JP4868209B2 - Projection optical system, exposure apparatus, and exposure method - Google Patents

Description

  The present invention relates to a projection optical system, an exposure apparatus, and an exposure method, and more particularly to a projection optical system suitable for an exposure apparatus used when manufacturing a microdevice 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.

  Therefore, in order to satisfy the requirement for the resolution of the projection optical system, it is necessary to shorten the wavelength λ of the illumination light (exposure light) and increase the image-side numerical aperture NA of the projection optical system. Specifically, the resolution of the projection optical system is represented by k · λ / NA (k is a process coefficient). The image-side numerical aperture NA is n, where n is the refractive index of the medium (usually a gas such as air) between the projection optical system and the photosensitive substrate, and θ is the maximum incident angle on the photosensitive substrate.・ It is expressed by sinθ.

  In this case, if an attempt is made to increase the image-side numerical aperture by increasing the maximum incident angle θ, the incident angle to the photosensitive substrate and the exit angle from the projection optical system increase, making it difficult to correct aberrations. A large effective image-side numerical aperture cannot be ensured without increasing the lens diameter. Furthermore, since the refractive index of gas is about 1, the image-side numerical aperture NA cannot be made 1 or more. Therefore, an immersion technique is known in which an image-side numerical aperture is increased by filling a medium such as a liquid having a high refractive index in the optical path between the projection optical system and the photosensitive substrate (for example, Patent Document 1). ).

International Publication No. WO2004 / 019128 Pamphlet

  However, in an immersion type projection optical system, the space between the projection optical system and the image plane (photosensitive substrate in the exposure apparatus) is filled with liquid, but the projection optical system and the object plane (mask in the exposure apparatus) Since the liquid is not filled with liquid during this period, the maximum exit angle of the imaging light beam from the object plane remains relatively large. As a result, the conventional immersion type projection optical system balances aberrations related to image height such as curvature of field and distortion, and aberrations related to numerical aperture such as spherical aberration and coma aberration. It is difficult to correct well.

  The present invention has been made in view of the above-described problems, and provides an aberration related to the image height while ensuring a large effective image-side numerical aperture by interposing a liquid in the optical path between the image plane and the image plane. It is an object of the present invention to provide a projection optical system having a good imaging performance by correcting aberrations related to the numerical aperture in a well-balanced manner. The present invention also provides an exposure apparatus and an exposure method capable of performing high-resolution and faithful projection exposure using a projection optical system having good imaging performance while ensuring a large effective image-side numerical aperture. The purpose is to provide.

In order to solve the above problems, in the first embodiment of the present invention, in the projection optical system for forming the image of the first surface on the second surface,
A first lens group disposed in an optical path between the first surface and the second surface;
A second lens group having a positive refractive power arranged continuously on the image side of the first lens group;
A third lens group having a negative refractive power, which is arranged subsequently to the image side of the second lens group;
A fourth lens group having positive refracting power and arranged continuously on the image side of the third lens group;
A fifth lens group having positive refracting power and arranged continuously on the image side of the fourth lens group,
The first lens group includes a biconcave first lens disposed closest to the first surface, a first meniscus lens disposed subsequent to the first lens and having a concave surface facing the object side, A second meniscus lens disposed following the first meniscus lens and having a concave surface facing the object side; a third meniscus lens disposed following the second meniscus lens and having a concave surface directed toward the object side; A fourth meniscus lens arranged following the meniscus lens and having a concave surface facing the object side;
The third lens group includes a front negative lens disposed closest to the object side in the third lens group and having a concave surface facing the image side, and disposed closest to the image side in the third lens group. A rear negative lens with a concave surface,
An aperture stop is disposed between the fourth lens group and the fifth lens group,
The fifth lens group includes an optical member positioned closest to the second surface among optical members having refractive power in the projection optical system,
A projection optical system is provided, wherein an optical path between the second surface and the optical member located closest to the second surface in the fifth lens group is filled with a predetermined liquid.

In the second aspect of the present invention, in the projection optical system for forming the image of the first surface on the second surface,
The optical path between the optical member located closest to the second surface among the optical members having refractive power in the projection optical system and the second surface is filled with a predetermined liquid,
The numerical aperture on the second surface side of the projection optical system is NA, and the distance along the optical axis between the optical member located closest to the first surface in the projection optical system and the first surface is WD. When the maximum value of the effective diameters of all optical surfaces in the projection optical system is FA,
0.02 <NA × WD / FA <0.08
A projection optical system characterized by satisfying the above conditions is provided.

