first complementary diffractive optical element A2 obtained by inverting the convex and concave surfaces of the first basic diffractive optical element A1, A second complementary diffractive optical element B2 obtained by inverting the convex surface and the concave surface of the folding optical element B1 is provided. That is, the second basic diffractive optical element B1 has a pattern obtained by rotating the pattern of the first basic diffractive optical element A1 by 90 degrees counterclockwise in the figure on the XZ plane. Further, the second complementary diffractive optical element B2 has a pattern obtained by rotating the pattern of the first complementary diffractive optical element A2 by 90 degrees counterclockwise in the figure on the XZ plane.

In FIG. 2, the hatched portion indicates a convex surface, and the non-hatched portion (blank portion) indicates a concave surface. That is, as shown in FIG. 3, each of the optical elements A 1, A 2, 61 and 82 has a binary diffractive optical element pattern composed of a repetition of a convex surface and a concave surface. The width W (and thus the pitch P (= 2 W) between the convex and concave surfaces) of the entire optical element! ; And the whole has a square outer shape with a length L (L = mP: m is an integer) on one side. The notation in which the hatched portion indicates a convex surface and the non-hatched portion (blank portion) indicates a concave surface is the same in other related FIGS. 10 and 23.

Therefore, the first complementary diffractive optical element A2 has a pattern that generates a light amplitude having a phase difference of 1Z2 wavelength (180 degrees) with respect to the light amplitude generated by the first basic diffractive optical element A1. The second complementary diffractive optical element B2 has a pattern that generates a light amplitude having a phase difference of 1Z2 wavelength (180 degrees) with respect to the light amplitude generated by the second basic diffractive optical element B1. Further, the step d between the convex surface and the concave surface (the height dimension between the convex portion and the concave portion) in each of the optical elements A 1, A 2, B 1 and B 2 is set so that the diffraction efficiency becomes the best, that is, the phase difference Is set according to the following equation (1) so that λΖ2.

ά = λ / {2 (n 1 -η 2)} (1)

Here, λ is the wavelength of the illumination light (exposure light), that is, the wavelength used, nl is the refractive index at the wavelength used of the glass substrate of the diffractive optical element 6 (61 to 64), and n 2 is the atmosphere of the illumination light path. Is the refractive index at the used wavelength of the medium that forms. Specifically, assuming that the used wavelength λ is 193 nm, the refractive index of the glass substrate is 1.5, and the refractive index of air or inert gas as the medium is 1.0, the step d is set to about 193 nm. Will be determined.

The pitch P of the convex and concave surfaces of each of the optical elements A 1, A 2, B 1, and B 2 depends on the desired diffraction angle 0 to be set for the diffractive optical element 6 (61 to 64). Is set according to the following equation (2).

P = A / sin0 (2)

Referring to FIG. 4, the diffractive optical element 61 of the first embodiment includes four types of blocks C1 to C4. In the first block C1, eight first basic diffractive optical elements A1 and eight second basic diffractive optical elements B1 are alternately arranged along both directions in the X and Z directions. I have. In the second block C2, eight first basic diffractive optical elements A1 and eight second complementary diffractive optical elements B2 are alternately arranged along both directions in the X and Z directions. I have.

Further, in the third block C3, eight first complementary diffractive optical elements A2 and eight second basic diffractive optical elements B1 are alternately arranged along both directions in the X and Z directions. ing. In the fourth block C4, eight first complementary diffractive optical elements A2 and eight second complementary diffractive optical elements B2 are alternately arranged along both directions in the X direction and the Z direction. Thus, each of the blocks C1 to C4 has a square (4LX4L) outer shape, and has the same size as each other.

Referring to FIG. 5, the diffractive optical element 61 of the first embodiment is composed of a large number of blocks C1 to C4 arranged vertically and horizontally and densely. Here, the blocks C1 to C4 have substantially the same number as each other, and are randomly arranged over the entire rectangular effective area (effective diameter) 61a of the diffractive optical element 61.

In the exposure apparatus shown in FIG. 1, the diffractive optical element 61 of the first embodiment is installed at the position of the diffractive optical element 6 for multipole illumination, and a parallel light beam is incident on the diffractive optical element 61. A four-point light intensity distribution as shown in Fig. 6 is obtained on the incident surface 8. Here, a two-point light intensity distribution along the X direction across the optical axis AX is formed by the action of the first basic diffractive optical element A1 and the first complementary diffractive optical element A2. Further, a two-point light intensity distribution along the Z direction with the optical axis AX interposed therebetween is formed by the action of the second basic diffractive optical element B1 and the second complementary diffractive optical element B2. FIG. 7 is a view for explaining the principle of forming a quadrupole illumination field on the incidence surface of the microlens array in the first embodiment. FIG. 8 is a diagram showing a quadrupole illumination field formed on the entrance surface of the microlens array in the first embodiment. Further, FIG. 9 shows a quadrupole formed on the incident surface of the microlens array as an optical integrator when the microlens array is used as the divergent light beam forming element in the first embodiment. It is a figure which shows Teruno. FIG. 7 shows a state in which a microlens array 4a is used in place of the diffractive optical element 4 as a divergent light beam forming element.

In FIG. 7, since the microlens array 4a composed of regular hexagonal microlenses is used as the divergent light beam forming element, a large number of light sources are formed on the rear focal plane. Light from a number of light sources forms a regular hexagonal light flux (regular hexagonal light intensity distribution) on the pupil plane of the afocal zoom lens 5. When the diffractive optical element 4 is used as the divergent light beam forming element, a circular light beam (circular light intensity distribution) is formed on the pupil plane of the focal zoom lens 5 as described above. .

The light beam from the regular hexagonal or circular light intensity distribution formed on the pupil plane of the afocal zoom lens 5 is emitted from the afocal zoom lens 5 and becomes a light beam having various angle components to form the diffractive optical element 6. Incident at 1. When a condensed light beam having various angle components enters the diffractive optical element 61, for example, a light beam al parallel to the optical axis AX passes through the diffractive optical element 61 and then moves with respect to the optical axis AX. It travels in the direction diffracted by an angle ± S (the −0 side is not shown). Also, for example, rays a 2 and a 3 having an angle of ± t with respect to the optical axis AX pass through the diffractive optical element 61 and then pass through the optical axis AX with respect to the soil (0 soil t) (one (0 soil t) side is not shown).

Thereafter, the light beams al, a 2 and a 3 reach the entrance surface of the microlens array 8 via the zoom lens 7 having the focal length f. On the other hand, the light beams b 1, b 2, and b 3 that have passed through the microlens elements different from the light beams a 1, a 2, and a 3 in the microlens array 4 a also pass through the diffractive optical element 61 and the zoom lens 7. Thus, the light reaches the same area as the light beams a1, a2, and a3 on the entrance surface of the microlens array 8. Paraphrase Then, on the entrance surface of the microlens array 8, the same area is illuminated in a superimposed manner by the light beams a1 to a3 and the light beams bl to b3.

As described above, when a parallel light beam enters the diffractive optical element 61, a four-point light intensity distribution as shown in FIG. 6 is formed on the incident surface of the microlens array 8. However, in practice, the diffractive optical element 61 is not a parallel beam but a cone (a regular hexagonal pyramid in the case of the microlens array 4a, and a cone in the case of the diffractive optical element 4). A light beam having an angle component defined by the light beam range of the shape is incident. Thus, as shown in FIG. 8 or FIG. 9, the entrance surface of the microlens array 8 is composed of a four-point light intensity distribution and a circular or regular hexagonal light flux. A polar illumination distribution (illumination field) is formed.

As a result, on the rear focal plane (illumination pupil plane) of the microlens array 8, a quadrupole secondary light source having substantially the same light intensity distribution as the quadrupole illumination field is formed. Here, the quadrupole secondary light source is composed of four circular or regular hexagonal substantial surface light sources, that is, two surface light sources symmetrically arranged in the X direction with the optical axis AX interposed therebetween and the optical axis AX. And two surface light sources symmetrically arranged in the Z-direction. Thus, in the first embodiment, a quadrupolar secondary light source substantially uniform on the illumination pupil plane is formed by the action of the diffractive optical element 61.

In the first embodiment, by changing the magnification of the afocal zoom lens 5, the distance between the center of each surface light source constituting the quadrupole secondary light source and the optical axis AX does not change. Only the size of the surface light source (the radius of the circle circumscribing the quadrupole secondary light source-the radius of the circle circumscribing the quadrupole secondary light source) can be changed. On the other hand, by changing the focal length of the zoom lens 7, both the distance and the size described above can be changed, and the entire quadrupole secondary light source can be enlarged or reduced similarly. You.

In the above-described first embodiment, four optical elements are arranged in each of the blocks C1 to C4 in the horizontal direction and the vertical direction. However, the present invention is not limited to this. Each of the blocks C1 to C4 can also be configured by arranging n (n≥2) optical elements in the horizontal and vertical directions. As in the first embodiment Blocking the four types of optical elements (A 1, A 2, B 1, B 2) and arranging them randomly involves arranging the optical elements (A 1, A 2, B 1, B 2). Compared to the case, it has been confirmed both experimentally and by calculation simulations that it is advantageous for reducing illuminance unevenness caused by interference noise.

(Second embodiment)

In the first embodiment, by the action of the diffractive optical element 61, two surface light sources arranged symmetrically in the X direction with the optical axis AX interposed therebetween and symmetrically arranged in the Z direction with the optical axis AX interposed therebetween. A cross-shaped quadrupole secondary light source consisting of two surface light sources is also formed. On the other hand, in the second embodiment, by the action of the diffractive optical element 62, the diffractive optical element 62 is composed of four surface light sources symmetrically arranged in a direction of 45 degrees with respect to the X axis with respect to the optical axis AX. An X-type quadrupole secondary light source is formed. Hereinafter, the second embodiment will be described focusing on the differences from the first embodiment.

FIG. 10 is a diagram schematically showing a configuration of a basic diffractive optical element and a complementary diffractive optical element included in the quadrupole illumination diffractive optical element in the second embodiment. FIG. 11 is a diagram schematically showing a configuration of four types of blocks included in the diffractive optical element for quadrupole illumination in the second embodiment. FIG. 12 is a diagram schematically showing an entire configuration of a diffractive optical element for quadrupole illumination in the second embodiment. Further, FIG. 13 is a diagram for explaining the basic operation of the diffractive optical element for quadrupole illumination in the first embodiment.

Referring to FIG. 10, the diffractive optical element 62 according to the second embodiment has a direction of +45 degrees around the + Y axis with respect to the + X direction (clockwise in the figure as a positive angle). A first basic diffractive optical element D 1 having a linear grating pattern along the first and a second basic diffractive optical element having a linear grating pattern along a direction at an angle of +145 degrees around the + Y axis with respect to the + Z direction. E1, the first complementary diffractive optical element D2 obtained by inverting the convex and concave surfaces of the first basic diffractive optical element D1, and the convex and concave surfaces of the second basic diffractive optical element E1 are inverted. And a second complementary diffractive optical element E2 obtained as a result.

