JP2003297727A - Illumination optical device, exposure apparatus, and method of exposure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination optical device achieving illuminating conditions which are different in two intersecting directions on an emitted surface. <P>SOLUTION: The illumination optical device comprises a first axicon system (7) which is disposed in an optical path between a light source means (1) and an optical integrator (10) and a second axicon system (8) which is disposed in an optical path between the first axicon system and the optical integrator. The first axicon system has a first prism (7a) which moves at least along the optical axis, and a second prism (7b) which is fixed along the optical axis in this order starting from the side of the light source means. The second axicon system has a third prism (8a) which is fixed at least along the optical axis, and a fourth prism (8b) which moves along the optical axis in this order starting from the side of the light source means. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating optical device and an exposure apparatus equipped with the illuminating optical device, and in particular for manufacturing a microdevice such as a semiconductor device, an image pickup device, a liquid crystal display device, a thin film magnetic head or the like by a lithography process. The present invention relates to an illumination optical device suitable for the exposure apparatus.

[0002]

2. Description of the Related Art In a typical exposure apparatus of this type,
The light flux emitted from the light source forms a secondary light source as a substantial surface light source including a large number of light sources via a fly-eye lens as an optical integrator. The light flux from the secondary light source is incident on the condenser lens after being limited through an aperture stop arranged near the rear focal plane of the fly-eye lens.

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

[0004]

Therefore, a circular secondary light source is formed on the back focal plane of the fly-eye lens, and its size is changed to obtain coherency σ (σ value = aperture stop diameter / A technique for changing the pupil diameter of the projection optical system, or the σ value = the numerical aperture on the exit side of the illumination optical system / the numerical aperture on the entrance side of the projection optical system) is drawing attention. In addition, a technique for forming a ring-shaped or quadrupole-shaped secondary light source on the rear focal plane of the fly-eye lens to improve the depth of focus and resolution of the projection optical system has been receiving attention.

However, in the prior art as described above, even in the case of the ordinary circular illumination based on the circular secondary light source, the modified illumination based on the annular or quadrupole secondary light source (annular illumination or quadrupole illumination) is used. Also in the case of (illumination), the cross-sectional shape of the light beam incident on one point on the mask, which is the surface to be illuminated, has the same positional relationship in two orthogonal directions on the mask. In other words, in the conventional technique, the illumination conditions are the same in two directions orthogonal to each other on the surface to be illuminated. As a result, when the mask pattern has directionality, it is not possible to realize optimum illumination conditions in two orthogonal directions on the mask.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an illumination optical device capable of realizing different illumination conditions in two orthogonal directions on a surface to be illuminated. . Further, the present invention uses an illumination optical device capable of realizing different illumination conditions in two orthogonal directions on a surface to be illuminated, and optimal illumination in two orthogonal directions on a mask having a directional pattern. An object of the present invention is to provide an exposure apparatus and an exposure method that can set conditions.

[0007]

In order to solve the above-mentioned problems, in the first invention of the present invention, an optical integrator for forming a secondary light source based on a light beam from a light source means, and an optical integrator from the optical integrator are provided. In an illumination optical device provided with a light guide optical system for guiding a light flux to a surface to be illuminated, the light source means and the optical integrator are arranged in an optical path between the incident angle of the incident light flux to the optical integrator, and A first axicon system for changing at least one of an incident position, and an incident angle and an incident position of a light flux incident on the optical integrator, which is arranged in an optical path between the first axicon system and the optical integrator. A second axicon system for changing at least one of
The first axicon system, in order from the light source means side, is configured to be movable at least along the optical axis, a first prism, and fixed along the optical axis and complementary to the refracting surface of the first prism. A second prism having a formed refracting surface, and the second axicon system is movable along the optical axis in order from the light source means side, and the third prism fixed at least along the optical axis. And a fourth prism having a refracting surface complementary to the refracting surface of the third prism. In this case, it is preferable that the second prism is fixed and the third prism is fixed.

According to a preferred aspect of the first invention, the second prism and the third prism are integrally formed. Further, the first prism has a refracting surface having a concave cross section, and the second prism has a refracting surface having a convex cross section that is complementary to the refracting surface having the concave cross section of the first prism. It is preferable that the third prism has a refracting surface having a concave section, and the fourth prism has a refracting surface having a convex section formed to be complementary to the refracting surface having the concave section of the third prism.

In this case, the first prism has a V-shaped refracting surface having a ridgeline along a first direction orthogonal to the optical axis, and the first prism has the optical axis and the first direction. It is preferable to have a V-shaped refracting surface having a ridge line along a second direction orthogonal to each other. Alternatively, one of the first prism and the third prism has a conical refracting surface centered on the optical axis, and the first prism and the third prism are provided.
The other of the prisms preferably has a V-shaped refracting surface having a ridge line along a direction orthogonal to the optical axis.

According to a second aspect of the present invention, an optical integrator for forming a secondary light source based on the light beam from the light source means, and a light guide optical system for guiding the light beam from the optical integrator to a surface to be illuminated. , An axicon system arranged in an optical path between the light source means and the optical integrator, for changing at least one of an incident angle and an incident position of an incident light beam to the optical integrator, and the axicon system is A first prism having a conical or V-shaped concave refracting surface, and a conical or V-shaped convex refracting surface complementary to the refracting surface of the first prism; 2 prisms, the axicon system is a circular shadow region formed corresponding to the apex of the conical refracting surface in the vicinity of the illumination pupil. Or the width of the linear shadow region formed corresponding to the ridgeline of the V-shaped refracting surface has a required shape and characteristics for making it 1/10 or less of the size of the entire luminous flux. Provided is a characteristic illumination optical device.

According to a preferred aspect of the second invention, a light flux conversion element for converting the light flux from the light source means into a light flux having a predetermined cross-sectional shape or a light flux having a predetermined light intensity distribution, and the light flux conversion element. Further comprising a first optical system arranged in an optical path between the optical integrator and the optical integrator, and a second optical system arranged in an optical path between the first optical system and the optical integrator. The system is arranged in the optical path of the first optical system near the illumination pupil.

In this case, the maximum diffraction angle of the diffractive optical element as the light beam conversion element is ψ _max, and the distance along the optical axis between the refracting surface of the first prism and the refracting surface of the second prism is L. , The apex angle of the conical refracting surface or the V
The crossing angle of the letter-shaped refracting surface is 2θ, the refractive index of the optical material forming the first prism and the second prism with respect to the light flux is n, and the refractive index of the first optical system is higher than that of the axicon system. When the focal length of the first lens group arranged on the light source means side is f ₁ , AL ≦ (f ₁ × sin ψ _max ) / 10 where A = (tan α × tan θ) / (tan θ−tan α) α = sin It is preferable to satisfy the condition of ⁻¹ (n × cos θ) + θ−90 (unit: degree).

According to a third aspect of the present invention, an optical integrator for forming a secondary light source based on a light beam from the light source means, and a light guide optical system for guiding the light beam from the optical integrator to an irradiation surface. , An axicon system formed of fluorite for changing at least one of an incident angle and an incident position of an incident light beam to the optical integrator, which is arranged in an optical path between the light source means and the optical integrator. An illumination optical device is provided.

According to a preferred aspect of the third invention, the light source means supplies light having a wavelength of 200 nm or less. The axicon system includes a first prism having a V-shaped concave cross-section refracting surface having a ridge line along a direction orthogonal to the optical axis, and a complement to the concave cross-section refracting surface of the first prism. It is preferable that the first prism is divided along a surface including the optical axis and the ridge line, and the second prism has a formed refracting surface having a V-shaped convex cross section.

According to a fourth aspect of the present invention, in an illumination optical device for illuminating a surface to be illuminated based on a light flux from a light source means, it has a V-shaped concave cross-section refracting surface having a ridge line along a predetermined direction. The present invention provides an illumination optical device including a prism, wherein the prism is divided along a predetermined surface including the ridge.

According to a preferred aspect of the fourth aspect of the invention, an optical integrator for forming a secondary light source based on the light beam from the light source means, and a light guide for guiding the light beam from the optical integrator to the illuminated surface. An optical optical system, an axicon system arranged in the optical path between the light source means and the optical integrator, and including the prism for changing at least one of an incident angle and an incident position of an incident light beam to the optical integrator. And are further equipped. In this case, the axicon system includes the prism having a V-shaped concave cross-section refracting surface having the ridge line along a direction orthogonal to the optical axis,
A second prism having a V-shaped convex cross-section refracting surface formed complementary to the concave cross-section refracting surface of the prism, wherein the prism is along a surface including an optical axis and the ridge line. It is preferably divided into two parts.

According to a fifth aspect of the present invention, in an illumination optical device for illuminating a surface to be illuminated, a secondary light source having a quadrupole light intensity distribution is formed on an illumination pupil plane based on a light beam from a light source means. And a light flux conversion element for converting the light flux from the light source means into four light fluxes, and the light flux conversion element is arranged in the optical path between the light flux conversion element and the illumination pupil plane to constitute the secondary light source. An axicon system for symmetrically moving one pair and the other pair of the two substantially planar light sources with respect to the optical axis, wherein the luminous flux conversion element is in a first direction orthogonal to the optical axis. Provided is an illumination optical device, characterized in that each of the four substantial surface light sources is formed around each corner point of a rectangle elongated along the center.

According to a preferred aspect of the fifth invention, the axicon system includes a first prism having a V-shaped concave cross-section refracting surface having a ridge line along the first direction, and the first prism. A first axicon system having a second prism having a V-shaped convex cross-section refracting surface formed complementarily with the concave cross-section refracting surface; and a second direction orthogonal to the optical axis and the first direction. A third prism having a V-shaped concave cross-section refracting surface having a ridge line, and a V-shaped convex cross-section refracting surface complementary to the concave cross-section refracting surface of the third prism. Having a fourth prism and having a second
It has an axicon system.

In a sixth invention of the present invention, the illumination optical device of the first invention to the fifth invention and a projection optical system for projecting and exposing the pattern of the mask arranged on the irradiation surface onto a photosensitive substrate are provided. Provided is an exposure apparatus characterized by being provided.

In a seventh invention of the present invention, a mask is illuminated through the illumination optical device of the first invention to the fifth invention, and an image of a pattern formed on the illuminated mask is projected and exposed on a photosensitive substrate. An exposure method is provided.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION According to one aspect of the present invention, a first axicon system is configured to be movable along an optical axis.
A second prism fixed along the optical axis, and a second axicon system including a third prism fixed along the optical axis.
It has a prism and a fourth prism configured to be movable along the optical axis. In other words, of the four prisms forming the first axicon system and the second axicon system,
Two prisms arranged on the outer side are configured to be movable along the optical axis, and two prisms arranged on the inner side are fixed along the optical axis.

