JP2007287885A - Illuminating optical apparatus, aligner, and method of manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminating optical system for illuminating an object surface in a projection optical system for forming an image with a light beam good in telecenricity. <P>SOLUTION: The illuminating optical system is so positioned that its optical axis (AXi) passes the center of an illumination region on an object surface (M) and deviates from the optical axis (AXp) of a projecting optical system (PL). It comprises a wave-front divided optical integrator (11) disposed in the optical path between a light source (1) and the object surface, a light guide optical system (12) for superimposedly guiding the wave-front divided optical beams from the optical integrator into the object surface and an illuminating region on an optically conjugate plane, and a polarizing member (10) disposed in the optical path between the light source and the integrator turnably around a specified axial line for bending the optical path to adjust the inclination of the main ray of light to the optical axis (AXi). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an illumination optical apparatus, an exposure apparatus, and a device manufacturing method, and more particularly to an illumination optical apparatus suitable for an exposure apparatus used when manufacturing a device such as a semiconductor element or a liquid crystal display element in a photolithography process. is there.

  In a photolithography process for manufacturing semiconductor elements, etc., a mask (or reticle) pattern image is projected and exposed on a photosensitive substrate (a wafer coated with a photoresist, a glass plate, etc.) via a projection optical system. An exposure apparatus is used. In the exposure apparatus, as the degree of integration of semiconductor elements and the like is improved, the resolving power (resolution) required for the projection optical system is increasing.

  In order to satisfy the requirements for the resolution of the projection optical system, it is necessary to shorten the wavelength of the illumination light (exposure light) and increase the image-side numerical aperture of the projection optical system. In general, in a projection optical system having a large image-side numerical aperture, it is desirable to use a catadioptric optical system from the viewpoint of obtaining the flatness of the image by satisfying the Petzval condition, and an effective field of view from the viewpoint of adaptability to all fine patterns. It is desirable to adopt an off-axis visual field catadioptric optical system that does not include an optical axis (for example, Patent Document 1).

JP 2003-307679 A

  In an off-axis visual field projection optical system without being limited to the catadioptric type, the center of the effective visual field or effective imaging region and the optical axis of the optical system are separated from each other by a predetermined distance. Tends to be rotationally asymmetric with respect to the center of the effective field of view or the effective imaging region, so that a so-called asymmetric telecentric error (asymmetric telecentricity error) is likely to occur. In the case of an exposure apparatus, if an asymmetric telecentric error occurs in the exposure area (effective imaging area of the projection optical system), an image formed on a photosensitive substrate with poor flatness is likely to be asymmetric, The stacking accuracy is likely to decrease.

  The present invention has been made in view of the above-described problems, and provides an illumination optical apparatus that can illuminate an object plane of a projection optical system so that an image is formed with a light beam having good telecentricity. With the goal. In addition, the present invention faithfully and accurately projects a fine pattern through a projection optical system in which an object surface is illuminated by an illumination optical device so that an image is formed with a light beam having good telecentricity. An object of the present invention is to provide an exposure apparatus capable of performing the above.

In order to solve the above problems, in the first aspect of the present invention, in an illumination optical apparatus that illuminates an object plane of a projection optical system based on light from a light source,
The optical axis of the illumination optical device passes through the center of the illumination area on the object plane and is positioned so as to be displaced from the optical axis of the projection optical system,
A wavefront splitting type optical integrator disposed in an optical path between the light source and the object plane;
A light guide optical system for superimposing each light beam, which has been wavefront-divided by the optical integrator, to an illumination area on the object plane or a conjugate plane optically conjugate with the object plane;
It is disposed in the optical path between the light source and the optical integrator, and is rotatable about a predetermined axis to adjust the inclination of the principal ray with respect to the optical axis of the illumination optical device on the object plane. Provided is an illumination optical device comprising a bending member that bends.

