WO2010061674A1 - Correction unit, illumination optical system, exposure device, and device manufacturing method - Google Patents

Abstract

An illumination optical system capable of almost homogeneously adjusting each pupil intensity distribution at each point on a surface to be irradiated.  A correction unit (9) for correcting the pupil intensity distribution formed on the illumination pupil of the illumination optical system is provided with a first substrate (91) and a second substrate (92) which is arranged behind the first substrate (91), wherein a first extinction pattern is formed on an ejection surface (91b) of the first substrate, and wherein a second extinction pattern is formed on an incidence surface (92a) of the second substrate correspondingly to the first extinction pattern.  The correction unit (9) is configured in such a manner that the relative position between the first extinction pattern and the second extinction pattern is changeable, and that the extinction rates of the first and second extinction patterns change according to changes in the relative position therebetween and changes in the incidence angle of the light to the first substrate.

Description

Correction unit, illumination optical system, exposure apparatus, and device manufacturing method

The present invention relates to a correction unit, an illumination optical system, an exposure apparatus, and a device manufacturing method. More specifically, the present invention relates to an illumination optical system suitable for an exposure apparatus for manufacturing a device such as a semiconductor element, an imaging element, a liquid crystal display element, and a thin film magnetic head in a lithography process.

In a typical exposure apparatus of this type, a secondary light source (generally an illumination pupil), which is a substantial surface light source composed of a number of light sources, passes through a fly-eye lens as an optical integrator. A predetermined light intensity distribution). Hereinafter, the light intensity distribution in the illumination pupil is referred to as “pupil intensity distribution”. The illumination pupil is a position where the illumination surface becomes the Fourier transform plane of the illumination pupil by the action of the optical system between the illumination pupil and the illumination surface (a mask or a wafer in the case of an exposure apparatus). Defined.

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

In order to accurately transfer the fine pattern of the mask onto the wafer, for example, an annular or multipolar (bipolar, quadrupolar, etc.) pupil intensity distribution is formed to improve the depth of focus and resolution of the projection optical system. The technique to make it is proposed (refer patent document 1).

US Patent Publication No. 2006/0055834

In order to faithfully transfer the fine pattern of the mask onto the wafer, not only the pupil intensity distribution is adjusted to the desired shape, but also the pupil intensity distribution for each point on the wafer as the final irradiated surface is almost uniform. It is necessary to adjust to. If there is a variation in the uniformity of the pupil intensity distribution at each point on the wafer, the line width of the pattern varies from position to position on the wafer, and the fine pattern of the mask has the desired line width over the entire exposure area. It cannot be faithfully transferred onto the wafer.

In addition, regardless of the shape of the pupil intensity distribution formed on the illumination pupil, a pair of regions spaced in a predetermined direction across the optical axis in the pupil intensity distribution for each point on the wafer as the final irradiated surface If the difference in the light intensity is too large, the pattern may be displaced from the desired position and burned.

The present invention has been made in view of the above-described problems, and an object thereof is to provide an illumination optical system capable of adjusting the pupil intensity distribution at each point on the irradiated surface almost uniformly. The present invention also provides an exposure apparatus that can perform good exposure under appropriate illumination conditions using an illumination optical system that adjusts the pupil intensity distribution at each point on the irradiated surface substantially uniformly. The purpose is to provide.

Furthermore, the present invention provides an illumination optical system capable of adjusting a light intensity difference between a pair of regions spaced apart in a predetermined direction across an optical axis in a pupil intensity distribution related to each point on an irradiated surface. With the goal. Further, the present invention provides an appropriate illumination using an illumination optical system that adjusts the light intensity difference between a pair of regions spaced in a predetermined direction across the optical axis in the pupil intensity distribution for each point on the irradiated surface. An object of the present invention is to provide an exposure apparatus capable of performing good exposure under conditions.

In order to solve the above problems, in the first embodiment of the present invention, a correction unit for correcting a pupil intensity distribution formed on an illumination pupil of an illumination optical system,
It is arranged in the illumination pupil space between the optical element having power adjacent to the front side of the illumination pupil and the optical element having power adjacent to the rear side of the illumination pupil, and is arranged on the optical axis of the illumination optical system. A light transmissive first substrate having a predetermined thickness along,
A light transmissive second substrate disposed behind the first substrate in the illumination pupil space and having a predetermined thickness along the optical axis;
The first substrate has a first dimming pattern formed on at least one of a light incident side surface and a light emission side surface;
The second substrate has a second dimming pattern formed corresponding to the first dimming pattern on at least one of a light incident side surface and a light emission side surface;
The relative position of the first dimming pattern and the second dimming pattern can be changed,
The dimming rate due to the first dimming pattern and the second dimming pattern changes according to a change in the relative position between the first substrate and the second substrate and a change in the incident angle of light on the first substrate. The correction unit is configured to be configured to provide a correction unit.

In the second embodiment of the present invention, a correction unit for correcting the pupil intensity distribution formed on the illumination pupil of the illumination optical system,
A first perpendicular to the optical axis of the illumination optical system in an illumination pupil space between an optical element having power adjacent to the front side of the illumination pupil and an optical element having power adjacent to the rear side of the illumination pupil. A first dimming pattern formed on the surface;
A second dimming pattern formed on a second surface parallel to the first surface and positioned rearward of the first surface in the illumination pupil space;
The first dimming pattern has at least one first unit dimming region;
The second dimming pattern has at least one second unit dimming region formed corresponding to the at least one first unit dimming region,
A correction unit is provided in which a part of the first unit dimming region and a part of the second unit dimming region overlap each other when viewed from the optical axis direction.

In the third aspect of the present invention, a correction unit for correcting the pupil intensity distribution formed on the illumination pupil of the illumination optical system,
It is arranged in an illumination pupil space between an optical element having power adjacent to the front side of the illumination pupil and an optical element having power adjacent to the rear side of the illumination pupil, and is arranged on the optical axis of the illumination optical system. A light transmissive first substrate having a predetermined thickness along,
A light transmissive second substrate disposed behind the first substrate in the illumination pupil space and having a predetermined thickness along the optical axis;
The first substrate has a first dimming pattern formed on at least one of a light incident side surface and a light emission side surface;
The second substrate has a second dimming pattern formed on at least one of a light incident side surface and a light emission side surface;
The first dimming pattern has at least one first unit dimming region;
The second dimming pattern has at least one second unit dimming region formed corresponding to the at least one first unit dimming region,
The first substrate and the second substrate are configured to be relatively movable along a first direction crossing the optical axis. The correction unit is provided.

In the fourth embodiment of the present invention, a correction unit for correcting the pupil intensity distribution formed on the illumination pupil of the illumination optical system,
It is arranged in an illumination pupil space between an optical element having power adjacent to the front side of the illumination pupil and an optical element having power adjacent to the rear side of the illumination pupil, and is arranged on the optical axis of the illumination optical system. A light transmissive first substrate having a predetermined thickness along,
A light transmissive second substrate disposed behind the first substrate in the illumination pupil space and having a predetermined thickness along the optical axis;
The first substrate has a first dimming pattern formed on at least one of a light incident side surface and a light emission side surface;
The second substrate has a second dimming pattern formed on at least one of a light incident side surface and a light emission side surface;
The first dimming pattern has at least one first unit dimming region;
The second dimming pattern has at least one second unit dimming region formed corresponding to the at least one first unit dimming region,
The first unit dimming region and the second unit dimming region give a first dimming rate to light incident on the first unit dimming region at a first incident angle, and Giving a second light attenuation rate different from the first light attenuation rate to light incident at a second incident angle different from the first angle of incidence on the one unit light attenuation region;
The correction unit is characterized in that the positional relationship between the first substrate and the second substrate can be changed.

In the fifth embodiment of the present invention, in the illumination optical system that illuminates the illuminated surface with light from the light source,
A distribution forming optical system having an optical integrator and forming a pupil intensity distribution in an illumination pupil on the rear side of the optical integrator;
An illumination optical system comprising: a correction unit according to any one of the first to fourth embodiments arranged in the illumination pupil space including the rear illumination pupil.

In the sixth aspect of the present invention, in the illumination optical system that illuminates the illuminated surface with light from the light source,
A distribution forming optical system having an optical integrator and forming a pupil intensity distribution in an illumination pupil on the rear side of the optical integrator;
A correction unit according to any one of the first to fourth embodiments arranged in the illumination pupil space including the rear illumination pupil,
The optical integrator has an elongated rectangular unit wavefront dividing surface along a predetermined direction, and the predetermined direction corresponds to a first direction in the correction unit.

According to a seventh aspect of the present invention, there is provided an exposure apparatus comprising the illumination optical system according to the fifth or sixth aspect for illuminating a predetermined pattern, and exposing the predetermined pattern onto a photosensitive substrate. To do.

In the eighth embodiment of the present invention, an exposure step of exposing the predetermined pattern to the photosensitive substrate using the exposure apparatus of the seventh embodiment;
Developing the photosensitive substrate to which the predetermined pattern is transferred, and forming a mask layer having a shape corresponding to the predetermined pattern on the surface of the photosensitive substrate;
And a processing step of processing the surface of the photosensitive substrate through the mask layer.

The illumination optical system according to the first embodiment of the present invention includes a correction unit that is arranged in an illumination pupil space including an illumination pupil on the rear side of the optical integrator and corrects a pupil intensity distribution formed in the illumination pupil. The correction unit includes a first substrate on which a first dimming pattern is formed, and a second substrate disposed on the rear side thereof and on which a second dimming pattern is formed, and the first dimming pattern and the second dimming pattern are provided. The relative position to the pattern can be changed. Further, the correction unit has a dimming rate by the first dimming pattern and the second dimming pattern in accordance with a change in the relative position between the first substrate and the second substrate and a change in the incident angle of the light to the first substrate. It is configured to change.

As a result, the dimming action of the correction unit can independently adjust the pupil intensity distribution for each point on the irradiated surface, and consequently the pupil intensity distribution for each point is adjusted to a distribution having substantially the same properties. It is possible. Therefore, in the illumination optical system according to the first aspect of the present invention, for example, the density filter that uniformly adjusts the pupil intensity distribution at each point on the irradiated surface and the pupil intensity distribution at each point are independently adjusted. Due to the cooperative action with the correction unit, the pupil intensity distribution at each point on the irradiated surface can be adjusted substantially uniformly. In the exposure apparatus of the present invention, it is possible to perform good exposure under appropriate illumination conditions using an illumination optical system that adjusts the pupil intensity distribution at each point on the irradiated surface almost uniformly. And by extension, a good device can be manufactured.

The illumination optical system according to the third embodiment of the present invention includes a correction unit including a pair of substrates disposed immediately before or immediately after the illumination pupil on the rear side of the optical integrator. At least one first unit attenuation region is formed on the incident surface or exit surface of the first substrate, and at least one second unit attenuation region is formed on the incident surface or exit surface of the second substrate corresponding to the first unit attenuation region. A unit dimming region is formed. For example, the first substrate and the second substrate are configured to be relatively movable along the long side direction of the unit wavefront dividing surface of the optical integrator.

With this configuration, the correction unit realizes various dimming rate characteristics in which the dimming rate varies according to various modes along a predetermined direction of the irradiated surface. Therefore, in the illumination optical system according to the third embodiment of the present invention, a pair of pupil intensity distributions related to each point on the irradiated surface are spaced apart in a predetermined direction across the optical axis by various dimming effects of the correction unit. The light intensity difference in the region can be adjusted. Further, in the exposure apparatus of the present invention, using an illumination optical system that adjusts the light intensity difference between a pair of regions spaced in a predetermined direction across the optical axis in the pupil intensity distribution for each point on the irradiated surface, Good exposure can be performed under appropriate illumination conditions, and thus a good device can be manufactured.

1 is a drawing schematically showing a configuration of an exposure apparatus according to a first embodiment of the present invention. It is a figure which shows the quadrupolar secondary light source formed in an illumination pupil in 1st Embodiment. It is a figure which shows the rectangular-shaped static exposure area | region formed on a wafer in each embodiment. It is a figure explaining the property of the quadrupole pupil intensity distribution which the light which injects into the center point P1 in a still exposure area | region in 1st Embodiment forms. It is a figure explaining the property of quadrupole pupil intensity distribution which the light which injects into the peripheral points P2 and P3 in a still exposure area | region in 1st Embodiment forms. (A) shows the light intensity distribution along the Z direction of the pupil intensity distribution related to the center point P1 in the first embodiment, and (b) shows the light intensity distribution along the Z direction of the pupil intensity distribution related to the peripheral points P2 and P3 in the first embodiment. It is a figure which shows typically light intensity distribution. It is the 1st figure showing roughly the composition of the amendment unit of a 1st embodiment. It is a 2nd figure which shows schematically the structure of the correction | amendment unit of 1st Embodiment. It is a 3rd figure which shows schematically the structure of the correction | amendment unit of 1st Embodiment. It is a 1st figure explaining the basic effect | action of the correction | amendment unit of 1st Embodiment. It is a 2nd figure explaining the basic effect | action of the correction | amendment unit of 1st Embodiment. It is a 3rd figure explaining the basic effect | action of the correction | amendment unit of 1st Embodiment. It is a 4th figure explaining the basic effect | action of the correction | amendment unit of 1st Embodiment. It is a figure which shows typically a mode that the pupil intensity distribution regarding the center point P1 is adjusted by the correction unit in 1st Embodiment. It is a figure which shows typically a mode that the pupil intensity distribution regarding the peripheral points P2, P3 is adjusted by the correction unit in the first embodiment. It is the 1st figure showing roughly the composition of the amendment unit concerning the modification of a 1st embodiment. 16A shows a state where a plurality of light-shielding linear regions are formed on the first substrate of the correction unit according to the modification of FIG. 16, and FIG. 9B shows a plurality of light-shielding linear regions on the second substrate. It is a figure which shows a mode that is formed. It is a 1st figure explaining the basic effect | action of the correction | amendment unit concerning the modification of FIG. It is the 2nd figure explaining the fundamental effect | action of the correction | amendment unit concerning the modification of FIG. It is the 3rd figure explaining the fundamental effect | action of the correction | amendment unit concerning the modification of FIG. It is a figure which shows schematically the structure of the exposure apparatus concerning 2nd Embodiment of this invention. It is a figure which shows the quadrupolar secondary light source formed in an illumination pupil in 2nd Embodiment. It is a figure explaining the property of quadrupole pupil intensity distribution which the light which injects into the peripheral point P2 in a still exposure area | region in 2nd Embodiment forms. It is a figure explaining the property of quadrupole pupil intensity distribution which the light which injects into the peripheral point P3 in a still exposure area | region in 2nd Embodiment forms. It is the 1st figure showing roughly the composition of the amendment unit of a 2nd embodiment. It is a 2nd figure which shows schematically the structure of the correction | amendment unit of 2nd Embodiment. It is a 3rd figure which shows schematically the structure of the correction | amendment unit of 2nd Embodiment. It is a 1st figure explaining the basic effect | action of the correction | amendment unit of 2nd Embodiment. It is a 2nd figure explaining the basic effect | action of the correction | amendment unit of 2nd Embodiment. It is a 3rd figure explaining the basic effect | action of the correction | amendment unit of 2nd Embodiment. It is a figure explaining the relationship between the 1st relative position of the 2nd substrate and the 3rd substrate to the 1st substrate in the 2nd embodiment, and the dimming effect of a correction unit. It is a figure which shows typically the magnitude | size of the light reduction effect which the correction | amendment unit of FIG. 31 exerts on a pair of surface light source. The figure which shows typically the magnitude | size of the dimming effect which a correction unit exerts on a pair of surface light source when a 2nd board | substrate and a 3rd board | substrate are set to the 2nd relative position with respect to a 1st board | substrate in 2nd Embodiment. It is. The figure which shows typically the magnitude | size of the dimming effect which a correction unit exerts on a pair of surface light source when a 2nd board | substrate and a 3rd board | substrate are set to the 3rd relative position with respect to a 1st board | substrate in 2nd Embodiment. It is. It is a figure which shows typically a mode that the pupil intensity distribution regarding the peripheral point P2 is adjusted by the correction unit in 2nd Embodiment. It is a figure which shows typically a mode that the pupil intensity distribution regarding the peripheral point P3 is adjusted by the correction unit in 2nd Embodiment. It is a flowchart which shows the manufacturing process of a semiconductor device. It is a flowchart which shows the manufacturing process of liquid crystal devices, such as a liquid crystal display element.