In the third aspect of the present invention, in the projection optical system for forming the image of the first surface on the second surface,
The optical path between the optical member located closest to the second surface among the optical members having refractive power in the projection optical system and the second surface is filled with a predetermined liquid,
The numerical aperture on the second surface side of the projection optical system is NA, the maximum effective diameter of all optical surfaces in the projection optical system is FA, and the negative value closest to the first surface in the projection optical system is When FS is the smaller effective diameter of the effective diameter of the optical surface on the first surface side of the lens and the effective diameter of the optical surface on the second surface side of the negative lens,
0.2 <NA × FS / FA <0.6
A projection optical system characterized by satisfying the above conditions is provided.

  According to a fourth aspect of the present invention, there is provided a projection optical system according to any one of the first to third aspects for projecting an image of a mask pattern set on the first surface onto a photosensitive substrate set on the second surface. An exposure apparatus is provided.

  In a fifth embodiment of the present invention, a substrate setting step for setting a photosensitive substrate on the second surface, and a mask pattern set on the first surface through the projection optical systems of the first to third embodiments. And an exposure step of projecting and exposing the image on the photosensitive substrate set on the second surface.

In a sixth aspect of the present invention, a substrate setting step for setting a photosensitive substrate on the second surface;
An exposure step of projecting and exposing an image of a mask pattern set on the first surface onto the photosensitive substrate set on the second surface via the projection optical systems of the first to third modes;
A developing step for developing the photosensitive substrate;
A device manufacturing method is provided.

  In the present invention, since the optical path between the optical member located closest to the image side among the optical members having refractive power in the projection optical system and the image plane is filled with the predetermined liquid, the projection optical system and the image plane Due to the action of the liquid (immersion) intervening in the optical path between the two, a relatively large effective image area can be ensured while ensuring a large effective image-side numerical aperture. Also, in the present invention, as will be described later, since the working distance on the object side is kept small according to the image-side numerical aperture, the aberration related to the image height and the aberration related to the numerical aperture can be corrected in a balanced manner. Can do.

  Thus, according to the present invention, a liquid is interposed in the optical path between the image plane and a large effective image-side numerical aperture is ensured, while the aberration related to the image height and the aberration related to the numerical aperture are balanced. A projection optical system that is corrected and has good imaging performance can be realized. Therefore, in the exposure apparatus and exposure method of the present invention, high-resolution and faithful projection exposure can be performed using a projection optical system having good imaging performance while ensuring a large effective image-side numerical aperture. As a result, a good device can be manufactured with high accuracy.

  In the present invention, the optical path between the optical member located on the most image side (second surface side: photosensitive substrate side in the exposure apparatus) among the optical members having refractive power in the projection optical system and the image surface is a predetermined value. Filled with liquid. As the liquid, it is possible to use a liquid that is transparent to the used light and has a refractive index as high as possible. In the case of an exposure apparatus, a liquid that is stable with respect to the photoresist applied to the substrate surface. Thus, in the present invention, a relatively large effective image is formed while ensuring a large effective image-side numerical aperture by interposing a liquid having a large refractive index in the optical path between the projection optical system and the image plane. An area can be secured.

  In the first embodiment of the present invention, among the refractive members constituting the projection optical system, the optical member arranged closest to the first surface is a biconcave first lens, and the four lenses following the first lens. The meniscus lens is arranged. In the immersion type projection optical system as in the first embodiment of the present invention, the image-side numerical aperture is increased, and accordingly, the object-side (first surface side) numerical aperture is also increased. At this time, in order to guide the light beam incident from the first surface side to the second lens group without deteriorating distortion and telecentricity, a biconcave lens is disposed closest to the object side, and subsequently to the biconcave lens. It is necessary to arrange four meniscus lenses (first to fourth meniscus lenses) having concave surfaces facing the object side.

  Here, when a lens having another shape is interposed between the biconcave lens as the first lens and the first meniscus lens, the incident angle and the exit angle of the light beam at each lens in the first lens group are increased. Since higher order aberrations occur, it is not preferable. Further, by arranging four meniscus lenses subsequent to the biconcave lens, the refractive power of each meniscus lens is suppressed, and the occurrence of high-order aberrations is reduced as much as possible. In order to correct distortion and telecentricity better, it is preferable that the first meniscus lens is a negative meniscus lens and the second meniscus lens is a positive meniscus lens.

  In the first embodiment of the present invention, the second lens group includes a second lens that is disposed adjacent to the fourth meniscus lens in the first lens group and has a convex surface facing the fourth meniscus lens. Is preferred. When the second lens closest to the first lens group in the second lens group does not have a convex surface facing the incident side, the incident angle of the chief ray incident on the second lens increases and higher-order distortion aberrations occur. Or coma aberration, which is not preferable. In addition, by forming the convex surfaces of the first lens group and the second lens group so as to face each other, an increase in the maximum lens diameter in the first to second lens groups can be suppressed.