In the second aspect of the present invention, in the illumination optical device that illuminates the object plane of the projection optical system based on the light from the light source,
The optical axis of the illumination optical device passes through the center of the illumination area on the object plane and is positioned so as to be displaced from the optical axis of the projection optical system,
First correction means for imparting a principal ray inclination that is rotationally symmetric with respect to the center of the illumination area;
Second correction means for imparting a rotationally asymmetric chief ray inclination with respect to the center of the illumination area;
Illumination optics characterized in that the first correction means and the second correction means correct the deterioration of the chief ray tilt with respect to the optical axis of the illumination optical device on the object plane generated in the projection optical system. Providing equipment.

  According to a third aspect of the present invention, the illumination optical device according to the first or second aspect is provided, and a predetermined pattern illuminated by the illumination optical device is exposed to the photosensitive substrate via the projection optical system. An exposure apparatus is provided.

In the fourth embodiment of the present invention, using the exposure apparatus of the third embodiment, an exposure step of exposing the predetermined pattern to the photosensitive substrate;
And a developing process for developing the photosensitive substrate that has undergone the exposure process.

  In the illumination optical device of the present invention, the principal ray on the object plane of the projection optical system is rotated by rotating a deflection member arranged in the optical path between the light source and the optical integrator and bending the optical path around a predetermined axis. And the object plane of the projection optical system is illuminated so that an image is formed with a light beam having good telecentricity. Therefore, in the exposure apparatus of the present invention, a fine pattern is faithfully and highly accurate through a projection optical system in which an object surface is illuminated by an illumination optical apparatus so that an image is formed with a light beam having good telecentricity. Thus, a good device can be manufactured.

  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 wafer W, which is a photosensitive substrate, the Y axis in the direction parallel to the plane of FIG. 1 in the plane of the wafer W, and the plane of the wafer W in FIG. The X axis is set in the direction perpendicular to the paper surface.

  Referring to FIG. 1, the exposure apparatus of this embodiment includes a light source 1 that supplies exposure light (illumination light). 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. A substantially parallel light beam emitted from the light source 1 is incident on the afocal lens 6 through the shaping optical system 2, the optical path bending reflector 3, the parallel plane plate 4 for correcting PS intensity, and the diffractive optical element 5. . The configuration and operation of the parallel flat plate 4 for correcting PS intensity will be described later.

  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 5. The afocal lens 6 is set so that the front focal position and the position of the diffractive optical element 5 substantially coincide with each other, and the rear focal position and the position of the predetermined surface 7 indicated by a broken line in the drawing substantially coincide with each other. System (non-focal optical system). The diffractive optical element 5 forms an annular (or multipolar, circular, etc.) light intensity distribution in its far field (or Fraunhofer diffraction region) when a parallel light beam having a rectangular cross section is incident. It has a function.

  Therefore, the substantially parallel light beam incident on the diffractive optical element 5 forms an annular light intensity distribution on the pupil plane of the afocal lens 6 and then exits from the afocal lens 6 with an annular angular distribution. A conical axicon system 8 is disposed at or near the pupil position in the optical path between the front lens group 6a and the rear lens group 6b of the afocal lens 6. The configuration and operation of the conical axicon system 8 will be described later. The light beam that has passed through the afocal lens 6 enters a micro fly's eye lens (or fly eye lens) 11 through a zoom lens 9 and a telecentric adjustment optical path bending reflector 10. The configuration and operation of the optical path bending reflecting mirror 10 for telecentric adjustment will be described later.

  The micro fly's eye lens 11 is, for example, an optical element composed of a large number of micro lenses having positive refractive power arranged vertically and horizontally and densely, and is the same wavefront division type optical integrator as the fly eye lens. The position of the predetermined surface 7 is disposed in the vicinity of the front focal position of the zoom lens 9, and the incident surface of the micro fly's eye lens 11 is disposed in the vicinity of the rear focal position of the zoom lens 9. In other words, the zoom lens 9 arranges the predetermined surface 7 and the incident surface of the micro fly's eye lens 11 substantially in a Fourier transform relationship, and consequently the pupil surface of the afocal lens 6 and the incident surface of the micro fly's eye lens 11. Are arranged almost conjugate optically. Accordingly, on the incident surface of the micro fly's eye lens 11, for example, an annular illumination field centered on the optical axis AXi is formed in the same manner as the pupil surface of the afocal lens 6.