As a result, in the present invention, the distance between the first moving mechanism for moving the first prism along the optical axis and the second moving mechanism for moving the fourth prism along the optical axis is reduced. Since a sufficiently large size is ensured, mechanical interference between the moving mechanisms can be reliably avoided, and a compact overall structure can be realized. In this case, it is preferable that the two inner prisms fixed along the optical axis are integrally formed as one prism. With this configuration, it is possible to improve the light transmittance of the axicon system, suppress the manufacturing error and the positioning error of the prism member, and realize a highly accurate and high-performance axicon system.

According to another aspect of the present invention, there is provided an axicon system in which a first prism having a conical or V-shaped concave section refracting surface and a conical or V-shaped convex section refracting surface. And a second prism having. The axicon system is a linear shape formed corresponding to the apex of the conical refracting surface in the vicinity of the illumination pupil or the diameter of the circular shadow region or the ridge of the V-shaped refracting surface. Has the required shape and characteristics to make the width of the shadow area of 1/10 or less of the size of the entire light flux. As a result, according to the present invention, a desired light intensity distribution can be obtained in the illumination pupil without being substantially affected by the linear shadow region and the circular shadow region.

In any of the aspects, in the illumination optical device of the present invention, the quadrupole-shaped or ring-shaped secondary light source is appropriately changed by the action of the axicon system, and the two different directions are orthogonal to each other on the illuminated surface. Lighting conditions can be realized.
Further, in the exposure apparatus and the exposure method of the present invention, an illumination optical device capable of realizing different illumination conditions in two orthogonal directions on a surface to be illuminated is used to make the patterns orthogonal to each other on a mask. Optimal lighting conditions can be set in two directions, and good microdevices can be manufactured under good lighting conditions.

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically showing the configuration of an exposure apparatus including an illumination optical device according to the first embodiment of the present invention. In FIG. 1, the Z axis is along the normal direction of the wafer which is the photosensitive substrate, the Y axis is in the direction parallel to the paper surface of FIG. 1 in the wafer plane, and the direction perpendicular to the paper surface of FIG. 1 in the wafer surface. The X axis is set for each. In FIG. 1, the illumination optical device is set to perform quadrupole illumination.

In the exposure apparatus of FIG. 1, as a light source 1 for supplying exposure light (illumination light), for example, a KrF excimer laser light source or 19 for supplying light having a wavelength of 248 nm is used.
An ArF excimer laser light source that supplies light with a wavelength of 3 nm is provided. A substantially parallel light beam emitted from the light source 1 along the Z direction has a rectangular cross section elongated along the X direction and enters a beam expander 2 including a pair of lenses 2a and 2b. Each lens 2a and 2
b has a negative refracting power and a positive refracting power in the plane of FIG. 1 (in the YZ plane). Therefore, the light beam incident on the beam expander 2 is expanded in the plane of the paper of FIG. 1 and shaped into a light beam having a predetermined rectangular cross section.

A substantially parallel light beam passing through a beam expander 2 as a shaping optical system is deflected in the Y direction by a bending mirror 3 and then diffracted optical element (DO) for quadrupole illumination.
E) It is incident on 4a. 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 a function of diffracting an incident beam at a desired angle. The diffractive optical element 4a is
When a parallel light flux having a rectangular cross section is incident, it has a function of forming a quadrupole light intensity distribution in the far field (Fraunhofer diffraction region). Thus, the diffractive optical element 4a constitutes a light beam conversion element for converting the light beam from the light source 1 into a quadrupole light beam.

The diffractive optical element 4a is constructed so that it can be inserted into and removed from the illumination optical path, and the diffractive optical element 4 for annular illumination is used.
a and the diffractive optical element 4c for normal circular illumination are switchable. The configurations and functions of the diffractive optical element 4b for annular illumination and the diffractive optical element 4c for ordinary circular illumination will be described later. Specifically, the diffractive optical element 4a
Are supported on a turret substrate (rotating plate: not shown in FIG. 1) rotatable about a predetermined axis parallel to the optical axis AX. On the turret substrate, a plurality of diffractive optical elements 4a for quadrupole illumination having different characteristics, a plurality of diffractive optical elements 4b for annular illumination having different characteristics, and a plurality of diffractive optical elements 4c for circular illumination having different characteristics are provided. It is provided along the circumferential direction.

Further, the turret substrate is constructed so as to be rotatable about an axis passing through the center point thereof and parallel to the optical axis AX. Therefore, by rotating the turret substrate, a desired diffractive optical element selected from a large number of diffractive optical elements 4a to 4c can be positioned in the illumination optical path. The rotation of the turret substrate (and thus switching between the diffractive optical elements 4a, 4b and 4c) is controlled by the control system 21.
It is performed by the first drive system 22 which operates based on the command from. However, the diffractive optical element 4 is not limited to the turret system, and may be a well-known slide system, for example.
It is also possible to switch between a, 4b and 4c.

The light beam that has passed through the diffractive optical element 4a enters an afocal lens (relay optical system: first optical system) 5. The afocal lens 5 is set so that the front focal position thereof and the position of the diffractive optical element 4a substantially coincide with each other, and the rear focal position thereof substantially coincides with the position of the predetermined surface 6 indicated by a broken line in the drawing. System (non-focus optical system). Therefore, the substantially parallel light flux that has entered the diffractive optical element 4 a forms a quadrupole light intensity distribution on the pupil surface of the afocal lens 5, and then is emitted from the afocal lens 5 as a substantially parallel light flux.

Incidentally, in the optical path between the front lens group (first lens group) 5a and the rear lens group (second lens group) 5b of the afocal lens 5, the first light source side is placed in order from the light source side.
The groove axicon system 7 and the second V-groove axicon system 8 are arranged, and the detailed configuration and operation thereof will be described later. In order to simplify the description, the basic configuration and operation of the first embodiment will be described below, ignoring the operations of the axicon systems 7 and 8.

The luminous flux passing through the afocal lens 5 is σ
Zoom lens for variable value (variable magnification optical system: second optical system) 9
And enters the microlens array (or fly-eye lens) 10 as an optical integrator. The microlens array 10 is an optical element composed of a large number of minute lenses having a positive refracting power which are vertically and horizontally densely arranged. In general, a microlens array is formed, for example, by subjecting a parallel flat glass plate to an etching treatment to form a group of microlenses.

Here, each minute lens forming the microlens array is smaller than each lens element forming the fly-eye lens. Further, unlike the fly-eye lens that includes lens elements that are isolated from each other, the microlens array is integrally formed with a large number of minute lenses that are not isolated from each other. However, the microlens array is the same as the fly-eye lens in that the lens elements having positive refracting power are arranged vertically and horizontally. In FIG. 1, the number of microlenses forming the microlens array 10 is shown to be much smaller than it actually is for the sake of clarity.

The σ value is R1 which is the size (diameter) of the pupil of the projection optical system PL, and R2 is the size (diameter) of the illumination light beam or the light source image formed on the pupil of the projection optical system PL. , NAi is the numerical aperture of the projection optical system PL on the mask (reticle) M side, and NAi is the numerical aperture of the illumination optical system that illuminates the mask (reticle) M. σ = NAi / NAo
= R2 / R1.

However, in the case of annular illumination, R2 is the outer diameter of the annular illumination light flux or annular light source image formed on the pupil of the projection optical system PL, and NAi is formed on the pupil of the illumination optical system. Is the numerical aperture determined by the outer diameter of the annular light flux.
In the case of multipole illumination such as quadrupole illumination, R2 is the size or diameter of a circle circumscribing a multipolar illumination light flux formed on the pupil of the projection optical system PL or a multipolar light source image, NAi
Is the numerical aperture determined by the size or diameter of the circle circumscribing the multipolar illumination light flux formed in the pupil of the illumination optical system. In the case of annular illumination, the annular ratio is defined as Ri / Ro, where Ro is the outer diameter of the annular illumination light flux and Ri is the inner diameter of the annular illumination light flux.

The position of the predetermined surface 6 is arranged near the front focal position of the zoom lens 9, and the incident surface of the microlens array 10 is arranged near the rear focal position of the zoom lens 9. In other words, the zoom lens 9 arranges the predetermined surface 6 and the incident surface of the microlens array 10 in a substantially Fourier transform relationship, and thus the pupil surface of the afocal lens 5 and the incident surface of the microlens array 10 are arranged. It is arranged almost optically conjugate. Therefore, like the pupil plane of the afocal lens 5, a quadrupole illumination field including four illumination fields decentered with respect to the optical axis AX is formed on the incident surface of the microlens array 10.

Here, the shape of each illumination field forming the quadrupole illumination field depends on the characteristics of the diffractive optical element 4a, but here, a quadrupole illumination field consisting of four circular illumination fields is used. Shall be formed. The overall shape of the quadrupole illumination field changes similarly depending on the focal length of the zoom lens 9. In addition,
The change of the focal length of the zoom lens 7 is performed by the second drive system 23 that operates based on a command from the control system 21.

Each microlens forming the microlens array 10 has a rectangular cross section similar to the shape of the illumination field to be formed on the mask M (and thus the shape of the exposure area to be formed on the wafer W). In this way, the light flux incident on the microlens array 10 is two-dimensionally divided by a large number of microlenses, and the rear focal plane (and thus the pupil of the illumination optical system) passes to the microlens array 10 as shown in FIG. Secondary light source having a light intensity distribution almost the same as the illumination field formed by the incident light flux of
A quadrupole secondary light source composed of four substantially circular surface light sources eccentric to X is formed. In this way, the microlens array 10 constitutes an optical integrator for forming multiple light sources based on the light flux from the light source 1.

The light flux from the quadrupole secondary light source formed on the rear focal plane of the microlens array 10 is subjected to the condensing function of the condenser optical system 11 and then passes through the mask blind 12 as an illumination field stop. Illuminate in a superimposed manner. The light flux passing through the rectangular opening (light transmitting portion) of the mask blind 12 is subjected to the converging action of the imaging optical system 13 and then illuminates the mask M in a superimposed manner. The light flux that has passed through the pattern of the mask M forms an image of the mask pattern on the wafer W via the projection optical system PL. A variable aperture stop for defining the numerical aperture of the projection optical system PL is provided on the entrance pupil plane of the projection optical system PL, and the variable aperture stop is driven by a third drive which operates based on a command from the control system 21. Performed by system 24.

In this way, by performing batch exposure or scan exposure while two-dimensionally drivingly controlling the wafer W in a plane (XY plane) orthogonal to the optical axis AX of the projection optical system PL, each exposure region of the wafer W is exposed. The pattern of the mask M is sequentially exposed. In the collective exposure, the mask pattern is collectively exposed to each exposure area of the wafer according to the so-called step-and-repeat method. In this case, the shape of the illumination area on the mask M is a rectangular shape close to a square, and the cross-sectional shape of each microlens of the microlens array 10 is also a rectangular shape close to a square.