That is, the second basic diffractive optical element E 1 has a pattern obtained by rotating the pattern of the first basic diffractive optical element D 1 90 degrees counterclockwise in the figure on the XZ plane. You. The second complementary diffractive optical element E 2 has a pattern obtained by rotating the pattern of the first complementary diffractive optical element D 2 by 90 degrees counterclockwise in the figure on the XZ plane. In the second embodiment, as in the first embodiment, each of the optical elements Dl, D2, E1, and E2 is a binary diffractive optical element pattern composed of a repetition of a convex surface and a concave surface. The width W of the convex surface and the concave surface is constant over the whole of each optical element, and has a square outer shape with one side having a length L (L = mP: m is an integer) as a whole. Referring to FIG. 11, the diffractive optical element 62 of the first embodiment includes four types of blocks F1 to F4. In the first block F1, nine first basic diffractive optical elements D1 and nine second basic diffractive optical elements E1 are alternately arranged along two directions which form 45 degrees with the X direction. Are arranged. In the second block F 2, nine first basic diffractive optical elements D 1 and nine second complementary diffractive optical elements E 2 are alternately arranged along two directions forming 45 ° with the X direction. Are arranged.

Further, in the third block F3, nine first complementary diffractive optical elements D2 and nine second basic diffractive optical elements E1 are alternately arranged along two directions forming 45 degrees with the X direction. They are arranged. In the fourth block F 4, nine first complementary diffractive optical elements D 2 and nine second complementary diffractive optical elements E 2 are alternately arranged along two directions forming 45 ° with the X direction. Are arranged. Thus, each of the blocks F1 to F4 has the same size as each other.

Referring to FIG. 12, the diffractive optical element 62 of the second embodiment is composed of a large number of blocks F1 to F4 arranged vertically and horizontally and densely. Here, each of the blocks F 1 to F 4 has substantially the same number as each other, and is randomly arranged over the entire rectangular effective area (effective diameter) 62 a of the diffractive optical element 62. At this time, a large number of blocks F1 to F4 are arranged with a predetermined margin so that no gap is generated in the effective area 62a.

In the exposure apparatus shown in FIG. 1, the diffractive optical element 62 of the second embodiment is installed at the position of the diffractive optical element 6 for multipole illumination, and a parallel light beam is made incident on the diffractive optical element 62. An X-shaped four-point light intensity distribution as shown in FIG. 13 is obtained on the incident surface of the array 8. Here, + around the Y axis with respect to the + X direction with the optical axis AX interposed The two-point light intensity distribution along the direction forming +45 degrees (clockwise in the figure as a positive angle) is the same as that of the first basic diffractive optical element D 1 and the first complementary diffractive optical element D 2. It is formed by action. In addition, the two-point light intensity distribution along a direction forming −45 degrees around the + Y axis with respect to the + Z direction with respect to the optical axis AX is represented by the second basic diffractive optical element E 1 and the second complementarity. It is formed by the action of the diffractive optical element E2.

Therefore, in the second embodiment, as shown in FIG. 14 or FIG. 15, the incident surface of the microlens array 8 has an X-shaped four-point light intensity distribution and a circular or regular hexagonal light flux. A four-pole illumination distribution (illumination field) consisting of the above composition is formed. As a result, on the rear focal plane (illumination pupil plane) of the microlens array 8, an X-type quadrupole secondary light source having substantially the same light intensity distribution as the quadrupole illumination field is formed. Thus, in the second embodiment, as in the first embodiment, a quadrupole secondary light source substantially uniform on the illumination pupil plane is formed by the action of the diffractive optical element 62. Also, in the second embodiment, as in the first embodiment, by changing the magnification of the afocal zoom lens 5, the center of each surface light source constituting the quadrupole secondary light source, the optical axis AX, It is possible to change only the size of each surface light source without changing the distance. On the other hand, by changing the focal length of the zoom lens 7, both the distance and the size described above are changed, and the entire quadrupole secondary light source can be similarly enlarged or reduced. Further, as for the method of arranging the optical elements in each of the blocks F1 to F4, various modifications are possible as in the first embodiment.

(Third embodiment)

In the first embodiment, a cross-shaped quadrupole secondary light source is formed by the action of the diffractive optical element 61, and in the second embodiment, an X-shaped quadrupole secondary light source is formed by the action of the diffractive optical element 62. Has formed. In contrast, in the third embodiment, an octupole secondary light source is formed by combining the operation of the diffractive optical element 61 and the operation of the diffractive optical element 62. Hereinafter, the third embodiment will be described by focusing on the differences from the first embodiment and the second embodiment.

In the third embodiment, the diffractive optical element 63 for octopole illumination is composed of four types of optical elements (A 1, A 2, B 2) included in the diffractive optical element 61 for quadrupole illumination in the first embodiment. 1, D 2), and (D l ′, D l, D 2) similar to the four types of optical elements (D l, D 2, E 1, E 2) included in the quadrupole illumination diffractive optical element 62 in the second embodiment. D 2 ′, E 1 ′, E 2 ′). Also, the diffractive optical element 63 of the third embodiment has blocks 01 to 4? It has four types of blocks DQ1 to DQ4 including 1, to F4.

FIG. 16 is a diagram conceptually showing the configurations of a basic diffractive optical element and complementary diffractive optical elements (D 1 D 2 ′, E l ′, E 2 ′) in the third embodiment. As described below, the patterns of the square boundary and the linear diffraction grating are patterned with a 45-degree inclination in order to combine them with blocks C1 to C4. FIG. 17 is a diagram conceptually showing the configuration of blocks F 1 ′ to F 4, which are constituted by optical elements (D 1, D 2, E 1, E 2 ′). FIG. 18 is a conceptual diagram of composing blocks DQ1 to DQ4 by combining blocks C1 to C4 and blocks F1 ′ to F4. FIG. 19 is a diagram conceptually showing a configuration of a diffractive optical element 63 of the third embodiment configured by arranging a large number of composite blocks DQ1 to DQ4 vertically and horizontally. Here, each of the composite blocks DQ1 to DQ4 has substantially the same number as each other, and is randomly arranged over the entire rectangular effective area of the diffractive optical element 63.

In the exposure apparatus shown in FIG. 1, the diffractive optical element 63 of the third embodiment is installed at the position of the diffractive optical element 6 for multipole illumination, and a parallel light beam is incident on the diffractive optical element 63. An 8-point light intensity distribution as shown in FIG. Here, a two-point light intensity distribution along the X direction across the optical axis AX is formed by the action of the first basic diffractive optical element A1 and the first complementary diffractive optical element A2. Further, a two-point light intensity distribution along the Z direction across the optical axis AX is formed by the action of the second basic diffractive optical element B1 and the second complementary diffractive optical element B2. Furthermore, a two-point light intensity distribution along a direction forming +45 degrees around the + Y axis with respect to the + X direction with respect to the optical axis AX (clockwise in the figure as a positive angle) is the first point. It is formed by the action of the basic diffraction optical element D 1 ′ and the first complementary diffraction optical element D 2 ′. In addition, the optical axis AX is interposed along the + Z direction at +45 degrees around the + Y axis. The two-point light intensity distribution is formed by the action of the second basic diffractive optical element E 1 ′ and the second complementary diffractive optical element E 2 ′.

Therefore, in the third embodiment, as shown in FIG. 21 or FIG. 22, the incident surface of the microlens array 8 has a light intensity distribution of eight points and a circular or regular hexagonal light flux. An 8-pole illumination distribution (illumination field) consisting of convolution is formed. As a result, on the rear focal plane (illumination pupil plane) of the microlens array 8, an octupole secondary light source having substantially the same light intensity distribution as the octupole illumination field is formed. Thus, in the third embodiment, the action of the diffractive optical element 63 forms a substantially uniform octupole secondary light source on the illumination pupil plane.

In the third embodiment, by changing the magnification of the afocal zoom lens 5, the distance between the center of each surface light source constituting the octupole secondary light source and the optical axis AX does not change. Only the size of the surface light source can be changed. On the other hand, by changing the focal length of the zoom lens 7, both the above-described distance and size can be changed, so that the entire 8-pole secondary light source can be similarly enlarged or reduced. (Fourth embodiment)

In the first and second embodiments, a quadrupole secondary light source is formed by the action of the diffractive optical element 61 or 62. On the other hand, in the fourth embodiment, a dipole secondary light source is formed by the action of the diffractive optical element 64. Hereinafter, the fourth embodiment will be described by focusing on the differences from the first embodiment and the second embodiment.

FIG. 23 is a diagram schematically showing a configuration of a basic diffractive optical element and a complementary diffractive optical element included in the dipole optical element for dipole illumination in the fourth embodiment. FIG. 24 is a diagram schematically showing the entire configuration of a dipole optical element for dipole illumination in the fourth embodiment. FIG. 25 is a diagram illustrating a random arrangement of each optical element in the fourth embodiment.

In the first embodiment and the second embodiment, assuming that the phase of the light beam generated by the basic diffractive optical elements (A 1, B 1, D 1, E 1) is 0, the complementary diffractive optical elements (A 2, B 2 , D 2, E 2) are set so that the phase of the luminous flux is 7T phase. In other words, the complementary diffractive optical element (A 2, B 2, D 2, E 2) is 1, Bl, D1, El) are set to generate an optical amplitude with a phase difference of 7 ° with respect to the optical amplitude generated. In contrast, in the fourth embodiment, assuming that the phase of the light beam generated by the basic diffractive optical element G1 is 0 phase, the phase of the light beam generated by the first to third complementary diffractive optical elements G2 to G4 is The phase is set to 7T / 2 phase, π phase, and 3πΖ2 phase, respectively.

In this case, the basic diffractive optical element G1 has, for example, the same pattern as the basic diffractive optical element A1 of the first embodiment. The second complementary diffractive optical element G3 has the same pattern as the complementary diffractive optical element A2 of the first embodiment (a pattern obtained by inverting the basic diffractive optical element A1). For the sake of simplicity, in FIG. 23, the number of uneven portions included in the basic diffractive optical element and the complementary diffractive optical element is reduced. In practice, it is desirable to set the outer shape (size) of the optical element so that a pair of concaves and convexes is equivalent to one pitch and a concave and convex pattern of 5 pitches or more is included.

On the other hand, the first complementary diffractive optical element G2 having a phase difference of πΖ2 is obtained by shifting the pattern of the basic diffractive optical element G1 by 1Z4, which is the pitch の of the concavo-convex pattern. The third complementary diffractive optical element G4 having a phase difference of 3ττ 32 is obtained by shifting the pattern of the basic diffraction optical element G1 by 3Ρ4. That is, the third complementary diffractive optical element G4 has a pattern in which the first complementary diffractive optical element G2 is inverted in phase. Each of the optical elements G1 to G4 has a square outer shape (boundary), and has substantially the same size as each other.

In the fourth embodiment, the intensity distributions (light divergence directions and intensities) of the light beams generated by the basic diffractive optical element G1 and the first to third complementary diffractive optical elements G2 to G4 are the same. Only the phase portion of the light amplitude that defines the intensity distribution differs. In this way, by randomly mixing four types of light fluxes having the same intensity distribution and different phases, regular interference noise can be significantly reduced. Referring to FIG. 24, the diffractive optical element 64 for dipole illumination of the fourth embodiment includes a number of basic diffractive optical elements G 1 and a first complementary diffractive optical element G 1 that are arranged vertically and horizontally and densely. 2 and a second complementary diffractive optical element G3 and a third complementary diffractive optical element G4. The numbers of the elements G 1 to G 4 are almost the same as each other, and the diffractive optical elements 64 The rectangular effective area (effective diameter) 64 is randomly arranged over the whole area. To randomly arrange the elements G1 to G4, as shown in FIG. 25, 0 in the random number sequence of (3, 2, 1, 0) corresponds to the basic diffractive optical element G1, and 1 A random number table is created by associating the first complementary diffractive optical element G2, 2 with the second complementary diffractive optical element G3, and 3 with the third complementary diffractive optical element G4. Here, as the random number sequence, a sequence containing substantially the same number of numbers 0 to 3 is selected and used. Then, by arranging the patterns of the respective elements G1 to G4 according to the created random number table, the configuration of the diffractive optical element 64 as shown in FIG. 24 is obtained.