  The overall shape of the annular illumination field changes in a similar manner depending on the focal length of the zoom lens 9 as will be described later. Each microlens constituting the micro fly's eye lens 11 has a rectangular cross section similar to the shape of the illumination field to be formed on the mask M (and thus the shape of the exposure region to be formed on the wafer W). The light beam incident on the micro fly's eye lens 11 is divided into wavefronts by a large number of microlenses, and has a light intensity distribution substantially the same as the illumination field formed by the incident light beam on the rear focal plane or in the vicinity thereof (and thus the illumination pupil plane). The secondary light source is formed, that is, a secondary light source composed of a substantial surface light source having an annular shape centering on the optical axis AXi.

  The light beam from the secondary light source formed on the rear focal plane of the micro fly's eye lens 11 or in the vicinity thereof illuminates the mask blind 13 in a superimposed manner after passing through the condenser optical system 12. Thus, a rectangular illumination field corresponding to the shape and focal length of each microlens constituting the micro fly's eye lens 11 is formed on the mask blind 13 as an illumination field stop. The light beam that has passed through the rectangular opening (light transmitting portion) of the mask blind 13 is subjected to the light condensing action of the imaging optical system 14 constituted by the four lens groups 14a to 14d, and then onto the mask stage MS. The held mask M is illuminated in a superimposed manner.

  A pattern to be transferred is formed on the mask M, and a rectangular (slit-like) pattern region having a long side along the X direction and a short side along the Y direction is illuminated in the entire pattern region. Is done. The light beam transmitted through the mask M forms an image of a mask pattern on the wafer (photosensitive substrate) W held on the wafer stage WS via the off-axis visual field type and catadioptric projection optical system PL. That is, a rectangular still exposure having a long side along the X direction and a short side along the Y 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 region. Thus, by moving (scanning) the mask M and the wafer W synchronously along the Y direction, the wafer W has a width equal to the long side of the static exposure region and the scanning amount (movement) of the wafer W. A mask pattern is scanned and exposed to a shot region having a length corresponding to the amount.

  The conical axicon system 8 includes, in order from the light source side, a first prism member 8a 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 8b facing the refractive surface. The concave conical refracting surface of the first prism member 8a and the convex conical refracting surface of the second prism member 8b are complementarily formed so as to be in contact with each other. Further, at least one of the first prism member 8a and the second prism member 8b is configured to be movable along the optical axis AXi, and the interval between the first prism member 8a and the second prism member 8b is configured to be variable. Has been.

  Here, in a state where the first prism member 8a and the second prism member 8b are in contact with each other, the conical axicon system 8 functions as a plane parallel plate and has no effect on the annular secondary light source formed. . However, when the first prism member 8a and the second prism member 8b 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) is kept 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 9 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 9 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 9, both the width and size (outer diameter) change without changing the annular ratio of the annular secondary light source. In this way, the annular ratio and size (outer diameter) of the annular secondary light source can be controlled by the action of the conical axicon system 8 and the zoom lens 9.

In the exposure apparatus of this embodiment, a polarization state measuring unit 16 for measuring the polarization state of illumination light (exposure light) incident on the wafer W is provided on a wafer stage WS for holding the wafer W. . The polarization state measurement unit 16 measures four Stokes parameters (S ₀ , S ₁ , S ₂ , S ₃ ) related to the illumination light on the wafer W based on the rotational phase shifter method. The measurement result of the polarization state measurement unit 16 is supplied to the control unit 20. The detailed configuration and operation of the polarization state measuring unit 16 are disclosed in Japanese Patent Laid-Open No. 2005-5521.