On the other hand, in the scan exposure, the mask pattern is scan-exposed to each exposure region of the wafer while moving the mask and the wafer relative to the projection optical system according to the so-called step-and-scan method. In this case, the shape of the illumination area on the mask M is a rectangle in which the ratio of the short side to the long side is, for example, 1: 3, and the cross-sectional shape of each microlens of the microlens array 10 is similar to this. Becomes

FIG. 3 is a perspective view schematically showing the configuration of two axicon systems arranged in the optical path between the front lens group and the rear lens group of the afocal lens in the first embodiment. In the first embodiment, as shown in FIG.
A first V-groove axicon system 7 and a second V-groove axicon system 8 are arranged in this order from the light source side in the optical path between the front lens group 5a and the rear lens group 5b of the afocal lens 5.

The first V-groove axicon system 7 has a first prism member 7a having a flat surface facing the light source side and a concave and V-shaped refracting surface facing the mask side, and a flat surface facing the mask side and the light source side. The second prism member 7b has a convex and V-shaped refracting surface. First prism member 7
The concave refracting surface of a is composed of two planes, and the line of intersection (ridgeline) thereof extends along the Z direction. The convex refracting surface of the second prism member 7b is formed so as to be able to come into contact with the concave refracting surface of the first prism member 7a, in other words, complementary to the concave refracting surface of the first prism member 7a.

That is, the convex refracting surface of the second prism member 7b is also composed of two planes, and the intersection line (ridge line) is Z.
It extends along the direction. In addition, the first prism member 7a
Are configured to be movable along the optical axis AX, the second prism member 7b is fixed along the optical axis AX, and the concave refracting surface of the first prism member 7a and the convex refracting surface of the second prism member 7b are The interval is variable. The change of the interval of the first V-groove axicon system 7 is performed by the fourth drive system 25 which operates based on the command from the control system 21.

The second V-groove axicon system 8 has a first prism member 8a having a flat surface facing the light source side and a concave V-shaped refracting surface facing the mask side, and a flat surface facing the mask side and the light source side. And a second prism member 8b having a convex V-shaped refracting surface. The concave refracting surface of the first prism member 8a is composed of two planes, and the line of intersection thereof extends along the X direction. The convex refracting surface of the second prism member 8b is formed to be complementary to the concave refracting surface of the first prism member 8a. That is, the second prism member 8
The convex refracting surface of b is also composed of two planes, and the line of intersection thereof extends along the X direction.

The first prism member 8a is fixed along the optical axis AX, the second prism member 8b is movable along the optical axis AX, and the second prism member 8a has a concave refracting surface and a second refractive surface. The distance from the convex refracting surface of the prism member 8b is variable. The change of the interval of the second V-groove axicon system 8 is performed by the fifth drive system 26 which operates based on the command from the control system 21.

Here, in a state where the concave refracting surface and the convex refracting surface facing each other are in contact with each other, the first V-groove axicon system 7 and the second V-groove axicon system 8 function and are formed as plane-parallel plates. There is no effect on the quadrupole secondary light source. However, the first V-groove axicon system 7 functions as a plane-parallel plate along the Z direction when the concave refracting surface and the convex refracting surface are separated, but functions as a beam expander along the X direction. In addition, the second V-groove axicon system 8 has X when the concave refracting surface and the convex refracting surface are separated from each other.
It functions as a plane-parallel plate along the direction, but functions as a beam expander along the Z direction.

FIG. 4 is a diagram for explaining the action of the zoom lens on the secondary light source formed in the quadrupole illumination of the first embodiment. In the quadrupole illumination of the first embodiment, when the focal length of the zoom lens 9 changes, the overall shape of the quadrupole secondary light source including the four circular surface light sources 42a to 42d changes similarly. . That is, the circular surface light sources 42a to 42d forming the quadrupole secondary light source move along the radial direction of the circle centered on the optical axis AX while maintaining the circular shape.

Then, the surface light sources 42a to 42d before the change.
Of the surface light sources 43a to 43d after the change passes through the optical axis AX, and the moving distance and the moving direction of the central point depend on the change of the focal length of the zoom lens 9. In addition, the surface light sources 42a to 42d before the change are set to the optical axis AX.
The angle of view from the optical axis AX is equal to the angle of view of the changed surface light sources 43a to 43d. In this way, by changing the focal length of the zoom lens 9, the annular ratio of the quadrupole secondary light source (diameter of a circle inscribed in four surface light sources /
Only the outer diameter (the diameter of the circle circumscribing the four surface light sources) can be changed without changing the diameter of the circle circumscribing the four surface light sources.

FIG. 5 is a diagram for explaining the action of the first V-groove axicon system and the second V-groove axicon system for the secondary light source formed in the quadrupole illumination of the first embodiment. As the distance between the first V-groove axicon system 7 changes, the predetermined surface 6
The incident angle of the incident light beam on the predetermined surface 6 does not change, but the incident angle of the incident light beam on the predetermined surface 6 changes along the X direction. As a result, as shown in FIG. 5A, the four circular surface light sources 44a to 44d do not move in the Z direction, but the optical axes AX along the X direction are maintained while maintaining their shapes and sizes. Move symmetrically across. That is, the first
If the distance between the V-groove axicon system 7 increases, the surface light source 44b
And 44c move in the -X direction, and surface light sources 44a and 44d move in the + X direction.

On the other hand, although the angle of incidence of the light beam incident on the predetermined surface 6 along the X direction does not change with the change in the spacing of the second V-groove axicon system 8, the light beam incident on the predetermined surface 6 in the Z direction. The incident angle along varies. As a result, as shown in FIG. 5B, the four circular surface light sources 44a to 44d are
Although it does not move in the X direction, it moves symmetrically across the optical axis AX along the Z direction while maintaining its shape and size. That is, when the distance between the second V-groove axicon system 8 is increased, the surface light sources 44a and 44b move in the + Z direction,
The surface light sources 44c and 44d move in the -Z direction.

Furthermore, when both the spacing of the first V-groove axicon system 7 and the spacing of the second V-groove axicon system 8 change, the incident angle of the incident light beam on the predetermined surface 6 along the X direction and the Z direction. Change together. As a result, as shown in FIG. 5C, each of the surface light sources 44a to 44d.
Moves symmetrically across the optical axis AX along the Z and X directions while maintaining its shape and size. That is, when the distance between the first V-groove axicon system 7 and the distance between the second V-groove axicon system 8 are both increased, the surface light source 44a.
Moves in the + Z direction and the + X direction, and the surface light source 44b is +
The surface light source 44c moves in the Z direction and the −X direction, the surface light source 44c moves in the −Z direction and the −X direction, and the surface light source 44d moves in the −Z direction and the + X direction.

Thus, the first V-groove axicon system 7, the second
By the actions of the V-groove axicon system 8 and the zoom lens 9, the position of each surface light source forming the quadrupole secondary light source can be moved over a wide range, and its size can be set within a predetermined range. Can be changed. However, in reality, the optical ratio is set to the moving ratio of each surface light source by the first V-groove axicon system 7 and the second V-groove axicon system 8 (that is, the coordinate position of the source light source to the coordinate position of the destination surface light source). Due to the above restrictions, the moving range of each surface light source is limited.

Therefore, in the first embodiment, three types of diffractive optical elements having different characteristics are provided as the diffractive optical element 4a for quadrupole illumination. That is, the first diffractive optical element for quadrupole illumination forms a quadrupole secondary light source (see FIG. 2) in which a quadrangle formed by connecting the center points of four surface light sources becomes a square. It In addition, the second diffractive optical element for quadrupole illumination forms a quadrupole secondary light source in which a quadrangle formed by connecting the center points of the four surface light sources becomes an elongated rectangle along the X direction. It Furthermore, the third quadrupole illumination diffractive optical element forms a quadrupole secondary light source in which a quadrangle formed by connecting the center points of the four surface light sources becomes an elongated rectangle along the Z direction. It

Thus, in the quadrupole illumination of the first embodiment,
Even if the moving ratio (and thus the moving range) of each surface light source by the first V-groove axicon system 7 and the second V-groove axicon system 8 is limited to some extent from the viewpoint of optical design, three types of four poles with different characteristics are used. By using the diffractive optical element for illumination together, the position of each surface light source can be freely moved in an annular region centered on the optical axis AX.

By the way, as described above, the diffractive optical element 4a is constructed so that it can be inserted into and removed from the illumination optical path, and is switched between the diffractive optical element 4b for annular illumination and the diffractive optical element 4c for ordinary circular illumination. It is configured to be possible. The annular illumination obtained by setting the diffractive optical element 4b instead of the diffractive optical element 4a in the illumination optical path will be briefly described below.

When the diffractive optical element 4a for illuminating the quadrupole is set in the illumination optical path instead of the diffractive optical element 4a for illuminating the quadrupole, an annular light beam is formed through the diffractive optical element 4b. The annular light flux formed via the diffractive optical element 4b enters the afocal lens 5 and forms a ring-shaped image (ring-shaped light source) on the pupil plane. The light from this ring-shaped image becomes a substantially parallel light beam, and the afocal lens 5
And is illuminated through the zoom lens 9 to form an annular illumination field centered on the optical axis AX on the incident surface of the microlens array 10. As a result, the microlens array 1
A secondary light source having substantially the same light intensity as that of the illumination field formed on the incident surface, that is, a ring-shaped secondary light source centered on the optical axis AX is formed on the rear focal plane of 0.

FIG. 6 is a diagram for explaining the action of the zoom lens with respect to the secondary light source formed in the annular illumination of the first embodiment. In the ring-shaped illumination of the first embodiment, by increasing the focal length of the zoom lens 9, the ring-shaped secondary light source 60a that was initially formed has a ring-shaped secondary light whose overall shape is enlarged in a similar manner. To the secondary light source 60c. In other words, the ring-shaped secondary light source is the zoom lens 9
By the action of, the width and size (outer diameter) both change without changing the annular zone ratio.

FIG. 7 is a diagram for explaining the action of the first V-groove axicon system and the second V-groove axicon system for the secondary light source formed in the annular illumination of the first embodiment. As described above, the incident angle along the Z direction of the incident light beam on the predetermined surface 6 does not change with the change in the spacing of the first V-groove axicon system 7, but the incident light beam on the predetermined surface 6 changes in the X direction. The incident angle along varies. As a result, as shown in FIG. 7A, each of the four quarter-arc surface light sources 61 to 64 forming the annular secondary light source 60a does not move in the Z direction but emits light along the X direction. It moves symmetrically about the axis AX. That is, when the distance between the first V-groove axicon system 7 increases,
The surface light sources 61 and 63 move in the -X direction, and the surface light source 62
And 64 move in the + X direction.

