JP5190804B2 - Dimming unit, illumination optical system, exposure apparatus, and device manufacturing method - Google Patents

Description

  The present invention relates to a dimming 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 illumination distribution on the wafer in order to accurately transfer the 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.

  The present invention has been made in view of the above-described problems, and an object of the present invention 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.

  In order to solve the above problems, in the first embodiment of the present invention, a dimming unit used in combination with a wavefront division type optical integrator disposed in an optical path of an illumination optical system that illuminates a surface to be irradiated, Provided behind the plurality of first refracting surfaces so as to correspond to the plurality of first refracting surfaces of the optical integrator having a predetermined refractive power in a first direction within a plane orthogonal to the optical axis of the illumination optical system. And disposed immediately after a boundary line between at least two adjacent second refracting surfaces of the plurality of second refracting surfaces of the optical integrator having a predetermined refractive power in the first direction. A dimming unit comprising a dimming unit having a dimming rate characteristic in which the dimming rate increases as the position of the light reaching reaches away from the center of the irradiated surface along the first direction. To provide a Tsu door.

  According to a second aspect of the present invention, there is provided a dimming unit used in combination with a wavefront division type optical integrator disposed in an optical path of an illumination optical system that illuminates a surface to be irradiated, the optical axis of the illumination optical system, Provided on the rear side of the plurality of first refracting surfaces so as to correspond to the plurality of first refracting surfaces of the optical integrator having a predetermined refractive power in a first direction within a plane orthogonal to the predetermined direction in the first direction. And a second orthogonal to the first direction in the plane, which is disposed immediately after the boundary line of at least two adjacent second refractive surfaces of the plurality of second refractive surfaces of the optical integrator having the refractive power of A linear light-shielding member extending substantially parallel to the boundary line extending in the direction, and the linear light-shielding member can be changed in either position or orientation. To provide a unit.

  In a third aspect of the present invention, in an illumination optical system that illuminates a surface to be irradiated based on light from a light source, a wavefront division type optical integrator disposed in an optical path of the illumination optical system, and a combination with the optical integrator The illumination optical system is provided with the light reduction unit of the first form or the second form used.

  According to a fourth aspect of the present invention, there is provided an exposure apparatus comprising the illumination optical system according to the third aspect for illuminating a predetermined pattern, and exposing the predetermined pattern onto a photosensitive substrate.

  In the fifth embodiment of the present invention, using the exposure apparatus of the fourth embodiment, an exposure step of exposing the predetermined pattern to the photosensitive substrate, and developing the photosensitive substrate to which the predetermined pattern is transferred, A development step for forming a mask layer having a shape corresponding to the predetermined pattern on the surface of the photosensitive substrate; and a processing step for processing the surface of the photosensitive substrate through the mask layer. A device manufacturing method is provided.

  In the illumination optical system of the present invention, the dimming unit of the dimming unit is provided immediately after the boundary line between adjacent refractive surfaces of the optical integrator. This dimming part has a dimming rate characteristic in which the dimming rate increases as the position of the light reaching the irradiated surface moves away from the center along a predetermined direction. Therefore, the pupil intensity distribution for each point on the irradiated surface is independently adjusted by the action of the dimming unit of the dimming unit, and consequently the pupil intensity distribution for each point is adjusted to a distribution having substantially the same property as each other. Is possible. As a result, in the illumination optical system of the present invention, for example, a density filter that uniformly adjusts the pupil intensity distribution at each point on the irradiated surface, and a dimming unit that independently adjusts the pupil intensity distribution for each point, With this cooperative action, the pupil intensity distribution at each point on the illuminated surface can be adjusted substantially uniformly. Thus, the exposure apparatus of the present invention can perform good exposure under appropriate illumination conditions using the 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.

It is a figure which shows schematically the structure of the exposure apparatus concerning embodiment of this invention. It is a perspective view which shows schematically the structure of the cylindrical micro fly's eye lens of FIG. It is a figure which shows the quadrupole secondary light source formed in an illumination pupil. It is a figure which shows the rectangular-shaped static exposure area | region formed on a wafer. 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 forms. It is a figure explaining the property of the quadrupole pupil intensity distribution which the light which injects into the peripheral points P2 and P3 in a still exposure area | region forms. (A) is a light intensity distribution along the Z direction of the pupil intensity distribution with respect to the center point P1, and (b) is a diagram schematically showing the light intensity distribution along the Z direction of the pupil intensity distribution with respect to the peripheral points P2 and P3. It is. It is a figure explaining the principal part structure and effect | action of the light reduction unit of this embodiment. It is a figure which shows roughly the whole structure of the light reduction unit of this embodiment. (A) shows a state in which a light beam group reaching the center point P1 forms a small light source of the original size, and (b) shows a light beam group reaching the peripheral points P2 and P3 and a small light source of the original size. It is a figure which shows typically a mode that a small small light source is formed. It is a 1st figure explaining the effect of the dimming unit of this embodiment. It is a 2nd figure explaining the effect of the dimming unit of this embodiment. It is a perspective view which shows roughly the structure of the cylindrical micro fly's eye lens which has another form from FIG. It is a figure which shows a mode that the light shielding member of a light reduction unit is arrange | positioned with respect to the cylindrical micro fly's eye lens of FIG. It is a figure which shows the structural example using the light shielding member which has a triangular cross section. It is a figure which shows the structural example using the light shielding member which has a rectangular-shaped cross section. It is a figure which shows the structural example using the light-shielding member extended locally in the state in which only one end was supported. It is a figure which shows the structural example using the light-shielding member which has a cross section which changes along a longitudinal direction. It is a figure which shows the 1st structural example which can change the position or attitude | position of a light shielding member. It is a figure which shows the 2nd structural example which can change the position or attitude | position of a light shielding member. It is a figure which shows the 3rd structural example which can change the position or attitude | position of a light shielding member. It is a figure which shows the 4th structural example which can change the position or attitude | position of a light shielding member. It is a figure which shows the 5th structural example which can change the position or attitude | position of a light shielding member. It is a figure which shows the 6th structural example which can change the position or attitude | position of a light shielding member. It is a figure which shows an example of the drive mechanism which changes the position or attitude | position of a light shielding member. 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 an 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, in the exposure apparatus of the present embodiment, exposure light (illumination light) is supplied from a light source 1. 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 emitted from the light source 1 is converted into a light beam having a required cross-sectional shape by the shaping optical system 2 and then enters the afocal lens 4 via, for example, a diffractive optical element 3 for annular illumination.