  FIG. 2 is a diagram showing a lens configuration of the projection optical system in the present embodiment. Referring to FIG. 2, the projection optical system PL of the present embodiment includes a refractive first imaging system G1 that forms a first intermediate image of the pattern of the mask M, and a mask based on light from the first intermediate image. A catadioptric second imaging system G2 that forms a second intermediate image of the pattern (image of the first intermediate image), and a final reduced image of the mask pattern on the wafer W based on the light from the second intermediate image. And a refraction-type third imaging system G3 to be formed.

  An optical path bending reflector M1 is disposed in the optical path between the first imaging system G1 and the second imaging system G2, and the optical path between the second imaging system G2 and the third imaging system G3. An optical path bending reflecting mirror M2 is disposed therein. The first imaging system G1 is composed of ten lenses L11 to L110, the second imaging system G2 is composed of two lenses L21 and L22 and a concave reflecting mirror CM, and the third imaging system G3 is 13 It consists of a single lens L31-L313.

  FIG. 3 is a diagram showing a positional relationship between a rectangular illumination area formed on the mask in the present embodiment, the optical axis of the illumination optical apparatus, and the optical axis of the projection optical system. In the present embodiment, the rectangular illumination area (corresponding to the effective field of view of the projection optical system PL) IR formed on the mask M by the illumination optical device (1-15) is, as shown in FIG. 3, the projection optical system PL. Is elongated from the optical axis AXp by a predetermined distance in the + Y direction along the X direction. The illumination optical axis AXi of the illumination optical device (1-15) is set so as to pass through the center of the rectangular illumination region IR. Accordingly, although not shown in the figure, corresponding to the rectangular illumination region IR, on the wafer W, a rectangular shape extending elongated along the X direction at a predetermined distance in the −Y direction from the projection optical axis AXp of the projection optical system. A static exposure region having a shape (corresponding to an effective imaging region of the projection optical system PL) is formed.

  FIG. 4 is a diagram schematically showing the telecentricity error of the projection optical system in the present embodiment. In FIG. 4, the position at which each principal ray perpendicularly incident on the image plane of the projection optical system PL (exposure plane of the wafer W) passes through the illumination area IR on the object plane (pattern plane of the mask M), and the projection optics A line segment connecting the principal ray position passing through a predetermined parallel plane set in parallel to the object plane on the wafer side by a predetermined distance from the object plane of the system PL is a line segment corresponding to the X direction component and the Y direction. Shown with line segments corresponding to components. The above-mentioned notation is the same in the following corresponding FIG. 5 and FIG.

  When there is no telecentric error (telecentricity error) in the projection optical system PL, there is no inclination of the principal ray with respect to the normal of the object plane, that is, no inclination of the principal ray with respect to the projection optical axis AXp or the illumination optical axis AXi. Only dots will appear in the matrix. In practice, however, as shown in FIG. 4, each principal ray passing through the illumination region IR has a position at the upper right end in the figure (coordinates of X = −100%, Y = + 100% with the illumination optical axis AXi as the origin). Position) and the position of the lower right corner (the coordinate position of X = + 100%, Y = + 100% with the illumination optical axis AXi as the origin), and is tilted with respect to the optical axes AXp, AXi, resulting in a telecentric error. .

  Here, the distribution of the telecentric error on the object plane of the projection optical system PL is symmetric with respect to the Y axis with the illumination optical axis AXi as the origin, but is asymmetric with respect to the X axis with the illumination optical axis AXi as the origin. It is rotationally asymmetric with respect to the optical axis AXi. Thus, the projection optical system PL of the present embodiment is an off-axis visual field type optical system, and the center of the illumination region IR and the projection optical axis AXp are separated from each other by a predetermined distance. A rotationally asymmetric telecentric error is likely to occur.