On the other hand, although the incident angle along the X direction of the light beam incident on the predetermined surface 6 does not change with the change in the interval of the second V-groove axicon system 8, the light beam incident on the predetermined surface 6 moves in the Z direction. The incident angle along varies. As a result, as shown in FIG. 7B, the surface light sources 61 to 64 do not move in the X direction but move symmetrically across the optical axis AX along the Z direction. That is, when the distance between the second V-groove axicon system 8 is increased, the surface light sources 61 and 62 move in the + Z direction, and the surface light sources 63 and 64 move in the −Z direction.

Further, when both the spacing of the first V-groove axicon system 7 and the spacing of the second V-groove axicon system 8 change, the incident angle of the incident light beam on the predetermined surface 6 along the X direction and the Z direction. Change together. As a result, as shown in FIG. 7C, the surface light sources 61 to 64 are
It moves symmetrically across the optical axis AX along the Z direction and the X direction. That is, when the distance between the first V-groove axicon system 7 and the distance between the second V-groove axicon system 8 increases, the surface light source 61 moves in the + Z direction and the −X direction, and the surface light source 62 moves in the + Z direction and the + X direction. The surface light source 63 moves in the −Z direction and the −X direction, and the surface light source 64 moves in the −Z direction and the + X direction. In this way, a quadrupole secondary light source composed of four independent arc-shaped surface light sources can be formed.

The operation of the first V-groove axicon system 7 and the second V-groove axicon system 8 and the operation of the zoom lens 9 in the annular illumination of the first embodiment have been described above individually, but the interaction of these optical members is explained. It enables various forms of ring illumination. Specifically, when the zoom lens 9 is actuated in the state shown in FIG. 7C, for example, the surface light source 62 moves along the radial direction of a circle centered on the optical axis AX, and its overall shape is changed. The surface light source 62a changes in a similar manner.

Further, instead of the diffractive optical element 4a for quadrupole illumination or the diffractive optical element 4b for annular illumination, a diffractive optical element 4c for circular illumination is set in the illumination optical path to obtain a normal circular illumination. Will be briefly described. In this case, the substantially parallel light beam incident on the diffractive optical element 4c is
After a circular light intensity distribution is formed on the pupil surface of the afocal lens 5, it becomes a substantially parallel light beam.
Is ejected from.

The light beam passing through the afocal lens 5 passes through the zoom lens 9 and forms a circular illumination field centered on the optical axis AX on the incident surface of the microlens array 10. As a result, in the rear focal plane of the microlens array 10 (that is, the pupil of the illumination optical system), a secondary light source having a light intensity distribution almost the same as the illumination field formed by the incident light beam, that is, the optical axis AX is centered. A circular secondary light source is formed.

In the circular illumination of the first embodiment, the initially formed circular secondary light source increases the focal length of the zoom lens 9 so that the overall shape is enlarged in a similar circular shape. Change to the secondary light source. In other words, in the circular illumination of the first embodiment, the size (outer diameter) of the circular secondary light source can be changed by changing the focal length of the zoom lens 9.

FIG. 8 is a view for explaining the action of the first V-groove axicon system and the second V-groove axicon system for the secondary light source formed in the circular illumination of the first embodiment. In the circular illumination of the first embodiment, when the interval of the first V-groove axicon system 7 is enlarged, as shown in FIG. 8A, four quadrant-circular surface light sources 66a to constitute a circular secondary light source. 6
Of the 6d, the surface light sources 66a and 66c move in the −X direction, and the surface light sources 66b and 66d move in the + X direction.

On the other hand, when the distance between the second V-groove axicon system 8 is increased, the surface light sources 66a and 66b move in the + Z direction, as shown in FIG. 8B, and the surface light sources 66c and 66.
d moves in the -Z direction. Further, when the distance between the first V-groove axicon system 7 and the distance between the second V-groove axicon system 8 are both increased, as shown in FIG. 8C, the surface light source 66a.
Moves in the + Z direction and the -X direction, and the surface light source 66b moves in the + direction.
The surface light source 66c moves in the Z direction and the + X direction, the surface light source 66c moves in the −Z direction and the −X direction, and the surface light source 66d moves in the −Z direction and the + X direction. Thus four independent four
A quadrupole secondary light source composed of a semicircular surface light source can be formed.

The operation of the first V-groove axicon system 7 and the second V-groove axicon system 8 and the operation of the zoom lens 9 in the circular illumination of the first embodiment have been individually described above, but due to the interaction of these optical members. Various forms of circular illumination are possible. However, in practice, there is a limit to the variable range of the outer diameter of the zoom lens 9 due to optical design restrictions. Therefore, in the first embodiment, two types of diffractive optical elements having different characteristics are provided as the diffractive optical element 4c for circular illumination.

That is, the first embodiment is suitable for changing the σ value in the range from a relatively small σ value, that is, a small σ value to an intermediate σ value, that is, a middle σ value by one of the circular illumination diffractive optical elements. A secondary light source having a circular shape is formed. Also, by the other circular illumination diffractive optical element,
Σ in the range from medium σ to relatively large σ value, that is, large σ
A circular secondary light source having a shape suitable for changing the value is formed. As a result, by using two types of diffractive optical elements for circular illumination in combination, it is possible to change the σ value in the range from small σ to large σ (for example, 0.1 ≦ σ ≦ 0.95).

The switching operation of the illumination conditions in the first embodiment will be specifically described below. First, the step-and-repeat method or step-and-repeat method
Information on various masks to be sequentially exposed according to the scanning method is input to the control system 21 via the input unit 20 such as a keyboard. The control system 21 stores information such as optimum line widths (resolutions) and depths of focus for various masks in an internal memory unit, and is suitable for the drive systems 22 to 26 in response to input from the input means 20. Control signals.

That is, when performing quadrupole illumination under the optimum resolution and depth of focus, the drive system 22 positions the diffractive optical element 4a for quadrupole illumination in the illumination optical path based on a command from the control system 21. . And having the desired form 4
In order to obtain the polar secondary light source, the drive systems 25 and 26 set the intervals between the axicon systems 7 and 8 based on the command from the control system 21, and the drive system 23 based on the command from the control system 21. The focal length of the zoom lens 9 is set. Further, the drive system 24 drives the variable aperture stop of the projection optical system PL based on a command from the control system 21.

Further, if necessary, the distance between the axicon systems 7 and 8 is changed by the driving systems 25 and 26, and the focal length of the zoom lens 9 is changed by the driving system 23, whereby the microlens array 10 is changed. The form of the quadrupole secondary light source formed on the rear focal plane can be appropriately changed. In this way, the overall size (outer diameter) and shape (annular ratio) of the quadrupole secondary light source and the position, shape, size, etc. of each surface light source can be changed as appropriate to achieve various values.
Polar lighting can be provided.

Further, when the annular illumination is performed under the optimum resolution and depth of focus, the drive system 22 sets the diffractive optical element 4b for the annular illumination in the illumination optical path based on the command from the control system 21. Position. Then, in order to obtain a ring-shaped secondary light source having a desired form, or to obtain a quadrupole-shaped secondary light source or a dipole-shaped secondary light source derived from the ring-shaped secondary light source. The drive systems 25 and 26 set the distance between the axicon systems 7 and 8 based on the command from the control system 21, and the drive system 23 sets the focal length of the zoom lens 9 based on the command from the control system 21. Further, the drive system 24 drives the variable aperture stop of the projection optical system PL based on a command from the control system 21.

Further, the microlens array 10 is changed by changing the distance between the axicon systems 7 and 8 by the driving systems 25 and 26 and changing the focal length of the zoom lens 9 by the driving system 23, if necessary. The form of the ring-shaped secondary light source formed on the rear focal plane, or the form of the quadrupole-shaped secondary light source or the dipole-shaped secondary light source obtained as a derivative can be appropriately changed. In this way, the overall size (outer diameter) and shape (ring ratio) of the ring-shaped secondary light source, and the position, shape, size, etc. of each surface light source obtained as a derivative are appropriately changed, and various ring shapes are obtained. Band lighting can be performed.

Further, when performing normal circular illumination under the optimum resolution and depth of focus, the drive system 22 drives the diffractive optical element 4c for circular illumination in the illumination optical path based on a command from the control system 21. To position. Then, in order to obtain a circular secondary light source having a desired shape, or to obtain a quadrupole secondary light source or a dipole secondary light source derived from the circular secondary light source. , The drive systems 25 and 26 are driven by the axicon system 7 based on a command from the control system 21.
Then, the drive system 23 sets the focal length of the zoom lens 9 based on a command from the control system 21. Further, the drive system 24 drives the variable aperture stop of the projection optical system PL based on a command from the control system 21.

Further, the microlens array 10 is changed by changing the distance between the axicon systems 7 and 8 by the drive systems 25 and 26 and changing the focal length of the zoom lens 9 by the drive system 23, as required. The form of the circular secondary light source formed on the rear focal plane of the rear side, or the form of the quadrupole secondary light source or the dipole secondary light source obtained as a derivative can be appropriately changed. Thus, the overall size of the circular secondary light source (and thus σ
Value), and the position, shape, size, etc. of each surface light source obtained as a derivative can be appropriately changed to perform various circular illuminations.

In the first embodiment, the first V-groove axicon system 7 and the second V-groove axicon system 8 are arranged in order from the light source side, but the arrangement order can be changed appropriately. Also, in each axicon system 7 and 8,
Although the first prism member having the concave refracting surface and the second prism member having the convex refracting surface are arranged in order from the light source side, the arrangement order may be reversed.

FIG. 9 is a view schematically showing the arrangement of an exposure apparatus having an illumination optical device according to the second embodiment of the present invention. Further, FIG. 10 is a perspective view schematically showing the configurations of a conical axicon system and a V-groove axicon system arranged in the optical path of the afocal lens in the second embodiment. The second embodiment has a configuration similar to that of the first embodiment. However, while two V-groove axicon systems are arranged in the optical path of the afocal lens 5 in the first embodiment, one conical axicon system and one V-groove axicon system are arranged in the second embodiment. The first point is
This is basically different from the embodiment. The second embodiment will be described below, focusing on the differences from the first embodiment.

In the second embodiment, as shown in FIG.
A conical axicon system 14 and a V-groove axicon system 15 are arranged in this order from the light source side in the optical path between the front lens group 5a and the rear lens group 5b of the afocal lens 5. The conical axicon system 14 includes, in order from the light source side, a first prism member 14a having a flat surface facing the light source side and a concave conical refracting surface facing the mask side, and a convex prism shape having the flat surface facing the mask side and the light source side. Second prism member 1 with its refracting surface facing
4b and.