  The afocal lens 4 is set so that the front focal position thereof and the position of the diffractive optical element 3 substantially coincide with each other, and the rear focal position thereof substantially coincides with the position of the predetermined surface 5 indicated by a broken line in the drawing. System (non-focal optical system). 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 is emitted from the afocal lens 4 with a ring-shaped angular distribution after forming a ring-shaped light intensity distribution on the pupil plane of the afocal lens 4. In the optical path between the front lens group 4a and the rear lens group 4b of the afocal lens 4, a density filter 6 is disposed at or near the pupil position. The density filter 6 has the 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 6 has a transmittance distribution with different transmittances depending on the incident position of light. The specific operation of the density filter 6 will be described later.

  The light passing through the afocal lens 4 passes through a zoom lens 7 for varying the σ value (σ value = mask-side numerical aperture of the illumination optical system / mask-side numerical aperture of the projection optical system), and a cylindrical micro as an optical integrator. The light enters the fly eye lens 9. As shown in FIG. 2, the cylindrical micro fly's eye lens 9 includes a first fly eye member (first optical member) 9a disposed on the light source side and a second fly eye member (second optical member) disposed on the mask side. ) 9b. On the light source side (incident side) surface of the first fly's eye member 9a and the light source side surface of the second fly's eye member 9b, a plurality of cylindrical refractive surfaces (cylindrical lens groups) arranged side by side in the X direction. 9aa and 9ba are formed with a pitch px. A plurality of cylindrical refractive surfaces (cylindrical lens groups) arranged side by side in the Z direction on the mask side (exit side) surface of the first fly eye member 9a and the mask side surface of the second fly eye member 9b. ) 9ab and 9bb are each formed with a pitch pz (pz> px).

  Focusing on the refraction action in the X direction of the cylindrical micro fly's eye lens 9 (that is, the refraction action in the XY plane), a group of parallel light beams incident along the optical axis AX are formed on the light source side of the first fly eye member 9a. Corresponding in the group of refracting surfaces 9ba formed on the light source side of the second fly's eye member 9b after being wavefront divided along the X direction by the refracting surface 9aa with a pitch px and receiving the condensing action on the refracting surface. The light is focused on the refracting surface to be focused on the rear focal plane of the cylindrical micro fly's eye lens 9. Focusing on the refractive action in the Z direction of the cylindrical micro fly's eye lens 9 (ie, the refractive action in the YZ plane), a group of parallel light beams incident along the optical axis AX are formed on the mask side of the first fly's eye member 9a. Corresponding in the group of refracting surfaces 9bb formed on the mask side of the second fly's eye member 9b after the wavefront is divided by the refracting surface 9ab with the pitch pz along the Z direction The light is focused on the refracting surface to be focused on the rear focal plane of the cylindrical micro fly's eye lens 9.

  As described above, the cylindrical micro fly's eye lens 9 is composed of the first fly eye member 9a and the second fly eye member 9b in which the cylindrical lens groups are arranged on both side surfaces, and the size of px is set in the X direction. It has the same optical function as a micro fly's eye lens in which a large number of rectangular minute refracting surfaces (unit wavefront dividing surfaces) having a size of pz in the Z direction are integrally formed vertically and horizontally. In the cylindrical micro fly's eye lens 9, a change in distortion due to variations in the surface shape of the micro-refractive surface is suppressed, and for example, manufacturing errors of a large number of micro-refractive surfaces formed integrally by etching process give the illuminance distribution. The influence can be kept small.

  The position of the predetermined surface 5 is disposed at or near the front focal position of the zoom lens 7, and the incident surface of the cylindrical micro fly's eye lens 9 (that is, the incident surface of the first fly's eye member 9 a) is the rear focal position of the zoom lens 7. Or it is arrange | positioned in the vicinity. In other words, the zoom lens 7 arranges the predetermined surface 5 and the incident surface of the cylindrical micro fly's eye lens 9 substantially in a Fourier transform relationship, and consequently the pupil surface of the afocal lens 4 and the cylindrical micro fly's eye lens 9. The incident surface is optically substantially conjugate. Accordingly, on the incident surface of the cylindrical micro fly's eye lens 9, 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. As described above, each unit wavefront dividing surface of the cylindrical micro fly's eye lens 9 has a rectangular shape having a long side along the Z direction and a short side along the X direction, and is formed on the mask M. It has a rectangular shape similar to the shape of the illumination area to be formed (and thus the shape of the exposure area to be formed on the wafer W).