  FIG. 5 is a diagram schematically illustrating a telecentricity error compensation operation in the present embodiment. FIG. 6 is a diagram schematically showing a result of compensating for the telecentricity error of the projection optical system in the present embodiment. In the present embodiment, in order to compensate for the telecentric error of the projection optical system PL, as shown in FIG. 5A, the characteristic of generating a principal ray tilt distribution that is rotationally symmetric with respect to the illumination optical axis AXi in the illumination region IR is provided. To the condenser optical system 12.

  Similarly, in order to compensate for the telecentric error of the projection optical system PL, as shown in FIG. 5C, a characteristic that generates a tilt distribution of the principal ray that is rotationally symmetric with respect to the illumination optical axis AXi in the illumination region IR is combined. This is applied to the image optical system 14. Furthermore, in this embodiment, in order to compensate for the telecentric error of the projection optical system PL, the optical path bending reflector 10 is rotated by a predetermined angle around a predetermined axis, as shown in FIG. In the illumination region IR, a tilt distribution of the principal ray that is rotationally asymmetric with respect to the illumination optical axis AXi, specifically, a tilt distribution of the principal ray that tilts in one direction along the Y direction is generated.

  Specifically, the telecentric adjustment optical path bending reflector 10 is disposed in the optical path between the light source 1 and the micro fly's eye lens 11 and is rotatable about a rotation axis (not shown) extending in the X direction. It is configured. The rotation of the optical path bending reflecting mirror 10 about the rotation axis is performed based on a command from the control unit 20, for example. Thus, in the present embodiment, as shown in FIG. 6, the telecentric error of the projection optical system PL is favorably compensated by the cooperative action of the condenser optical system 12, the imaging optical system 14, and the optical path bending reflector 10. Yes.

  In other words, in the present embodiment, the condenser optical system 12 and the imaging optical system 14 as the first correction means for imparting a rotationally symmetrical principal ray inclination with respect to the center of the illumination area IR, and the center of the illumination area IR. The tilt of the principal ray with respect to the illumination optical axis AXi on the object plane of the projection optical system PL can be adjusted by the optical path bending reflecting mirror 10 as the second correction means for giving the inclination of the rotationally asymmetric principal ray. . As a result, it is possible to satisfactorily compensate for the telecentric error of the projection optical system PL, that is, to correct the deterioration of the principal ray tilt with respect to the illumination optical axis AXi on the object plane that occurs in the projection optical system PL.

  As described above, in the illumination optical devices (1 to 15) of the present embodiment, the object plane of the projection optical system PL can be illuminated so that an image is formed with a light beam having good telecentricity. Therefore, in the exposure apparatus of the present embodiment, an image is formed with a light beam having good telecentricity through the projection optical system PL in which the object plane is illuminated by the illumination optical apparatus (1-15), and a fine pattern is formed. Projection exposure can be performed with high accuracy and high fidelity.

  In the above-described embodiment, the condenser optical system 12 is a mask blind in which each light beam divided by the micro fly's eye lens 11 as an optical integrator is arranged at a position optically conjugate with the object plane of the projection optical system PL. 13 functions as a light guide optical system that superimposes the light to the illumination field (illumination area) at 13, but the light guide optical system 12 is preferably configured as an fsin θ optical system. In this case, even if the optical path bending reflector 10 for telecentric adjustment is rotated around a predetermined axis, the illumination area (and hence the mask M) on the mask blind 13 is changed only by changing the angle of the incident light to the mask blind 13. It is possible to compensate for only the telecentric error of the projection optical system PL without moving the illumination area).

  In the above-described embodiment, the present invention is applied to the off-axis visual field type and catadioptric projection optical system PL. However, the present invention is not limited to this, and other general projection optical systems can be used. The present invention can also be applied to an illumination optical device that illuminates an object surface. In the above-described embodiment, the telecentric error of the projection optical system PL is compensated by rotating the optical path bending reflector 10 around a predetermined axis. However, instead of the optical path bending reflector 10 or the optical path. In addition to the bending reflector 10, other suitable deflecting members that bend the optical path can be used. In the above-described embodiment, each light beam divided by the micro fly's eye lens 11 illuminates the mask blind 13 via the condenser optical system 12 in a superimposed manner. However, the present invention is not limited to this. The arrangement of the mask blind 13 and the imaging optical system 14 may be omitted, and the mask M may be directly illuminated in a superimposed manner via the condenser optical system 12.