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a drawing schematically showing a configuration of an exposure apparatus according to the first embodiment of the present invention. In FIG. 1, the Z axis along the normal direction of the exposure surface (transfer surface) of the wafer W, which is a photosensitive substrate, and the Y axis in the direction parallel to the paper surface of FIG. In the W exposure plane, the X axis is set in a direction perpendicular to the paper surface of FIG.

Referring to FIG. 1, exposure light (illumination light) is supplied from a light source 1 in the exposure apparatus of the first embodiment. As the light source 1, for example, an ArF excimer laser light source that supplies light with a wavelength of 193 nm, a KrF excimer laser light source that supplies light with a wavelength of 248 nm, or the like can be used. The light beam emitted from the light source 1 enters the afocal lens 4 via the shaping optical system 2 and the diffractive optical element 3 for annular illumination. The shaping optical system 2 has a function of converting a substantially parallel light beam from the light source 1 into a substantially parallel light beam having a predetermined rectangular cross section and guiding it to the diffractive optical element 3.

The afocal lens 4 is set so that the front focal position thereof and the position of the diffractive optical element 3 substantially coincide with each other, and the rear focal position thereof substantially coincides with the position of the predetermined plane IP indicated by a broken line in the drawing. System (non-focal optical system). The diffractive optical element 3 is formed by forming a step having a pitch of about the wavelength of exposure light (illumination light) on the substrate, and has a function of diffracting an incident beam to a desired angle. Specifically, the diffractive optical element 3 for annular illumination has a function of forming an annular light intensity distribution in the far field (or Fraunhofer diffraction region) when a parallel light beam having a rectangular cross section is incident. Have.

Therefore, the substantially parallel light beam incident on the diffractive optical element 3 forms an annular light intensity distribution on the pupil plane of the afocal lens 4 and then exits from the afocal lens 4 with an annular angular distribution. In the optical path between the front lens group 4a and the rear lens group 4b of the afocal lens 4, a density filter 5 and a conical axicon system 6 are disposed at or near the pupil position. The density filter 5 has a form of a plane parallel plate, and a dense pattern of light-shielding dots made of chromium, chromium oxide or the like is formed on the optical surface thereof. That is, the density filter 5 has a transmittance distribution with different transmittances depending on the incident position of light. The specific operation of the density filter 5 and the configuration and operation of the conical axicon system 6 will be described later.

The light passing through the afocal lens 4 passes through a zoom lens 7 for varying a σ value (σ value = mask-side numerical aperture of the illumination optical system / mask-side numerical aperture of the projection optical system), and is a micro fly as an optical integrator. The light enters the eye lens (or fly eye lens) 8. The micro fly's eye lens 8 is, for example, an optical element composed of a large number of micro lenses having positive refracting power arranged vertically and horizontally and densely, and by performing etching treatment on a parallel plane plate, a micro lens group is formed. It is configured.

Each micro lens constituting the micro fly's eye lens is smaller than each lens element constituting the fly eye lens. Further, unlike a fly-eye lens composed of lens elements isolated from each other, a micro fly-eye lens is formed integrally with a large number of micro lenses (micro refractive surfaces) without being isolated from each other. However, the micro fly's eye lens is the same wavefront division type optical integrator as the fly eye lens in that lens elements having positive refractive power are arranged vertically and horizontally. As the micro fly's eye lens 8, for example, a cylindrical micro fly's eye lens can be used. The configuration and action of the cylindrical micro fly's eye lens are disclosed in, for example, US Pat. No. 6,913,373.

The position of the predetermined plane IP is disposed at or near the front focal position of the zoom lens 7, and the incident surface of the micro fly's eye lens 8 is disposed at or near the rear focal position of the zoom lens 7. In other words, the zoom lens 7 arranges the predetermined plane IP and the incident surface of the micro fly's eye lens 8 substantially in a Fourier transform relationship, and consequently the pupil surface of the afocal lens 4 and the incident surface of the micro fly's eye lens 8. Are arranged almost conjugate optically.

Therefore, on the incident surface of the micro fly's eye lens 8, for example, an annular illumination field centered on the optical axis AX is formed in the same manner as the pupil surface of the afocal lens 4. The overall shape of the annular illumination field changes in a similar manner depending on the focal length of the zoom lens 7. The entrance surface (that is, the unit wavefront dividing surface) of each microlens in the micro fly's eye lens 8 is, for example, a rectangular shape having a long side along the Y direction and a short side along the X direction. It has a rectangular shape similar to the shape of the illumination area to be formed above (and thus the shape of the exposure area to be formed on the wafer W).

The light beam incident on the micro fly's eye lens 8 is two-dimensionally divided, and an illumination field formed on the incident surface of the micro fly's eye lens 8 at the rear focal plane or a position in the vicinity thereof (and hence the position of the illumination pupil). A secondary light source having substantially the same light intensity distribution as the light source, that is, a secondary light source (pupil intensity distribution) composed of a ring-shaped substantial surface light source centered on the optical axis AX. A correction unit 9 is disposed at or near the rear focal plane of the micro fly's eye lens 8. The configuration and operation of the correction unit 9 will be described later.

An illumination aperture stop (not shown) having a ring-shaped opening (light transmitting part) corresponding to a ring-shaped secondary light source on the rear focal plane of the micro fly's eye lens 8 or in the vicinity thereof if necessary. ) Is arranged. The illumination aperture stop is configured to be detachable with respect to the illumination optical path, and is configured to be switchable with a plurality of aperture stops having apertures having different sizes and shapes. As an aperture stop switching method, for example, a well-known turret method or slide method can be used. The illumination aperture stop is disposed at a position optically conjugate with an entrance pupil plane of the projection optical system PL described later, and defines a range that contributes to illumination of the secondary light source.

The light that has passed through the micro fly's eye lens 8 and the correction unit 9 illuminates the mask blind 11 in a superimposed manner via the condenser optical system 10. Thus, a rectangular illumination field corresponding to the shape and focal length of the microlens of the micro fly's eye lens 8 is formed on the mask blind 11 as an illumination field stop. The light that has passed through the rectangular opening (light transmission portion) of the mask blind 11 passes through the imaging optical system 12 including the front lens group 12a and the rear lens group 12b, and the mask M on which a predetermined pattern is formed. Are illuminated in a superimposed manner. That is, the imaging optical system 12 forms an image of the rectangular opening of the mask blind 11 on the mask M.

A pattern to be transferred is formed on the mask M held on the mask stage MS, and a rectangular shape having a long side along the Y direction and a short side along the X direction in the entire pattern region ( The pattern area of the slit shape is illuminated. The light transmitted through the pattern area of the mask M forms an image of the mask pattern on the wafer (photosensitive substrate) W held on the wafer stage WS via the projection optical system PL. That is, a rectangular stationary image having a long side along the Y direction and a short side along the X direction on the wafer W so as to optically correspond to the rectangular illumination area on the mask M. A pattern image is formed in the exposure area (effective exposure area).

Thus, according to the so-called step-and-scan method, the mask stage MS and the wafer stage WS along the X direction (scanning direction) in the plane (XY plane) orthogonal to the optical axis AX of the projection optical system PL, As a result, by moving (scanning) the mask M and the wafer W synchronously, the wafer W has a width equal to the dimension in the Y direction of the static exposure region and corresponds to the scanning amount (movement amount) of the wafer W. A mask pattern is scanned and exposed to a shot area (exposure area) having a length.

The conical axicon system 6 includes, in order from the light source side, a first prism member 6a having a flat surface facing the light source side and a concave conical refractive surface facing the mask side, and a convex conical shape facing the plane toward the mask side and the light source side. And a second prism member 6b facing the refractive surface. The concave conical refracting surface of the first prism member 6a and the convex conical refracting surface of the second prism member 6b are complementarily formed so as to be in contact with each other. Further, at least one of the first prism member 6a and the second prism member 6b is configured to be movable along the optical axis AX, and the interval between the first prism member 6a and the second prism member 6b is configured to be variable. Has been.

Here, in a state where the first prism member 6a and the second prism member 6b are in contact with each other, the conical axicon system 6 functions as a plane parallel plate and has no effect on the annular secondary light source formed. . However, if the first prism member 6a and the second prism member 6b are separated from each other, the width of the annular secondary light source (1/2 of the difference between the outer diameter and the inner diameter of the annular secondary light source) becomes constant. While maintaining, the outer diameter (inner diameter) of the annular secondary light source changes. That is, the annular ratio (inner diameter / outer diameter) and size (outer diameter) of the annular secondary light source change.

The zoom lens 7 has a function of enlarging or reducing the entire shape of the annular secondary light source in a similar manner. For example, by enlarging the focal length of the zoom lens 7 from a minimum value to a predetermined value, the entire shape of the annular secondary light source is similarly enlarged. In other words, due to the action of the zoom lens 7, both the width and size (outer diameter) change without changing the annular ratio of the annular secondary light source. As described above, the annular ratio and size (outer diameter) of the annular secondary light source can be controlled by the action of the conical axicon system 6 and the zoom lens 7.

In the first embodiment, as described above, the secondary light source formed by the micro fly's eye lens 8 is used as a light source, and the mask M arranged on the irradiated surface of the illumination optical system (2 to 12) is Koehler illuminated. For this reason, the position where the secondary light source is formed is optically conjugate with the position of the aperture stop AS of the projection optical system PL, and the formation surface of the secondary light source is the illumination pupil plane of the illumination optical system (2 to 12). Can be called. Typically, the irradiated surface (the surface on which the mask M is disposed or the surface on which the wafer W is disposed when the illumination optical system including the projection optical system PL is considered) is optical with respect to the illumination pupil plane. A Fourier transform plane.

The pupil intensity distribution is a light intensity distribution (luminance distribution) on the illumination pupil plane of the illumination optical system (2 to 12) or a plane optically conjugate with the illumination pupil plane. When the number of wavefront divisions by the micro fly's eye lens 8 is relatively large, the overall light intensity distribution formed on the incident surface of the micro fly's eye lens 8 and the overall light intensity distribution of the entire secondary light source (pupil intensity distribution). ) And a high correlation. For this reason, the light intensity distribution on the incident surface of the micro fly's eye lens 8 and the surface optically conjugate with the incident surface can also be referred to as a pupil intensity distribution. In the configuration of FIG. 1, the diffractive optical element 3, the afocal lens 4, the zoom lens 7, and the micro fly's eye lens 8 are distribution forming optics that form a pupil intensity distribution in the illumination pupil behind the micro fly's eye lens 8. The system is configured.

In place of the diffractive optical element 3 for annular illumination, a plurality of diffractive optical elements (not shown) for multipole illumination (dipole illumination, quadrupole illumination, octupole illumination, etc.) are set in the illumination optical path. Polar lighting can be performed. A diffractive optical element for multipole illumination forms a light intensity distribution of multiple poles (bipolar, quadrupole, octupole, etc.) in the far field when a parallel light beam having a rectangular cross section is incident. It has the function to do. Accordingly, the light beam that has passed through the diffractive optical element for multipole illumination is incident on the incident surface of the micro fly's eye lens 8 from, for example, an illumination field having a plurality of predetermined shapes (arc shape, circular shape, etc.) centered on the optical axis AX. To form a multipolar illuminator. As a result, the same multipolar secondary light source as the illumination field formed on the incident surface is also formed on or near the rear focal plane of the micro fly's eye lens 8.

Also, instead of the diffractive optical element 3 for annular illumination, a normal circular illumination can be performed by setting a diffractive optical element (not shown) for circular illumination in the illumination optical path. The diffractive optical element for circular illumination has a function of forming a circular light intensity distribution in the far field when a parallel light beam having a rectangular cross section is incident. Therefore, the light beam that has passed through the diffractive optical element for circular illumination forms, for example, a circular illumination field around the optical axis AX on the incident surface of the micro fly's eye lens 8. As a result, a secondary light source having the same circular shape as the illumination field formed on the incident surface is also formed on or near the rear focal plane of the micro fly's eye lens 8. Also, instead of the diffractive optical element 3 for annular illumination, various forms of modified illumination can be performed by setting a diffractive optical element (not shown) having appropriate characteristics in the illumination optical path. As a switching method of the diffractive optical element 3, for example, a known turret method or slide method can be used.