  The light beam incident on the cylindrical micro fly's eye lens 9 is two-dimensionally divided, and is formed on the incident surface of the cylindrical micro fly's eye lens 9 at the rear focal plane or a position in the vicinity thereof (and thus the position of the illumination pupil). A secondary light source having substantially the same light intensity distribution as the illumination field, that is, a secondary light source (pupil intensity distribution) composed of a ring-shaped substantial surface light source centered on the optical axis AX is formed. A dimming unit 10 is arranged immediately after the cylindrical micro fly's eye lens 9. The configuration and operation of the dimming unit 10 will be described later. An illumination aperture stop (not shown) having an annular opening (light transmitting portion) corresponding to an annular secondary light source on the rear focal plane of the cylindrical micro fly's eye lens 9 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 cylindrical micro fly's eye lens 9 and the dimming unit 10 illuminates the mask blind 12 in a superimposed manner via the condenser optical system 11. Thus, a rectangular illumination field corresponding to the shape and focal length of the unit wavefront dividing surface of the cylindrical micro fly's eye lens 9 is formed on the mask blind 12 as an illumination field stop. The light that has passed through the rectangular opening (light transmission portion) of the mask blind 12 passes through the imaging optical system 13 including the front lens group 13a and the rear lens group 13b, and the mask M on which a predetermined pattern is formed. Are illuminated in a superimposed manner. That is, the imaging optical system 13 forms an image of the rectangular opening of the mask blind 12 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.

  In the present embodiment, as described above, the secondary light source formed by the cylindrical micro fly's eye lens 9 is used as the light source, and the mask M arranged on the irradiated surface of the illumination optical system (2-13) 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 (2-13). 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 (2-13) or a plane optically conjugate with the illumination pupil plane. When the number of wavefront divisions by the cylindrical micro fly's eye lens 9 is relatively large, the global light intensity distribution formed on the incident surface of the cylindrical micro fly's eye lens 9 and the global light intensity distribution of the entire secondary light source (pupil) Intensity distribution). For this reason, the light intensity distribution on the incident surface of the cylindrical micro fly's eye lens 9 and a 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 cylindrical micro fly's eye lens 9 are distributions that form a pupil intensity distribution in the illumination pupil behind the cylindrical micro fly's eye lens 9. The forming optical 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 (two-pole illumination, four-pole 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. Therefore, the light flux that has passed through the diffractive optical element for multipole illumination is irradiated on the incident surface of the cylindrical micro fly's eye lens 9 with, for example, an illumination field having a plurality of predetermined shapes (arc shape, circular shape, etc.) centered on the optical axis AX A multipolar illumination field consisting of As a result, the same multipolar secondary light source as the illumination field formed on the incident surface is formed on the rear focal plane of the cylindrical micro fly's eye lens 9 or in the vicinity thereof. Moreover, instead of the diffractive optical element 3 for annular illumination, a normal circular illumination can be performed by setting a diffractive optical element (not shown) for circular illumination in the illumination optical path. The diffractive optical element for circular illumination has a function of forming a circular light intensity distribution in the far field when a parallel light beam having a rectangular cross section is incident. Therefore, the light beam that has passed through the diffractive optical element for circular illumination forms, for example, a circular illumination field around the optical axis AX on the incident surface of the cylindrical micro fly's eye lens 9. 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 cylindrical micro fly's eye lens 9. 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 effects of the present embodiment, the rear focal plane of the cylindrical micro fly's eye lens 9 or the illumination pupil in the vicinity thereof has four arcs 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. In the following description, the term “illumination pupil” simply refers to the illumination pupil in the rear focal plane of the cylindrical micro fly's eye lens 9 or in the vicinity thereof. Referring to FIG. 3, the quadrupole pupil intensity distribution 20 formed in the illumination pupil includes the surface light sources 20a and 20b spaced in the X direction with the optical axis AX interposed therebetween, and the Z direction with the optical axis AX interposed therebetween. And a pair of arcuate substantial surface light sources 20c and 20d spaced apart from each other. The X direction in the illumination pupil is the short side direction of the rectangular unit wavefront dividing surface of the cylindrical micro fly's eye lens 9 and corresponds to the scanning direction of the wafer W. Further, the Z direction in the illumination pupil is the long side direction of the rectangular unit wavefront dividing surface of the cylindrical micro fly's eye lens 9, and the scanning orthogonal direction perpendicular to the scanning direction of the wafer W (Y direction on the wafer W). It corresponds to.

  As shown in FIG. 4, a rectangular still exposure region ER having a long side along the Y direction and a short side along the X direction is formed on the wafer W. 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. 5, in the case of a quadrupole pupil intensity distribution 21 formed by light incident on the center point P1 in the static exposure region ER, the surface light source 21c and the surface light source 21c spaced apart in the Z 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. 6, in the case of a quadrupole pupil intensity distribution 22 formed by light incident on peripheral points P2 and P3 spaced from the center 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 Z 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. 7A, the light intensity distribution along the Z direction 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 Z 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 Z 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 present embodiment, as described above, the density filter 6 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 cylindrical micro fly's eye lens 9 by the rear lens group 4b and the zoom lens 7. Therefore, the light intensity distribution formed on the incident surface of the cylindrical micro fly's eye lens 9 is adjusted (corrected) by the action of the density filter 6, and as a result, the rear focal plane of the cylindrical micro fly's eye lens 9 or the illumination pupil in the vicinity thereof. The pupil intensity distribution formed at the same time is also adjusted. However, the density filter 6 uniformly adjusts the pupil intensity distribution for each point in the still 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 6, for example, adjustment is made so that the quadrupole pupil intensity distribution 21 with respect to the center point P <b> 1 becomes substantially uniform, so that the light intensities of the surface light sources 21 a to 21 d 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 static exposure region ER on the wafer W almost uniformly by the action of the density filter 6, the pupil intensity for each point can be adjusted by means other than the density filter 6. 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 present embodiment, in order to make 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 substantially coincide, specifically, in the pupil intensity distribution 22 related to the peripheral points P2 and P3, A dimming unit 10 is provided as an adjusting means for adjusting the light intensity of the light sources 22a and 22b to be smaller than the light intensity of the surface light sources 22c and 22d. FIG. 8 is a diagram for explaining the main configuration and operation of the dimming unit according to the present embodiment. FIG. 9 is a diagram schematically showing the overall configuration of the dimming unit according to the present embodiment. Referring to FIG. 8, of the pair of fly eye members 9a and 9b constituting the cylindrical micro fly's eye lens 9, two adjacent in the Z direction on the exit side of the second fly eye member 9b on the rear side (mask side). Immediately after the boundary line 9bc of the two refracting surfaces 9bb, a light shielding member 10a extending linearly along the X direction is disposed in parallel with the boundary line 9bc. The light shielding member 10a has, for example, a circular cross section and is made of a suitable metal. Further, as schematically shown in FIG. 9, the light shielding member 10a is spaced in the Z direction so as to act on a pair of surface light sources 20a and 20b spaced in the X direction in the quadrupole pupil intensity distribution 20. A required number (four in FIG. 9 exemplarily in FIG. 9) is arranged at a distance.