In the exposure apparatus shown in FIG. 1, the diffractive optical element 64 of the fourth embodiment is installed at the position of the diffractive optical element 6 for multipole illumination, and a parallel light beam is made incident on the diffractive optical element 64. On the incident surface of the array 8, a two-point light intensity distribution as shown in FIG. 26 is obtained. Therefore, in the fourth embodiment, as shown in FIG. 27 or FIG. 28, the incident surface of the microlens array 8 is formed by a two-point light intensity distribution and a circular or regular hexagonal light beam. A dipole illumination distribution (illumination field) consisting of the composition is formed.

As a result, on the rear focal plane (illumination pupil plane) of the microlens array 8, a dipole secondary light source having substantially the same light intensity distribution as the dipole illumination field is formed. Thus, in the fourth embodiment, a substantially uniform dipole-shaped secondary light source is formed on the illumination pupil plane by the action of the diffractive optical element 64.

In the fourth embodiment, by changing the magnification of the afocal zoom lens 5, the distance between the center of each surface light source constituting the dipole secondary light source and the optical axis AX does not change. Only the size of the surface light source can be changed. On the other hand, by changing the focal length of the zoom lens 7, both the distance and the size described above can be changed, and the entire dipole secondary light source can be similarly enlarged or reduced. In the fourth embodiment, since the basic diffractive optical element G1 has the same pattern as the basic diffractive optical element A1 of the first embodiment, a dipole bilaterally symmetric with respect to the optical axis AX in the X direction. A secondary light source is formed. However, when the basic diffractive optical element G1 has the same pattern as the basic diffractive optical element B1 of the first embodiment, the optical axis AX is sandwiched. It is possible to form a dipole secondary light source symmetrical in the Z direction. When the basic diffractive optical element G1 has the same pattern as the basic diffractive optical element D1 or E1 of the second embodiment, it is symmetrical with respect to the optical axis AX in a direction at 45 degrees with respect to the X direction. It is possible to form a bipolar secondary light source.

In the fourth embodiment, a case has been described in which a total of four types of phases are randomly arranged in the basic diffractive optical element and the complementary diffractive optical element. However, the present invention is not limited to this, and the types of phases are further increased. Then (even more types of complementary diffractive optical elements), more uniform illumination can be performed. In general, when a plurality of complementary diffractive optical elements having different phases are set for one basic diffractive optical element, it is preferable that the phase difference changes at substantially equal intervals in order to improve the effect of reducing interference noise. When one kind of complementary diffractive optical element is used as in the first to third embodiments, it is desirable that the phase of the complementary diffractive optical element is shifted by π with respect to the basic diffractive optical element. By randomly arranging the optical element and the complementary diffractive optical element, a minimum random phase effect can be achieved. In this case, the number of types of complementary diffractive optical elements is small, and there is an advantage that patterning becomes easy. The method of setting a plurality of types of complementary diffractive optical elements can be applied to the above-described first to third embodiments.

When a secondary light source having a plurality of poles is formed on the illumination pupil plane as described above, it is ideal that the light intensity distribution of each of the surface light sources constituting the secondary light source has a top hat shape. However, in reality, a phenomenon (so-called peripheral sag) in which the light intensity decreases slowly at the periphery (edge) due to diffraction occurs. In particular, it is necessary to minimize peripheral sag due to primary light, which depends on the periodicity of the optical element itself, rather than the effect of diffraction on the line-and-space pattern.

That is, for example, in the diffraction element (block) C1 in the first embodiment, A1 and B1 are periodically arranged as shown in FIG. A 1 is an illumination component in the X direction, and B 1 is a diffractive element element that carries an illumination component in the Z direction. That is, for example, the B 1 element does not contribute at all in the X direction, and the A 1 element does not contribute at all in the Z direction. In other words, for example, as far as the X direction is concerned, In other words, the C1 element can be considered as a pattern in which the B1 portion is completely shielded from light. Therefore, for example, when considering in the X direction, the C1 element is a black-and-white diffractive element in which one set of the A1 pattern having the size of L and the light-shielding portion having the size of L is arranged at a period of 2L. This causes an additional diffraction component to be generated essentially. This is exactly the same for the Z direction.

Since such an additional diffraction component becomes a factor of the surroundings, it is necessary to keep it below a certain value. Here, FIG. 29 is a diagram schematically showing a light intensity profile of each surface light source constituting the multipolar secondary light source. In the same figure, if there is no additional diffraction component, only the main component indicated by M becomes the final distribution of the surface light source, but actually the additional diffraction component indicated by S And superimposes it on the principal component M, causing peripheral sagging. In the figure, S illustrates only the + 1st-order component of the additional diffraction component, and in fact, the 1st-order component and higher-order components are also generated. However, the contribution of the higher-order components is small, so it is sufficient to consider only the first-order components here. In addition, since the diffracted light is generated symmetrically, only the absolute value (for example, only the + 1st-order component) may be considered here.

The diffraction angle 0 of the additional diffraction component S (+ 1st-order component) can be estimated by the following basic formula (3a), assuming a black-and-white diffraction element whose pitch is 2 L of the above principle. In monkey.

2 Lsin0! = Λ (3 a)

Here, λ is the illumination light wavelength. Further, assuming that the focal length of the zoom lens 7 is ί, the shift amount Δχ due to the additional diffraction component is calculated as shown in the following equation (3b).

Δχ = f sin ^ f λ / (2 L) (3 b)

In equation (3b), sin0 is calculated by substituting the equation estimated by equation (3a).

The smaller the deviation Δχ, the smaller the effect of the additional diffraction component. As for the allowable capacity of Δχ, good illumination can be performed if the size φ (diameter) of 1Z5 or less as the surface light source of Μ, which is the original main component, is less. This condition is given by the following equation (3c). f λ / (2 L) <φ / 5 (3 c)

That is, in each embodiment, it is preferable that the conditional expression (4) obtained by modifying the expression (3c) is satisfied.

L> 2.5 X f X λ / φ (4)

Further, in each embodiment, in order to improve the illuminance contrast in the multipolar secondary light source, at least 4 light beams are included in the element light flux corresponding to each optical element constituting the diffractive optical element 4 as the divergent light beam forming element. It is preferable to position the diffractive optical element 6 (61-64) so that one optical element is included. When the microlens array 4a is used as the divergent light beam forming element, the diffractive optical element is so arranged that at least four optical elements are included in the element light beam corresponding to each optical element (each minute lens element). Preferably, element 6 (61-64) is positioned.

In the above-described first to third embodiments, a plurality of blocks arranged at random over the entire diffractive optical element are provided. In each block, two types of optical elements are alternately arranged by the same number. I have. In this arrangement method, partial regularity is introduced, so that it is possible to enhance the directivity and to average the illuminance unevenness due to the random phase effect to the extent that interference noise does not substantially occur.

However, without being limited to the above-described arrangement method, each of the first to third embodiments may have a random arrangement over the entire diffractive optical element in the same manner as in the fourth embodiment. it can. Further, the diffractive optical element may include a plurality of blocks, and a large number of optical elements may be randomly arranged in each block. In this case, it is preferable that the various optical elements have substantially the same number as each other. Further, it is preferable that the diffractive optical element includes a plurality of types of blocks, and the form of the random arrangement differs for each type of blocks.

Next, the partial random arrangement will be specifically described with reference to the first embodiment. FIG. 34 is a diagram schematically showing a configuration of a mask used for manufacturing a diffractive optical element by lithography. FIG. 35 is a diagram showing a diffractive optical element formed on a glass substrate using the mask of FIG. Referring to FIG. 34, in the center of the mask, two block patterns AAP1 and AAP2 are provided. For example, it is formed by EB drawing.

In the block pattern AAP1, first to fourth block elements C1, C2, C3, and C4 are randomly arranged throughout the block, each having 100 pieces. For the rule of the random arrangement in the block pattern AAP1, for example, the same random number sequence as in FIG. 25 is used. Similarly, the first to fourth block elements C 1, C 2, C 3, and C 4 are also randomly arranged in the block panel AA P 2, each having 100 elements. However, the rule of the random arrangement in the block pattern AAP2 is different from the rule of the random arrangement in the block pattern AAP1. That is, in the block pattern AAP2, random arrangement is performed using a random number sequence different from the random number sequence used for the block pattern AAP1.

Also, three alignment marks are drawn around the mask. The alignment mark am serves as a position reference for exposing the block patterns AAP1 and AAP2 on the glass substrate coated with the resist by reduced projection exposure. Furthermore, a pair of cutting guide patterns (guide windows) GP are drawn on the mask. The cutting guide pattern GP is used to mark a cutting line for cutting the diffractive optical element into a predetermined shape.

The mask is formed with, for example, a line and space pattern LS as a control rule pattern for controlling the line width and the etching depth. That is, the pattern LS is a test pattern including a linear line-and-space pattern having a line width of about 2 xm inside the pattern LS, and before and after the exposure of the block patterns AAP1 and AAP2, The LS is printed outside the effective diameter of the diffractive optical element, and is used for line width control and etching depth control.

The diffractive optical element shown in FIG. 35 is obtained by alternately exposing the block patterns AAP1 and AAP2 4 × 12 times using the mask of FIG. 34, and developing and etching. In the diffractive optical element thus generated, the elements are not arranged randomly over the entire effective diameter, but are so-called partially random arranged. In such a partial random arrangement, each staggered block has Since the elements are randomly arranged and the coherence of the excimer laser is finite, predetermined optical performance can be exhibited. In addition, a diffractive optical element can be easily and inexpensively manufactured using one reticle master (mask). Note that in order to achieve a higher interference noise reduction effect, in addition to the two block patterns AAP1 and AAP2, another block having a different internal random arrangement such as AAP3, AAP4,. It is preferable to appropriately prepare a pattern. Then, all the blocks are sequentially exposed on the diffractive optical element, developed and etched, so that elements CI, C2, C3, and C4 are arranged in a random array over the entire effective diameter as shown in FIG. The manufactured diffractive optical element can be manufactured.

By the way, if all the block patterns cannot be arranged on the mask shown in Fig. 34, the remaining block patterns are drawn on one or more other masks, and all the masks are sequentially replaced while changing the mask. The diffractive optical element can be manufactured by exposing the block pattern on a glass substrate. The method of buttering the diffractive optical element by the partially random arrangement described above with reference to FIGS. 34 and 35 as an example is applicable to not only the first embodiment but also all embodiments of the present invention. It is possible to do so. That is, in each embodiment, it is possible to manufacture a mask of a diffractive optical element similar to that of FIG. 34, and to manufacture a diffractive optical element by partial random patterning similar to that of FIG. 35 using the mask. . In all the embodiments of the present invention, as a material of a substrate for patterning a diffractive optical element, for example, synthetic stone, quartz, fluorite, or the like can be used.