In the following description, in order to facilitate understanding of the operational effects of the first embodiment, the illumination pupil in the rear focal plane of the micro fly's eye lens 8 or in the vicinity thereof has four arc shapes as shown in FIG. It is assumed that a quadrupole pupil intensity distribution (secondary light source) 20 composed of a substantial surface light source (hereinafter simply referred to as “surface light source”) 20a, 20b, 20c and 20d is formed. Further, it is assumed that the correction unit 9 is arranged on the rear side (mask side) from the formation surface of the quadrupole pupil intensity distribution 20. Further, in the following description, the term “illumination pupil” simply refers to the illumination pupil in the rear focal plane of the micro fly's eye lens 8 or in the vicinity thereof.

Referring to FIG. 2, a quadrupole pupil intensity distribution 20 formed on the illumination pupil has a pair of surface light sources 20a and 20b spaced apart in the X direction across the optical axis AX, and the optical axis AX. A pair of arc-shaped substantial surface light sources 20c and 20d spaced apart in the Y direction. The X direction in the illumination pupil is the short side direction of the rectangular microlens of the micro fly's eye lens 8 (the short side direction of the rectangular unit wavefront dividing surface) and corresponds to the scanning direction of the wafer W. . Further, the Y direction in the illumination pupil is the long side direction of the rectangular microlens of the micro fly's eye lens 8 (the long side direction of the unit wavefront dividing surface), and the scanning orthogonal direction (perpendicular to the scanning direction of the wafer W) Corresponding to the Y direction on the wafer W).

On the wafer W, as shown in FIG. 3, a rectangular still exposure region ER having a long side along the Y direction and a short side along the X direction is formed. Correspondingly, a rectangular illumination area (not shown) is formed on the mask M. Here, the quadrupole pupil intensity distribution formed on the illumination pupil by light incident on one point in the still exposure region ER has substantially the same shape without depending on the position of the incident point. However, the light intensity of each surface light source constituting the quadrupole pupil intensity distribution tends to differ depending on the position of the incident point.

Specifically, as shown in FIG. 4, in the case of a quadrupole pupil intensity distribution 21 formed by light incident on the center point P <b> 1 in the still exposure region ER, the surface light sources 21 c spaced apart in the Y direction and The light intensity of 21d tends to be higher than the light intensity of the surface light sources 21a and 21b spaced apart in the X direction. On the other hand, as shown in FIG. 5, in the case of a quadrupole pupil intensity distribution 22 formed by light incident on peripheral points P2 and P3 spaced from the central point P1 in the still exposure region ER in the Y direction, The light intensities of the surface light sources 22c and 22d spaced in the Y direction tend to be smaller than the light intensities of the surface light sources 22a and 22b spaced in the X direction.

In general, regardless of the outer shape of the pupil intensity distribution formed on the illumination pupil, the pupil intensity distribution related to the center point P1 in the still exposure region ER on the wafer W (the pupil formed on the illumination pupil by the light incident on the center point P1). As shown in FIG. 6A, the light intensity distribution along the Y direction (intensity distribution) of the intensity distribution has a concave curve distribution that is smallest at the center and increases toward the periphery. On the other hand, the light intensity distribution along the Y direction of the pupil intensity distribution related to the peripheral points P2 and P3 in the static exposure region ER on the wafer W is the largest at the center and toward the periphery as shown in FIG. It has a decreasing convex curve distribution.

The light intensity distribution along the Y direction of the pupil intensity distribution does not depend much on the position of the incident point along the X direction (scanning direction) in the still exposure region ER, but the Y direction in the still exposure region ER. There is a tendency to change depending on the position of the incident point along the (scanning orthogonal direction). As described above, when the pupil intensity distribution (pupil intensity distribution formed on the illumination pupil by the light incident on each point) on each point in the still exposure region ER on the wafer W is not substantially uniform, for each position on the wafer W. Further, the line width of the pattern varies, and the fine pattern of the mask M cannot be faithfully transferred onto the wafer W with a desired line width over the entire exposure region.

In the first embodiment, as described above, the density filter 5 having a transmittance distribution with different transmittance according to the incident position of light is disposed at or near the pupil position of the afocal lens 4. The pupil position of the afocal lens 4 is optically conjugate with the incident surface of the micro fly's eye lens 8 by the rear lens group 4b and the zoom lens 7. Therefore, the light intensity distribution formed on the entrance surface of the micro fly's eye lens 8 is adjusted (corrected) by the action of the density filter 5 and, as a result, formed on the rear focal plane of the micro fly's eye lens 8 or the illumination pupil near it. The pupil intensity distribution to be adjusted is also adjusted.

However, the density filter 5 uniformly adjusts the pupil intensity distribution for each point in the static exposure region ER on the wafer W without depending on the position of each point. As a result, by the action of the density filter 5, for example, adjustment is made so that the quadrupole pupil intensity distribution 21 with respect to the center point P1 becomes substantially uniform, so that the light intensities of the surface light sources 21a to 21d become substantially equal to each other. In this case, however, the difference in light intensity between the surface light sources 22a and 22b and the surface light sources 22c and 22d in the quadrupole pupil intensity distribution 22 with respect to the peripheral points P2 and P3 becomes larger.

That is, in order to adjust the pupil intensity distribution for each point in the still exposure region ER on the wafer W almost uniformly by the action of the density filter 5, the pupil intensity for each point can be adjusted by means other than the density filter 5. It is necessary to adjust the distribution to distributions having the same properties. Specifically, for example, in the pupil intensity distribution 21 related to the center point P1 and the pupil intensity distribution 22 related to the peripheral points P2 and P3, the magnitude relationship between the light intensities of the surface light sources 21a and 21b and the surface light sources 21c and 21d and the surface light sources 22a and 22a. It is necessary to match the magnitude relationship of the light intensity between 22b and the surface light sources 22c and 22d at substantially the same ratio.

In the first embodiment, in order to substantially match the properties of the pupil intensity distribution related to the center point P1 and the properties of the pupil intensity distribution related to the peripheral points P2 and P3, the surface light sources 22a, A correction unit 9 is provided as an adjusting means for adjusting the light intensity of 22b to be smaller than the light intensity of the surface light sources 22c and 22d. As shown in FIGS. 7 and 8, the correction unit 9 includes a pair of light transmissive substrates 91 and 92 having a predetermined thickness along the optical axis AX (corresponding to the Z direction). Each of the substrates 91 and 92 has a form of a plane parallel plate formed of an optical material such as quartz or fluorite.

The first substrate 91 has, for example, a circular outer shape centered on the optical axis AX, and is fixedly positioned in such a posture that its incident surface 91a is orthogonal to the optical axis AX. The second substrate 92 is disposed on the rear side (mask side) of the first substrate 91 and has, for example, a circular outer shape centered on the optical axis AX. Further, the second substrate 92 is configured to be movable in the optical axis AX direction (Z direction) while maintaining the posture in which the incident surface 92a is orthogonal to the optical axis AX. In the correction unit 9, the second substrate 92 moves in the optical axis AX direction based on a command from the drive control system 99. The second substrate 92 is fixedly positioned and the first substrate 91 is configured to be movable in the optical axis AX direction, or both the substrates 91 and 92 are configured to be movable in the optical axis AX direction. You can also.

Referring to FIG. 9, light-shielding dots 51a, 51b and 52a, 52b having the same outer shape and the same size are formed on the exit surface 91b of the substrate 91 and the incident surface 92a of the substrate 92 according to a predetermined distribution. Has been. Here, each light-shielding dot 51a, 51b, 52a, 52b as a unit dimming region is made of, for example, chromium or chromium oxide. The light shielding dots 52a are distributed so as to correspond to the light shielding dots 51a on a one-to-one basis, and the light shielding dots 52b are distributed so as to correspond to the light shielding dots 51b on a one-on-one basis.

Here, the group of light shielding dots 51a and the group of light shielding dots 52a are arranged so as to act on the light from the surface light source 20a, and the group of light shielding dots 51b and the group of light shielding dots 52b are from the surface light source 20b. It arrange | positions so that it may act on light. In FIG. 9, for the sake of clarity, the pair of light shielding dots 51 a and 51 b formed on the exit surface 91 b of the substrate 91 and the pair of light shielding dots 52 a and 52 b formed on the incident surface 92 a of the substrate 92. Only shows.

Hereinafter, in order to facilitate understanding of the description, each of the light shielding dots 51a, 51b, 52a, 52b has a circular outer shape, and the light shielding dots 51a and 52a overlap each other when viewed from the optical axis AX direction. It is assumed that the light shielding dots 51b and 52b overlap each other when viewed from the optical axis AX direction. In order to facilitate understanding of the description, the operation of the correction unit 9 will be described by focusing on only the pair of light shielding dots 51a and 51b on the substrate 91 and the pair of light shielding dots 52a and 52b on the substrate 92. .

In a reference state (reference position) along the optical axis AX direction of the second substrate 92, light that is parallel to the optical axis AX is incident on a combined light-reducing region that is a combination of circular light-shielding dots 51a and 52a. Then, on the surface immediately after the correction unit 9 and parallel to the exit surface 92b, as shown on the left side of FIG. 10 (a), the region 51aa attenuated by the circular light-shielding dot 51a and the circular shape The regions 52aa dimmed by the light shielding dots 52a overlap each other. That is, immediately after the correction unit 9, the circular dimming areas 51aa and 52aa form a dimming area having an area equivalent to one circular dimming area 51aa.

When light parallel to the optical axis AX is incident on the correction unit 9, the second substrate 92 moves in the + Z direction from the reference state, and the distance between the substrates 91 and 92 in the optical axis AX direction, and thus the light shielding dots 51a and 52a. Even if the distance in the optical axis AX direction increases, the dimming regions 51aa and 52aa do not change while overlapping as shown on the right side of FIG. Similarly, when light parallel to the optical axis AX is incident, the illustration is omitted even when the second substrate 92 moves in the −Z direction from the reference state and the distance between the light shielding dots 51a and 52a becomes small. The dimming areas 51aa and 52aa do not change while overlapping.

In the reference state along the optical axis AX direction of the second substrate 92, the angle of the light incident on the combined dimming region composed of the combination of the circular light shielding dots 51a and 52a with respect to the optical axis AX is, for example, along the YZ plane. As shown on the left side of FIG. 10 (b), the dimming areas 51aa and 52aa move in the Z direction by different distances immediately after the correction unit 9, and the dimming areas 51aa and The overlapping area with 52aa monotonously decreases. As a result, in the state shown on the left side of FIG. 10B, the circular dimming regions 51aa and 52aa are larger than the area of one circular dimming region 51aa according to the area of the overlapping region. And a dimming region having an area smaller than the area of two.

When the second substrate 92 moves in the + Z direction from the state shown on the left side of FIG. 10B and the distance between the light shielding dots 51a and 52a monotonously increases, as shown on the right side of FIG. 10B, The overlapping area between the dimming areas 51aa and 52aa monotonously decreases, and the area of the dimming area formed by the dimming areas 51aa and 52aa monotonously increases. Also, from the state shown on the left side of FIG. 10B, when the second substrate 92 moves in the −Z direction and the distance between the light shielding dots 51a and 52a monotonously decreases, the illustration is omitted. The overlapping area of 51aa and 52aa increases monotonously, and the area of the dimming area formed by the dimming areas 51aa and 52aa monotonously decreases.

Thus, in the correction unit 9, when the distance between the substrates 91 and 92 in the optical axis AX direction is constant, the combined dimming region composed of the circular light-shielding dots 51 a and 52 a is used to transmit light to the first substrate 91. It exhibits a dimming effect in which the dimming rate increases as the incident angle increases. This is because the left side of FIG. 11 (a) is compared with the left side of FIG. 11 (b), and the right side of FIG. 11 (a) is compared with the right side of FIG. 11 (b). Is clearer. Similarly, when the distance between the substrates 91 and 92 in the optical axis AX direction is constant, the light attenuation angle of the combined light reduction region composed of the circular light-shielding dots 51b and 52b is also large in the first substrate 91. As it becomes, the dimming effect of increasing the dimming rate is exhibited.

Further, in the correction unit 9, when the incident angle of the light with respect to the first substrate 91 is 0 degree, that is, when the light parallel to the optical axis AX is incident, the combined reduction composed of the circular light shielding dots 51a and 52a is reduced. In the optical region, regardless of the change in the distance between the substrates 91 and 92 in the optical axis AX direction, the light attenuation rate remains unchanged and a relatively small constant light reduction effect is exhibited. This is apparent from a comparison between the left diagram in FIG. 11A and the right diagram in FIG. Similarly, when light parallel to the optical axis AX is incident, the combined dimming region composed of the circular light-shielding dots 51b and 52b is relatively small and constant regardless of the change in the distance between the substrates 91 and 92. Exhibits the dimming effect.

Further, in the correction unit 9, when the incident angle of light with respect to the first substrate 91 is constant (a predetermined value where the incident angle is not 0 degree), the combined dimming region composed of the circular light-shielding dots 51a and 52a is As the distance between the substrates 91 and 92 in the optical axis AX direction increases, the light reduction rate increases. This is apparent from a comparison between the left side of FIG. 11B and the right side of FIG. 11B. Similarly, in the correction unit 9, when the incident angle of light with respect to the first substrate 91 is constant, the combined dimming region composed of the circular light shielding dots 51 b and 52 b is also the optical axis AX of the substrates 91 and 92. It exhibits a dimming effect in which the dimming rate increases as the direction spacing increases.

In the first embodiment, the first substrate 91 and the second substrate 92 are configured to be relatively movable along the optical axis AX direction. In addition, the correction unit 9 includes a pair of surface light sources 20a and 20b spaced apart in the X direction (the short side direction of the unit wavefront dividing surface) across the optical axis AX in the quadrupole pupil intensity distribution 20. It is configured to act on light and not to light from a pair of surface light sources 20c and 20d spaced apart in the Y direction (long side direction of the unit wavefront dividing surface) across the optical axis AX.

Referring now to FIG. 12, the light reaching the center point P1 in the static exposure region ER on the wafer W, that is, the light reaching the center point P1 ′ of the opening of the mask blind 11 is directed to the correction unit 9 ( That is, it is incident on the first substrate 91 at an incident angle of zero. In other words, the light from the surface light sources 21a and 21b of the pupil intensity distribution 21 with respect to the center point P1 enters the first substrate 91 at an incident angle of 0.

On the other hand, as shown in FIG. 13, the light reaching the peripheral points P2 and P3 in the static exposure region ER on the wafer W, that is, the light reaching the peripheral points P2 ′ and P3 ′ of the opening of the mask blind 11 9 is incident at a relatively large incident angle ± θ. In other words, the light from the surface light sources 22a and 22b of the pupil intensity distribution 22 related to the peripheral points P2 and P3 is incident on the first substrate 91 at a relatively large incident angle ± θ.