The concave conical refracting surface of the first prism member 14a and the convex conical refracting surface of the second prism member 14b are formed so as to be able to come into contact with each other. In addition, the first prism member 14a is configured to be movable along the optical axis AX, and the second prism member 14b is configured to move along the optical axis A.
It is fixed along X, and the distance between the concave conical refracting surface of the first prism member 14a and the convex conical refracting surface of the second prism member 14b is variable. The change of the interval of the conical axicon system 14 is performed by the drive system 27 which operates based on the command from the control system 21.

When the concave conical refracting surface of the first prism member 14a and the convex conical refracting surface of the second prism member 14b are in contact with each other, the conical axicon system 14 is used.
Functions as a plane-parallel plate and has no effect on the formed quadrupole secondary light source. However, when the concave conical refracting surface of the first prism member 14a and the convex conical refracting surface of the second prism member 14b are separated from each other, the conical axicon system 1
4 functions as a so-called beam expander.
Therefore, the angle of the light flux incident on the predetermined surface 6 changes as the distance between the conical axicon systems 14 changes.

Further, the V-groove axicon system 15 has a flat surface facing the light source side and a concave and V-shaped refracting surface facing the mask side, like the first V-groove axicon system 7 in the first embodiment. It is composed of one prism member 15a and a second prism member 15b having a flat surface facing the mask side and a convex V-shaped refracting surface facing the light source side. The concave refracting surface of the first prism member 15a is composed of two flat surfaces, and the intersecting line (ridgeline) thereof extends along the Z direction. The convex refracting surface of the second prism member 15b is formed so as to come into contact with the concave refracting surface of the first prism member 15a, in other words, complementary to the concave refracting surface of the first prism member 15a.

That is, the convex refracting surface of the second prism member 15b is also composed of two planes, and the line of intersection (ridgeline) thereof extends along the Z direction. In addition, the first prism member 1
5a is fixed along the optical axis AX, and the second prism member 1
5b is configured to be movable along the optical axis AX, and has a concave refracting surface of the first prism member 15a and the second prism member 15b.
The distance from the convex refracting surface is variable. The change in the interval of the V-groove axicon system 15 is performed by the drive system 28 that operates based on a command from the control system 21.

Here, when the concave refracting surface and the convex refracting surface facing each other are in contact with each other, the V-groove axicon system 1 is used.
5 functions as a plane-parallel plate and has no influence on the formed quadrupole secondary light source. However, similar to the first V-groove axicon system 7 in the first embodiment, the V-groove axicon system 15 functions as a plane parallel plate along the Z direction when the concave refraction surface and the convex refraction surface are separated from each other. , Functions as a beam expander along the X direction. 9 and 10, the V-groove axicon system 15 has the same configuration as the first V-groove axicon system 7 in the first embodiment, but may have the same configuration as the second V-groove axicon system 8.

FIG. 11 is a view for explaining the action of the conical axicon system on the secondary light source formed in the quadrupole illumination of the second embodiment. In the quadrupole illumination of the second embodiment, by increasing the interval of the conical axicon system 14,
Circular surface light sources 40a to 4 constituting a polar secondary light source
0d moves outward along the radial direction of a circle centered on the optical axis AX, and its shape changes from a circular shape to an elliptical shape. That is, the circular surface light sources 40a to
40d center point and each elliptical surface light source 41a after change
A line segment connecting the center point of 41d passes through the optical axis AX, and the moving distance of the center point depends on the interval of the conical axicon system 14.

Further, each circular surface light source 40a before change
To 40d from the optical axis AX (the angle formed by a pair of tangents from the optical axis AX to the surface light sources 40a to 40) and the angle of the changed elliptical surface light sources 41a to 41d from the optical axis AX. Is equal to. Then, the diameter of each of the circular surface light sources 40a to 40d before the change is equal to the minor diameter along the radial direction of the circle centered on the optical axis AX of each of the changed elliptical surface light sources 41a to 41d. . In addition, the size of the major axis along the circumferential direction of the circle around the optical axis AX of each of the elliptical surface light sources 41a to 41d after the change is equal to the diameter of each of the circular surface light sources 40a to 40d before the change. It depends on the spacing of the conical axicon system 14.

Therefore, when the interval of the conical axicon system 14 is expanded from zero to a predetermined value, the quadrupole secondary light source composed of four circular surface light sources becomes four elliptical surface light sources. Change to a quadrupole secondary light source composed,
The outer diameter and the annular ratio can be changed without changing the width of the secondary light source before the change. Here, the width of the quadrupole secondary light source is defined as 1/2 of the difference between the diameter of the circle circumscribing the four surface light sources, that is, the outer diameter and the diameter of the circle inscribed in the four surface light sources, ie, the inner diameter. It The annular ratio of the quadrupole secondary light source is defined as the ratio of the inner diameter to the outer diameter (inner diameter / outer diameter).

As described above, in the quadrupole illumination of the second embodiment, since only one V-groove axicon system 15 is arranged, the shape of each circular surface light source which constitutes the quadrupole secondary light source. And it is not possible to change only the position two-dimensionally while maintaining the size. However, by selectively using the plurality of diffractive optical elements 4a for quadrupole illumination and utilizing the effects of the conical axicon system 14, the V-groove axicon system 15, and the zoom lens 9, a circle centered on the optical axis AX is obtained. In the annular region, the position, shape and size of each surface light source can be changed appropriately.

FIG. 12 is a view for explaining the action of the conical axicon system with respect to the secondary light source formed in the annular illumination of the second embodiment. In the ring-shaped illumination of the second embodiment, the ring-shaped secondary light source 60a that is initially formed expands the interval of the conical axicon system 14 so that its width (1 / the difference between the outer diameter and the inner diameter). (2: indicated by an arrow in the figure) does not change, but changes to a secondary light source 60b in the shape of a ring in which both the outer diameter and the inner diameter are enlarged. In other words, the ring-shaped secondary light source, by the action of the conical axicon system 14,
The ring zone ratio and the size (outer diameter) both change without changing the width.

However, in practice, there is a limit to the range of change of the annular zone ratio by the conical axicon system 14 due to optical design restrictions. Therefore, in the second embodiment, two types of diffractive optical elements having different characteristics are provided as the diffractive optical element 4b for annular illumination. In other words, in the second embodiment, a ring-shaped secondary light source having a shape suitable for changing the ring-ratio in the range of 0.5 to 0.68 is provided by one of the diffractive optical elements for ring-shaped illumination. Form. Further, by the other diffractive optical element for ring zone illumination, for example, 0.68 to
A zone-shaped secondary light source having a shape suitable for changing the zone ratio in the range of 0.8 is formed. As a result, it becomes possible to change the annular zone ratio within the range of 0.5 to 0.8 by using two kinds of diffractive optical elements for annular illumination in combination.

As described above, since only one V-groove axicon system 15 is arranged in the annular illumination of the second embodiment, the quadrupole secondary light source is derived from the annular secondary light source. Can't get However, by selectively using a plurality of diffractive optical elements 4b for annular illumination and utilizing the functions of the conical axicon system 14, the V-groove axicon system 15, and the zoom lens 9, the entire annular secondary light source is obtained. The appropriate size and shape (ring ratio), or the position, shape and size of each surface light source constituting a dipole-shaped secondary light source derived from the ring-shaped secondary light source. You can

Further, in the circular illumination of the second embodiment, 1
Since only one V-groove axicon system 15 is placed,
It is not possible to obtain a quadrupole secondary light source as a derivative of the circular secondary light source. However, the plurality of circular illumination diffractive optical elements 4c are selectively used, and the effects of the conical axicon system 14, the V-groove axicon system 15, and the zoom lens 9 are utilized, so that the entire circular secondary light source is The position of each surface light source that composes a dipole-shaped secondary light source derived from a secondary light source of various sizes or circular shapes,
The shape and size can be changed as appropriate.

FIG. 13 is a view schematically showing the arrangement of an exposure apparatus having an illumination optical device according to the third embodiment of the present invention. The third embodiment has a configuration similar to that of the first embodiment. However, the third embodiment is basically different from the first embodiment in that an internal reflection type optical integrator (rod type integrator 70) is used in place of the wavefront division type optical integrator (microlens array 10). It's different. The third embodiment will be described below, focusing on the differences from the first embodiment.

In the third embodiment, the light source side is provided in the optical path between the diffractive optical element 4 and the rod type integrator 70 corresponding to the arrangement of the rod type integrator 70 in place of the microlens array 10. A zoom lens 71, a second diffractive optical element (or a microlens array) 72, and an input lens 73 are arranged in this order from. Also, a mask blind 1 as an illumination field stop.
2 is arranged in the vicinity of the exit surface of the rod type integrator 70.

Here, the zoom lens 71 is arranged so that its front focal position substantially coincides with the position of the diffractive optical element 4 and its rear focal position substantially coincides with the position of the second diffractive optical element 72. . The focal length of the zoom lens 71 is changed by the drive system 29 that operates based on the command from the control system 21. Further, the input lens 73 is arranged such that its front focus position substantially coincides with the position of the second diffractive optical element 72, and its rear focus position substantially coincides with the position of the incident surface of the rod type integrator 70.

The rod type integrator 70 is an internal reflection type glass rod made of a glass material such as quartz glass or fluorite, and utilizes total internal reflection on the boundary surface between the inside and the outside, that is, the inside surface to collect light. A number of light source images corresponding to the number of internal reflections are formed along a plane parallel to the rod entrance plane. Here, most of the light source images formed are virtual images, but only the light source image at the center (condensing point) is the real image. That is, the light flux incident on the rod type integrator 70 is angularly divided by internal reflection, and a secondary light source composed of a large number of light source images is formed along a plane that passes through the converging point and is parallel to the incident plane.

Therefore, in the quadrupole illumination (annular illumination or circular illumination) of the third embodiment, the light flux that has passed through the diffractive optical element 4a (4b or 4c) selectively installed in the illumination optical path is the zoom lens 71. A quadrupole (annular or circular) illumination field is formed on the second diffractive optical element 72 via. The light flux that has passed through the second diffractive optical element 72 is condensed near the entrance surface of the rod type integrator 70 via the input lens 73. FIG. 14 is a diagram for explaining the operation of the second diffractive optical element in the third embodiment.

As shown in FIG. 14A, when the second diffractive optical element 72 is not arranged, the light beam passing through the zoom lens 71 and the input lens 73 is almost on the incident surface 70a of the rod type integrator 70. Focus on one point. As a result, a large number of light sources formed on the incident side by the rod type integrator 70 become very dissipative (the filling rate of each light source with respect to the entire secondary light source becomes small), and a substantial surface light source can be obtained. I can not do it.