  Specifically, as shown in FIG. 9, the dimming unit 10 of the present embodiment includes a plurality of light shielding members 10 a extending linearly along the X direction at intervals in the Z direction, and the plurality of light shielding members. In order to hold | maintain 10a in a predetermined position, it is comprised by the holding member 10b which supports the both ends of each light shielding member 10a. When each light shielding member 10a does not have a required bending rigidity, each light shielding member 10a can be maintained in a straight line by supporting both ends of the light shielding member 10a with a required tension applied. In FIG. 8, in order to facilitate understanding of the function and effect of the light shielding member 10a (and hence the function and effect of the dimming unit 10), a pair of light shielding members corresponding to the two boundary lines 9bc adjacent in the Z direction. 10a shows a state in which 10a is arranged. Referring to FIG. 8, in the quadrupole pupil intensity distribution 20, the light forming the surface light sources 20 a and 20 b spaced in the X direction acts immediately after passing through the cylindrical micro fly's eye lens 9. However, the light forming the surface light sources 20c and 20d spaced in the Z direction is not affected by the light shielding member 10a. Hereinafter, with reference to FIG. 8, attention is paid to a light beam group forming one small light source 20aa (or 20ba) among a large number of small light sources constituting the surface light source 20a (or 20b) via one refractive surface 9bb. Then, the operation of the light shielding member 10a as the light reducing portion will be described.

  The light beam group L1 reaching the center point P1 in the static exposure region ER on the wafer W passes through the central region along the Z direction of the refractive surface 9bb. Therefore, the light beam group L1 receives the refraction action of the refraction surface 9bb without receiving the action of the light shielding member 10a, and forms a small light source having the original size (light quantity) in the illumination pupil. That is, the light ray group L1 forms one small light source with the original light amount among the many small light sources constituting the surface light source 21a (or 21b) of the pupil intensity distribution 21 with respect to the center point P1. On the other hand, the light ray group L2 reaching the peripheral point P2 in the still exposure region ER passes through a region away from the central region along the Z direction of the refractive surface 9bb. As a result, a part of the light beam group L2 having passed through the refracting surface 9bb is incident on the light shielding member 10a, and the remaining part reaches the formation surface of the small light source (the surface of the illumination pupil) without entering the light shielding member 10a. The light that is incident and reflected on the light shielding member 10a is guided outside the illumination light path, for example, without contributing to the formation of the pupil intensity distribution. In this way, a part of the light beam group L2 is subjected to the refracting action of the refracting surface 9bb and the dimming action of the light shielding member 10a, and the remaining part is only subjected to the refracting action of the refracting surface 9bb to illuminate a small light source smaller than the original size. Form in the pupil. That is, the light beam group L2 forms one small light source among a large number of small light sources constituting the surface light source 22a (or 22b) of the pupil intensity distribution 22 with respect to the peripheral point P2 as a small light source having a light amount smaller than the original. .

  A part of the light beam L3 reaching the peripheral point P3 in the still exposure region ER also enters the light shielding member 10a after passing through the refracting surface 9bb, and the remaining part is small without entering the light shielding member 10a after passing through the refracting surface 9bb. Reach the formation surface of the light source. As a result, the light beam group L3, like the light beam group L2, partly receives the refraction action of the refracting surface 9bb and the dimming action of the light shielding member 10a, and the remaining part receives only the refraction action of the refracting surface 9bb. A small light source smaller than this is formed on the illumination pupil. That is, the light ray group L3 forms one small light source among a large number of small light sources constituting the surface light source 22a (or 22b) of the pupil intensity distribution 22 related to the peripheral point P3 as a small light source having a light amount smaller than the original. . In this way, the ray group L1 reaching the center point P1 in the still exposure region ER has an original size as shown schematically in FIG. 10A in the surface light sources 21a and 21b of the quadrupole pupil intensity distribution 21. The small light sources 31 having the same length (that is, the original light amount) are formed in a matrix. On the other hand, ray groups L2 and L3 reaching the peripheral points P2 and P3 in the still exposure region ER are schematically shown in FIG. 10B in the surface light sources 22a and 22b of the quadrupole pupil intensity distribution 22. As described above, the small light source 32a having the original size (original light amount) and the small light source 32b smaller than the original (smaller light amount than the original) are formed in a matrix.

  Actually, unlike the schematic diagram shown in FIG. 10B, the small light source 32b corresponds to the position along the Z direction and the number n of the light shielding member 10a at n positions along the Z direction. They are formed side by side along the X direction. Accordingly, in the surface light sources 22a and 22b of the pupil intensity distribution 22 related to the peripheral points P2 and P3, the small light source 32b having a smaller light amount than the original light source L2 and L3 is affected by the light-reducing effect of the light shielding member 10a. The overall light intensity decreases according to the ratio of the total number. Here, the proportion of the small light source 32b depends on the number n of the light shielding members 10a acting on the surface light sources 22a and 22b. Further, the degree to which the light beam groups L2 and L3 are subjected to the light reducing action of the light shielding member 10a, that is, the light attenuation rate, depends on the shape of the cross section of the light shielding member 10a. Generally, as the point at which the light ray group reaches the still exposure region ER is further away from the central point P1 along the Y direction, the light ray group passes through a region away from the central region along the Z direction of the refractive surface 9bb. In other words, the ratio of the light incident on the light shielding member 10a and blocked is larger than the ratio of the light incident on the refractive surface 9bb. In other words, the degree to which the light ray group reaching one point in the still exposure region ER is subjected to the dimming action of the light blocking member 10a is determined in the Y direction (scanning) from the center point P1 of the still exposure region ER to the point where the light ray group reaches. It increases as the distance along the (orthogonal direction) increases. In other words, the light blocking member 10a as the light reduction unit increases the light reduction rate as the position of the light beam reaching the still exposure region ER as the irradiated surface is separated from the center of the still exposure region ER along the Y direction. It has a good light attenuation rate characteristic.