In each of the above embodiments and modifications, the period (pitch) P of the linear grating pattern is set to about 0.1 m to 250 m, and the area of the effective diameter of the basic diffraction optical element and the complementary diffraction optical element is set. Should be set to about 5 mx 5 m to 100 mx 000 zm, and the number of basic diffractive optical elements and complementary diffractive optical elements within the effective diameter of the diffractive optical element should be set to about 10 or more. Can be.

By the way, the exposure apparatus shown in FIG. 1 uses a microlens array 8, which is an optical integrator of a wavefront division type, to form a multipolar secondary light source. However, a rod integrator (rod-type integrator) which is an internal reflection type optical integrator can be used instead of the microlens array 8. FIG. 30 is a diagram schematically showing a configuration of a main part when a rod integrator is used instead of the microlens array in the exposure apparatus of FIG. Referring to FIG. 30, corresponding to the arrangement of the rod integrator -1 instead of the microlens array 8, the input lens is provided in the optical path between the zoom lens 7 and the rod integrator 801. 8, and a relay lens 83 in the optical path between the rod's integrator 81 and the condenser optical system 9. Here, the surface A shown in FIG. 30 corresponds to the entrance surface of the microlens array 8 in FIG. 1, and the surface B shown in FIG. 30 corresponds to the exit surface of the microlens array 8 in FIG. ing.

Rod Integral is an internal reflection type glass rod made of glass material such as quartz glass or fluorite, and is a focal point using the total reflection at the boundary between the inside and the outside, that is, the inside. The number of light sources corresponding to the number of internal reflections is formed along a plane parallel to the rod incidence plane through the rod. Here, most of the light sources formed are virtual images, but only the light source at the center (focus point) is a real image. In other words, the light beam incident on the rod integrator 81 is divided in the angular direction by internal reflection, and a secondary light source consisting of a number of light sources is formed along a plane passing through the focal point and parallel to the incident plane.

Therefore, the light beam that has passed through the diffractive optical element 6 (61 to 64) forms a multipolar illumination field on the A surface, and then enters the input surface of the rod / integrator 81 via the input lens 82. Focuses near 8 1 a. In this way, the luminous flux from the multipolar secondary light source formed on the incident side by the rod / integrator 81 is superimposed on the exit surface 81b, and then the relay lens 83 and the condenser optical system A reticle (mask) 13 on which a predetermined pattern is formed is superimposedly illuminated via 9.

It is also possible to remove the relay lens 83 and the condenser optical system 9 and install the exit surface 81b of the rod integral 81 near the reticle 13. Alternatively, remove the zoom lens 7 and the input lens 82, and The entrance surface 81a of the antenna 81 can be placed near the exit surface of the diffractive optical element 6 (61 to 64). Alternatively, remove the zoom lens 7, the input lens 82, the relay lens 83, and the condenser optics 9, and set the entrance surface 81a of the rod integument 81 near the exit surface of the diffractive optical element 6 (61 to 64). At the same time, the exit surface 81b of the rod 'Integral 81' can be installed near the reticle 13.

Further, in the exposure apparatus shown in FIG. 1, in the optical path between the light source 1 and the diffraction optical element 4 as a divergent light beam forming element, for example, JP-A-9-1205060 and JP-A-10-125585 An optical delay system disclosed in Japanese Patent Application Laid-Open No. 2000-277421 or the like can be additionally provided. Hereinafter, a case where an optical delay system is provided in the optical path between the bending mirror 13 and the diffractive optical element 4 will be briefly described.

In this case, the light beam converted into a desired cross-sectional shape via the shaping optical system 2 and the bending mirror 13 enters an optical delay system including a total reflection mirror and a partial reflection mirror. In the optical delay system, a part of the light beam transmitted through the partial reflection mirror enters the diffractive optical element 4, and the remaining light beam reflected by the partial reflection mirror enters the total reflection mirror. The light beam reflected by the total reflection mirror is incident on the partial reflection mirror, a part of the light beam transmitted through the partial reflection mirror is incident on the diffractive optical element 4, and the remaining light beam reflected by the partial reflection mirror is totally reflected. Light enters the mirror.

Thus, in the optical delay system, the incident beam is converted into a plurality of beam groups that are sequentially optically delayed by multiple reflections that are repeated between the total reflection mirror and the partial reflection mirror. As a result, interference noise on the wafer conjugate plane can be reduced by the action of the optical delay system. For a more detailed configuration and operation of the optical delay system, for example, JP-A-9-205060, JP-A-10-125585, and JP-A-2000-277421 can be referred to.

In each of the above embodiments, a binary diffractive optical element pattern is used. However, the present invention is not limited to this, and a blazed diffractive optical element pattern or a multi-valued diffractive optical element pattern may be used. You can also. Hereinafter, referring to FIGS. 31A to 31C, a blaze type diffractive optical element pattern, a multi-valued type diffractive optical element pattern, And a binary type diffractive optical element pattern will be generally described.

FIG. 31A is a cross-sectional view of a blaze-type diffractive optical element cut along a cross section in the periodic direction. FIG. 31B is a cross-sectional view of a multi-valued diffractive optical element cut along a cross section in the periodic direction. Yes, FIG. 31C is a cross-sectional view of the binary diffractive optical element cut along a cross section in the periodic direction. Referring to FIG. 31A, the cut surface of the blazed diffractive optical element has a sawtooth shape, and the pitch P at which the steps occur in a sawtooth shape is given by Expression (2).

Also, the depth d in the cross section. Is given by the following equation (5), where n is the refractive index of the substrate and 1 is the refractive index of the gas on which the substrate is placed.

d ₀ = AZ (n-1) (5)

It is possible to use a basic diffractive optical element having such a blaze-type diffractive optical element pattern and a complementary diffractive optical element. In this case, the pattern of the basic diffractive optical element and the complementary diffractive optical element is not a binary type having a convex surface and a concave surface, but a pattern whose cross-sectional shape changes in the height direction. In generating such a pattern with different height directions, it is possible to use a gray scale mask whose transmittance changes gradually.

Referring to FIG. 31B, the cut surface of the multi-valued diffractive optical element has a shape that approximates the sawtooth shape of FIG. 31A to an L-stage (L≥3) step-like shape. Then, the boundary of each step can be easily defined by dividing the range of the pitch P into L according to the step area of each step. FIG. 31B shows the case of an 8-level phase diffractive optical element with L = 8. Assuming that the refractive index of the substrate is n and the refractive index of the gas on which the substrate is disposed is 1, the depth d J in the cross section is given by the following equation (6).

d _L = A. (L-1) / {L · (n-1)} (6)

It is possible to use a basic diffractive optical element and a complementary diffractive optical element having such a multilevel diffractive optical element pattern. In this case, the pattern of the basic diffractive optical element and the complementary diffractive optical element is not a binary type having a convex surface and a concave surface, but has a step shape in cross section and a pattern that changes in the height direction. Such height differences In generating such a pattern, it is possible to use a gray scale mask whose transmittance changes stepwise and in multiple steps.

Referring to FIG. 31C, the cut surface of the binary diffractive optical element has a shape when L = 2 in the stepwise approximation of FIG. 31B. That is, the cut surface of the binary type diffraction optical element, as shown in 3 1 C diagram, rectangular represented by two steps of a convex area portion and concave regions portion for the thickness d ₂ direction It becomes a shape pattern. The boundaries of each rectangular area can be given by PZ2. The depth d ₂ in the cross section is given by the following equation (7), where n is the refractive index of the substrate and 1 is the refractive index of the gas on which the substrate is disposed.

ά ₂ = λ / {2 · (η-1)} (7)

Further, in each of the above-described embodiments and modifications, the basic diffractive optical element having a pattern obtained by arranging the linear lattice-like diffractive optical element patterns based on a predetermined azimuth angle in a substantially dense pattern is used. This realizes a diffractive optical element having However, as an optical member having the same optical performance as this diffractive optical element, a basic member having a refraction surface pattern obtained by arranging prism-like refraction surfaces set based on a predetermined azimuth angle almost densely. It is also possible to realize a refractive optical element having a refractive element.

Specifically, a design in which the diffraction angle of a blazed diffractive optical element is replaced by the refractive angle of a micro-refractive element (such as a microphone aperture prism) can be used. Such refractive elements can be densely arranged to include a predetermined azimuthal component. However, if densely arranged as a complete refraction element, the sag amount during glass etching becomes too large.Therefore, at the position of the appropriate sag amount, the phase difference for the wavelength is patterned by taking in the step structure that is considered equivalent. It is desirable.

In manufacturing the above-described refractive optical element, after patterning the basic refractive element, the pattern is converted into a mask pattern (such as a gray scale mask) for manufacturing a micro refractive element, and the mask pattern is coated with a resist. The exposed glass substrate is exposed, developed and etched.

Next, a brief description will be given of a typical manufacturing process of the diffractive optical element in each embodiment. I will tell. First, the focal length of the relay lens, the effective diameter of the luminous flux, the wavelength of the light source, and the divergent luminous flux included from a predetermined light source to the final stage (most mask side) optical integrator (microlens array 8 in each embodiment). The pitch of the linear grating diffractive optical element is set based on the relationship with the divergence angle of the forming element. Then, a predetermined azimuth angle is set according to a desired illumination method, and an effective diameter of the basic diffractive optical element is set. At this time, the effective diameter of the basic diffractive optical element is set such that a plurality of basic diffractive optical elements or complementary diffractive optical elements are included in the element light flux corresponding to each optical element constituting the divergent light beam forming element.

Next, the linear grating diffractive optical element is set at a predetermined azimuth, and the pattern of the basic diffractive optical element is set. Further, a pattern of one or a plurality of complementary diffractive optical elements having the same intensity distribution as that of the basic diffractive optical element and a phase different from that of the basic diffractive optical element is set. A diffractive optical element pattern in which the basic diffractive optical element obtained in this way and one or more kinds of complementary diffractive optical elements are respectively integrated by approximately the same number within the effective diameter is set.

At this time, the arrangement positions of the basic diffractive optical element and the complementary diffractive optical element are randomized (whole random or partially random). A wave optics simulation is performed on the thus patterned diffractive optical element, and the pitch of the basic diffractive optical element, the phase of the complementary diffractive optical element, and the type of the phase are optimized. Next, a reticle (mask) is manufactured in accordance with the optimized pattern of the diffractive optical element, and the reticle is used to print the pattern on a resist-coated glass substrate. After that, a development process, an etching process, and a process of forming an AR (anti-reflection) coat are performed.

In the above embodiments, the basic diffractive optical element and the complementary diffractive optical element having such a binary diffractive optical element pattern are used. In this case, it is possible to use a so-called black-and-white type mask (only a transmission part and a light shielding part). In addition, as the material of the substrate on which the diffraction optical element is patterned, for example, synthetic quartz, quartz, fluorite, or the like can be used.

(Fifth embodiment) In the first embodiment, by the action of the diffractive optical element 61, two surface light sources arranged symmetrically in the X direction with the optical axis AX interposed therebetween and symmetrically arranged in the Z direction with the optical axis AX interposed therebetween. It has a cross-shaped quadrupole illumination distribution (secondary light source) consisting of two surface light sources. On the other hand, in the fifth embodiment, block elements C 1 d to C 4 d in which a new simple transmission portion is added to block elements C 1 to C 4 included in the diffractive optical element 61 are adopted. The quintuple illumination distribution is formed by adding one pole on the optical axis to the four poles of the first embodiment. That is, the fifth embodiment is a five-pole illumination embodiment having an intensity distribution also on the optical axis. Hereinafter, the fifth embodiment will be described by focusing on the differences from the first embodiment.