  By the way, in the above-described embodiment, the P-polarized light that reaches the wafer W due to the PS reflectance difference (difference between the reflectance with respect to the P-polarized component and the reflectance with respect to the S-polarized component) of the reflecting surface arranged in the optical path. A difference between the light intensity of the component and the light intensity of the S-polarized component, that is, a PS intensity difference is likely to occur. In particular, in the reflective mirrors 3, 10, 15, M1, and M2 that bend the optical path by 45 degrees, the PS reflectance difference tends to be relatively large. When a relatively large PS intensity difference occurs in the light reaching the wafer W, patterns having different line widths in the vertical direction and the horizontal direction are transferred onto the wafer W.

  In the present embodiment, for example, the optical path bending reflector 3 and the diffractive optical element 5 are used as PS intensity correction members for compensating PS reflectance differences such as the optical path bending reflectors 3, 10, 15, M1, and M2. A parallel plane plate 4 configured to be rotatable about a rotation axis (not shown) extending in the X direction is disposed in the parallel optical path between the two. The parallel flat plate 4 for correcting PS intensity is a required PS transmittance difference for compensating the PS reflectance difference in the optical path bending reflector (difference between the transmittance for the P-polarized component and the transmittance for the S-polarized component). Is obtained, for example, based on a command from the control unit 20, and is rotated by a predetermined angle around the rotation axis.

Thus, the light reaching the wafer W by the difference in the PS transmittance according to the incident angle of the light beam on the plane parallel plate 4 inclined with respect to the optical axis AXi and the film characteristics of the thin film applied to the surface of the plane parallel plate 4. The PS intensity difference is corrected (adjusted). Alternatively, the light reaching the wafer W can be obtained by the difference in PS transmittance according to the incident angle of the light beam on the plane-parallel plate 4 inclined with respect to the optical axis AXi and the Fresnel coefficient of the plane-parallel plate 4 where no thin film is applied. PS intensity difference is corrected. Specifically, for example, the mask M (and thus the wafer W) is illuminated in a non-polarized state, and the Stokes parameter S _{1 of the} light reaching the wafer W approaches 0 while referring to the measurement result of the polarization state measuring unit 16. By tilting the plane parallel plate 4 for correcting PS intensity with respect to the optical axis AXi, the PS intensity difference of the light reaching the wafer W can be corrected as needed.

  In the above description regarding the correction of the PS intensity difference, the reflecting mirrors 3, 10, 15, M1, and M2 are all arranged so as to bend the optical path in the YZ plane, and therefore, around the rotation axis extending in the X direction. By tilting the plane parallel plate 4, the PS intensity difference of the light reaching the wafer W is corrected. In general, for example, when a reflector that folds the optical path in the YZ plane and a reflector that folds the optical path in the XZ plane coexist, the parallel plane plate is inclined around the rotation axis extending in the combined direction of the X direction and the Y direction. Thus, the PS intensity difference of the light reaching the wafer W can be corrected. Alternatively, one parallel plane plate is tilted around the rotation axis extending in the X direction and another parallel plane plate is tilted around the rotation axis extending in the Y direction, thereby correcting the PS intensity difference of the light reaching the wafer W. can do.

  Further, in the above-described embodiment, the position along the optical axis AXi direction of the mask blind 13 including a relatively large number of driving portions may vary with time. In this case, for example, the first lens group 14a in the imaging optical system 14 is moved in the direction of the optical axis AXi, and the optical conjugate relationship between the mask blind 13 and the mask M (and thus the wafer W) is maintained. Can do. The movement of the first lens group 14a in the imaging optical system 14 along the direction of the optical axis AXi is performed based on a command from the control unit 20, for example.