  Thus, in the pupil intensity distribution 21 related to the center point P1, the light forming the surface light sources 21a and 21b is not affected by the light-shielding member 10a, so the light intensity of the surface light sources 21a and 21b is maintained at its original size. Is done. Since the light forming the surface light sources 21c and 21d is not affected by the light-reducing action of the light shielding member 10a, the light intensity of the surface light sources 21c and 21d is maintained at the original size. As a result, as shown in FIG. 11, the pupil intensity distribution 21 related to the center point P1 remains the original distribution without being subjected to the dimming action of the light shielding member 10a. That is, the property that the light intensity of the surface light sources 21c and 21d spaced in the Z direction is larger than the light intensity of the surface light sources 21a and 21b spaced in the X direction is maintained as it is. On the other hand, in the pupil intensity distribution 22 related to the peripheral points P2 and P3, a part of the light from the surface light sources 22a and 22b is subjected to the dimming action of the light shielding member 10a, so the overall light intensity of the surface light sources 22a and 22b is descend. Since the light from the surface light sources 22c and 22d is not subjected to the dimming action of the light shielding member 10a, the light intensity of the surface light sources 22c and 22d is maintained at the original size. 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 property different from the original distribution 22 by the dimming action of the light shielding member 10a as shown in FIG. That is, in the adjusted pupil intensity distribution 22 ′, the light intensity of the surface light sources 22c and 22d spaced in the Z direction is larger than the light intensity of the surface light sources 22a ′ and 22b ′ spaced in the X direction. It changes to properties.

  Thus, due to the action of the light shielding member 10a (and hence the action of the dimming part of the light shielding unit 10), the pupil intensity distribution 22 for the peripheral points P2 and P3 has a distribution 22 having substantially the same properties as the pupil intensity distribution 21 for the center point P1. Adjusted to '. 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 related 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 distributions having substantially the same properties by the action of the light shielding unit 10. In other words, the light blocking member 10a serving as a light reducing unit disposed immediately after the cylindrical micro fly's eye lens 9 is necessary for adjusting the pupil intensity distributions at the respective points to distributions having substantially the same properties. It has a required light attenuation rate characteristic, that is, a light attenuation rate characteristic in which the light attenuation rate increases as the position of the light reaching the still exposure region ER as the irradiated surface moves away from the center point P1 along the Y direction. As described above, the required light attenuation rate characteristics of the light reduction portion are realized by appropriately setting the number of light shielding members 10a, the cross-sectional shape of the light shielding members 10a, and the like.

  As described above, the light shielding unit 10 of the present embodiment is disposed immediately after the boundary line 9bc of the refracting surface 9bb adjacent in the Z direction on the exit side of the cylindrical micro fly's eye lens 9 as a wavefront division type optical integrator. A light shielding member 10a extending linearly along the X direction in parallel with the boundary line 9bc is provided. The light blocking member 10a as the light reducing portion has a required light attenuation rate characteristic in which the light attenuation rate increases as the position of the light reaching the stationary exposure region ER, which is the irradiated surface, moves away from the center point P1 along the Y direction. Have. Accordingly, the pupil intensity distribution for each point on the irradiated surface is independently adjusted by the action of the light reducing unit of the light shielding unit 10 obtained by appropriately setting the arrangement position, the number, the cross-sectional shape, etc. of the light shielding member 10a. As a result, the pupil intensity distribution for each point can be adjusted to distributions having substantially the same properties. Further, in the illumination optical system (2 to 13) of the present embodiment, the light shielding unit 10 as an adjustment unit that independently adjusts the pupil intensity distribution regarding each point in the still exposure region ER on the wafer W, The pupil intensity distribution for each point is adjusted substantially uniformly by the cooperative action with the density filter 6 that has a required transmittance characteristic that changes according to the incident position and uniformly adjusts the pupil intensity distribution for each point. be able to. Therefore, the exposure apparatus (1 to WS) of the present embodiment uses the illumination optical system (2 to 13) that adjusts the pupil intensity distribution at each point in the still exposure region ER on the wafer W almost uniformly. Therefore, 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 is faithfully applied on the wafer W with a desired line width over the entire exposure region. Can be transferred to.

  In the present embodiment, it is conceivable that the light amount distribution on the wafer (irradiated surface) W is affected by, for example, the adjustment operation of the light reduction unit of the light shielding unit 10. In this case, the exposure amount is changed by changing the illuminance distribution in the still exposure region ER or changing the shape of the still exposure region (illumination region) ER as required by the action of the light amount distribution adjusting unit having a known configuration. Distribution can be changed. Specifically, as the light amount 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 description, the cylindrical micro fly's eye lens 9 having the form shown in FIG. 2 is used as the wavefront division type optical integrator. However, without being limited thereto, for example, a cylindrical micro fly's eye lens 19 having another form as shown in FIG. 13 may be used. As shown in FIG. 13, the cylindrical micro fly's eye lens 19 includes a first fly eye member 19a disposed on the light source side and a second fly eye member 19b disposed on the mask side. A plurality of cylindrical refracting surfaces (cylindrical lens groups) 19aa and 19ab arranged side by side in the X direction are formed at a pitch p1 on the light source side surface and the mask side surface of the first fly-eye member 19a. ing. A plurality of cylindrical refracting surfaces (cylindrical lens groups) 19ba and 19bb arranged side by side in the Z direction are respectively formed on the light source side surface and the mask side surface of the second fly-eye member 19b at a pitch p2 (p2>). p1).