12 and 13, reference numeral B1 indicates the outermost point along the X direction of the surface light source 20a (21a, 22a), and reference numeral B2 indicates the X direction of the surface light source 20b (21b, 22b). The point of the outermost edge along is shown. In order to facilitate understanding of the explanation related to FIGS. 12 and 13, the outermost point (see FIG. 2 and the like) along the Z direction of the surface light source 20c (21c, 22c) is indicated by reference numeral B3. The point on the outermost edge along the Z direction of the surface light source 20d (21d, 22d) (see FIG. 2 and the like) is indicated by reference numeral B4. However, as described above, the light from the surface light source 20c (21c, 22c) and the surface light source 20d (21d, 22d) is not affected by the correction unit 9.

Thus, in the pupil intensity distribution 21 related to the center point P1, the light from the surface light sources 21a and 21b is subjected to the dimming action of the correction unit 9, but the decrease in the light intensity is relatively small. Since the light from the surface light sources 21c and 21d does not receive the dimming action of the correction unit 9, the light intensity does not change. As a result, as shown in FIG. 14, the pupil intensity distribution 21 related to the center point P1 is adjusted to a pupil intensity distribution 21 ′ having substantially the same properties as the original distribution 21 even if the correction unit 9 receives the dimming action. Only. That is, also in the pupil intensity distribution 21 ′ adjusted by the correction unit 9, the light intensity of the surface light sources 21 c and 21 d spaced apart in the Y direction is higher than that of the surface light sources 21 a ′ and 21 b ′ spaced in the X direction. Properties greater than light intensity are maintained.

On the other hand, in the pupil intensity distribution 22 related to the peripheral points P2 and P3, the light from the surface light sources 22a and 22b is subjected to the dimming action of the correction unit 9, and the light intensity is relatively reduced. Here, the degree of decrease in the intensity of light from the surface light sources 22a and 22b can be adjusted by changing the distance between the substrates 91 and 92 in the correction unit 9. On the other hand, the light from the surface light sources 22c and 22d does not receive the dimming action of the correction unit 9, and therefore the light intensity does not change. As a result, the pupil intensity distribution 22 relating to the peripheral points P2 and P3 is adjusted to a pupil intensity distribution 22 'having a different property from the original distribution 22 by the dimming action of the correction unit 9, as shown in FIG. That is, in the pupil intensity distribution 22 ′ adjusted by the correction unit 9, the light intensity of the surface light sources 22c and 22d spaced in the Y direction is greater than the light of the surface light sources 22a ′ and 22b ′ spaced in the X direction. It changes to a property larger than strength.

Thus, due to the dimming action of the correction unit 9, the pupil intensity distribution 22 relating to the peripheral points P2 and P3 is adjusted to a distribution 22 'having substantially the same properties as the pupil intensity distribution 21' relating to the center point P1. Similarly, the pupil intensity distribution for each point arranged along the Y direction between the center point P1 and the peripheral points P2 and P3, and hence the pupil intensity distribution for each point in the still exposure region ER on the wafer W is also the center. The distribution is adjusted to a distribution having substantially the same property as the pupil intensity distribution 21 ′ relating to the point P1. In other words, the pupil intensity distribution for each point in the still exposure region ER on the wafer W is adjusted to a distribution having substantially the same property by the dimming action of the correction unit 9. In other words, the correction unit 9 has a necessary light attenuation rate characteristic necessary for adjusting the pupil intensity distribution for each point to a distribution having substantially the same property.

As described above, in the correction unit 9 of the first embodiment, a plurality of circular light-shielding dots 51a and 51b are formed on the emission surface 91b of the first substrate 91 as a first dimming pattern according to a predetermined distribution. Has been. A plurality of circular light-shielding dots 52a and 52b are formed on the incident surface of the second substrate 92 as a second dimming pattern so as to have a one-to-one correspondence with the plurality of light-shielding dots 51a and 51b. . The circular light-shielding dots 51a and 52a have the same size and overlap each other when viewed from the optical axis AX direction. Similarly, the circular light-shielding dots 51b and 52b have the same size and overlap each other when viewed from the optical axis AX direction.

Further, the first substrate 91 and the second substrate 92 are configured to be relatively movable along the optical axis AX direction. Therefore, the combined light-reducing region composed of the circular light-shielding dots 51a and 52a and the combined light-reduced region composed of the circular light-shielding dots 51b and 52b have a large incident angle of light due to the so-called parallax effect. As the light attenuation rate increases monotonously as the distance between the substrates 91 and 92 increases, the light attenuation rate monotonously increases. However, when the incident angle of light is 0 degree, the light attenuation rate is constant without depending on the change in the distance between the substrates 91 and 92.

As described above, the correction unit 9 can change the first substrate 91 according to the change in the distance between the first substrate 91 and the second substrate 92 (generally, the change in the relative position) and the change in the incident angle of the light to the first substrate 91. The dimming rate by the dimming pattern (51a, 51b) and the second dimming pattern (52a, 52b) is changed. Further, the correction unit 9 is disposed at a position near the illumination pupil, that is, a position where the position information of the light on the mask M (or wafer W) that is the irradiated surface is converted into the angle information of the light. Therefore, the dimming action of the correction unit 9 of the first embodiment can independently adjust the pupil intensity distribution for each point on the irradiated surface, and consequently the pupil intensity distribution for each point has substantially the same property. It is possible to adjust to the distribution of.

In the illumination optical system (2 to 12) of the first embodiment, the correction unit 9 that independently adjusts the pupil intensity distribution for each point in the still exposure region ER on the wafer W, and the pupil intensity for each point. By the cooperative action with the density filter 5 that uniformly adjusts the distribution, the pupil intensity distribution for each point can be adjusted substantially uniformly. Therefore, in the exposure apparatus (2 to WS) of the first embodiment, the illumination optical system (2 to 12) that adjusts the pupil intensity distribution at each point in the static exposure region ER on the wafer W almost uniformly is used. Thus, good exposure can be performed under appropriate illumination conditions according to the fine pattern of the mask M, and as a result, the fine pattern of the mask M can be formed on the wafer W with a desired line width over the entire exposure region. Can be faithfully transferred.

In the first embodiment, an operation for adjusting the pupil intensity distribution for each point in the still exposure region ER substantially uniformly, and more generally an operation for adjusting the pupil intensity distribution for each point to a required distribution is, for example, a projection. This is performed based on the measurement result of a pupil intensity distribution measuring device (not shown) that measures the pupil intensity distribution on the pupil plane of the projection optical system PL based on light via the optical system PL. The pupil intensity distribution measuring apparatus includes, for example, a CCD imaging unit having an imaging surface disposed at a position optically conjugate with the pupil position of the projection optical system PL, and the pupil intensity relating to each point on the image plane of the projection optical system PL. The distribution (pupil intensity distribution formed on the pupil plane of the projection optical system PL by the light incident on each point) is monitored. For the detailed configuration and operation of the pupil intensity distribution measuring apparatus, reference can be made to US Patent Publication No. 2008/0030707.

Specifically, the measurement result of the pupil intensity distribution measuring device is supplied to a control unit (not shown). The control unit outputs a command to the drive control system 99 of the correction unit 9 so that the pupil intensity distribution on the pupil plane of the projection optical system PL becomes a desired distribution based on the measurement result of the pupil intensity distribution measuring device. The drive control system 99 controls the position of the second substrate 92 in the Z direction based on a command from the control unit, and adjusts the pupil intensity distribution for each point in the still exposure region ER on the wafer W to a required distribution.

In the first embodiment, it is conceivable that the light amount distribution on the wafer (irradiated surface) W is affected by, for example, the dimming action (adjusting action) of the correction unit 9. In this case, the illuminance distribution in the still exposure region ER or the shape of the still exposure region (illumination region) ER can be changed as necessary by the action of the light quantity distribution adjusting unit having a known configuration. Specifically, as the light quantity distribution adjusting unit for changing the illuminance distribution, configurations described in Japanese Patent Application Laid-Open Nos. 2001-313250 and 2002-1000056 (and US Pat. Nos. 6,771,350 and 6927836 corresponding thereto). And techniques can be used. Further, as the light amount distribution adjusting unit for changing the shape of the illumination area, the configuration and method described in the pamphlet of International Patent Publication No. WO2005 / 048326 (and the corresponding US Patent Publication No. 2007/0014112) are used. Can do.

In the above-described first embodiment, the correction unit includes a pair of substrates 91 and 92 having the form of a plane-parallel plate arranged perpendicular to the optical axis AX according to the specific form shown in FIGS. 9 is constituted. Then, circular light-shielding dots 51a and 51b as first dimming patterns are distributed and formed on the emission surface 91b of the first substrate 91, and the second dimming pattern is formed on the incident surface 92a of the second substrate 92. Circular light-shielding dots 52a and 52b are distributed. However, the present invention is not limited to this, and various configurations are possible for the specific configuration of the correction unit 9.

For example, the form of the substrate constituting the correction unit 9 (outer shape, etc.), the posture of the substrate, the number of unit dimming areas forming each dimming pattern, the shape of the unit dimming area, the formation surface of the unit dimming area Various forms are possible with respect to the position (incident surface or exit surface), the distribution form of the unit dimming region, the arrangement position of the correction unit 9, and the like. Specifically, in the first embodiment described above, as the light transmissive substrates 91 and 92, for example, a substrate having at least one surface having a curvature can be used.

Further, in the first embodiment described above, the pair of substrates 91 and 92 are configured to be relatively movable along the optical axis AX direction. However, the present invention is not limited to this, and a correction unit that exhibits the same operation as the correction unit 9 according to the first embodiment described above may be configured by a pair of substrates that can be relatively rotated around the optical axis AX. it can. Referring to FIG. 16, the correction unit 9A according to the modified example of the first embodiment includes a pair of light transmissive substrates 93 and 94 having a predetermined thickness along the optical axis AX. Each of the substrates 93 and 94 is in the form of a plane parallel plate formed of an optical material such as quartz or fluorite.

The first substrate 93 has, for example, a circular outer shape centered on the optical axis AX, and can rotate around the optical axis AX while maintaining a posture in which the incident surface 93a is orthogonal to the optical axis AX. It is configured. The second substrate 94 is disposed on the rear side of the first substrate 93 and has, for example, a circular outer shape centered on the optical axis AX. Further, the second substrate 94 is configured to be rotatable around the optical axis AX while maintaining a posture in which the incident surface 94a is orthogonal to the optical axis AX. In the correction unit 9A, the first substrate 93 and the second substrate 94 rotate around the optical axis AX based on a command from the drive control system 99A.

On the exit surface 93b of the substrate 93, as shown in FIG. 17A, a plurality of light-shielding linear regions 53a and a plurality of light-shielding properties arranged along the circumferential direction of a circle centered on the optical axis AX. The linear region 53b is formed. Further, on the incident surface 94a of the substrate 94, as shown in FIG. 17 (b), a plurality of light-shielding linear regions 54a and a plurality of light-shielding linear regions 54a arranged along the circumferential direction of a circle centered on the optical axis AX. A light-shielding linear region 54b is formed. In FIG. 17A, in order to facilitate understanding of the description, the appearance of the exit surface 93b viewed from the incident surface 93a side of the substrate 93 in the optical axis AX direction is shown. Each linear region 53a, 53b, 54a, 54b as a unit dimming region is made of, for example, chromium or chromium oxide. Further, the linear regions 54a are distributed so as to correspond one-to-one with the linear regions 53a, and the linear regions 54b are distributed so as to correspond one-to-one with the linear regions 53b.

Hereinafter, in order to facilitate understanding of the description, the linear regions 53a, 53b, 54a, 54b have the same shape and size as each other, and are equiangular along the circumferential direction of a circle centered on the optical axis AX. It is assumed that they are arranged and extend radially from the optical axis AX at intervals. Further, at the reference rotation position of the first substrate 93, the group of linear regions 53a are in an angle range of 90 degrees between the + X axis and the + Y axis, and the group of linear regions 53b are -X axis and -Y axis. In the range of angles between. On the other hand, at the reference rotation position of the second substrate 94, the group of linear regions 54a is in an angle range between the + X axis and the −Y axis, and the group of linear regions 54b is between the −X axis and the + Y axis. It is assumed that it is in the angle range.

In the reference state (reference rotation position) of the substrates 93 and 94, as shown in FIG. 18, the group of linear regions 53a, 53b, 54a, 54b are not overlapped with each other when viewed from the optical axis AX direction and in the circumferential direction. Is spaced along. Therefore, the light from the surface light sources 20a to 20d is uniformly reduced by the linear regions 53a, 53b, 54a, and 54b without depending on the incident angle to the correction unit 9A (and thus the substrate 93). In other words, in the reference state of the substrates 93 and 94, the so-called parallax effect is not exhibited, and the dimming action by the linear regions 53a, 53b, 54a, 54b is constant.

When the substrate 93 is rotated from the reference state of FIG. 18 by a predetermined angle counterclockwise in FIG. 18 and the substrate 94 is rotated from the reference state of FIG. 18 by a predetermined angle clockwise in FIG. 18, the thick line is shown in FIG. Thus, for example, the three linear regions 53a and the three linear regions 54a overlap each other when viewed from the optical axis AX direction, and the three linear regions 53b and the three linear regions 54b are viewed from the optical axis AX direction. To overlap each other. In the state shown in FIG. 19, the combined dimming region 55a composed of three linear regions 53a and 54a that overlap each other and the combined dimming region 55b composed of three linear regions 53b and 54b that overlap each other have a so-called parallax effect. As a result, a dimming effect in which the dimming rate monotonously increases as the incident angle of light increases is exhibited. Here, the combined dimming region 55a composed of the three linear regions 53a and 54a acts on the light from the surface light source 20a, and the combined dimming region 55b composed of the three linear regions 53b and 54b is the surface light source 20b. Acts on the light from.

Furthermore, when the substrate 93 is rotated by a predetermined angle counterclockwise in FIG. 18 from the state shown in FIG. 19 and the substrate 94 is rotated by a predetermined angle clockwise in FIG. 18 from the state shown in FIG. As shown in FIG. 5, for example, the five linear regions 53 a and the five linear regions 54 a overlap each other when viewed from the optical axis AX direction, and the five linear regions 53 b and the five linear regions 54 b are in the optical axis AX direction. As a result, the overlapping state can be obtained. That is, the overlapping regions 55a and 55b where the linear regions 53a, 53b, 54a, and 54b overlap when viewed from the optical axis AX direction are larger than the state shown in FIG. In the state shown in FIG. 20, the combined dimming region 55a composed of the five linear regions 53a and 54a and the combined dimming region 55b composed of the five linear regions 53b and 54b increase as the incident angle of light increases. Demonstrates a dimming effect in which the dimming rate increases monotonously.