  In the exposure apparatus of the above-described embodiment, the reticle (mask) is illuminated by the illumination device (illumination process), and the transfer pattern formed on the mask is exposed to the photosensitive substrate using the projection optical system (exposure process). Thus, a micro device (semiconductor element, imaging element, liquid crystal display element, thin film magnetic head, etc.) can be manufactured. Hereinafter, referring to the flowchart of FIG. 7 for an example of a method for obtaining a semiconductor device as a micro device by forming a predetermined circuit pattern on a wafer or the like as a photosensitive substrate using the exposure apparatus of the present embodiment. I will explain.

  First, in step 301 of FIG. 7, a metal film is deposited on one lot of wafers. In the next step 302, a photoresist is applied onto the metal film on the one lot of wafers. Thereafter, in step 303, using the exposure apparatus of the present embodiment, the image of the pattern on the mask is sequentially exposed and transferred to each shot area on the wafer of one lot via the projection optical system. Thereafter, in step 304, the photoresist on the one lot of wafers is developed, and in step 305, the resist pattern is etched on the one lot of wafers to form a pattern on the mask. Corresponding circuit patterns are formed in each shot area on each wafer.

  Thereafter, a device pattern such as a semiconductor element is manufactured by forming a circuit pattern of an upper layer. According to the semiconductor device manufacturing method described above, a semiconductor device having an extremely fine circuit pattern can be obtained with high throughput. In steps 301 to 305, a metal is deposited on the wafer, a resist is applied on the metal film, and exposure, development, and etching processes are performed. Prior to these processes, on the wafer. It is needless to say that after forming a silicon oxide film, a resist may be applied on the silicon oxide film, and steps such as exposure, development, and etching may be performed.

  In the exposure apparatus of this embodiment, a liquid crystal display element as a micro device can be obtained by forming a predetermined pattern (circuit pattern, electrode pattern, etc.) on a plate (glass substrate). Hereinafter, an example of the technique at this time will be described with reference to the flowchart of FIG. In FIG. 8, in the pattern formation process 401, a so-called photolithography process is performed in which the exposure pattern of the present embodiment is used to transfer and expose the mask pattern onto a photosensitive substrate (such as a glass substrate coated with a resist). By this photolithography process, a predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. Thereafter, the exposed substrate undergoes steps such as a developing step, an etching step, and a resist stripping step, whereby a predetermined pattern is formed on the substrate, and the process proceeds to the next color filter forming step 402.

  Next, in the color filter forming step 402, a large number of sets of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix or three of R, G, and B A color filter is formed by arranging a plurality of stripe filter sets in the horizontal scanning line direction. Then, after the color filter forming step 402, a cell assembly step 403 is executed. In the cell assembly step 403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern formation step 401, the color filter obtained in the color filter formation step 402, and the like.

  In the cell assembly step 403, for example, liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern formation step 401 and the color filter obtained in the color filter formation step 402, and a liquid crystal panel (liquid crystal cell) is obtained. ). Thereafter, in a module assembling step 404, components such as an electric circuit and a backlight for performing a display operation of the assembled liquid crystal panel (liquid crystal cell) are attached to complete a liquid crystal display element. According to the above-described method for manufacturing a liquid crystal display element, a liquid crystal display element having an extremely fine circuit pattern can be obtained with high throughput.

In the exposure apparatus of the above-described embodiment, an ArF excimer laser light source or a KrF excimer laser light source is used. However, the present invention is not limited to this, and other appropriate light sources such as an F ₂ laser light source are used. You can also. In the above-described embodiment, the present invention is applied to the illumination optical apparatus that illuminates the object plane of the projection optical system mounted on the exposure apparatus. However, the present invention is not limited to this, and the projection optical system The present invention can be applied to a general illumination optical device that illuminates an object surface.