FIG. 36 is a diagram showing a pentapole illumination field formed on the entrance surface of the microlens array in the fifth embodiment. FIG. 37 is a view for explaining the basic operation of the pentapole illumination diffractive optical element in the fifth embodiment. Further, FIG. 38 is a diagram schematically showing an overall configuration of a diffractive optical element for five-pole illumination in the fifth embodiment. FIG. 39 is a diagram schematically showing a configuration of a block element included in the diffractive optical element for quintuple illumination in the fifth embodiment.

As shown in FIG. 38, the diffractive optical element 100 for five-pole illumination in the fifth embodiment is composed of a large number of block elements C 1 d to C 4 d arranged vertically and horizontally and densely. ing. Each of the block elements C 1 d to C 4 d has a rectangular outer shape (boundary), and has substantially the same size as each other. In addition, the same number of the block elements C 1 d to C 4 d is included for each type, and the rectangular effective area of the diffractive optical element 100 is

(Effective diameter) 100a is randomly arranged over the entirety, or is randomly arranged within the block obtained by dividing the whole into several blocks. As shown in FIG. 39, the block elements C 1 d to (: 4 d include the blocks C 1 to C 4 described in the first embodiment, respectively. This is an element in which a simple transparent portion H is arranged adjacent to the block C1 in the X direction in the embodiment.Similarly, the block element C2d is a device in which the simple transparent portion H is adjacent to the block C2 in the X direction. Block elements C 3 d and C 4 d are elements in which complementary simple transmission portions H d are arranged adjacent to blocks C 3 and C 4, respectively, in the X direction. Here, the simple transmissive portion H and the complementary simple transmissive portion Hd are intended to simply transmit the incident light beam and travel straight, and usually do not perform special fine patterning inside the elements H and Hd. In other words, the simple transmission portion H is a simple plane portion leaving the surface of the glass substrate forming the diffractive optical element as it is. Further, the complementary simple transmission portion Hd is a plane portion obtained by etching the glass substrate forming the diffractive optical element up to the depth d shown in Expression (1) within the effective diameter of the element Hd.

Since the surfaces of the elements H and Hd are simply planar, the light incident on the element H or Hd simply passes through and goes straight, except for some diffraction. However, the light beam transmitted through the simple transmission portion H and the light beam transmitted through the complementary simple transmission portion Hd have an optical path difference of λZ2 corresponding to the step d. That is, the simple transmission portion Η is a portion on which no special processing is performed on the glass surface, and the complementary simple transmission portion Hd is obtained by simply and substantially uniformly etching the glass by a predetermined optical path difference with respect to the simple transmission portion H. It is only an element.

If the divergence angle (diffraction angle) 0 of the quadrupole component is different from that in the first embodiment, the elements A 1, A 2, B 1, The pitch of B2 is set based on equation (2), and the desired block elements C1d to C4d are set by combining the elements H and Hd, and the corresponding diffractive optical element is set. Can be formed.

As described above, in the fifth embodiment using the diffractive optical element 100, a quadrupole component having a predetermined divergence angle is generated by the light transmitted through the blocks C1 to C4, and the elements H and Hd are simultaneously generated. A monopole component having an intensity near the optical axis is generated by the transmitted light, and quintuple illumination as shown in FIG. 36 can be performed by combining the quadrupole component and the monopole component.

That is, when the diffractive optical element 100 of the fifth embodiment is positioned in the illumination optical path and a parallel light beam is incident thereon, the incident surface of the microlens array 8 has four cross-shaped points as shown in FIG. A total of five-point light intensity distributions are formed, which are composed of a three-point light intensity distribution and a one-point light intensity distribution near the optical axis. However, as in the first embodiment, actually, the diffractive optical element 100 is not a parallel light beam, but a cone (in the case of the microlens array 4a, a regular hexagonal pyramid, a diffractive optical element 4). Luminous flux range A light beam having an angle component defined by the surroundings enters. Thus, as shown in FIG. 36, the entrance surface of the microlens array 8 has a pentapole illumination composed of a combination of a 5-point light intensity distribution and a circular (or regular hexagonal) light beam. A distribution (Teruno) is formed.

As a result, on the rear focal plane (illumination pupil plane) of the microlens array 8, a pentapole secondary light source having substantially the same light intensity distribution as the pentapole illumination field is formed. Here, the five-pole secondary light source is composed of five circular (or regular hexagonal) substantial surface light sources, that is, two symmetrically arranged in the X direction across the optical axis AX. It consists of a surface light source, two surface light sources symmetrically arranged in the Z direction with the optical axis AX interposed, and one surface light source arranged near the optical axis AX. Thus, in the fifth embodiment, a substantially uniform pentapole secondary light source is formed on the illumination pupil plane by the action of the diffractive optical element 100.

In the fifth embodiment, as in the first embodiment, by changing the magnification of the afocal zoom lens 5, the center of each of the surface light sources constituting the pentapole secondary light source and the optical axis AX are changed. The size of each surface light source (the radius of the circle circumscribing the quadrupolar secondary light source, the radius of the circle circumscribing the quadrupolar secondary light source, and the monopole shape on the optical axis) without changing the distance Only the diameter of the secondary light source). On the other hand, by changing the focal length of the zoom lens 7, both the above-described distance and size can be changed, so that the entire pentapole secondary light source can be similarly enlarged or reduced.

In the fifth embodiment, as a modified example of the block elements C 1 d to C 4 d, block elements C 1 d to C 4 d as shown in FIG. 40 can be used. The block element C 1 d is configured by cutting the block C 1 and the simple transmission portion H into almost half by a straight line parallel to the X-axis, and alternately replacing them as shown in FIG. The block element C 2 d is the same as the block element C 1 d. The block element C 3 d is configured by cutting the block C 3 and the complementary simple transmission portion H d into a half parallel to a straight line parallel to the X-axis, and alternately replacing them as shown in FIG. The block element C 4 d is the same as the block element C 3 d. By using a diffractive optical element including the block elements C 1 d to C 4 d having such an arrangement, the quadrupole illumination component and the optical axis The illumination balance with the one-sided illumination component is improved. Similarly, the internal patterns of the block elements C ld to C 4 d are further subdivided, and subdivided elements obtained by subdividing the element patterns of C 1 to C 4 corresponding to the four pole components, and the one pole component near the optical axis. By using a new block element obtained by staggering or randomly arranging the subdivision elements in which the H and Hd regions corresponding to the above are alternately arranged, the four-pole illumination component and the one-pole near the optical axis are used. The illumination balance with the illumination component can be further improved.

In the fifth embodiment, the blocks C1, C2 and the simple transparent portion H have the same area, and the blocks C3, C4 and the complementary simple transparent portion Hd have the same area. It is desirable to do.

(Sixth embodiment)

In the second embodiment, by the action of the diffractive optical element 62, two surface light sources and an optical axis along a direction forming +45 degrees around + Y axis with respect to + X direction with respect to the optical axis AX with respect to the optical axis AX X-type quadrupole illumination distribution (secondary light source) consisting of two surface light sources along a direction that forms an angle of +145 degrees around the Y axis with respect to the + Z direction with AX interposed . On the other hand, in the sixth embodiment, block elements F 1 d to F 4 d in which a new simple transmission portion is added to block elements F 1 to F 4 included in the diffractive optical element 62 are adopted. Therefore, a five-pole illumination distribution is formed by adding one pole on the optical axis to the four poles of the second embodiment. Hereinafter, the sixth embodiment will be described by focusing on the differences from the second embodiment.

FIG. 41 is a diagram showing a pentapole illumination field formed on the entrance surface of the microlens array in the sixth embodiment. FIG. 42 is a view for explaining the basic operation of the diffractive optical element for pentapole illumination in the sixth embodiment. FIG. 43 is a view schematically showing an entire configuration of a diffractive optical element for five-pole illumination in the sixth embodiment. FIG. 44 is a diagram schematically showing a configuration of a block element included in the diffractive optical element for quintuple illumination in the sixth embodiment.

As shown in FIG. 43, the pentapole illumination diffractive optical element 101 in the sixth embodiment is composed of a large number of block elements F 1 d to F 4 d arranged vertically and horizontally and densely. ing. The block elements F1d to F4d each have the outer shape (boundary) shape shown in FIG. 43 or FIG. 44, and have substantially the same size (area) as each other. Also, The block elements F 1 d to F 4 d are included in substantially the same number for each type, and are randomly arranged over the entire rectangular effective area (effective diameter) 101 a of the diffractive optical element 101? Or, the whole is divided into several blocks, and is randomly arranged in the block.

As shown in FIG. 44, the block elements F 1 d to F 4 d include the blocks F 1 to F 4 described in the second embodiment, respectively. For example, the block element Fid is an element in which a simple transmission portion H is arranged adjacent to the block F1 of the second embodiment in the X direction. Similarly, the block element F 2 d is an element in which a simple transparent portion H is arranged adjacent to the block F 2 in the X direction. The block elements F 3 d and F 4 d are elements in which complementary simple transmission portions H d are arranged adjacent to the blocks F 3 and F 4 in the X direction, respectively. Here, the shape of the boundary line of the simple transparent portion H and the complementary simple transparent portion Hd according to the sixth embodiment is different from that of the simple transparent portion H and the complementary simple transparent portion Hd in the fifth embodiment. However, the setting of the etching depth d and the effect as an element are the same. If the divergence angle (diffraction angle) 0 of the quadrupole component is different from that in the second embodiment, the elements D 1, D 2, E 1, and D 1 included in the blocks F 1 to F 4 for the corresponding divergence angle 0 The pitch of E2 is set based on equation (2), and the desired block elements F1d to F4d are set by combining the elements H and Hd, and the corresponding diffractive optical element is set. Can be formed.

As described above, in the sixth embodiment using the diffractive optical element 101, a quadrupole component having a predetermined divergence angle is generated by the light transmitted through the blocks F1 to F4, and the elements H and Hd are simultaneously generated. The transmitted light generates a monopole component having an intensity near the optical axis. By combining the quadrupole component and the monopole component, a quintuple illumination as shown in FIG. 41 can be performed.

That is, when the diffractive optical element 101 of the sixth embodiment is positioned in the illumination optical path and a parallel light beam is incident, the X-shaped four points are incident on the incident surface of the microlens array 8 as shown in FIG. A five-point light intensity distribution is formed, which is composed of a light intensity distribution having a point shape and a light intensity distribution having a point near the optical axis. However, as in the second embodiment, actually, the diffractive optical element 101 is not a parallel light beam but has a cone shape (microlens array). A light beam having an angular component defined by a light beam range of a regular hexagonal pyramid in the case of 4a and a cone in the case of the diffractive optical element 4 enters. Thus, as shown in Fig. 41, the five-point light intensity distribution and the circular shape

5-pole illumination distribution consisting of a composition with a light beam (or regular hexagonal shape)

(Teruno) is formed.