As described above, in the correction unit 9A, the first dimming pattern (53a, 53b) and the second dimming pattern are changed according to the change in the relative rotational position of the first substrate 93 and the second substrate 94 around the optical axis AX. The size of the overlapping regions 55a and 55b where the light patterns (54a and 54b) overlap with each other when viewed from the optical axis AX direction is changed. In the correction unit 9A, when the incident angle of light with respect to the first substrate 93 is constant, the overlapping regions 55a and 55b between the first dimming pattern (53a and 53b) and the second dimming pattern (54a and 54b) are large. As it becomes, the dimming effect of increasing the dimming rate is exhibited.

That is, in the correction unit 9A, the first dimming pattern (in accordance with the change in the relative position of the first substrate 93 and the second substrate 94 around the optical axis AX and the change in the incident angle of the light to the first substrate 93). 53a, 53b) and the second light attenuation pattern (54a, 54b) change the light attenuation rate. Accordingly, as in the case of the first embodiment described above, the pupil intensity distribution for each point in the still exposure region ER on the wafer W is independently determined by the dimming action of the correction unit 9A according to the modification of FIG. It is possible to adjust the pupil intensity distribution for each point to distributions having substantially the same properties.

In the modification of FIG. 16, both the substrates 93 and 94 are rotated around the optical axis AX. However, the present invention is not limited to this, and at least one of the substrates 93 and 94 is rotated around the optical axis AX. The correction unit can also be configured by rotating. Further, in the modification of FIG. 16, according to the specific form shown in FIGS. 16 and 17, the correction unit 9A is composed of a pair of substrates 93 and 94 having the form of a plane parallel plate arranged perpendicular to the optical axis AX. Is configured. However, the present invention is not limited to this, and various forms are possible for the specific configuration of the correction unit 9A.

For example, the form of the substrate constituting the correction unit 9A (outer shape, etc.), the posture of the substrate, the number of unit dimming areas forming each dimming pattern, the shape of the unit dimming area, the formation surface of the unit dimming area Various forms are possible with respect to the position (incident surface or exit surface), the distribution form of the unit attenuation region, the arrangement position of the correction unit 9A, and the like. Specifically, in the modification of FIG. 16, as the light transmissive substrates 93 and 94, for example, a substrate having at least one surface having a curvature can be used.

In the modification of FIG. 16, the pair of substrates 93 and 94 are configured to be relatively rotatable around the optical axis AX. However, the present invention is not limited to this, and a pair of substrates that are relatively movable in a direction crossing the optical axis AX (typically, any direction along the XY plane orthogonal to the optical axis AX) can be used. A correction unit having the same operation as that of the correction unit 9A according to the modified example can be configured. In this case, the overlapping region where the first dimming pattern and the second dimming pattern overlap as seen from the optical axis direction according to the change in the relative position along the direction crossing the optical axis between the first substrate and the second substrate. It is important that the size of the is changed.

Further, in the first embodiment described above and the modifications thereof, the rear side of the micro fly's eye lens 8 or the rear side (mask side) of the pupil intensity distribution 20 formed on the illumination pupil near the rear focal plane. The correction unit 9 (9A) is arranged. However, the present invention is not limited to this, and the correction unit 9 (9A) can also be arranged at the position of the formation surface of the pupil intensity distribution 20 or the front side (light source side) thereof. Further, the position of the illumination pupil on the rear side of the micro fly's eye lens 8 or the vicinity thereof, for example, the position of the illumination pupil between the front lens group 12a and the rear lens group 12b of the imaging optical system 12 or the vicinity thereof. Further, the correction unit 9 (9A) can be arranged.

Generally, the correction unit according to the first embodiment of the present invention for correcting the pupil intensity distribution formed on the illumination pupil is adjacent to the optical element having power adjacent to the front side of the illumination pupil and the rear side of the illumination pupil. A light-transmissive first substrate disposed in an illumination pupil space between the optical elements having power and having a predetermined thickness along the optical axis; and disposed behind the first substrate in the illumination pupil space. And a light transmissive second substrate having a predetermined thickness along the optical axis. A first dimming pattern is formed on the first substrate, a second dimming pattern is formed on the second substrate corresponding to the first dimming pattern, and the first dimming pattern and the second dimming pattern are The relative position can be changed. That is, at least one of the first substrate and the second substrate is configured to be movable in a predetermined direction or rotatable about a predetermined axis. In the “illumination pupil space”, there may be a parallel plane plate or a plane mirror having no power.

In the above-described first embodiment and its modification, the unit attenuation region that forms the dimming pattern of the substrate is formed as a light-blocking region that blocks incident light by a light-blocking dot made of, for example, chromium or chromium oxide. ing. However, the present invention is not limited to this, and the unit dimming area may have a form other than the form of the light shielding area. For example, at least one of the plurality of dimming patterns can be formed as a scattering region for scattering incident light or as a diffraction region for diffracting incident light. Generally, a scattering region is formed by roughening a required region of a light-transmitting substrate, and a diffraction region is formed by applying a diffractive surface forming process to the required region.

FIG. 21 is a drawing schematically showing a configuration of an exposure apparatus according to the second embodiment of the present invention. In FIG. 21, the Z-axis is along the normal direction of the exposure surface (transfer surface) of wafer W, which is a photosensitive substrate, and the Y-axis is in the direction parallel to the paper surface of FIG. Within the W exposure surface, the X axis is set in a direction perpendicular to the paper surface of FIG. The second embodiment has a configuration similar to that of the first embodiment, but particularly the configuration of the correction unit 19 is different from that of the first embodiment.

More specifically, in the first embodiment, the density filter 5 and the conical axicon system 6 are arranged at or near the pupil position of the afocal lens 4, but in the second embodiment, the density filter is not necessary and is installed. However, the conical axicon system can be installed if necessary, but its installation is omitted. In FIG. 21, the same reference numerals as those in FIG. 1 are assigned to components having the same functions as those in the first embodiment of FIG. In the following, focusing on the differences from the first embodiment, explanations of the configuration and operation of the second embodiment will be described while omitting the overlapping description with the first embodiment.

In the exposure apparatus of the second embodiment, light emitted from the light source 1 enters the afocal lens 4 via the shaping optical system 2 and the diffractive optical element 3 for annular illumination. The light passing through the afocal lens 4 enters the micro fly's eye lens 8 through the predetermined surface IP and the zoom lens 7. The light beam incident on the micro fly's eye lens 8 is two-dimensionally divided, and the illumination pupil at or near the rear focal plane thereof is, for example, a secondary comprising a substantial surface light source having an annular shape centering on the optical axis AX. A light source (pupil intensity distribution) is formed. A correction unit 19 is disposed at or near the rear focal plane of the micro fly's eye lens 8. The configuration and operation of the correction unit 19 will be described later.

The light that has passed through the micro fly's eye lens 8 and the correction unit 19 illuminates the mask M in a superimposed manner via the condenser optical system 10, the mask blind 11, and the imaging optical system 12. The light that has passed through the pattern area of the mask M forms an image of the mask pattern on the wafer W via the projection optical system PL. In this way, the mask pattern in the shot area (exposure area) of the wafer W is obtained by synchronously moving (scanning) the mask M and the wafer W along the X direction (scanning direction) in accordance with the step-and-scan method. Are subjected to scanning exposure.

In the following description, in order to facilitate understanding of the effects of the second embodiment, a quadrupolar shape as shown in FIG. 22 is provided on the rear focal plane of the micro fly's eye lens 8 or in the vicinity of the illumination pupil. It is assumed that a pupil intensity distribution (secondary light source) 30 is formed. It is assumed that the correction unit 19 is disposed immediately after the formation surface of the quadrupole pupil intensity distribution 30. In the following description, the term “illumination pupil” simply refers to the illumination pupil at or near the rear focal plane of the micro fly's eye lens 8.

Referring to FIG. 22, a quadrupole pupil intensity distribution 30 formed on the illumination pupil includes a pair of arcuate substantial surface light sources 30a and 30b spaced apart in the X direction across the optical axis AX, And a pair of arc-shaped substantial surface light sources (hereinafter simply referred to as “surface light sources”) 30 c and 30 d spaced apart in the Z direction across the optical axis AX. The X direction in the illumination pupil is the short-side direction of the rectangular microlens of the micro fly's eye lens 8 (that is, the short-side direction of the unit wavefront dividing surface) and corresponds to the scanning direction of the wafer W. The Z direction in the illumination pupil is the long side direction of the rectangular microlens of the micro fly's eye lens 8 (that is, the long side direction of the unit wavefront dividing surface), and the scanning orthogonal direction orthogonal to the scanning direction of the wafer W (Y direction on the wafer W).

On the wafer W, as shown in FIG. 3 referred to in the description of the first embodiment, a rectangular still exposure region ER having a long side along the Y direction and a short side along the X direction. A rectangular illumination area (not shown) is formed on the mask M so as to correspond to the static exposure area ER. Here, the quadrupole pupil intensity distribution formed on the illumination pupil by light incident on one point in the still exposure region ER has substantially the same shape without depending on the position of the incident point. However, the light intensity of each surface light source constituting the quadrupole pupil intensity distribution may differ depending on the position of the incident point.

As a relatively simple example, light incident on peripheral points P2 and P3 in the still exposure region ER forms a quadrupole pupil intensity distribution schematically shown in FIGS. 23 and 24, respectively, on the illumination pupil. think about. That is, in the quadrupole pupil intensity distribution 32 formed by the light incident on the peripheral point P2 spaced from the central point P1 in the still exposure region ER in the + Y direction, as shown in FIG. 23, as shown in FIG. 32b and 32d are substantially equal to each other, and the light intensity of the surface light source 32c is greater than the light intensity of the other surface light sources.

Further, in the quadrupole pupil intensity distribution 33 formed by the light incident on the peripheral point P3 spaced in the −Y direction from the center point P1 in the still exposure region ER, as shown in FIG. It is assumed that the light intensities of 33a, 33b and 33c are substantially equal to each other, and the light intensity of the surface light source 33d is larger than the light intensities of other surface light sources. As described above, in the pupil intensity distribution regarding each point on the wafer W, the light of a pair of regions spaced apart in the Z direction (direction corresponding to the scanning orthogonal direction (Y direction on the wafer W)) across the optical axis AX. If the difference in intensity is too large, the pattern printed on the shot area (the peripheral positions corresponding to the peripheral points P2 and P3 in the example shown in FIGS. 23 and 24) may be displaced from the desired position. .

In the second embodiment, in the pupil intensity distributions 32 and 33 relating to the peripheral points P2 and P3, between the pair of surface light sources 32c and 32d and the pair of surface light sources 33c and 33d spaced apart in the Z direction with the optical axis AX interposed therebetween. A correction unit 19 is provided as an adjustment means for adjusting the difference in light intensity between the two. As shown in FIGS. 25 and 26, the correction unit 19 includes three light transmissive substrates 191, 192, and 193 having a predetermined thickness along the optical axis AX (corresponding to the Y direction). Each of the substrates 191 to 193 has the form of a plane parallel plate formed of an optical material such as quartz or fluorite.

The first substrate 191 has, for example, a circular outer shape centered on the optical axis AX, and is fixedly positioned in such a posture that its incident surface 191a is orthogonal to the optical axis AX. The second substrate 192 is disposed on the rear side of the first substrate 191 and has an outer shape corresponding to a region through which light from the surface light source 30c passes, for example, a fan-shaped outer shape. In addition, the second substrate 192 is configured to be movable in the Z direction (long side direction of the unit wavefront dividing plane) while maintaining the posture in which the incident surface 192a is orthogonal to the optical axis AX.

The third substrate 193 is disposed on the rear side of the first substrate 191 and has an outer shape corresponding to a region through which light from the surface light source 30d passes, for example, a fan-shaped outer shape. Further, the third substrate 193 is configured to be movable in the Z direction while maintaining the posture in which the incident surface 193a is orthogonal to the optical axis AX. Hereinafter, in order to simplify the description, the second substrate 192 and the third substrate 193 have a symmetric configuration with respect to the XY plane passing through the optical axis AX, and the incident surface 192a of the second substrate 192 and the third substrate 193 The incident surface 193a is on the same plane. In the correction unit 19, the second substrate 192 and the third substrate 193 move in the Z direction based on a command from the drive control system 194.

Referring to FIG. 27, on the exit surface 191b of the substrate 191, the incident surface 192a of the substrate 192, and the incident surface 193ab of the substrate 193, light-shielding dots 151, 152, and 153 having the same outer shape and the same size are provided. It is formed according to a predetermined distribution. Here, each of the light-shielding dots 151 to 153 as the unit dimming region is made of, for example, chromium or chromium oxide. Further, the light shielding dots 151 are distributed so as to have a one-to-one correspondence with the light shielding dots 152 and 153. Here, the group of light shielding dots 151 are arranged so as to act on the light from the surface light sources 30c and 30d, and the group of light shielding dots 152 are arranged so as to act on the light from the surface light source 30c. The characteristic dots 153 are arranged so as to act on the light from the surface light source 30d.

In FIG. 27, for the sake of clarity, a pair of light-shielding dots 151 formed on the exit surface 191b of the substrate 191, one light-shielding dot 152 formed on the incident surface 192a of the substrate 192, and the incidence of the substrate 193. Only one light-shielding dot 153 formed on the surface 193a is shown. Hereinafter, in order to facilitate understanding of the description, each of the light shielding dots 151 to 153 has a circular outer shape, and the light shielding dots 151 and 152 are light-transmitted in the reference state (reference position) of the second substrate 192. It is assumed that the light-shielding dots 151 and 153 overlap each other when viewed in the optical axis AX direction in the reference state of the third substrate 193 when viewed in the axis AX direction. In order to facilitate understanding of the explanation, the correction unit is focused on only the pair of light shielding dots 151 on the substrate 191, one light shielding dot 152 on the substrate 192, and one light shielding dot 153 on the substrate 193. The operation of 19 will be described.

In the reference state of the second substrate 192, when light parallel to the optical axis AX is incident on the combined light reduction region composed of the combination of the circular light shielding dots 151 and 152, the light is emitted immediately after the correction unit 19 and emitted. On the surface parallel to the surface 192b, as shown in FIG. 28A, the region 151a dimmed by the circular light-shielding dot 151 and the region 152a dimmed by the circular light-shielding dot 152 are Overlap each other. That is, immediately after the correction unit 19, the circular dimming areas 151a and 152a form a dimming area having an area corresponding to one of the circular dimming areas 151a.