  Focusing on the refractive action in the X direction of the cylindrical micro fly's eye lens 19 (that is, the refractive action in the XY plane), a group of parallel light beams incident along the optical axis AX are formed on the light source side of the first fly's eye member 19a. Corresponding in the group of refracting surfaces 19ab formed on the mask side of the first fly's eye member 19a after the wavefront is divided at the pitch p1 along the X direction by the refracting surfaces 19aa The light is focused on the refracting surface to be focused on the rear focal plane of the cylindrical micro fly's eye lens 19. Focusing on the refractive action in the Z direction of the cylindrical micro fly's eye lens 19 (that is, the refractive action in the YZ plane), a group of parallel beams incident along the optical axis AX are formed on the light source side of the second fly's eye member 19b. Corresponding in the group of refracting surfaces 19bb formed on the mask side of the second fly's eye member 19b after the wave front is divided at the pitch p2 along the Z direction by the refracting surfaces 19ba of the second fly-eye member 19b. The light is focused on the refracting surface to be focused on the rear focal plane of the cylindrical micro fly's eye lens 19.

  As described above, the cylindrical micro fly's eye lens 19 is composed of the first fly eye member 19a and the second fly eye member 19b in which the cylindrical lens groups are arranged on both side surfaces, and has a size of p1 in the X direction. It has a large number of rectangular microscopic refracting surfaces (unit wavefront dividing surfaces) having a size of p2 in the direction. That is, the cylindrical micro fly's eye lens 19 has a rectangular unit wavefront dividing surface having a long side along the Z direction and a short side along the X direction. When the cylindrical micro fly's eye lens 19 is used, a dimming unit 10 including a linear light-shielding member 10a having a circular cross section, for example, is attached as in the case of the cylindrical micro fly's eye lens 9 of FIG. Thus, the same effects as those of the above-described embodiment can be exhibited. Specifically, as shown in FIG. 14, two refractive surfaces adjacent to each other in the Z direction on the exit side of the second fly eye member 19b on the rear side (mask side) of the pair of fly eye members 19a and 19b. Immediately after the border line 19bc of 19bb, a light shielding member 10a extending in a straight line along the X direction is arranged in parallel with the border line 19bc. For example, as schematically illustrated in FIG. 9, the light shielding member 10 a serving as the light reduction unit is required to be spaced apart in the Z direction so as to act on the pair of surface light sources 20 a and 20 b spaced in the X direction. The number is arranged.

  More generally, without being limited to a cylindrical micro fly's eye lens, a plurality of first refracting surfaces having a predetermined refractive power in a first direction in a plane orthogonal to the optical axis of the illumination optical system, A dimming unit used in combination with a wavefront division type optical integrator provided on the rear side so as to correspond to the first refracting surface and having a plurality of second refracting surfaces having a predetermined refractive power in the first direction. The present invention can be applied to this. In this case, at least two adjacent second refracting surfaces have a dimming portion having a dimming rate characteristic in which the dimming rate increases as the position of the light reaching the irradiated surface increases from the center along the first direction. It is placed immediately after the boundary line.

  Moreover, in the above-mentioned embodiment, the light reduction part of the light reduction unit 10 is comprised by the light-shielding member 10a which has a circular shaped cross section and extends from the position corresponding to the surface light source 20a to the position corresponding to the surface light source 20b. Yes. However, the present invention is not limited to this, and various forms are possible with respect to the specific configuration of the light-reducing portion and the specific configuration of the light shielding member. For example, a light shielding member 10aa having a triangular cross section as shown in FIG. 15 or a light shielding member 10ab having a rectangular cross section as shown in FIG. 16 may be used. That is, not only the arrangement position and the number of the linear light shielding members but also various cross-sectional shapes thereof are possible. Moreover, as shown in FIG. 17, among the pair of surface light sources 23a and 23b spaced apart in the X direction, a plurality of light shielding members 10ac arranged corresponding to one surface light source 23a and the other surface light source 23b. And a holding member 10b that supports only one end of each of the light shielding members 10ac, 10ad in order to hold the light shielding members 10ac, 10ad in a predetermined position. The optical unit 10 can also be configured. As shown in FIG. 18, a light-shielding member having a relatively large cross-sectional area at the end portions corresponding to the surface light sources 23a and 23b and a relatively small cross-sectional area at the central portion (generally, a cross-section changing along the longitudinal direction). It is also possible to use a light shielding member) 10ae. In the configuration example of FIGS. 17 and 18, for example, in a quintuple pupil intensity distribution, only a pair of surface light sources 23 a and 23 b spaced apart in the X direction are dimmed, and the pair of surface light sources 23 a and 23 b are given. There is an advantage that the surface light source 23e that is sandwiched and positioned on the optical axis AX is not dimmed, or unnecessary dimming effect on the surface light source 23e is suppressed to a small level.

  In the above-described embodiment, the linear light shielding member 10a is fixedly positioned. However, the present invention is not limited to this, and any one of the position and posture of one or a plurality of linear light shielding members can be changed. Further, when a plurality of linear light shielding members are provided, at least one of the relative position and the relative posture between one linear light shielding member and the other linear light shielding member can be changed. It can also be configured. With this configuration, it is possible to improve the degree of freedom in changing the light attenuation rate characteristic (light attenuation rate distribution) of the light reduction unit of the light shielding unit. For example, as shown in FIG. 19, a plurality of linear light shielding members 10af can be configured to be movable integrally or individually in the direction along the optical axis AX, that is, the Y direction. In this case, as a certain light shielding member 10af moves away from the refracting surface 9bb, the light attenuation rate by the light shielding member 10af decreases. Further, as shown in FIG. 20, at least one linear light shielding member 10af can be configured to be rotatable around an axis extending in the X direction (an axis orthogonal to the optical axis AX). In this case, as a certain light shielding member 10af rotates, the light attenuation rate due to the end portion of the light shielding member 10af away from the refractive surface 9bb decreases.