As a result, on the rear focal plane (illumination pupil plane) of the microlens array 8, a pentapole secondary light source having substantially the same light intensity distribution as the pentapole illumination field is formed. Here, the five-pole secondary light source is a five-circular (or regular hexagonal) substantial surface light source, that is, about + Y axis with respect to + X direction with optical axis AX interposed. Two surface light sources along the +45 degree direction and two surface light sources along the +45 degree direction around the + Y direction with respect to the + Z direction across the optical axis AX, It is composed of one surface light source arranged near the optical axis AX. Thus, in the sixth embodiment, a substantially uniform pentapole secondary light source is formed on the illumination pupil plane by the action of the diffractive optical element 101.

In the sixth embodiment, similarly to the second embodiment, by changing the magnification of the afocal zoom lens 5, the distance between the center of each surface light source constituting the five-pole secondary light source and the optical axis AX is changed. The size of each surface light source (the radius of the circle circumscribing the quadrupolar secondary light source, the radius of the circle circumscribing the quadrupolar secondary light source, and the Only the diameter of the secondary light source). On the other hand, by changing the focal length of the zoom lens 7, both the above-described distance and size can be changed, so that the entire pentapole secondary light source can be similarly enlarged or reduced.

In the sixth embodiment, as a modified example of the block elements F1d to F4d, the elements of F1 to F4 corresponding to the four-pole components included in F1d to F4d in FIG. The pattern is subdivided into segmented elements denoted by Dl, D2, El, and E2, and the H and Hd regions corresponding to one-pole components near the optical axis are similarly segmented elements. Improve the illumination balance between the quadrupole illumination component and the monopole illumination component near the optical axis by using a new block element in which the elements are arranged in a staggered arrangement as shown in Fig. 45. Can be. Similarly, the internal patterns of the block elements F1d to F4d are further subdivided, and the element patterns of F1 to F4 corresponding to the four-pole components are subdivided. By using a new block element obtained by staggering or randomly arranging the subdivided elements and the subdivided elements in which the H and Hd regions corresponding to one pole component near the optical axis are detailed. The illumination balance between the four-pole illumination component and the one-pole illumination component near the optical axis can be further improved. Further, in the sixth embodiment, the blocks Fl, F2 and the simple transmission part H have the same area, and the blocks F3, F4 and the complementary simple transmission part Hd have the same area. It is desirable to set.

(Seventh embodiment)

In the fourth embodiment, a dipole-shaped illumination distribution (secondary light source) symmetrically arranged in the X direction with respect to the optical axis AX is formed by the action of the diffractive optical element 64. On the other hand, in the seventh embodiment, the elements G 1 d to G 4 d obtained by adding a new simple transmission portion to the elements G 1 to G 4 included in the diffractive optical element 64 are adopted. A three-pole illumination distribution is formed by adding one pole on the optical axis to the two poles in the four embodiments. Hereinafter, the seventh embodiment will be described by focusing on the differences from the fourth embodiment.

FIG. 46 is a diagram showing a tripolar illumination field formed on the entrance surface of the microlens array in the seventh embodiment. FIG. 47 is a view for explaining the basic operation of the diffractive optical element for triode illumination in the seventh embodiment. Further, FIG. 48 is a diagram schematically showing an entire configuration of a diffractive optical element for triode illumination in the seventh embodiment. FIG. 49 is a diagram schematically showing a configuration of a block element included in the diffractive optical element for triode illumination in the seventh embodiment.

As shown in FIG. 48, the diffractive optical element 102 for tripolar illumination in the seventh embodiment is composed of a number of elements Gld to G4d arranged vertically and horizontally and densely. The elements Gld to G4d all have a rectangular outer shape (boundary) and have substantially the same size as each other. The elements G 1 d to G 4 d are included in substantially the same number for each type, and are randomly arranged over the entire rectangular effective area (effective diameter) 102 a of the diffractive optical element 102. Or the whole is divided into several blocks and arranged randomly in that block.

As shown in FIG. 49, the elements G ld to G 4 d include the elements G 1 to G 4 described in the fourth embodiment, respectively. For example, the element GI d is the element of the fourth embodiment. An element in which a simple transmission portion H is arranged adjacent to Gl in the X direction. Similarly, the element G 2 d is an element in which a simple transmission portion H is arranged adjacent to the element G 2 in the X direction. Elements G 3 d and G 4 d are elements in which complementary simple transmission portions H d are arranged adjacent to the elements G 3 and G 4 in the X direction, respectively. Here, the simple transmission portion H and the complementary simple transmission portion Hd according to the seventh embodiment have the same configuration and operation as the simple transmission portion H and the complementary simple transmission portion Hd in the fifth embodiment.

If the divergence angle (diffraction angle) 0 of the dipole component is different from that of the fourth embodiment, the pitch of the elements G1 to G4 for the corresponding divergence angle 0 is set based on equation (2). By combining these elements H and Hd, desired elements G1d to G4d can be set and corresponding diffractive optical elements can be formed.

As described above, in the seventh embodiment using the diffractive optical element 102, a dipole component having a predetermined divergence angle is generated by light transmitted through the elements G1 to G4, and the elements H and Hd are simultaneously generated. The transmitted light generates a monopole component having an intensity near the optical axis.Three-pole illumination along the X direction as shown in Fig. 46 is performed by combining these dipole components and the monopole component. Can be.

That is, when the diffractive optical element 102 of the seventh embodiment is positioned in the illumination optical path and a parallel light beam is incident, the optical axis AX is set on the incident surface of the microlens array 8 as shown in FIG. A total of five-point light intensity distributions, consisting of two-point light intensity distributions symmetrically arranged in the X direction and a one-point light intensity distribution near the optical axis, are formed. However, in the same manner as in the fourth embodiment, the diffractive optical element 102 does not have a parallel light beam but a conical shape (a regular hexagonal pyramid shape in the case of the microlens array 4a, a diffractive optical element). In the case of 4, a light beam having an angle component defined by the light beam range of a cone shape is incident. Thus, as shown in FIG. 46, the entrance surface of the microlens array 8 has a three-pole configuration composed of a three-point light intensity distribution and a circular (or regular hexagonal) light flux. An illumination distribution (illumination field) is formed.

As a result, on the rear focal plane (illumination pupil plane) of the microlens array 8, a tripolar secondary light source having substantially the same light intensity distribution as the tripolar illumination field is formed. Here, the tripolar secondary light source is a three circular (or regular hexagonal) substantially planar light source, That is, it is composed of two surface light sources arranged symmetrically in the X direction with respect to the optical axis AX and one surface light source arranged near the optical axis AX. Thus, in the seventh embodiment, a substantially uniform tripolar secondary light source is formed on the illumination pupil plane by the action of the diffractive optical element 102.

In the seventh embodiment, as in the fourth embodiment, the distance between the center of each surface light source constituting the tripolar secondary light source and the optical axis AX is changed by changing the magnification of the afocal zoom lens 5. Without changing the size of each surface light source (the radius of the circle circumscribing the dipole secondary light source, the radius of the circle circumscribing the dipole secondary light source, and the size of the monopole on the optical axis). Only the diameter of the secondary light source). On the other hand, by changing the focal length of the zoom lens 7, both the above-described distance and size can be changed, so that the entire tripolar secondary light source can be similarly enlarged or reduced.

In the seventh embodiment, similarly to the fifth and sixth embodiments, the internal patterns of the elements G 1 d to G 4 d are subdivided and the element patterns of G 1 to G 4 corresponding to the two-pole components are divided. A new element obtained by alternately or randomly arranging subdivision elements obtained by subdividing the subdivision elements and subdivision elements obtained by subdividing the H and Hd regions corresponding to the one-pole component near the optical axis. By using the elements G 1 d to G 4 d as modified examples, the illumination balance between the dipole illumination component and the monopole illumination component near the optical axis can be improved. In the seventh embodiment, the elements Gl and G2 and the simple transmission part H are set to have the same area, and the elements G3 and G4 and the complementary simple transmission part Hd are set to have the same area. It is desirable.

(Eighth embodiment)

FIG. 50 is a diagram showing a nine-pole illumination field formed on the entrance surface of the microlens array in the eighth embodiment. FIG. 51 is a diagram for explaining the basic operation of the diffractive optical element for nine-pole illumination in the eighth embodiment. As described above, in the third embodiment, by combining the operation of the diffractive optical element 61 according to the first embodiment and the operation of the diffractive optical element 62 according to the second embodiment, the octopole illumination distribution ( Secondary light source). Similarly, in the eighth embodiment, the operation of the diffractive optical element 100 according to the fifth embodiment and the operation of the diffractive optical element 101 according to the sixth embodiment are combined. As a result, as shown in Fig. 51, a 9-pole illumination distribution (Terino) composed of a composition of a 9-point light intensity distribution and a circular (or regular hexagonal) light beam, A nine-pole illumination distribution as shown in FIG. 50 can be formed.

In each of the above-described embodiments and modifications, a diffractive optical element including a linear grating pattern is used. However, as an optical member having optical performance similar to that of this type of diffractive optical element, a diffractive optical element substantially similar to the diffractive optical element is used. Refractive optical elements that generate the same light amplitude can also be used.

Further, in each of the embodiments and the modifications of the above-described diffractive optical element, a binary diffractive optical element pattern is used.

As in the modification of the fourth embodiment, a blaze-type diffractive optical element pattern or a multi-valued diffractive optical element pattern can be used.

In addition, the technical contents described with respect to the first to fourth embodiments and their modifications can be applied to the fifth to eighth embodiments and their modifications. In the exposure apparatus according to each of the above-described embodiments, the mask (reticle) is illuminated by the illumination optical device (illumination process), and the transfer pattern formed on the mask is exposed on the photosensitive substrate using the projection optical system. By performing the (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 microdevice by forming a predetermined circuit pattern on a wafer or the like as a photosensitive substrate using the exposure apparatus of each of the above-described embodiments is shown in FIG. This will be described with reference to a flowchart.

First, in step 301 of FIG. 32, 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 wafer of the lot. 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 the lot through the projection optical system using the exposure apparatus of each embodiment described above. You. After that, in step 304, the photoresist on the wafer of the lot is developed, and then in step 304, the resist pattern is formed on the wafer of the lot. By performing etching as a mask, a circuit pattern corresponding to the pattern on the mask is formed in each shot area on each wafer. Thereafter, devices such as semiconductor elements are manufactured by forming a circuit pattern of the upper layer. According to the above-described semiconductor device manufacturing method, a semiconductor device having an extremely fine circuit pattern can be obtained with good throughput.

In the exposure apparatus of each of the above embodiments, 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. 3'3. In FIG. 33, in a pattern forming step 401, a pattern of a mask is transferred and exposed to a photosensitive substrate (a glass substrate coated with a resist, etc.) using the exposure apparatus of each of the above-described embodiments. An optical lithography process is performed. By this photolithography step, a predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. After that, the exposed substrate is subjected to various processes such as a developing process, an etching process, a resist stripping process, etc., so that a predetermined pattern is formed on the substrate, and the next color filter forming step 402 is performed. Transition.

Next, in the color filter forming process 402, R (Red), G (Green), B

A set of three dots corresponding to (Blue) is arranged in a matrix, or a set of three stripe filters of R, G, B is arranged in the horizontal scanning line direction. Form. Then, after the color filter forming step 402, a cell assembling step 400 is executed. In the cell assembling step 403, a liquid crystal panel is formed by using 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.

(Liquid crystal cell). In the cell assembling step 403, for example, a liquid crystal is interposed 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. Inject the liquid crystal panel

(Liquid crystal cell).