In the reference state of the second substrate 192, when the angle with respect to the optical axis AX of the light incident on the combined dimming region composed of the circular light shielding dots 151 and 152 increases monotonously from 0 degrees along the YZ plane, for example, Immediately after the correction unit 19, as shown in FIG. 28B, the dimming areas 151a and 152a move in the Z direction by different distances, and the area where the dimming areas 151a and 152a overlap is monotonously reduced. As a result, in the state shown in FIG. 28B, the circular dimming regions 151a and 152a are larger than the area of one circular dimming region 151a according to the area of the overlapping region. A dimming region having an area smaller than the area of two is formed.

Thus, in the reference state of the second substrate 192, the combined light reduction region composed of the circular light shielding dots 151 and 152 has a light attenuation rate that increases as the incident angle of light with respect to the first substrate 191 increases. Demonstrate the effect. Similarly, in the reference state of the third substrate 193, the combined light reduction region composed of the circular light shielding dots 151 and 153 is a decrease in which the light reduction rate increases as the incident angle of light with respect to the first substrate 191 increases. Exhibits light action.

Next, when the incident angle of light with respect to the first substrate 191 is constant, for example, when the incident angle of light is 0 degrees (when the angle of the incident light with respect to the optical axis AX is 0 degrees), the second Consider the case where the substrate 192 moves in the Z direction from the reference state. As described above, when the second substrate 192 is in the reference state, immediately after the correction unit 19, the light is attenuated by the region 151 a dimmed by the circular light shielding dot 151 and the circular light shielding dot 152. The regions 152a overlap each other. That is, as shown in FIG. 28A, immediately after the correction unit 19, the circular dimming areas 151a and 152a are dimming areas having an area corresponding to one of the circular dimming areas 151a. Form.

On the other hand, when the second substrate 192 moves monotonously from the reference state in the Z direction, immediately after the correction unit 19, the dimming area 152a moves in the Z direction and the area overlapping the dimming area 151a monotonously decreases. That is, as shown in FIG. 28B, immediately after the correction unit 19, the circular dimming regions 151a and 152a correspond to one of the circular dimming regions 151a according to the area of the overlapping region. A dimming region having an area larger than the area of the minute and smaller than the area of the two is formed.

Thus, when the incident angle of light with respect to the first substrate 191 is 0 degree, when the incident angle of light is generally constant, the combined dimming region composed of the circular light-shielding dots 151 and 152 is As the amount of movement along the Z direction from the reference state of the second substrate 192 increases, the light reduction rate increases. Similarly, when the incident angle of light with respect to the first substrate 191 is constant, the combined dimming region composed of the circular light-shielding dots 151 and 153 extends along the Z direction from the reference state of the third substrate 193. It exhibits a dimming effect in which the dimming rate increases as the amount of movement increases.

In the second embodiment, the first substrate 191 and the second substrate 192 are centered on a reference state in which circular light-shielding dots 151 and 152 that are unit dimming regions overlap each other when viewed from the optical axis AX direction. A part of the light-shielding dot 151 and a part of the light-shielding dot 152 are configured to be relatively movable within a range where they overlap when viewed from the optical axis AX direction. Similarly, the first substrate 191 and the third substrate 193 have a light-shielding dot centered on a reference state in which circular light-shielding dots 151 and 153 that are unit dimming regions overlap each other when viewed from the optical axis AX direction. A part of 151 and a part of light-shielding dot 153 are configured to be relatively movable within a range where they overlap each other when viewed from the optical axis AX direction.

As shown in FIG. 25, the correction unit 19 acts on the light from the pair of surface light sources 30c and 30d spaced apart in the Z direction across the optical axis AX in the quadrupole pupil intensity distribution 30. To do. However, the correction unit 19 does not act on the light from the pair of surface light sources 30a and 30b spaced in the X direction across the optical axis AX.

Further, as shown in FIG. 29, the light reaching the center point P1 in the static exposure region ER on the wafer W, that is, the light reaching the center point P1 ′ of the opening of the mask blind 11 is transmitted to the correction unit 19 ( That is, it is incident on the first substrate 191) at an incident angle of zero. In other words, the light from the surface light source 31c of the pupil intensity distribution 31 with respect to the center point P1 is incident on the first substrate 191 and the second substrate 192 at the incident angle 0, and the light from the surface light source 31d is the first at the incident angle 0. The light enters the substrate 191 and the third substrate 193. Although illustration of the pupil intensity distribution 31 is omitted, the surface light sources 31a to 31d are formed in the same manner as the surface light sources 32a to 32d (33a to 33d) of the pupil intensity distribution 32 (33).

On the other hand, as shown in FIG. 30, the light reaching the peripheral points P2 and P3 in the static exposure region ER on the wafer W, that is, the light reaching the peripheral points P2 ′ and P3 ′ of the opening of the mask blind 11 19 is incident at a relatively large incident angle ± θ. In other words, light from the surface light sources 32c and 33c of the pupil intensity distributions 32 and 33 relating to the peripheral points P2 and P3 is incident on the first substrate 191 and the second substrate 192 at a relatively large incident angle ± θ. Light from the surface light sources 32d and 33d is incident on the first substrate 191 and the third substrate 193, respectively, at a relatively large incident angle ± θ.

29 and 30, the outermost point (see FIG. 22 and the like) along the Z direction of the surface light source 30c (31c to 33c) is denoted by reference numeral B3, and the surface light source 30d (31d to 33d) A point at the outermost edge along the Z direction (see FIG. 22 and the like) is indicated by reference sign B4. In order to facilitate understanding of the description related to FIG. 29 and FIG. 30, reference numeral B1 indicates the outermost point along the X direction of the surface light source 30a (31a to 33a), and reference numeral B2 indicates the surface light source. The outermost edge point along the X direction of 30b (31b to 33b) is shown. However, as described above, the light from the surface light sources 30a (31a to 33a) and the surface light sources 30b (31b to 33b) is not affected by the correction unit 19.

31, FIG. 33 and FIG. 34 are diagrams for explaining the relationship between the relative positions of the second substrate and the third substrate with respect to the first substrate and the dimming action of the correction unit. In FIG. 31, the second substrate 192 is in the reference state, and the light shielding dots 151 on the first substrate 191 and the light shielding dots 152 on the second substrate 192 overlap each other when viewed from the optical axis AX direction. On the other hand, the third substrate 193 is moved by a predetermined distance in the + Z direction from the reference state, and part of the light shielding dots 151 on the first substrate 191 and part of the light shielding dots 152 on the second substrate 192 are light. They overlap when viewed from the direction of the axis AX.

The light reaching the center point P 1 in the static exposure region ER on the wafer W, that is, the light reaching the center point P 1 ′ of the opening of the mask blind 11 is incident on the first substrate 191 at an incident angle of 0. Therefore, in the case of light reaching the center point P1 'from the surface light source 30c through the first substrate 191 and the second substrate 192, the amount of light blocked by the combined dimming region of the light blocking dots 151 and 152 is the smallest. In the case of light reaching the center point P1 'from the surface light source 30d through the first substrate 191 and the third substrate 193, the amount of light blocked by the combined light reduction region of the light blocking dots 151 and 153 is relatively large.

The light reaching the peripheral points P2 and P3 in the static exposure region ER on the wafer W, that is, the light reaching the peripheral points P2 ′ and P3 ′ of the opening of the mask blind 11 is relatively incident on the first substrate 191. Incident at an angle θ. Hereinafter, in order to simplify the description, the peripheral point P2 ′ corresponding to the peripheral point P2 in the still exposure region ER is located on the + Z direction side of the opening of the mask blind 11, and the peripheral point P3 in the still exposure region ER. It is assumed that the peripheral point P3 ′ corresponding to is located on the −Z direction side.

Therefore, in the case of light reaching the peripheral points P2 ′ and P3 ′ from the surface light source 30c through the first substrate 191 and the second substrate 192, the amount of light blocked by the combined light reduction region of the light blocking dots 151 and 152 is compared. Big. In the case of light reaching the peripheral point P2 'from the surface light source 30d through the first substrate 191 and the third substrate 193, the amount of light blocked by the combined light reduction region of the light blocking dots 151 and 153 is relatively small. In the case of light reaching the peripheral point P3 'from the surface light source 30d through the first substrate 191 and the third substrate 193, the amount of light blocked by the combined dimming region of the light blocking dots 151 and 153 is the largest.

That is, as shown in the center of FIG. 32, among the quadrupole pupil intensity distributions related to the center point P1, the dimming effect by the correction unit 19 on the surface light source 31c on the + Z direction side is the smallest, and the surface on the −Z direction side The dimming effect of the correction unit 19 on the light source 31d is relatively large. Thus, in FIG. 32 and the relevant portions of FIGS. 33 and 34, the magnitude of the dimming action of the correction unit 19 is schematically represented by the width dimension in the Z direction of the hatched area extending in the X direction. Yes.

Further, as shown on the left side of FIG. 32, in the quadrupole pupil intensity distribution related to the peripheral point P2, the dimming effect by the correction unit 19 on the surface light source 32c is relatively large, and the reduction by the correction unit 19 on the surface light source 32d. The light effect is relatively small. Further, as shown on the right side of FIG. 32, in the quadrupole pupil intensity distribution related to the peripheral point P3, the dimming effect by the correction unit 19 on the surface light source 33c is relatively large, and the reduction by the correction unit 19 on the surface light source 33d. The light effect is the largest.

Further, as shown in FIG. 33, when the second substrate 192 moves from the reference state by a predetermined distance in the −Z direction and the third substrate 193 moves from the reference state by a predetermined distance in the + Z direction, the center point P1 is related. Of the quadrupole pupil intensity distribution, the dimming effect by the correction unit 19 on the surface light source 31c and the dimming effect by the correction unit 19 on the surface light source 31d are both relatively large. Of the quadrupole pupil intensity distribution related to the peripheral point P2, the light reduction effect by the correction unit 19 on the surface light source 32c is the largest, and the light reduction effect by the correction unit 19 on the surface light source 32d is relatively small. Of the quadrupole pupil intensity distribution related to the peripheral point P3, the dimming effect by the correction unit 19 on the surface light source 33c is relatively small, and the dimming effect by the correction unit 19 on the surface light source 33d is the largest.

Further, as shown in FIG. 34, when the second substrate 192 moves by a predetermined distance in the + Z direction from the reference state and the third substrate 193 moves by a predetermined distance in the −Z direction from the reference state, the center point P1 is related. Of the quadrupole pupil intensity distribution, the dimming effect by the correction unit 19 on the surface light source 31c and the dimming effect by the correction unit 19 on the surface light source 31d are both relatively large. Of the quadrupole pupil intensity distribution related to the peripheral point P2, the dimming effect by the correction unit 19 on the surface light source 32c is relatively small, and the dimming effect by the correction unit 19 on the surface light source 32d is the largest. Of the quadrupole pupil intensity distribution related to the peripheral point P3, the light reduction effect by the correction unit 19 on the surface light source 33c is the largest, and the light reduction effect by the correction unit 19 on the surface light source 33d is relatively small.

Thus, for example, the second substrate 192 is set at a required position along the Z direction, and the third substrate 193 is set at a required position along the Z direction so that the optical axis AX is sandwiched in the Z direction. The difference in light intensity as shown in FIGS. 23 and 24 existing between the pair of surface light sources 32c and 32d and between the pair of surface light sources 33c and 33d can be adjusted.

Specifically, the second substrate 192 of the correction unit 19 is at a position moved from the reference state by a required distance along the −Z direction, and the third substrate 193 is moved from the reference state by a required distance along the + Z direction. 35, in the pupil intensity distribution 32 related to the peripheral point P2, the light from the surface light sources 32a and 32b is not affected by the dimming action of the correction unit 19, so that the light intensity does not change as shown in FIG. . The light from the surface light source 32c is subjected to the dimming action of the correction unit 19, and its light intensity is relatively greatly reduced. Even if the light from the surface light source 32d is subjected to the dimming action of the correction unit 19, the decrease in the light intensity is relatively small. As a result, in the pupil intensity distribution 32 ′ relating to the peripheral point P <b> 2 adjusted by the correction unit 19, the light intensity of the surface light source 32 c ′ spaced apart in the Z direction is approximately equal to the light intensity of the surface light source 32 d ′. Alternatively, the difference between the light intensity of the surface light source 32c 'and the light intensity of the surface light source 32d' is adjusted to a required light intensity difference.

Further, as shown in FIG. 36, in the pupil intensity distribution 33 related to the peripheral point P3, the light from the surface light sources 33a and 33b is not affected by the dimming action of the correction unit 19, and therefore the light intensity does not change. Even if the light from the surface light source 33c is subjected to the dimming action of the correction unit 19, the decrease in the light intensity is relatively small. The light from the surface light source 33d is subjected to the dimming action of the correction unit 19, and its light intensity is relatively reduced. As a result, in the pupil intensity distribution 33 ′ related to the peripheral point P <b> 3 adjusted by the correction unit 19, the light intensity of the surface light source 33 c ′ spaced apart in the Z direction is approximately equal to the light intensity of the surface light source 33 d ′. Alternatively, the difference between the light intensity of the surface light source 33c 'and the light intensity of the surface light source 33d' is adjusted to a required light intensity difference.

The operation of adjusting the difference between the light intensity of the surface light source 32c ′ and the light intensity of the surface light source 32d ′ and the difference between the light intensity of the surface light source 33c ′ and the light intensity of the surface light source 33d ′ to a required light intensity difference is as follows. For example, the measurement is performed based on the measurement result of a pupil intensity distribution measuring device (not shown) that measures the pupil intensity distribution on the pupil plane of the projection optical system PL based on light via the projection optical system PL. Specifically, the measurement result of the pupil intensity distribution measuring device is supplied to a control unit (not shown). The control unit outputs a command to the drive control system 194 of the correction unit 19 so that the pupil intensity distribution on the pupil plane of the projection optical system PL becomes a desired distribution based on the measurement result of the pupil intensity distribution measuring device. The drive control system 194 controls the position of the second substrate 192 and the third substrate 193 in the Z direction based on a command from the control unit, and the difference between the light intensity of the surface light source 32c ′ and the light intensity of the surface light source 32d ′ and The difference between the light intensity of the surface light source 33c ′ and the light intensity of the surface light source 33d ′ is adjusted to a required light intensity difference.