  As shown in FIG. 21, in a plurality of linear light shielding members 10ag arranged with respect to the surface light source 20a and a plurality of linear light shielding members 10ah arranged with respect to the surface light source 20b, an XZ plane (optical axis AX) Further, the degree of freedom in changing the light attenuation rate distribution can be improved by configuring the positions of the respective light shielding members in the plane orthogonal to the unit) so that they can be changed integrally or individually. In addition, as shown in FIG. 21, the length can be changed between a certain light shielding member and another light shielding member. Further, as shown in FIG. 22, for example, by configuring the light shielding member 10ag to be movable in the Y direction (direction of the optical axis AX) from the state shown in FIG. be able to. In addition, as shown in FIG. 22, it can also change so that the number of the corresponding light-shielding members may differ between the surface light sources 20a and 20b. Further, as shown in FIG. 23, for example, by configuring the light shielding member 10ag to be rotatable around an axis extending in the Y direction (optical axis AX or an axis parallel to the optical axis AX) from the state shown in FIG. The degree of freedom in changing the light rate distribution can also be improved.

  Further, as shown in FIG. 24, for example, the light shielding member 10ai extending in the Z direction is configured to be rotatable around an axis extending in the X direction (a direction orthogonal to the Z direction and the optical axis AX direction), thereby reducing the light attenuation rate. The degree of freedom of changing the distribution can also be improved. In the example of FIG. 24, it is assumed that the dimming rate distribution is changed in accordance with the distance from the optical axis in the area within the surface light source 20a. In addition, each structural example of FIGS. 19-24 mentioned above can be mutually combined, and the combination can be made arbitrary.

  FIG. 25 shows an example of a drive mechanism when the linear light shielding member is configured to be movable. FIG. 25 (a) corresponds to FIGS. 19 and 20, and shows a driving mechanism that moves each light shielding member 10af in a direction along the optical axis AX and rotates it around an axis orthogonal to the optical axis AX. FIG. 25B corresponds to FIG. 21 and shows a driving mechanism for changing the position of each light shielding member 10ah.

  In FIG. 25 (a), each light shielding member 10af extending in the X direction is connected to the drive unit 31 at both ends thereof, and these drive units 31 are provided on the holding member 10b. Each drive unit 31 rotates the light shielding member 10af around the X axis and moves the light shielding member 10af along the Y direction. Here, if the drive amount along the Y direction is the same in the drive units 31 at both ends of the light shielding member 10af, the position along the Y direction of the light shielding member 10af is changed. If the drive amount along the Y direction is different in the drive units 31 at both ends of the light shielding member 10af, the light shielding member 10af can be rotated around the Z axis.

  In FIG. 25B, among the light shielding members extending in the X direction, the light shielding member 10 ag on the + Z direction side is connected to the drive unit 32, and the light shielding member 10 ah on the −Z direction side is connected to the drive unit 33. . These drive parts 32 and 33 are provided on the holding member 10b. Each driving unit 32 rotates the light shielding member 10ag around the Z axis and changes the position along the Z direction. In addition, each drive unit 33 rotates the light shielding member 10ah around the Z axis and changes the position along the Z direction.

  The adjustment of the position / posture of the light shielding member 10 described above is based on the observation result of the pupil luminance distribution (pupil intensity distribution) at a plurality of positions on the irradiated surface. This is done by controlling the drive unit so as to obtain a desired distribution (intensity). Here, when observing the pupil luminance distribution, pupil luminance distribution measurement disclosed in, for example, Japanese Patent Application Laid-Open No. 2006-54328, Japanese Patent Application Laid-Open No. 2003-22967, and US Patent Publication No. 2003/0038225 corresponding thereto. An apparatus can be used.

  Further, 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.

  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. 26 is a flowchart showing a manufacturing process of a semiconductor device. As shown in FIG. 26, 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. 27 is a flowchart showing manufacturing steps of a liquid crystal device such as a liquid crystal display element. As shown in FIG. 27, 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 appropriate laser light sources are used. 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, 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 the irradiated surface other than the mask or wafer is illuminated. The present invention can also be applied to a general illumination optical system.

DESCRIPTION OF SYMBOLS 1 Light source; 3 Diffractive optical element; 4 Afocal lens; 6 Density filter 7 Zoom lens; 10 Dimming unit; 10a Light-shielding member 9, 19 Cylindrical micro fly's eye lens (optical integrator)
11 Condenser optics; 12 Mask blind; 13 Imaging optics M Mask; PL Projection optics; AS Aperture stop; W Wafer

Claims (27)