It is a figure which shows schematically the structure of the exposure apparatus concerning embodiment of this invention. It is a figure which shows the lens structure of the projection optical system in this embodiment. It is a figure which shows the positional relationship of the rectangular-shaped illumination area | region formed on a mask in this embodiment, the optical axis of an illumination optical apparatus, and the optical axis of a projection optical system. It is a figure which shows typically the error of the telecentricity of the projection optical system in this embodiment. It is a figure which shows typically the compensation effect | action of the error of the telecentricity in this embodiment. It is a figure which shows typically the result by which the error of the telecentricity of the projection optical system was compensated in this embodiment. It is a flowchart of the method at the time of obtaining the semiconductor device as a microdevice. It is a flowchart of the method at the time of obtaining the liquid crystal display element as a microdevice.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Shaping optical system 3, 15, M1, M2 Optical path bending reflective mirror 4 Parallel plane plate 5 for PS intensity correction 5 Diffractive optical element 6 Afocal lens 8 Conical axicon system 9 Zoom lens 10 Optical path bending for telecentric adjustment Reflector 11 Micro fly-eye lens 12 Condenser optical system 13 Mask blind 14 Imaging optical system 16 Polarization state measurement unit 20 Control unit M Mask PL Projection optical system W Wafer

Claims (8)

In an illumination optical device that illuminates an object plane of a projection optical system based on light from a light source,
The optical axis of the illumination optical device passes through the center of the illumination area on the object plane and is positioned so as to be displaced from the optical axis of the projection optical system,
A wavefront splitting type optical integrator disposed in an optical path between the light source and the object plane;
A light guide optical system for superimposing each light beam, which has been wavefront-divided by the optical integrator, to an illumination area on the object plane or a conjugate plane optically conjugate with the object plane;
It is disposed in the optical path between the light source and the optical integrator, and is rotatable about a predetermined axis to adjust the inclination of the principal ray with respect to the optical axis of the illumination optical device on the object plane. An illumination optical apparatus comprising: a deflecting member that bends. In an illumination optical device that illuminates an object plane of a projection optical system based on light from a light source,
The optical axis of the illumination optical device passes through the center of the illumination area on the object plane and is positioned so as to be displaced from the optical axis of the projection optical system,
First correction means for imparting a principal ray inclination that is rotationally symmetric with respect to the center of the illumination area;
Second correction means for imparting a rotationally asymmetric chief ray inclination with respect to the center of the illumination area;
Illumination optics characterized in that the first correction means and the second correction means correct the deterioration of the chief ray tilt with respect to the optical axis of the illumination optical device on the object plane generated in the projection optical system. apparatus. A wavefront division type optical integrator disposed in an optical path between the light source and the object plane;
The first correction means has a light guide optical system for superposingly guiding each light beam that has been wavefront-divided by the optical integrator to an illumination area on the object plane or a conjugate plane optically conjugate with the object plane. And
The second correcting means is disposed in an optical path between the light source and the optical integrator, and adjusts an inclination of a principal ray with respect to an optical axis of the illumination optical device on the object plane around a predetermined axis. The illumination optical apparatus according to claim 2, further comprising a deflecting member that is rotatable and bends the optical path. The illumination optical apparatus according to claim 1, wherein the light guide optical system is an fsin θ optical system. 2. A field stop disposed at or near the conjugate plane, and an imaging optical system disposed in an optical path between the field stop and the object plane. 5. The illumination optical device according to 3 or 4. An illumination optical device according to claim 1 is provided, and a predetermined pattern illuminated by the illumination optical device is exposed to a photosensitive substrate through the projection optical system. Exposure device. The exposure apparatus according to claim 6, wherein the projection optical system is a catadioptric optical system. An exposure step of exposing the predetermined pattern to the photosensitive substrate using the exposure apparatus according to claim 6 or 7,
And a developing step of developing the photosensitive substrate that has undergone the exposure step.

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