Therefore, in the third embodiment, the second diffractive optical element 72 as the light beam diverging element is replaced by the input lens 73.
It is arranged near the front focus position of. Thus, FIG.
As shown in FIG. 4B, the light flux diverged through the second diffractive optical element 72 is condensed with a predetermined spread on the incident surface 70a of the rod type integrator 70 through the input lens 73. As a result, a large number of light sources formed on the incident side by the rod type integrator 70 become very solid (the filling rate of each light source with respect to the entire secondary light source becomes large), and the secondary light source as a substantial surface light source. Can be obtained.

The light flux from the quadrupole (ring-shaped or circular) secondary light source formed on the incident side by the rod type integrator 70 is superposed on the exit surface thereof, and then,
Via the mask blind 12 and the imaging optical system 13,
The mask M on which a predetermined pattern is formed is illuminated. In the third embodiment, the first V-groove axicon system 7 and the second V-groove axicon system 8 are arranged in order from the light source side in the optical path between the front lens group 71a and the rear lens group 71b of the zoom lens 71. Has been done.

Therefore, also in the quadrupole illumination of the third embodiment, as in the first embodiment, a plurality of diffractive optical elements 4a for quadrupole illumination are selectively used, and the first V-groove axicon system 7 and the second V-groove are used. By utilizing the actions of the axicon system 8 and the zoom lens 71, the position, shape and size of each surface light source forming the annular secondary light source are appropriately set in the annular region centered on the optical axis AX. Can be changed.

Also in the annular illumination of the third embodiment, as in the first embodiment, a plurality of diffractive optical elements 4b for annular illumination are selectively used, and the first V-groove axicon system 7 and the second V-groove are used. Axicon system 8 and zoom lens 71
By utilizing the effect of the above, the overall size and shape (ring ratio) of the ring-shaped secondary light source, or the dipole-shaped secondary light source or 4 derived from the ring-shaped secondary light source or 4
The position, shape, and size of each surface light source forming the polar secondary light source can be appropriately changed.

Further, also in the circular illumination of the third embodiment, as in the first embodiment, a plurality of diffractive optical elements 4c for circular illumination are selectively used, and the first V groove axicon system 7 and the second V groove axicon system are used. 8 and zoom lens 7
By utilizing the action of 1, the overall size of the circular secondary light source, or a dipole secondary light source or a quadrupole secondary light source derived from the circular secondary light source The position, shape, and size of each surface light source that composes can be appropriately changed.

Although not shown, the wavefront splitting type optical integrator (microlens array 10) in the second embodiment is replaced with an internal reflection type optical integrator (rod type integrator 70).
The fourth embodiment using is also possible. In this case, the zoom lens 71, the second diffractive optical element (or microlens array) 72, and the input lens 73 are arranged in this order from the light source side in the optical path between the diffractive optical element 4 and the rod integrator 70. Is the same as in the third embodiment. Thus, in the fourth embodiment, the conical axicon system 14, the V-groove axicon system 15, and the zoom lens 71.
By utilizing the action of, various quadrupole illumination, annular illumination, and circular illumination can be performed as in the second embodiment.

As described above, in the first to fourth embodiments, by changing the spacing of the V-groove axicon system (7, 8 or 15), the overall size and shape of the secondary light source is X. Direction or Z direction. As a result, different illumination conditions can be realized in the two orthogonal directions (X direction and Y direction) on the mask M, and by extension, the optimal illumination conditions in the two orthogonal directions on the mask M having a directional pattern. Can be set.

A pair of V-groove axicon systems 7 and 8
The first embodiment and the third embodiment having only the above are particularly suitable for a lithography process of a memory (DRAM or the like). Further, the second embodiment and the fourth embodiment provided with only the conical axicon system 14 and one V-groove axicon system 15 are particularly suitable for a lithography process of a logic device (MPU or the like). Further, a modification including a conical axicon system and a pair of V-groove axicon systems is also possible, and this modification is suitable for a lithography process of a general microdevice including a semiconductor device.

Next, the characteristic structure and operation of the present invention in each embodiment will be described in more detail. First, in the first embodiment (the same applies to the third embodiment), the first
The V-groove axicon system 7 (first axicon system) includes a first prism member 7a configured to be movable along the optical axis AX and a second prism member fixed along the optical axis AX in order from the light source side. 7b and. The second V-groove axicon system 8 (second axicon system) is a first prism member 8a fixed along the optical axis AX in order from the light source side.
And a second prism member 8b configured to be movable along the optical axis AX.

As described above, in the first embodiment, the four prism members (7a, 7b, 8a, 8b) forming the first V-groove axicon system 7 and the second V-groove axicon system 8 are arranged outside. Two prism members (7a, 8
b) is configured to be movable along the optical axis AX, and the two prism members (7b, 8a) arranged on the inside are provided with the optical axis AX.
Is fixed along. As a result, in the first embodiment, a first moving mechanism (not shown) for moving the first prism member 7a along the optical axis AX and a second moving mechanism for moving the second prism member 8b along the optical axis AX. Since a sufficiently large distance is secured to the second moving mechanism (not shown), mechanical interference between the moving mechanisms can be reliably avoided, and a compact overall structure can be realized.

Also in the second embodiment (similarly to the fourth embodiment), the conical axicon system 14 (first axicon system) is arranged so as to be movable along the optical axis AX in order from the light source side. It is composed of one prism member 14a and a second prism member 14b fixed along the optical axis AX. The V-groove axicon system 15 (second axicon system) has a first prism member 15a fixed along the optical axis AX and a second prism configured to be movable along the optical axis AX in order from the light source side. It is composed of a prism member 15b.

As described above, in the second embodiment, the conical axicon system 14 and the V-groove axicon system 15 are formed.
Two prism members (14a, 14b, 15a, 15b)
Of the two prism members (14
a, 15b) is movable along the optical axis AX,
Two prism members (14b, 15) arranged inside
a) is fixed along the optical axis AX. As a result, also in the second embodiment, a first moving mechanism (not shown) for moving the first prism member 14a along the optical axis AX.
And a second moving mechanism (not shown) for moving the second prism member 15b along the optical axis AX are sufficiently large, so that mechanical interference between the moving mechanisms is surely avoided. Therefore, a compact overall structure can be realized.

In the first embodiment, as shown in FIG. 15, the four prism members (7a, 7b, 8) forming the first V-groove axicon system 7 and the second V-groove axicon system 8 are formed.
Of the a, 8b), it is preferable that the two inner prism members (7b, 8a) fixed along the optical axis AX are integrally formed as one prism member 7a8b. With this configuration, the transmittance of light in the first V-groove axicon system 7 and the second V-groove axicon system 8 can be improved, and the manufacturing error and the positioning error of the prism member can be suppressed, which in turn results in a highly accurate and high-performance axicon system. Can be realized. Similarly, although not shown,
The four prism members (14 included in the conical axicon system 14 and the V-groove axicon system 15 according to the second embodiment).
a, 14b, 15a, 15b), two inner prism members (14b, 15b) fixed along the optical axis AX.
It is preferable to integrally form a) as one prism member.

FIG. 16 is a diagram for explaining the general optical action of the conical axicon system and the V-groove axicon system. Further, FIG. 17 shows a circular shadow region formed corresponding to the apex of the conical refracting surface of the conical axicon system and a straight line formed corresponding to the ridge of the V-shaped refracting surface of the V groove axicon system. It is a figure which shows the shadow area of. Referring to FIG. 16, a light beam incident on the first prism member of the conical axicon system or the V-groove axicon system in parallel to the optical axis AX forms an angle α with the optical axis AX due to the refraction action. It is emitted in a direction away from AX and enters the second prism member.

The light beam incident on the second prism member is refracted and then emitted parallel to the optical axis AX. At this time, the height h2 of the light beam emitted from the second prism member parallel to the optical axis AX and the optical axis of the light beam incident on the first prism member parallel to the optical axis AX. The difference from the height h1 from AX is Δh (= h2-h
It becomes 1). The angle α (unit: degree) is expressed by the following equation (1).

## EQU1 ## α = sin ⁻¹ {n × sin (90−θ)} + θ−90 = sin ⁻¹ (n × cos θ) + θ−90 (1)

Here, n is the refractive index of the optical material forming the first and second axicon prism members to the exposure light. In each embodiment, the light source 1 is an ArF excimer laser light source (wavelength 193).
nm), more generally, for example, 200 n
When using a light source that supplies light having a wavelength of m or less,
Each axicon system (7,8,1) using fluorite (CaF ₂ )
By forming 4, 15), the durability against laser light can be improved.

On the other hand, Δh is expressed by the following equation (2). Δh = A × L (2) However, A = (tan α × tan θ) / (tan θ−tan α)

Here, L is the distance along the optical axis AX between the refracting surface of the first prism member and the refracting surface of the second prism member in each axicon system (see FIG. 16). Further, 2θ is the apex angle of the conical refracting surface in the conical axicon system or the intersection angle of the V-shaped refracting surface in the V-groove axicon system.

By the way, in the circular illumination of the first embodiment, the distance between the refracting surface of the first prism member 7a and the refracting surface of the second prism member 7b of the first V-groove axicon system 7 and the second V-groove axicon system 8 are adjusted. When the distance between the refracting surface of the first prism member 8a and the refracting surface of the second prism member 8b is both set to a predetermined distance, the microlens array 10
The circular secondary light source formed on the rear focal plane of
As shown in FIG. 7 (a), a cross-shaped shadow area (indicated by a blank area in the figure) is formed corresponding to the ridge line of the V-shaped refracting surface of the first V-groove axicon system 7 and the second V-groove axicon system 8. To be done.

Further, in the circular illumination of the second embodiment,
When the distance between the refracting surface of the first prism member 14a and the refracting surface of the second prism member 14b of the conical axicon system 14 is set to a predetermined distance, a circular shape formed on the rear focal plane of the microlens array 10. The secondary light source of FIG.
As shown in (b), a circular shadow area (indicated by a blank area in the drawing) is formed corresponding to the apex of the conical refracting surface of the conical axicon system 14.

In this case, the diameter D1 of the circular secondary light source formed on the back focal plane of the microlens array 10 is
It is expressed by the following equation (3). The width D2 of the linear shadow area and the diameter D2 of the circular shadow area that form the cross shadow area are expressed by the following equation (4).

## EQU2 ## D1 = 2 × f ₃ × (f ₁ × sin ψ _max ) / f ₂ (3) D2 = 2 × Δh × f ₃ / f ₂ = 2 × A × L × f ₃ / f ₂ (4)

Here, ψ _max is the maximum diffraction angle of the diffractive optical element 4 as the light beam conversion element. Further, f ₁ is a focal length of the front lens group (first lens group) 5a of the afocal lens (first optical system) 5. Furthermore, f ₂ is
Rear lens group of afocal lens 5 (second lens group)
The focal length is 5b. Further, f ₃ is the focal length of the zoom lens (second optical system) 9.