Then, in the module assembly process 404, the assembled liquid crystal panel (liquid A liquid crystal display element is completed by attaching various components such as an electric circuit and a backlight that perform the display operation of the crystal cell. 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, the light source 1 is an ArF excimer laser light source that supplies light having a wavelength of 193 nm (or a KrF excimer laser light source that supplies light having a wavelength of 248 nm). While using the light source), without being limited thereto, 1 5 7 nm and F ₂ laser light source for supplying light of wavelength, g-ray (4 3 6 nm) and i-line (3 6 5 nm) For example, a mercury lamp that supplies the light of the above. When a mercury lamp is used, the light source 1 has a configuration including a mercury lamp, an elliptical mirror, and a collimator lens.

Further, in the above-described embodiment, the present invention has been described by taking as an example a projection exposure apparatus having an illumination optical device. However, the present invention is applied to a general illumination optical device for illuminating an irradiated surface other than a mask. Obviously you can. Industrial potential

As described above, the diffractive optical element of the present invention is used, for example, in an illumination optical device and has a substantially uniform multipole (quadrupole, octupole, dipole) illuminance on the illumination pupil plane. A distribution can be formed. Further, in the illumination optical device of the present invention, it is possible to perform various types of favorable multi-pole illumination while suppressing a light amount loss by using a diffractive optical element that forms a substantially uniform multi-pole illuminance distribution on an illumination pupil plane. Can be.

Further, the exposure apparatus incorporating the illumination optical apparatus of the present invention and the exposure method using the illumination optical apparatus of the present invention employ an illumination optical apparatus capable of performing various types of favorable multi-pole illumination while suppressing a light amount loss. Thus, the mask pattern can be faithfully transferred onto the photosensitive substrate under the optimal lighting conditions for the mask. Further, in the present invention, a good microdevice can be manufactured by using the exposure apparatus and the exposure method of the present invention capable of faithfully transferring a mask pattern onto a photosensitive substrate.

Claims

The scope of the claims

1. A first basic diffractive optical element having a linear grating pattern along a first direction, a second basic diffractive optical element having a linear grating pattern along a second direction different from the first direction,

A first complementary diffractive optical element having a pattern that generates a light amplitude having a first phase difference with respect to the light amplitude generated by the first basic diffractive optical element;

A second complementary diffractive optical element having a pattern that generates a light amplitude having a second phase difference with respect to the light amplitude generated by the second basic diffractive optical element,

A diffractive optical element, wherein the first basic diffractive optical element, the second basic diffractive optical element, the first complementary diffractive optical element, and the second complementary diffractive optical element are substantially densely arranged.

2. A first basic diffractive optical element having a linear grating pattern along a first direction, a second basic diffractive optical element having a linear grating pattern along a second direction different from the first direction,

With a simple transmission part having substantially no deflection effect,

A diffractive optical element, wherein the first basic diffractive optical element, the second basic diffractive optical element, and the simple transmission portion are arranged substantially densely.

3. The diffractive optical element according to claim 2,

A first complementary diffractive optical element having a pattern for generating a light amplitude having a first phase difference with respect to the light amplitude generated by the first basic diffractive optical element;

A second complementary diffractive optical element having a pattern that generates a light amplitude having a second phase difference with respect to the light amplitude generated by the second basic diffractive optical element;

A diffractive optical element, further comprising: a complementary simple transmission section having a pattern that generates a light amplitude having a fifth phase difference with respect to the light amplitude generated by the simple transmission section.

4. The diffractive optical element according to claim 3,

The diffractive optical element, wherein the fifth phase difference is approximately 1Z2 wavelength.

5. The diffractive optical element according to any one of claims 1 to 4, wherein

The diffractive optical element, wherein the first phase difference and the second phase difference are approximately 波長 wavelength.

6. The diffractive optical element according to any one of claims 1 to 5,

The diffractive optical element includes a plurality of first basic diffractive optical elements, a plurality of second basic diffractive optical elements, a plurality of first complementary diffractive optical elements, and a plurality of second complementary diffractive optical elements. A diffractive optical element, characterized in that:

7. The diffractive optical element according to claim 6, wherein

The plurality of first basic diffractive optical elements, the plurality of second basic diffractive optical elements, the plurality of first complementary diffractive optical elements, and the plurality of second complementary diffractive optical elements are substantially equal in number to each other. Characteristic diffractive optical element.

8. The diffractive optical element according to claim 6 or 7,

The plurality of first basic diffractive optical elements, the plurality of second basic diffractive optical elements, the plurality of first complementary diffractive optical elements, and the plurality of second complementary diffractive optical elements are the entirety of the diffractive optical element. A diffractive optical element, which is arranged randomly over

9. The diffractive optical element according to claim 6 or 7,

The diffractive optical element includes a plurality of blocks, and in each block, the plurality of first basic diffractive optical elements, the plurality of second basic diffractive optical elements, and the plurality of first complementary circuits. A diffractive optical element, wherein a folding optical element and the plurality of second complementary diffractive optical elements are randomly arranged.

10. The diffractive optical element according to claim 9, wherein

In each block, the plurality of first basic diffractive optical elements, the plurality of second basic diffractive optical elements, the plurality of first complementary diffractive optical elements, and the plurality of second complementary diffractive optical elements are substantially the same in number. A diffractive optical element, comprising:

11. The diffractive optical element according to claim 9 or 10, wherein the diffractive optical element includes a plurality of types of blocks, and a form of a random arrangement differs for each type of block. Diffractive optical element.

12. The diffractive optical element according to claim 6 or 7,

A plurality of first blocks in which the first basic diffractive optical elements and the second basic diffractive optical elements are alternately arranged by substantially the same number;

A plurality of second blocks in which the first basic diffractive optical elements and the second complementary diffractive optical elements are alternately arranged by an approximately same number;

A plurality of third blocks in which the first complementary diffractive optical elements and the second basic diffractive optical elements are alternately arranged by substantially the same number;

A diffractive optical element, comprising: a plurality of fourth blocks in which the first complementary diffractive optical element and the second complementary diffractive optical element are alternately arranged by substantially the same number.

13. In the diffractive optical element according to claim 12,

The diffractive optical element includes a plurality of middle blocks, and in each of the middle blocks, the plurality of first blocks, the plurality of second blocks, the plurality of third blocks, and the plurality of fourth blocks are randomly arranged in substantially the same number. A diffractive optical element characterized by being made.

14. The diffractive optical element according to claim 13, wherein the diffractive optical element includes a plurality of types of middle blocks, and the form of the random arrangement differs for each type of middle block. Diffractive optical element.

15. The diffractive optical element according to claim 12,

The diffractive optical element, wherein the diffractive optical element includes substantially the same number of the plurality of first to fourth blocks, and each block is randomly arranged throughout the diffractive optical element.

16. In the diffractive optical element according to any one of claims 1 to 15,

The first basic diffractive optical element, the second basic diffractive optical element, the first complementary diffractive optical element, and the second complementary diffractive optical element have a substantially square outer shape. .

17. The diffractive optical element according to claim 16, wherein

The first direction is substantially parallel to one side of the diffractive optical element having the substantially square outer shape, and the second direction is substantially parallel to the other side of the diffractive optical element having the substantially square outer shape. A diffractive optical element, characterized in that:

18. The diffractive optical element according to any one of claims 1 to 17,

The linear grating pattern has one of a binary diffractive optical element pattern, a blazed diffractive optical element pattern, and a multi-valued diffractive optical element pattern. element.

1 9. In the illumination optical device that illuminates the irradiated surface,

To form a secondary light source with a quadrupolar light intensity distribution on the illumination pupil plane, the incident light flux An illumination optical device, comprising: the diffractive optical element according to any one of claims 1 to 18 for converting light into four light beams.

20. The illumination optical device according to claim 19,

A light source unit for supplying a light beam, an angle light beam forming unit for converting the light beam from the light source unit into a light beam having various angle components with respect to the optical axis, and causing the light beam to enter a first predetermined surface. An illumination field forming means including a diffractive optical element for forming a quadrupole illumination field on the second predetermined surface based on the light beam having the various angle components incident on the first predetermined surface. And further comprising

The angle beam forming means includes an optical member including a plurality of optical elements, and the diffractive optical element includes a basic diffractive optical element or a complementary diffractive optical element in an element light beam corresponding to each optical element of the optical member. The illumination optical device is characterized by being positioned so that a total of four or more are included.

2 1. Light source means for supplying a light beam;

A quadrupole secondary light source having substantially the same light intensity distribution as the quadrupole illumination field is formed based on the light flux from the quadrupole illumination field formed on the second predetermined surface. A light guiding optical system for guiding a light beam from the optical integrator to the surface to be irradiated.

The diffractive optical element includes a plurality of first basic diffractive optical elements having a linear grating pattern along a first direction, and a plurality of linear diffractive optical elements having a linear grating pattern along a second direction different from the first direction. A second basic diffractive optical element; An illumination optical device, wherein the folding optical element and the plurality of second basic diffractive optical elements are arranged almost densely.

22. The illumination optical device according to claim 21.

The illumination optical device, wherein the plurality of first basic diffractive optical elements and the plurality of second basic diffractive optical elements are alternately arranged by substantially the same number.

23. The illumination optical device according to claim 21 or 22, wherein the diffractive optical element has a first phase difference with respect to a light amplitude generated by the first basic diffractive optical element. A plurality of first complementary diffractive optical elements having a pattern that generates

A plurality of second complementary diffractive optical elements each having a pattern that generates a light amplitude having a second phase difference with respect to the light amplitude generated by the second basic diffractive optical element; An illumination, wherein the diffractive optical element, the plurality of second basic diffractive optical elements, the plurality of first complementary diffractive optical elements, and the plurality of second complementary diffractive optical elements are arranged substantially densely. Optical device.

24. In the illumination optical device according to claim 23,

The illumination optical device, wherein the first phase difference and the second phase difference are approximately ほぼ wavelength.

25. The illumination optical device according to claim 23, wherein the plurality of first basic diffractive optical elements, the plurality of second basic diffractive optical elements, and the plurality of first complements. An illumination optical device, wherein the number of diffractive optical elements and the plurality of second complementary diffractive optical elements are substantially equal to each other.

26. The illumination optical device according to any one of claims 23 to 25, wherein The plurality of first basic diffractive optical elements, the plurality of second basic diffractive optical elements, the plurality of first complementary diffractive optical elements, and the plurality of second complementary diffractive optical elements are the entirety of the diffractive optical element. An illumination optical device, wherein the illumination optical device is arranged in a random manner.

27. The illumination optical device according to any one of claims 23 to 25, wherein

The diffractive optical element includes a plurality of blocks, and in each block, the plurality of first basic diffractive optical elements, the plurality of second basic diffractive optical elements, the plurality of first complementary diffraction optical elements, and the plurality of second diffractive optical elements. An illumination optical device, wherein complementary diffraction optical elements are randomly arranged.

28. In the illumination optical device according to claim 27,

In each block, the plurality of first basic diffractive optical elements, the plurality of second basic diffractive optical elements, the plurality of first complementary diffractive optical elements, and the plurality of second complementary diffractive optical elements are substantially the same in number. An illumination optical device, comprising:

29. The illumination optical device according to claim 27 or 28, wherein the diffractive optical element includes a plurality of types of blocks, and a form of a random arrangement differs for each type of blocks. Illumination optical device characterized.