A dimming unit used in combination with a wavefront division type optical integrator disposed in an optical path of an illumination optical system that illuminates an illuminated surface,
Provided behind the plurality of first refracting surfaces so as to correspond to the plurality of first refracting surfaces of the optical integrator having a predetermined refractive power in a first direction within a plane orthogonal to the optical axis of the illumination optical system. And disposed immediately after a boundary line between at least two adjacent second refracting surfaces of the plurality of second refracting surfaces of the optical integrator having a predetermined refractive power in the first direction. A dimming unit, comprising: a dimming unit having a dimming rate characteristic in which the dimming rate increases as the position of the reaching light moves away from the center of the irradiated surface along the first direction. The said light reduction part has a linear light-shielding member extended substantially parallel to the said boundary line extended along the 2nd direction orthogonal to the said 1st direction within the said plane. Dimming unit. The dimming unit according to claim 2, further comprising a holding member that supports both ends of the linear light shielding member in order to hold the linear light shielding member at a predetermined position. The dimming unit according to claim 3, wherein the holding member supports both ends of the linear light shielding member in a state in which a necessary tension is applied to the linear light shielding member. 5. The dimming unit according to claim 3, wherein the linear light shielding member has a cross section that changes along a longitudinal direction thereof. The dimming unit according to claim 2, further comprising a holding member that supports only one end of the linear light shielding member in order to hold the linear light shielding member at a predetermined position. . The dimming unit according to claim 2, wherein either one of the position and the posture of the linear light shielding member is changeable. The dimming unit according to claim 7, wherein the linear light shielding member is movable in a direction along the optical axis of the illumination optical system. The dimming unit according to claim 7 or 8, wherein a position of the linear light shielding member in the plane orthogonal to the optical axis of the illumination optical system can be changed. 10. The light attenuation according to claim 7, wherein the linear light shielding member is rotatable about the optical axis of the illumination optical system or an axis parallel to the optical axis. unit. The dimming unit according to any one of claims 7 to 10, wherein the linear light shielding member is rotatable about an axis orthogonal to the optical axis of the illumination optical system. The linear light shielding member is disposed immediately after a first boundary line between the two adjacent second refractive surfaces of the plurality of second refractive surfaces of the optical integrator having a predetermined refractive power in the first direction. A first linear light-shielding member and a second boundary line between two adjacent second refractive surfaces of the plurality of second refractive surfaces of the optical integrator having a predetermined refractive power in the first direction. A second linear light shielding member disposed immediately after,
12. At least one of a relative position and a relative posture of the first linear light shielding member and the second linear light shielding member can be changed. The dimming unit according to any one of the above. A dimming unit used in combination with a wavefront division type optical integrator disposed in an optical path of an illumination optical system that illuminates an illuminated surface,
Provided behind the plurality of first refracting surfaces so as to correspond to the plurality of first refracting surfaces of the optical integrator having a predetermined refractive power in a first direction within a plane orthogonal to the optical axis of the illumination optical system. And disposed immediately after a boundary line between at least two adjacent second refractive surfaces of the plurality of second refractive surfaces of the optical integrator having a predetermined refractive power in the first direction, and within the plane, A linear light shielding member extending substantially parallel to the boundary line extending along a second direction orthogonal to the first direction;
The dimming unit, wherein the linear light shielding member can be changed in either position or orientation. The plurality of first refracting surfaces of the optical integrator are substantially refracting in a second direction orthogonal to the first direction in the plane, and the plurality of second refracting surfaces are substantially non-refracting in the second direction. The dimming unit according to claim 1, wherein the dimming unit is a force. The optical integrator includes a first optical member and a second optical member in order from the light incident side, and the plurality of first refracting surfaces extend along the first direction on the emission side of the first optical member. 15. The plurality of second refracting surfaces are arranged along the first direction on the exit side of the second optical member. Dimming unit. The plurality of first refracting surfaces are substantially non-refractive in a second direction orthogonal to the first direction in the plane, and the plurality of second refracting surfaces are substantially non-refractive in the second direction;
On the incident side of the first optical member, a plurality of third refractive surfaces having a predetermined refractive power in the second direction and having almost no refractive power in the first direction are arranged along the second direction. ,
On the incident side of the second optical member, a plurality of fourth lenses having a predetermined refractive power in the second direction and substantially non-refracting power in the first direction so as to correspond to the plurality of third refractive surfaces. The dimming unit according to claim 15, wherein refracting surfaces are arranged along the second direction. The optical integrator includes a first optical member and a second optical member in order from the light incident side, and the plurality of first refracting surfaces extend along the first direction on the incident side of the second optical member. 15. The plurality of second refracting surfaces are arranged along the first direction on the exit side of the second optical member. Dimming unit. The plurality of first refracting surfaces are substantially non-refractive in a second direction orthogonal to the first direction in the plane, and the plurality of second refracting surfaces are substantially non-refractive in the second direction;
On the incident side of the first optical member, a plurality of third refractive surfaces having a predetermined refractive power in the second direction and having almost no refractive power in the first direction are arranged along the second direction. ,
On the exit side of the first optical member, a plurality of fourth lenses having a predetermined refractive power in the second direction and substantially non-refractive power in the first direction so as to correspond to the plurality of third refractive surfaces. The dimming unit according to claim 17, wherein refracting surfaces are arranged along the second direction. The dimming unit according to any one of claims 1 to 18, wherein the optical integrator has a rectangular unit wavefront division surface that is elongated along the first direction. In the illumination optical system that illuminates the illuminated surface based on the light from the light source,
A wavefront splitting optical integrator disposed in the optical path of the illumination optical system;
An illumination optical system comprising: the dimming unit according to any one of claims 1 to 19 used in combination with the optical integrator. 21. The illumination optical system according to claim 20, further comprising a distribution forming optical system that forms a pupil intensity distribution in an illumination pupil at a rear side of the optical integrator. 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 20 or 21. The predetermined pattern and the photosensitive substrate are moved relative to each other along a scanning direction with respect to a projection optical system that forms an image of the predetermined pattern on the photosensitive substrate, and the predetermined pattern is transferred to the photosensitive substrate. 23. The method according to claim 20, wherein the first direction in the optical integrator corresponds to a direction orthogonal to the scanning direction, and is used in combination with a projection exposure apparatus that performs projection exposure. The illumination optical system described. 24. An exposure apparatus comprising the illumination optical system according to claim 20 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 25. The exposure apparatus according to claim 24, wherein the pattern is projected and exposed onto the photosensitive substrate. 26. The exposure apparatus according to claim 25, wherein the first 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 24 to 26;
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.

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