Referring to the equation (4), the gap L between the refracting surface of the first prism member and the refracting surface of the second prism member is set to zero, that is, the refracting surface of the first prism member and the second prism member. By contacting the refracting surface of
It can be seen that the generation of cross-shaped shadow areas and circular shadow areas can be avoided. However, the apex portion of the conical concave refracting surface of the first prism member 14a of the conical axicon system 14 and the ridge portion of the V-shaped concave refracting surface of the first groove member of the V-groove axicon system (7, 8) are desired. It is difficult to form an ideal shape with the surface accuracy of. When the refracting surface of the first prism member and the refracting surface of the second prism member are brought into contact with each other, the second prism member 14b of the conical axicon system 14 is brought into contact.
The apex portion of the conical convex refracting surface and the ridge portion of the V-shaped convex refracting surface of the second prism member of the V-groove axicon system (7, 8) are easily damaged.

Therefore, in reality, it is impossible to bring the refracting surface of the first prism member and the refracting surface of the second prism member into contact with each other, and the refracting surface of the first prism member and the refraction surface of the second prism member are refracted. The distance L from the surface cannot be made smaller than a predetermined value. As a result, it is inevitable that a cross-shaped shadow area or a circular shadow area is generated in the circular secondary light source. In this case, when the circular illumination with a small σ is particularly performed, the diameter D1 of the circular secondary light source formed on the rear focal plane of the microlens array 10 becomes small, so that a cross-shaped shadow region or a circular shadow is generated. The proportion of the area occupied by the secondary light source increases,
As a result, the influence on the light intensity distribution in the illumination pupil increases. Therefore, it is necessary to keep the width D2 of the cross shadow area and the diameter D2 of the circular shadow area as small as possible.

Specifically, in order to obtain a desired light intensity distribution in the illumination pupil without being substantially affected by the cross shadow area or the circular shadow area, the width D2 of the cross shadow area or The diameter D2 of the circular shadow area is set to the microlens array 10.
Diameter D1 of the circular secondary light source formed on the rear focal plane
1/10 or less, that is, D1 ≦ D2 / 1
It is necessary to satisfy the condition of 0. D1 ≦ D2 / 1
Specifically, the condition of 0 is represented by the following equation (5) and finally by the equation (6) with reference to the equations (3) and (4). 2 × A × L × f ₃ / f ₂ ≦ 2 × f ₃ × (f ₁ × sin ψ _max ) / (10 × f ₂ ) (5) A × L ≦ (f ₁ × sin ψ _max ) / 10 (6)

As described above, the V-groove axicon system (7,
It is difficult to form the ridge portion of the V-shaped concave refracting surface of the first prism member of 8) with an ideal shape with desired surface accuracy. As a result, the distance L between the refracting surface of the first prism member and the refracting surface of the second prism member cannot be made smaller than a predetermined value, and a cross-shaped shadow area is generated in the circular secondary light source. . Therefore, the minimum distance between the refracting surface of the first prism member and the refracting surface of the second prism member is made as small as possible, and by extension, the width D2 of the cross-shaped shadow region formed in the circular secondary light source is made as small as possible. As shown in FIG. 18, two prism members 81 and 82 divided along a plane including the optical axis AX and the ridgeline of the refracting surface (in the figure, a plane including the optical axis AX and perpendicular to the paper surface). It is effective to configure the first prism 83 with.

In this case, for example, the split prism member 81
The outer end face 81b facing the face 81a along the optical axis AX of
While the fixed support surface 84 of the holding mechanism is brought into contact with the outer end surface 82b of the split prism member 82 facing the surface 82a along the optical axis AX, the movable support surface 85 of the holding mechanism is brought into contact with the outer end surface 82b of the split prism member 82 along the arrow F. Force. In this way, the surface 81a of the split prism member 81 and the surface 82a of the split prism member 82 are held in a so-called surface-touch state without interposing an adhesive or the like.

By the way, the apex angle 2θ (unit: degree) of the conical refracting surface in the conical axicon system or the crossing angle 2θ of the V-shaped refracting surface in the V-groove axicon system is 9 theoretically.
Although it is larger than 0 degrees and smaller than 180 degrees, it is actually preferable that the following conditional expression (7) is satisfied. 120 <2θ <160 (7)

Below the lower limit of conditional expression (7), the same Δ
This is inconvenient because the interval L required to generate h is too small and it becomes difficult to control Δh with high accuracy. On the other hand, if the upper limit of conditional expression (7) is exceeded, the interval L required to generate the same Δh is too large, which leads to an increase in the size of the axicon system and, in turn, a device. As described above, there are restrictions on the apex angle 2θ or the crossing angle 2θ in the axicon system, and also in the distance L between the refracting surfaces in the axicon system. Therefore, particularly in the quadrupole illumination, there is an optical design restriction on the movement ratio of each surface light source by the V-groove axicon system (that is, the coordinate position of the movement source surface light source with respect to the movement destination surface light source). There is a limit to the moving range of the surface light source.

Therefore, in the first embodiment, a quadrupole secondary light source is initially formed such that the quadrangle formed by connecting the center points of the four surface light sources is an elongated rectangle, and the first V-groove axicon is used. Due to the actions of the system 7 and the second V-groove axicon system 8, a wider variety of quadrupole illumination can be performed. Specifically, in the first embodiment, as shown in FIG. 5, the quadrangle formed by connecting the center points of the four surface light sources by the first diffractive optical element for quadrupole illumination becomes a square. A quadrupole secondary light source is initially formed, and a first V-groove axicon system 7 is formed.
By the action of the second V-groove axicon system 8, each surface light source is maintained in the Z direction and the X direction while maintaining its shape and size.
The optical axis AX is symmetrically moved along the direction.

In addition to this, in the first embodiment, as shown in FIG.
As shown in (a), by the second diffractive optical element for quadrupole illumination, the quadrangle formed by connecting the center points of the four surface light sources becomes a long and narrow rectangle along the X direction. Form a secondary light source. Further, in the first embodiment, FIG.
As shown in (b), by the third diffractive optical element for illuminating quadrupoles, the quadrangle formed by connecting the center points of the four surface light sources becomes a slender rectangle along the Z direction. Form a secondary light source. Then, by the action of the first V-groove axicon system 7 and the second V-groove axicon system 8, as shown by the arrows in the figure, each surface light source is maintained along its optical axis along the Z and X directions while maintaining its shape and size. Move symmetrically across AX.

In the exposure apparatus according to each of the above embodiments,
A mask (reticle) is illuminated by an illumination optical device (illumination step), and a transfer pattern formed on the mask is exposed on a photosensitive substrate using a projection optical system (exposure step), thereby producing a microdevice (semiconductor element). , Imaging devices, liquid crystal display devices, thin film magnetic heads, etc.) can be manufactured. 20 is a flowchart showing an example of a method for obtaining a semiconductor device as a micro device by forming a predetermined circuit pattern on a wafer or the like as a photosensitive substrate using the exposure apparatus of each of the above-described embodiments. It will be described with reference to FIG.

First, in step 301 of FIG. 20,
A metal film is deposited on one lot of wafers. In the next step 302, photoresist is applied on the metal film on the wafer of the 1 lot. Then step 30
3, the image of the pattern on the mask is sequentially exposed and transferred to each shot area on the wafer of the one lot through the projection optical system by using the exposure apparatus of each of the above-described embodiments. Then, in step 304, the photoresist on the one lot of wafers is developed, and in step 305, the resist pattern is used as a mask on the one lot of wafers to form a pattern on the mask. Corresponding circuit patterns are formed in each shot area on each wafer. After that, a device such as a semiconductor element is manufactured by forming a circuit pattern on an upper layer. According to the above-described semiconductor device manufacturing method, it is possible to obtain a semiconductor device having an extremely fine circuit pattern with high throughput.

Further, in the exposure apparatus of each of the above-mentioned embodiments,
A liquid crystal display element as a microdevice can be obtained by forming a predetermined pattern (circuit pattern, electrode pattern, etc.) on a plate (glass substrate). Hereinafter, an example of the method at this time will be described with reference to the flowchart in FIG. 21, in a pattern forming step 401, a so-called photolithography step is performed in which the mask pattern is transferred onto a photosensitive substrate (such as a glass substrate coated with a resist) by using the exposure apparatus according to each of the above-described embodiments. It By this photolithography process, a predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. After that, the exposed substrate is subjected to a developing process, an etching process, a resist stripping process, and the like to form a predetermined pattern on the substrate, and then the process proceeds to the next color filter forming process 402.

Next, in the color filter forming step 402, 3 corresponding to R (Red), G (Green) and B (Blue)
Many sets of one dot are arranged in a matrix,
Alternatively, a color filter in which a plurality of R, G, and B stripe filter sets are arranged in the horizontal scanning line direction is formed. Then, after the color filter forming step 402, the cell assembling step 403 is executed. In the cell assembly step 403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern formation step 401, the color filter obtained in the color filter formation step 402, and the like. In the cell assembling step 403, for example, a liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern forming step 401 and the color filter obtained in the color filter forming step 402 to form a liquid crystal panel (liquid crystal cell). ) Is manufactured.

After that, in a module assembling step 404, each component such as an electric circuit and a backlight for performing a display operation of the assembled liquid crystal panel (liquid crystal cell) is attached to complete a liquid crystal display element. According to the method of manufacturing a liquid crystal display element described above, a liquid crystal display element having an extremely fine circuit pattern can be obtained with high throughput.

In each of the above-described embodiments, the quadrupole-shaped or annular-shaped secondary light source is exemplarily formed in the modified illumination, but the two-pole surface light source is eccentric to the optical axis. It is also possible to form a so-called multi-pole or multi-pole secondary light source such as a rectangular secondary light source or an octopole secondary light source composed of eight surface light sources eccentric to the optical axis.

In each of the above embodiments, the present invention has been described by taking the projection exposure apparatus equipped with the illumination optical device as an example. Obviously, the invention can be applied.

[0137]

As described above, in the illumination optical apparatus of the present invention, the quadrupole-shaped or annular-shaped secondary light source is appropriately changed by the action of the axicon system so that it can be changed in two orthogonal directions on the illuminated surface. Lighting conditions different from each other can be realized. Therefore, in the exposure apparatus and the exposure method incorporating the illumination optical device of the present invention, which can realize different illumination conditions in the two directions orthogonal to each other on the surface to be illuminated, the two orthogonal directions on the mask having a directional pattern are provided. Optimal illumination conditions can be set depending on the direction, and good microdevices can be manufactured under good illumination conditions.