As described above, in the correction unit 19 of the second embodiment, the second substrate 192 having the light-shielding dots 152 and 153 formed on the incident surface is different from the first substrate 191 having the light-shielding dots 151 formed on the exit surface. The third substrate 193 is configured to be relatively movable along the Z direction, which is the long side direction of the unit wavefront dividing surface. Accordingly, as is apparent with reference to FIGS. 32 to 34, the correction unit 19 has a dimming rate according to various modes along the Y direction (corresponding to the Z direction in the illumination pupil) in the still exposure region ER. Realizes various dimming rate characteristics that change. In the above description, attention is paid only to the pair of light shielding dots 151 on the substrate 191, one light shielding dot 152 on the substrate 192, and one light shielding dot 153 on the substrate 193. Obviously, the correction unit 19 exhibits the same operation as described above even when the distributions 151 to 153 are distributed.

Therefore, in the illumination optical system (2 to 12) of the second embodiment, the dimming action of the correction unit 19 causes the pupil intensity distribution for each point in the still exposure region ER to be in the Y direction across the optical axis AX. It is possible to adjust the difference in light intensity between a pair of spaced regions (in the example of FIGS. 23 and 24, between the pair of surface light sources 32c and 32d and between the pair of surface light sources 33c and 33d). it can. In the exposure apparatus (2 to WS) of the second embodiment, a pair of regions spaced apart in the Y direction across the optical axis AX in the pupil intensity distribution for each point in the static exposure region ER on the wafer W. Using the illumination optical system (2 to 12) that adjusts the difference in light intensity, it is possible to perform good exposure under appropriate illumination conditions according to the fine pattern of the mask M. As a result, the fine pattern of the mask M can be formed. The entire exposure area can be faithfully transferred onto the wafer W at a desired position and with a desired line width.

In the second embodiment, it is conceivable that the light amount distribution on the wafer (irradiated surface) W is affected by, for example, the dimming action (adjusting action) of the correction unit 19. In this case, the illuminance distribution in the still exposure region ER or the shape of the still exposure region (illumination region) ER can be changed as necessary by the action of the light quantity distribution adjusting unit having a known configuration.

In the second embodiment described above, the correction unit is constituted by three substrates 191 to 193 having the form of parallel plane plates arranged perpendicular to the optical axis AX according to the specific form shown in FIGS. 19 is constituted. Then, circular light-shielding dots 151 serving as a first dimming pattern are distributed and formed on the emission surface of the first substrate 191. On the incident surface of the second substrate 192 and the incident surface of the third substrate 193, a circular light-shielding dot 152 as a second dimming pattern and a circular light-shielding dot 153 as a third dimming pattern are provided. Distribution is formed. However, the present invention is not limited to this, and various configurations are possible for the specific configuration of the correction unit 19.

For example, the number of substrates constituting the correction unit 19, the form of the substrate (outer shape, etc.), the posture of the substrate, the direction of relative movement between the substrates, the number of unit dimming areas forming each dimming pattern, and unit dimming Various forms are possible with respect to the shape of the region, the position of the formation surface of the unit dimming region (incident surface or exit surface), the distribution form of the unit dimming region, the arrangement position of the correction unit 19, and the like. Specifically, the second substrate 192 and the third substrate 193 are integrated, the first substrate 191 is configured to be movable along the Z direction, or one of the second substrate 192 and the third substrate 193 Even if the installation of is omitted, the same effect as in the second embodiment described above can be exhibited. Further, as the light transmissive substrate, for example, a substrate in which at least one surface has a curvature can be used.

In the second embodiment described above, the correction unit 19 is located behind (on the mask side) the formation surface of the pupil intensity distribution 30 formed on the rear focal plane of the micro fly's eye lens 8 or the illumination pupil in the vicinity thereof. Is arranged. However, the present invention is not limited to this, and the correction unit 19 can also be arranged at the position of the formation surface of the pupil intensity distribution 30 or the front side (light source side) thereof. Further, the position of the illumination pupil on the rear side of the micro fly's eye lens 8 or the vicinity thereof, for example, the position of the illumination pupil between the front lens group 12a and the rear lens group 12b of the imaging optical system 12 or the vicinity thereof. In addition, the correction unit 19 can be arranged.

In general, a correction unit according to the third embodiment of the present invention for correcting the pupil intensity distribution formed on the illumination pupil is adjacent to the optical element having power adjacent to the front side of the illumination pupil and the rear side of the illumination pupil. A light-transmissive first substrate disposed in an illumination pupil space between the optical elements having power and having a predetermined thickness along the optical axis; and disposed behind the first substrate in the illumination pupil space. And a light transmissive second substrate having a predetermined thickness along the optical axis. A first dimming pattern having at least one first unit dimming region is formed on the first substrate, and at least one second unit dimming formed corresponding to the first unit dimming region is formed on the second substrate. A second dimming pattern having a light region is formed. The first substrate and the second substrate are configured to be relatively movable along a first direction that crosses the optical axis. In the “illumination pupil space”, there may be a parallel plane plate or a plane mirror having no power.

In the second embodiment described above, the unit dimming area for forming the dimming pattern of the substrate is formed as a light blocking area that blocks incident light by a light blocking dot made of, for example, chromium or chromium oxide. However, the present invention is not limited to this, and the unit dimming area may have a form other than the form of the light shielding area. For example, at least one of the plurality of dimming patterns can be formed as a scattering region for scattering incident light or as a diffraction region for diffracting incident light. Generally, a scattering region is formed by roughening a required region of a light-transmitting substrate, and a diffraction region is formed by applying a diffractive surface forming process to the required region.

In the second embodiment described above, the second substrate 192 and the third substrate 193 are configured to be movable relative to the first substrate 191, respectively. However, the present invention is not limited to this, and all the substrates 191 to 193 may be fixedly installed. In this case, a part of the first unit dimming region (corresponding to the light shielding dot 151) of the first substrate 191 and a part of the second unit light reducing region (corresponding to the light shielding dot 152) of the second substrate 192 are formed. A portion of the first unit attenuation region of the first substrate 191 and a part of the third unit attenuation region (corresponding to the light shielding dot 153) of the third substrate 193 overlap with each other when viewed from the optical axis AX direction. It is important that the substrates 191 to 193 are fixedly positioned so as to overlap when viewed from the axis AX direction.

Specifically, in the configuration corresponding to the above-described second embodiment, the first unit dimming region and the second unit dimming region are displaced in the Z direction, and the first unit dimming region and the third unit dimming are included. Each substrate 191 to 193 is fixedly positioned in a state where the region is displaced in the Z direction. Even in the configuration in which each substrate is fixedly positioned, the second substrate 192 and the third substrate 193 can be integrated, or the installation of one of the second substrate 192 and the third substrate 193 can be omitted. .

That is, in general, the correction unit according to the second embodiment of the present invention according to the configuration in which the respective substrates are fixedly positioned has the first dimming formed on the first surface perpendicular to the optical axis in the illumination pupil space. And a second dimming pattern that is positioned on the rear side of the first surface in the illumination pupil space and formed on a second surface parallel to the first surface. The first dimming pattern has at least one first unit dimming area, and the second dimming pattern has at least one second unit dimming area formed corresponding to the first unit dimming area. A part of the first unit dimming region and a part of the second unit dimming region overlap each other when viewed from the optical axis direction.

Further, referring to the first embodiment and the second embodiment, the correction unit according to the fourth embodiment of the present invention is arranged in the illumination pupil space and has a light transmission property having a predetermined thickness along the optical axis. And a light-transmissive second substrate that is disposed behind the first substrate in the illumination pupil space and has a predetermined thickness along the optical axis, and the first substrate is located on the light incident side. And a second substrate having at least one of a light incident side surface and a light emission side surface. A second dimming pattern formed on the surface. The first dimming pattern has at least one first unit dimming area, and the second dimming pattern has at least one second unit dimming formed corresponding to the at least one first unit dimming area. Has a region. The first unit dimming region and the second unit dimming region provide a first dimming rate for light incident on the first unit dimming region at a first incident angle, and the first unit dimming region A second dimming rate different from the first dimming rate is given to light incident at a second incident angle different from the first incident angle to the dimming region, and the first substrate and the second substrate The positional relationship of can be changed.

In the above description, the operational effects of the present invention are described by taking, as an example, modified illumination in which a quadrupole pupil intensity distribution is formed on the illumination pupil, that is, quadrupole illumination. However, the present invention is not limited to quadrupole illumination. For example, annular illumination in which an annular pupil intensity distribution is formed, multipolar illumination in which a multipolar pupil intensity distribution other than quadrupole is formed, and the like. In contrast, it is apparent that the same effects can be obtained by applying the present invention.

In the above-described embodiment, a variable pattern forming apparatus that forms a predetermined pattern based on predetermined electronic data can be used instead of a mask. By using such a variable pattern forming apparatus, the influence on the synchronization accuracy can be minimized even if the pattern surface is placed vertically. As the variable pattern forming apparatus, for example, a DMD (digital micromirror device) including a plurality of reflecting elements driven based on predetermined electronic data can be used. An exposure apparatus using DMD is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-304135, pamphlet of International Patent Publication No. 2006/080285 and US Patent Publication No. 2007/0296936 corresponding thereto. In addition to a non-light-emitting reflective spatial light modulator such as DMD, a transmissive spatial light modulator may be used, or a self-luminous image display element may be used. Note that a variable pattern forming apparatus may be used even when the pattern surface is placed horizontally. Here, the teachings of US Patent Publication No. 2007/0296936 are incorporated by reference.

In the above-described embodiment, the micro fly's eye lens 8 is used as the optical integrator, but instead, an internal reflection type optical integrator (typically a rod type integrator) may be used. In this case, the condensing lens is arranged on the rear side of the zoom lens 7 so that the front focal position thereof coincides with the rear focal position of the zoom lens 7, and the incident end is located at or near the rear focal position of the condensing lens. Position the rod-type integrator so that is positioned. At this time, the exit end of the rod integrator is the position of the illumination field stop 11. When a rod type integrator is used, a position optically conjugate with the position of the aperture stop AS of the projection optical system PL in the field stop imaging optical system 12 downstream of the rod type integrator can be called an illumination pupil plane. . In addition, since a virtual image of the secondary light source of the illumination pupil plane is formed at the position of the entrance surface of the rod integrator, this position and a position optically conjugate with this position are also called the illumination pupil plane. Can do. Here, the zoom lens 7, the above-described condenser lens, and the rod integrator can be regarded as a distribution forming optical system.

Further, in the above-described embodiment, instead of or in addition to the diffractive optical element 3, for example, it is constituted by a large number of minute element mirrors arranged in an array and whose tilt angle and tilt direction are individually driven and controlled. A spatial light modulation element that converts the cross section of the light beam into a desired shape or a desired size by dividing the light beam into small units for each reflecting surface and deflecting the light beam may be used. An illumination optical system using such a spatial light modulator is disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-353105.

The exposure apparatus of the above-described embodiment is manufactured by assembling various subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Is done. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

Next, a device manufacturing method using the exposure apparatus according to the above-described embodiment will be described. FIG. 37 is a flowchart showing manufacturing steps of a semiconductor device. As shown in FIG. 37, in the semiconductor device manufacturing process, a metal film is vapor-deposited on a wafer W to be a semiconductor device substrate (step S40), and a photoresist, which is a photosensitive material, is applied on the vapor-deposited metal film. (Step S42). Subsequently, using the exposure apparatus of the above-described embodiment, the pattern formed on the mask (reticle) M is transferred to each shot area on the wafer W (step S44: exposure process), and the transfer of the wafer W after the transfer is completed. Development, that is, development of the photoresist to which the pattern has been transferred is performed (step S46: development process). Thereafter, using the resist pattern generated on the surface of the wafer W in step S46 as a mask, processing such as etching is performed on the surface of the wafer W (step S48: processing step).

Here, the resist pattern is a photoresist layer in which unevenness having a shape corresponding to the pattern transferred by the exposure apparatus of the above-described embodiment is generated, and the recess penetrates the photoresist layer. is there. In step S48, the surface of the wafer W is processed through this resist pattern. The processing performed in step S48 includes, for example, at least one of etching of the surface of the wafer W or film formation of a metal film or the like. In step S44, the exposure apparatus of the above-described embodiment performs pattern transfer using the wafer W coated with the photoresist as the photosensitive substrate, that is, the plate P.

FIG. 38 is a flowchart showing a manufacturing process of a liquid crystal device such as a liquid crystal display element. As shown in FIG. 38, in the liquid crystal device manufacturing process, a pattern forming process (step S50), a color filter forming process (step S52), a cell assembling process (step S54), and a module assembling process (step S56) are sequentially performed.

In the pattern forming process of step S50, a predetermined pattern such as a circuit pattern and an electrode pattern is formed on the glass substrate coated with a photoresist as the plate P using the exposure apparatus of the above-described embodiment. In this pattern formation process, an exposure process for transferring the pattern to the photoresist layer using the exposure apparatus of the above-described embodiment and development of the plate P to which the pattern is transferred, that is, development of the photoresist layer on the glass substrate are performed. And a developing step for generating a photoresist layer having a shape corresponding to the pattern, and a processing step for processing the surface of the glass substrate through the developed photoresist layer.

In the color filter forming step of step S52, a large number of sets of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix or three R, G, and B A color filter is formed by arranging a plurality of stripe filter sets in the horizontal scanning direction.

In the cell assembly process in step S54, a liquid crystal panel (liquid crystal cell) is assembled using the glass substrate on which the predetermined pattern is formed in step S50 and the color filter formed in step S52. Specifically, for example, a liquid crystal panel is formed by injecting liquid crystal between a glass substrate and a color filter. In the module assembling process in step S56, various components such as an electric circuit and a backlight for performing the display operation of the liquid crystal panel are attached to the liquid crystal panel assembled in step S54.

In addition, the present invention is not limited to application to an exposure apparatus for manufacturing a semiconductor device, for example, an exposure apparatus for a display device such as a liquid crystal display element formed on a square glass plate or a plasma display, It can also be widely applied to an exposure apparatus for manufacturing various devices such as an image sensor (CCD or the like), a micromachine, a thin film magnetic head, and a DNA chip. Furthermore, the present invention can also be applied to an exposure process (exposure apparatus) when manufacturing a mask (photomask, reticle, etc.) on which mask patterns of various devices are formed using a photolithography process.