30. The illumination optical device according to any one of claims 23 to 25, wherein

A plurality of third blocks in which the first complementary diffractive optical elements and the second basic diffractive optical elements are alternately arranged by substantially the same number; An illumination optical device, comprising: a plurality of fourth blocks in which the first complementary diffractive optical elements and the second complementary diffractive optical elements are alternately arranged by substantially the same number.

31. The illumination optical device according to claim 30, wherein

The diffractive optical element includes a plurality of medium blocks, and in each medium block, the plurality of first blocks, the plurality of second blocks, the plurality of third blocks, and the plurality of fourth blocks are randomly arranged in substantially the same number. An illumination optical device, comprising:

3 2. The illumination optical device according to claim 31, wherein:

The illumination optical device, wherein the diffractive optical element includes a plurality of types of middle blocks, and the form of the random arrangement is different for each type of middle blocks.

33. The illumination optical device according to claim 30, wherein

The illumination optical device, wherein the diffractive optical element includes substantially the same number of the plurality of first to fourth blocks, and the blocks are randomly arranged throughout the diffractive optical element.

34. The illumination optical device according to any one of claims 21 to 33, wherein

The illumination optical device, wherein the first basic diffractive optical element, the second basic diffractive optical element, the first complementary diffractive optical element, and the second complementary diffractive optical element have a substantially square outer shape. .

35. The illumination optical device according to claim 34, wherein

The first direction is substantially parallel to one side of the diffractive optical element having the substantially square outer shape, and the second direction is substantially parallel to the other side of the diffractive optical element having the substantially square outer shape. An illumination optical device, characterized in that:

36. The illumination optical device according to any one of claims 21 to 35, wherein

37. The illumination optical device according to claim 35 or 36, wherein the illumination field forming unit is disposed in an optical path between the diffractive optical element and the optical integrator. Optical system,

The size of each surface light source constituting the quadrupole secondary light source is Φ, the length of one side of the basic diffractive optical element having the substantially square external shape is L, and the center wavelength of the light beam is λ. , Where f is the focal length of the optical system,

L> 2.5 X ί λ / φ

3 8. In the illumination optical device that illuminates the surface to be irradiated,

The diffractive optical element includes: a plurality of basic diffractive optical elements having a linear grating pattern along a certain direction; and a light amplitude having a predetermined phase difference with respect to a light amplitude generated by the basic diffractive optical element. An illumination optical device, comprising: a plurality of complementary diffractive optical elements each having a pattern to be formed, wherein the plurality of basic diffractive optical elements and the plurality of complementary diffractive optical elements are substantially densely arranged.

3 9. In the illumination optical device that illuminates the irradiated surface,

To form a secondary light source with a tripolar light intensity distribution on the illumination pupil plane, the incident light flux Equipped with a diffractive optical element for converting

The diffractive optical element includes: a plurality of basic diffractive optical elements having a linear grating pattern along a certain direction; and a plurality of simple transmission portions having substantially no deflecting action. The illumination optical device, wherein the plurality of simple transmission portions are arranged almost densely.

40. The illumination optical device according to claim 39, wherein

A plurality of complementary diffractive optical elements having a pattern that generates a light amplitude having a predetermined phase difference with respect to the light amplitude generated by the basic diffractive optical element,

An illumination optical device, further comprising: a plurality of complementary simple transmission portions having a pattern that generates a light amplitude having a fifth phase difference with respect to the light amplitude generated by the simple transmission portion.

41. The illumination optical device according to claim 40, wherein

The illumination optical device, wherein the fifth phase difference is approximately 波長 wavelength.

42. The illumination optical device according to any one of claims 38 to 41, wherein

The illumination optical device, wherein the predetermined phase difference is approximately 波長 wavelength.

43. The illumination optical device according to any one of claims 38 to 42, wherein

The illumination optical device, wherein the plurality of basic diffractive optical elements and the plurality of complementary diffractive optical elements have substantially the same number as each other.

44. The illumination optical device according to any one of claims 38 to 43, wherein

The plurality of basic diffractive optical elements and the plurality of complementary diffractive optical elements, Illuminating optical device characterized by being randomly arranged over the entirety of optical elements

45. The illumination optical device according to any one of claims 38 to 44, wherein

The illumination optical device according to claim 1, wherein the diffractive optical element includes a plurality of blocks, and in each block, the plurality of basic diffractive optical elements and the plurality of complementary diffractive optical elements are randomly arranged in substantially the same number.

46. The illumination optical device according to claim 45, wherein

The illumination optical device, wherein the diffractive optical element includes a plurality of types of blocks, and a random array form of the plurality of basic diffractive optical elements and the plurality of complementary diffractive optical elements is different for each type of block. .

47. The illumination optical device according to any one of claims 38 to 46, wherein

The illumination optical device, wherein the basic diffractive optical element and the complementary diffractive optical element have a substantially square outer shape.

48. The illumination optical device according to any one of claims 38 to 47, wherein

The illumination optics, wherein the linear grating pattern has one of a binary diffractive optical element pattern, a blazed diffractive optical element pattern, and a multi-valued diffractive optical element pattern. apparatus.

4 9. In the illumination optical device that illuminates the irradiation surface,

The diffractive optical element is a first basic element having a linear lattice pattern along a first direction. A diffractive optical element; a second elementary diffractive optical element having a linear grating pattern along a second direction substantially orthogonal to the first direction; and a third element forming an angle of about 45 degrees with the first direction. A third basic diffractive optical element having a linear grating pattern along a direction, a linear grating pattern along a fourth direction substantially 45 degrees from the first direction and substantially orthogonal to the third direction; A fourth basic diffractive optical element having

An illumination optical device, wherein the first to fourth basic diffractive optical elements are substantially densely arranged.

50. The illumination optical device according to claim 49, wherein

The diffractive optical element includes: a first complementary diffractive optical element having a pattern that generates a light amplitude having a first phase difference with respect to a light amplitude generated by the first basic diffractive optical element; and the second basic diffractive optical element. A second complementary diffractive optical element having a pattern that generates a light amplitude having a second phase difference with respect to the light amplitude generated by the element; and a third complementary diffractive optical element that generates a third light amplitude generated by the third basic diffractive optical element. A third complementary diffractive optical element having a pattern that generates a light amplitude having a phase difference, and a light amplitude having a fourth phase difference with respect to the light amplitude generated by the fourth basic diffractive optical element A fourth complementary diffractive optical element having a pattern, wherein the first to fourth basic diffractive optical elements and the first to fourth complementary diffractive optical elements are arranged substantially densely. Illumination optics according to claim 49 .

51. The illumination optical device according to claim 50, wherein

The illumination optical device, wherein the first phase difference, the second phase difference, the third phase difference, and the fourth phase difference are approximately 1Z2 wavelengths.

52. The illumination optical device according to claim 50 or 51, wherein the diffractive optical element includes a plurality of the first to fourth basic diffractive optical elements and a plurality of the first to the first. An illumination optical device comprising a fourth complementary diffractive optical element.

53. The illumination optical device according to claim 52, wherein the plurality of first to fourth basic diffractive optical elements and the plurality of first to fourth complementary diffractive optical elements are substantially equal in number to each other. An illumination optical device, comprising:

54. The illumination optical device according to claim 52 or 53, wherein the plurality of first to fourth basic diffractive optical elements and the plurality of first to fourth complementary diffractive optical elements are: An illumination optical device, wherein the diffraction optical elements are randomly arranged over the entirety.

55. The illumination optical device according to claim 52 or 53, wherein the diffractive optical element includes a plurality of blocks, and each block includes the plurality of first to fourth basic diffractive optical elements. An illumination optical device, wherein the plurality of first to fourth complementary diffractive optical elements are randomly arranged.

56. The illumination optical device according to claim 55, wherein

An illumination optical apparatus, wherein in each of the packs, the plurality of first to fourth basic diffractive optical elements and the plurality of first to fourth complementary diffractive optical elements are substantially the same in number.

57. The illumination optical device according to claim 55 or 56, wherein the diffractive optical element includes a plurality of types of blocks, and a form of a random arrangement differs for each type of block. Illumination optical device characterized.

58. The illumination optical device according to claim 52 or 53, wherein a plurality of the first basic diffractive optical elements and the second basic diffractive optical elements are alternately arranged by substantially the same number. The first block,

The first basic diffractive optical element and the second complementary diffractive optical element alternate by approximately the same number. A plurality of second blocks arranged in

A plurality of fourth blocks in which the first complementary diffractive optical elements and the second complementary diffractive optical elements are alternately arranged by substantially the same number;

A plurality of fifth blocks in which the third basic diffractive optical elements and the fourth basic diffractive optical elements are alternately arranged by substantially the same number;

A plurality of sixth blocks in which the third basic diffractive optical elements and the fourth complementary diffractive optical elements are alternately arranged by the same number, and

A plurality of seventh blocks in which the third complementary diffractive optical element and the fourth basic diffractive optical element are alternately arranged by the same number, and

An illumination optical device, comprising: a plurality of eighth blocks in which the third complementary diffractive optical elements and the fourth complementary diffractive optical elements are alternately arranged by substantially the same number.

59. The illumination optical device according to claim 58, wherein

The illumination optical device, wherein the diffractive optical element includes a plurality of middle blocks, and in each of the middle blocks, the plurality of first to eighth blocks are randomly arranged by substantially the same number.

60. The illumination optical device according to claim 59, wherein

61. The illumination optical device according to claim 58, wherein

The illumination optical device, wherein the diffractive optical element includes substantially the same number of the plurality of first to eighth blocks, and each block is randomly arranged throughout the diffractive optical element.

6 2. In the illumination optical device for illuminating the irradiation surface,

An illumination characterized in that the diffractive optical element is positioned such that a total of four or more basic diffractive optical elements or complementary diffractive optical elements are included in an element light beam corresponding to each optical element of the optical member. Optical device.

6 3. Light source means for supplying a light beam;

A multi-pole secondary light source having substantially the same light intensity distribution as the multi-pole illumination field is formed based on the light flux from the multi-pole illumination field formed on the second predetermined surface. And optical lingerie for the evening

The diffractive optical element is constituted by arranging a plurality of basic diffractive optical elements having a substantially square outer shape and having a predetermined diffractive optical element pattern in a substantially dense manner. Having an optical system arranged in the optical path between the diffractive optical element and the optical integrator, The size of each surface light source that constitutes the multipole secondary light source is Ψ, the length of one side of the basic diffractive optical element is, the center wavelength of the light beam is λ, and the focal length of the optical system is f

L> 2.5 X f Χ λ /

6 4. The diffractive optical element according to any one of claims 1 to 18 or the illumination optics according to any one of claims 38 to 48 A refracting optical element that generates substantially the same light amplitude as a diffractive optical element in an apparatus.

6 5. In an illumination optical device for illuminating an irradiation surface,

In order to form a secondary light source having a predetermined light intensity distribution on the illumination pupil plane, a refracting optical element according to claim 64 for converting an incident light beam into a light beam having a predetermined cross-sectional shape is provided. An illumination optical device, comprising:

66. The illumination optical device according to any one of claims 19 to 63 or 65, and a pattern of a mask disposed on the surface to be irradiated is projected onto a photosensitive substrate. An exposure apparatus comprising: a projection optical system for performing exposure.

67. A pattern formed on the illuminated mask, the mask being illuminated via the illumination optical device according to any one of claims 19 to 63 or 65. An exposure method comprising projecting and exposing the image of (1) on a photosensitive substrate.