[Brief description of drawings]

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

FIG. 2 is a diagram schematically showing the configuration of a quadrupole secondary light source formed on the back focal plane of the microlens array.

FIG. 3 is a perspective view schematically showing the configuration of two axicon systems arranged in the optical path between the front lens group and the rear lens group of the afocal lens in the first embodiment.

FIG. 4 is a diagram for explaining the action of the zoom lens with respect to the secondary light source formed in the quadrupole illumination of the first embodiment.

FIG. 5 is a diagram for explaining the action of the first V-groove axicon system and the second V-groove axicon system for the secondary light source formed in the quadrupole illumination of the first embodiment.

FIG. 6 is a diagram for explaining the action of the zoom lens with respect to the secondary light source formed in the annular illumination of the first embodiment.

FIG. 7 is a diagram for explaining the action of the first V-groove axicon system and the second V-groove axicon system for the secondary light source formed in the annular illumination of the first embodiment.

FIG. 8 is a view for explaining the action of the first V-groove axicon system and the second V-groove axicon system for the secondary light source formed in the circular illumination of the first embodiment.

FIG. 9 is a diagram schematically showing a configuration of an exposure apparatus including an illumination optical device according to a second embodiment of the present invention. It is a perspective view which shows roughly the structure of the conical axicon system and V groove | channel axicon system arrange | positioned in the optical path of the afocal lens in 2nd Embodiment.

FIG. 10 is a perspective view schematically showing the configurations of a conical axicon system and a V-groove axicon system arranged in the optical path of the afocal lens in the second embodiment.

FIG. 11 is a diagram for explaining the action of the conical axicon system on the secondary light source formed in the quadrupole illumination of the second embodiment.

FIG. 12 is a diagram for explaining the action of a conical axicon system with respect to a secondary light source formed in the annular illumination of the second embodiment.

FIG. 13 is a diagram schematically showing a configuration of an exposure apparatus including an illumination optical device according to a third embodiment of the present invention.

FIG. 14 is a diagram for explaining the operation of the second diffractive optical element in the third embodiment.

FIG. 15 is a perspective view schematically showing a configuration in which two inner prism members that are fixed along the optical axis are integrally formed among the four prism members that form the two axicon systems.

FIG. 16 is a diagram illustrating general optical actions of a conical axicon system and a V-groove axicon system.

FIG. 17 is a circular shadow region formed corresponding to the apex of a conical refracting surface of a conical axicon system and a linear shadow formed corresponding to a ridge of a V-shaped refracting surface of a V-groove axicon system. It is a figure showing a field.

FIG. 18 is a diagram showing an example in which a V-groove axicon-type first prism is configured with two prism members divided along an edge line.

FIG. 19 is a diagram showing an example of initially forming a quadrupole secondary light source in which a quadrangle formed by connecting the center points of four surface light sources is an elongated rectangle.

FIG. 20 is a flowchart of a method for obtaining a semiconductor device as a micro device.

FIG. 21 is a flowchart of a method for obtaining a liquid crystal display element as a micro device.

[Explanation of symbols]

1 light source 4 Diffractive optical element 5 Afocal lens 7,8,16 V groove axicon system 9 Zoom lens 10 micro lens array 11 Condenser optical system 12 mask blinds 13 Imaging optical system 14 Conical axicon system 70 Rod type integrator 71 Zoom lens 73 Input lens M mask PL projection optical system W wafer 20 Input means 21 Control system 22-29 drive system

Claims (18)

[Claims] 1. An illumination optical device comprising an optical integrator for forming a secondary light source based on a light beam from a light source means, and a light guide optical system for guiding the light beam from the optical integrator to a surface to be illuminated. A first axicon system arranged in an optical path between the light source means and the optical integrator for changing at least one of an incident angle and an incident position of an incident light beam to the optical integrator; A second axicon system arranged in an optical path between the axicon system and the optical integrator for changing at least one of an incident angle and an incident position of an incident light beam to the optical integrator, and the first axicon The system can be moved along the optical axis at least from the light source means side. And a second prism fixed along the optical axis and having a refracting surface formed to be complementary to the refracting surface of the first prism, wherein the second axicon system is In order from the light source means side, it has at least a third prism fixed along the optical axis, and a refracting surface configured to be movable along the optical axis and complementary to the refracting surface of the third prism. An illumination optical device comprising a fourth prism. 2. The illumination optical device according to claim 1, wherein the second prism and the third prism are integrally formed. 3. The first prism has a refracting surface with a concave cross section, and the second prism has a refracting surface with a convex cross section formed complementarily with the refracting surface of the concave cross section of the first prism. The third prism has a refracting surface having a concave cross section, and
3. The illumination optical device according to claim 1, wherein the prism has a convex cross-section refracting surface formed to be complementary to the concave cross-section refracting surface of the third prism. 4. The first prism has a V-shaped refracting surface having a ridge line along a first direction orthogonal to the optical axis, and the first prism is orthogonal to the optical axis and the first direction. The illumination optical device according to claim 3, further comprising a V-shaped refracting surface having a ridge line along the second direction. 5. One of the first prism and the third prism has a conical refracting surface having an optical axis as a center, and the other of the first prism and the third prism is orthogonal to the optical axis. The illumination optical apparatus according to claim 3, further comprising a V-shaped refracting surface having a ridge line along a direction in which the illumination optical device is formed. 6. An optical integrator for forming a secondary light source based on a light beam from a light source means, a light guiding optical system for guiding the light beam from the optical integrator to an irradiation surface, the light source means and the And an axicon system for changing at least one of an incident angle and an incident position of a light beam incident on the optical integrator, the axicon system being arranged in an optical path between the optical integrator and the optical integrator. A first prism having a refracting surface with a concave concave cross section, and a second prism having a conical or V-shaped convex refracting surface that is complementary to the refracting surface of the first prism. The axicon system has a diameter of a circular shadow region formed corresponding to an apex of the conical refracting surface in the vicinity of an illumination pupil or the diameter of the circular shadow region. 1/10 the width of the linear shadow area of the entire light flux magnitude of which is formed corresponding to the ridge-shaped refractive surface
An illuminating optical device having the required shape and characteristics for: 7. A light flux conversion element for converting a light flux from the light source means into a light flux having a predetermined cross-sectional shape or a light flux having a predetermined light intensity distribution, and between the light flux conversion element and the optical integrator. The optical system further includes a first optical system arranged in an optical path, and a second optical system arranged in an optical path between the first optical system and the optical integrator, wherein the axicon system is the first optical system. The illumination optical device according to claim 6, wherein the illumination optical device is disposed in the vicinity of the illumination pupil in the optical path of. 8. The maximum diffraction angle of the diffractive optical element as the light beam conversion element as [psi _{ma x,} the spacing along the optical axis between the refractive surface and the refractive surface of the second prism of the first prism L
And the apex angle of the conical refracting surface or the crossing angle of the V-shaped refracting surface is 2θ, and the refractive index of the optical material forming the first prism and the second prism with respect to the light flux is n, When the focal length of the first lens group arranged on the light source means side of the axicon system in the first optical system is f ₁ , AL ≦ (f ₁ × sin ψ _max ) / 10 where A = The illumination optical device according to claim 7, wherein a condition of (tan α × tan θ) / (tan θ-tan α) α = sin ⁻¹ (n × cos θ) + θ-90 (unit: degree) is satisfied. 9. An optical integrator for forming a secondary light source based on a light flux from a light source means, a light guiding optical system for guiding the light flux from the optical integrator to an irradiation surface, the light source means and the It is arranged in an optical path between the optical integrator and an axicon system formed of fluorite for changing at least one of an incident angle and an incident position of an incident light beam to the optical integrator. Illumination optical device. 10. The illumination optical device according to claim 9, wherein the light source means supplies light having a wavelength of 200 nm or less. 11. The axicon system includes a first prism having a V-shaped concave section refracting surface having a ridgeline along a direction orthogonal to an optical axis, and a concave section refracting surface of the first prism. A second prism having a V-shaped convex cross-section refracting surface formed in a complementary manner, wherein the first prism is divided along a surface including an optical axis and the ridge line. The method according to claim 9 or 10, characterized in that
The illumination optical device according to. 12. An illumination optical device for illuminating a surface to be illuminated based on a light beam from a light source means, comprising a prism having a V-shaped concave cross-section refraction surface having a ridge line along a predetermined direction, and the prism. Is an illumination optical device, wherein the illumination optical device is divided along a predetermined surface including the ridge. 13. An optical integrator for forming a secondary light source based on the light flux from the light source means, a light guiding optical system for guiding the light flux from the optical integrator to the illuminated surface, and the light source means. Is disposed in the optical path between the optical integrator and the optical integrator, further comprising an axicon system including the prism for changing at least one of the incident angle and the incident position of the incident light beam to the optical integrator. 13. The illumination optical device according to claim 12, wherein the illumination optical device is a device. 14. The axicon system has a prism having a V-shaped concave cross-section refracting surface having the ridge line along a direction orthogonal to an optical axis, and a complementary surface of the prism having the concave cross-section refracting surface. And a second prism having a refracting surface having a V-shaped convex cross-section formed in, and the prism is divided along a surface including an optical axis and the ridgeline. 13. The illumination optical device according to item 13. 15. An illumination optical device for illuminating a surface to be illuminated, wherein a secondary light source having a quadrupole light intensity distribution is formed on an illumination pupil plane based on a light beam from the light source means. Luminous flux conversion element for converting the luminous flux of the above into four luminous fluxes, and four substantial surface light sources that are arranged in the optical path between the luminous flux conversion element and the illumination pupil plane and constitute the secondary light source. An axicon system for symmetrically moving one of the pair and the other pair with the optical axis sandwiched therebetween, wherein the light flux conversion element is elongated along a first direction orthogonal to the optical axis. An illumination optical device, wherein each of the four substantial surface light sources is formed around each corner point of a rectangle. 16. The axicon system includes a first prism having a V-shaped concave cross-section refracting surface having a ridge line along the first direction, and a complement of the concave cross-section refracting surface of the first prism. A first axicon system having a second prism having a V-shaped convex cross-section refracting surface, and a V-shape having a ridge line along an optical axis and a second direction orthogonal to the first direction. A third prism having a refracting surface having a concave cross section, and a fourth prism having a V-shaped convex refracting surface complementary to the refracting surface having the concave cross section of the third prism.
The illumination optical device according to claim 15, further comprising a second axicon system having a prism. 17. An illumination optical apparatus according to claim 1, and a projection optical system for projecting and exposing a pattern of a mask arranged on the surface to be illuminated onto a photosensitive substrate. The exposure apparatus is characterized in that 18. A mask is illuminated through the illumination optical device according to claim 1, and an image of a pattern formed on the illuminated mask is projected and exposed on a photosensitive substrate. An exposure method characterized by the above.