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

In the above-described embodiment, a so-called immersion method is applied in which the optical path between the projection optical system and the photosensitive substrate is filled with a medium (typically liquid) having a refractive index larger than 1.1. You may do it. In this case, as a method for filling the liquid in the optical path between the projection optical system and the photosensitive substrate, a method for locally filling the liquid as disclosed in International Publication No. WO 99/49504, A method of moving a stage holding a substrate to be exposed as disclosed in Japanese Patent Laid-Open No. 6-124873 in a liquid bath, or a stage having a predetermined depth on a stage as disclosed in Japanese Patent Laid-Open No. 10-303114. A technique of forming a liquid tank and holding the substrate in the liquid tank can be employed. Here, the teachings of WO99 / 49504, JP-A-6-124873 and JP-A-10-303114 are incorporated by reference.

In the above-described embodiment, a so-called polarization illumination method disclosed in US Publication Nos. 2006/0170901 and 2007/0146676 can also be applied. Here, the teachings of US Patent Publication No. 2006/0170901 and US Patent Publication No. 2007/0146676 are incorporated by reference.

In the above-described embodiment, the present invention is applied to a step-and-scan type exposure apparatus that scans and exposes the pattern of the mask M on the shot area of the wafer W. However, the present invention is not limited to this, and the present invention can also be applied to a step-and-repeat type exposure apparatus that repeats the operation of collectively exposing the pattern of the mask M to each exposure region of the wafer W.

In the above-described embodiment, the present invention is applied to the illumination optical system that illuminates the mask (or wafer) in the exposure apparatus. However, the present invention is not limited to this, and an object other than the mask (or wafer) is used. The present invention can also be applied to a general illumination optical system that illuminates the irradiation surface.

1 Light Source 3 Diffractive Optical Element 4 Afocal Lens 5 Density Filter 6 Conical Axicon System 7 Zoom Lens 8 Micro Fly Eye Lens (Optical Integrator)
9, 19 Correction unit 91, 92, 191, 192, 193 Substrate 10 Condenser optical system 11 Mask blind 12 Imaging optical system M Mask MS Mask stage PL Projection optical system AS Aperture stop W Wafer WS Wafer stage

Claims (45)

A correction unit for correcting the pupil intensity distribution formed on the illumination pupil of the illumination optical system,
It is arranged in an illumination pupil space between an optical element having power adjacent to the front side of the illumination pupil and an optical element having power adjacent to the rear side of the illumination pupil, and is arranged on the optical axis of the illumination optical system. A light transmissive first substrate having a predetermined thickness along,
A light transmissive second substrate disposed behind the first substrate in the illumination pupil space and having a predetermined thickness along the optical axis;
The first substrate has a first dimming pattern formed on at least one of a light incident side surface and a light emission side surface;
The second substrate has a second dimming pattern formed corresponding to the first dimming pattern on at least one of a light incident side surface and a light emission side surface;
The relative position of the first dimming pattern and the second dimming pattern can be changed,
The dimming rate due to the first dimming pattern and the second dimming pattern changes according to a change in the relative position between the first substrate and the second substrate and a change in the incident angle of light on the first substrate. It is comprised so that it may be correct | amended. 2. The correction unit according to claim 1, wherein at least one of the first substrate and the second substrate is configured to be movable in a predetermined direction or rotatable about a predetermined axis. At least one of the first substrate and the second substrate is configured to be movable in the optical axis direction, and the first dimming pattern and the second dimming pattern overlap each other when viewed from the optical axis direction. The correction unit according to claim 2, wherein the correction unit is configured as follows. The first dimming pattern has at least one first unit dimming region, and the second dimming pattern is formed corresponding to the at least one first unit dimming region, and the first unit dimming region is formed. The correction unit according to claim 3, further comprising at least one second unit dimming area having the same outer shape and the same size as the light area. At least one of the first substrate and the second substrate is configured to be rotatable around the optical axis, and according to a change in the relative position of the first substrate and the second substrate around the optical axis, The correction unit according to claim 2, wherein the first dimming pattern and the second dimming pattern are configured so that a size of an overlapping region where the first dimming pattern and the second dimming pattern overlap as viewed from the optical axis direction is changed. . The first dimming pattern includes a plurality of first unit dimming regions arranged along a circumferential direction of a circle centering on an intersection between the first substrate and the optical axis. 5. The correction unit according to 5. The correction unit according to claim 6, wherein the plurality of first unit dimming areas are arranged at an equal angle along a circumferential direction of the circle. The correction unit according to claim 7, wherein the first unit attenuation region has a linear region extending radially from the center of the circle at an interval. At least one of the first substrate and the second substrate is configured to be movable in a direction across the optical axis, and a relative position of the first substrate and the second substrate along the direction across the optical axis. The size of the overlapping region where the first dimming pattern and the second dimming pattern overlap with each other when viewed from the optical axis direction is changed in accordance with the change of 2. The correction unit according to 2. The correction unit according to claim 1, wherein the first substrate and the second substrate have a form of a plane parallel plate. The correction unit according to claim 10, wherein the first substrate and the second substrate maintain a parallel state to each other. The first dimming pattern is formed on the surface on the emission side of the first substrate, and the second dimming pattern is formed on the surface on the incident side of the second substrate. The correction unit according to any one of 1 to 11. The first dimming pattern has a plurality of first unit dimming regions formed in a distribution,
The said 2nd light attenuation pattern has a some 2nd unit light attenuation area | region distributedly formed corresponding to the said some 1st unit light attenuation area | region, The any one of Claim 1 thru | or 12 characterized by the above-mentioned. The correction unit described in 1. 14. The correction unit according to claim 1, wherein at least one of the first dimming pattern and the second dimming pattern has a light shielding region that blocks incident light. The correction unit according to claim 1, wherein at least one of the first dimming pattern and the second dimming pattern includes a scattering region that scatters incident light. The correction unit according to claim 1, wherein at least one of the first dimming pattern and the second dimming pattern includes a diffraction region that diffracts incident light. A correction unit for correcting the pupil intensity distribution formed on the illumination pupil of the illumination optical system,
A first perpendicular to the optical axis of the illumination optical system in an illumination pupil space between an optical element having power adjacent to the front side of the illumination pupil and an optical element having power adjacent to the rear side of the illumination pupil. A first dimming pattern formed on the surface;
A second dimming pattern formed on a second surface parallel to the first surface and positioned rearward of the first surface in the illumination pupil space;
The first dimming pattern has at least one first unit dimming region;
The second dimming pattern has at least one second unit dimming region formed corresponding to the at least one first unit dimming region,
A correction unit, wherein a part of the first unit dimming region and a part of the second unit dimming region overlap each other when viewed from the optical axis direction. The first unit dimming area and the second unit dimming area have the same outer shape and the same size, and the first unit dimming area and the second unit dimming area have the optical axis. The correction unit according to claim 17, wherein the correction unit is misaligned along a first direction that crosses. It is arranged in an illumination pupil space between an optical element having power adjacent to the front side of the illumination pupil and an optical element having power adjacent to the rear side of the illumination pupil, and is arranged on the optical axis of the illumination optical system. A light transmissive first substrate having a predetermined thickness along,
A light transmissive second substrate disposed behind the first substrate in the illumination pupil space and having a predetermined thickness along the optical axis;
The first dimming pattern is formed on at least one of a light incident side surface and a light emission side surface of the first substrate,
19. The second dimming pattern is formed on at least one of a light incident side surface and a light emission side surface of the second substrate. Correction unit. A correction unit for correcting the pupil intensity distribution formed on the illumination pupil of the illumination optical system,
It is arranged in an illumination pupil space between an optical element having power adjacent to the front side of the illumination pupil and an optical element having power adjacent to the rear side of the illumination pupil, and is arranged on the optical axis of the illumination optical system. A light transmissive first substrate having a predetermined thickness along,
A light transmissive second substrate disposed behind the first substrate in the illumination pupil space and having a predetermined thickness along the optical axis;
The first substrate has a first dimming pattern formed on at least one of a light incident side surface and a light emission side surface;
The second substrate has a second dimming pattern formed on at least one of a light incident side surface and a light emission side surface;
The first dimming pattern has at least one first unit dimming region;
The second dimming pattern has at least one second unit dimming region formed corresponding to the at least one first unit dimming region,
The correction unit, wherein the first substrate and the second substrate are configured to be relatively movable along a first direction crossing the optical axis. The first unit dimming region and the second unit dimming region have the same outer shape and the same size.
The first substrate dimming and the second substrate are centered on a reference state in which the first unit dimming region and the second unit dimming region overlap each other when viewed from the optical axis direction. 21. The correction unit according to claim 20, wherein a part of the region and a part of the second unit dimming region are configured to be relatively movable within a range where they overlap each other when viewed from the optical axis direction. The correction unit according to any one of claims 19 to 21, wherein the first substrate and the second substrate have a shape of a plane parallel plate. The correction unit according to claim 22, wherein the first substrate and the second substrate are arranged in parallel to each other. The first dimming pattern is formed on the surface on the emission side of the first substrate, and the second dimming pattern is formed on the surface on the incident side of the second substrate. The correction unit according to any one of 19 to 23. The first dimming pattern has a plurality of first unit dimming regions formed in a distribution,
25. The second dimming pattern includes a plurality of second unit dimming regions distributed in correspondence with the plurality of first unit dimming regions. The correction unit described in 1. 26. The correction unit according to claim 17, wherein at least one of the first unit dimming region and the second unit dimming region has a light blocking region that blocks incident light. . The correction according to any one of claims 17 to 26, wherein at least one of the first unit dimming region and the second unit dimming region has a scattering region for scattering incident light. unit. The correction according to any one of claims 17 to 27, wherein at least one of the first unit dimming region and the second unit dimming region has a diffraction region for diffracting incident light. unit. A correction unit for correcting the pupil intensity distribution formed on the illumination pupil of the illumination optical system,
It is arranged in an illumination pupil space between an optical element having power adjacent to the front side of the illumination pupil and an optical element having power adjacent to the rear side of the illumination pupil, and is arranged on the optical axis of the illumination optical system. A light transmissive first substrate having a predetermined thickness along,
A light transmissive second substrate disposed behind the first substrate in the illumination pupil space and having a predetermined thickness along the optical axis;
The first substrate has a first dimming pattern formed on at least one of a light incident side surface and a light emission side surface;
The second substrate has a second dimming pattern formed on at least one of a light incident side surface and a light emission side surface;
The first dimming pattern has at least one first unit dimming region;
The second dimming pattern has at least one second unit dimming region formed corresponding to the at least one first unit dimming region,
The first unit dimming region and the second unit dimming region give a first dimming rate to light incident on the first unit dimming region at a first incident angle, and Giving a second light attenuation rate different from the first light attenuation rate to light incident at a second incident angle different from the first angle of incidence on the one unit light attenuation region;
The correction unit characterized in that the positional relationship between the first substrate and the second substrate can be changed. The dimming rate due to the first dimming pattern and the second dimming pattern changes according to a change in the relative position between the first substrate and the second substrate and a change in the incident angle of light on the first substrate. 30. The correction unit according to claim 29, wherein the correction unit is configured to. 30. The correction unit according to claim 29, wherein a part of the first unit dimming area and a part of the second unit dimming area overlap each other when viewed from the optical axis direction. 30. The correction unit according to claim 29, wherein the first substrate and the second substrate are configured to be relatively movable along a first direction crossing the optical axis. In the illumination optical system that illuminates the illuminated surface with light from the light source,
A distribution forming optical system having an optical integrator and forming a pupil intensity distribution in an illumination pupil on the rear side of the optical integrator;
33. An illumination optical system comprising: the correction unit according to claim 1 arranged in the illumination pupil space including the rear illumination pupil. The optical integrator has a rectangular unit wavefront dividing surface that is elongated along a predetermined direction, and the correction unit is spaced apart in the direction orthogonal to the predetermined direction across the optical axis of the illumination optical system at the illumination pupil. The illumination optical system according to claim 33, wherein the illumination optical system is positioned so as to act on light from the pair of regions. In the illumination optical system that illuminates the illuminated surface with light from the light source,
A distribution forming optical system having an optical integrator and forming a pupil intensity distribution in an illumination pupil on the rear side of the optical integrator;
The correction unit according to any one of claims 1 to 32, which is disposed in the illumination pupil space including the illumination pupil on the rear side,
The optical integrator has an elongated rectangular unit wavefront dividing surface along a predetermined direction, and the predetermined direction corresponds to a first direction in the correction unit. 36. The light quantity distribution adjustment unit for changing an illuminance distribution on the irradiated surface or a shape of an illumination area formed on the irradiated surface, according to any one of claims 33 to 35. Lighting optics. The illumination optical system according to claim 36, wherein the light quantity distribution adjustment unit corrects an influence on the light quantity distribution on the irradiated surface by the correction unit. The projection pupil is used in combination with a projection optical system that forms a surface optically conjugate with the irradiated surface, and the illumination pupil is at a position optically conjugate with an aperture stop of the projection optical system. The illumination optical system according to any one of 33 to 37. The distribution forming optical system forms the pupil intensity distribution in an illumination pupil adjacent to the optical integrator;
The illumination optical system according to any one of claims 33 to 38, wherein the correction unit is arranged in the adjacent illumination pupil. The distribution forming optical system includes a relay optical system that guides light from the optical integrator to form a pupil intensity distribution on the rear illumination pupil,
The illumination optical system according to any one of claims 33 to 38, wherein the correction unit is disposed in the illumination pupil space including the rear illumination pupil. 41. The illumination optical system according to claim 40, wherein the relay optical system forms a position optically conjugate with an illumination pupil adjacent to the optical integrator in the rear illumination pupil. 42. An exposure apparatus comprising the illumination optical system according to any one of claims 33 to 41 for illuminating a predetermined pattern, and exposing the predetermined pattern onto a photosensitive substrate. A projection optical system for forming an image of the predetermined pattern on the photosensitive substrate, and moving the predetermined pattern and the photosensitive substrate relative to the projection optical system along a scanning direction to 44. The exposure apparatus according to claim 42, wherein the pattern is projected and exposed onto the photosensitive substrate. 44. The exposure apparatus according to claim 43, wherein the predetermined direction in the optical integrator corresponds to a direction orthogonal to the scanning direction. An exposure step of exposing the predetermined pattern to the photosensitive substrate using the exposure apparatus according to any one of claims 42 to 44;
Developing the photosensitive substrate to which the predetermined pattern is transferred, and forming a mask layer having a shape corresponding to the predetermined pattern on the surface of the photosensitive substrate;
And a processing step of processing the surface of the photosensitive substrate through the mask layer.

Images