  In the first embodiment of the present invention, the third lens group includes a third lens disposed in the optical path between the front negative lens and the rear negative lens and having a convex surface facing the first surface. Is preferred. If the third lens does not have a shape having a convex surface on the incident side, the incident angle of the principal ray incident on the third lens is increased, and higher-order distortion and coma are generated, which is not preferable.

  In the first embodiment of the present invention, it is preferable that all the optical members having refractive power in the fifth lens group are positive lenses. The fifth lens group plays a role of forming an image with a large image-side numerical aperture. If a negative lens is interposed in the fifth lens group, the aperture of the fifth lens group itself may increase or be larger. An attempt to obtain the image-side numerical aperture is not preferable because the light rays are totally reflected in the fifth lens group and cannot be imaged.

In the first embodiment of the present invention, when the focal length of the first lens group is F1 and the total length of the projection optical system is L,
0.4 <F1 / L <0.8 (1)
It is preferable to satisfy the following conditions.

  If the upper limit value of conditional expression (1) is exceeded, the focal length of the first lens group becomes long, and the size of the partial area in the first lens and the first meniscus lens becomes too large, so that the distortion aberration is corrected well. It becomes difficult. On the other hand, if the lower limit of conditional expression (1) is not reached, correction of spherical aberration and coma becomes difficult, which is not preferable.

In the first embodiment of the present invention, when the focal length of the third lens group is F3 and the focal length of the fifth lens group is F5,
−0.4 <F5 / F3 <−0.3 (2)
It is preferable to satisfy the following conditions.

  When trying to obtain a large image-side numerical aperture as in the projection optical system of the first aspect of the present invention, it is necessary to reduce the focal length of the fifth lens group. In the first embodiment of the present invention, the Petzval sum generated in the fifth lens group is corrected by the third lens group having a negative refractive power. Here, when the upper limit value of conditional expression (2) is exceeded, the focal length of the fifth lens group becomes too long, and not only the necessary image-side numerical aperture cannot be secured, but also it leads to excessive correction of Petzval sum, which is not preferable. Further, when the lower limit value of conditional expression (2) is not reached, correction of Petzval sum is insufficient, which is not preferable.

  In a projection optical system having a large image-side numerical aperture, aberrations related to image height (field curvature, distortion, etc.) are highly independent of aberrations related to numerical aperture (spherical aberration, coma aberration, etc.). For correction, it is effective to arrange the lens component at a position before the light beam spreads from the object surface (first surface: mask surface in the exposure apparatus) as much as possible. For this purpose, the working distance (work distance) WD on the object side of the projection optical system, that is, the distance along the optical axis between the optical member located closest to the object side in the projection optical system and the object plane is set to the image side. It is preferable to make it small according to the numerical aperture NA.

Therefore, in the second embodiment of the present invention, the following conditional expression (3) is satisfied in addition to the configuration in which a liquid having a large refractive index is interposed in the optical path between the projection optical system and the image plane. In conditional expression (3), NA is the numerical aperture on the image side of the projection optical system, WD is the working distance on the object side of the projection optical system, and FA is the maximum effective diameter of the projection optical system.
0.02 <NA × WD / FA <0.08 (3)

  If the upper limit value of conditional expression (3) is exceeded, the working distance WD on the object side becomes too large, satisfying the Petzval sum condition, and thus making it difficult to correct the field curvature well, Correction is also difficult, and as a result, it becomes difficult to correct the aberration related to the image height and the aberration related to the numerical aperture in a balanced manner. On the other hand, if the lower limit of conditional expression (3) is not reached, the maximum effective diameter FA of the projection optical system becomes too large, and the optical system becomes large in the radial direction. In order to exhibit the effect of the present invention more satisfactorily, it is preferable to set the upper limit value of conditional expression (3) to 0.07 and the lower limit value to 0.04. In the projection optical system according to the first embodiment described above, it is preferable that this conditional expression (3) is satisfied.

  Further, in order to flatten the image surface, it is necessary to satisfactorily correct the curvature of field by suppressing Petzval sum. For this purpose, it is effective to dispose a negative lens at a position where the cross section of the light beam is small as close as possible to the object plane. In other words, reducing the maximum effective diameter FA of the projection optical system (maximum effective diameter (diameter) of all optical surfaces in the projection optical system) makes correction of the Petzval sum more difficult, so it is the maximum effective. In accordance with the diameter FA, it is preferable to dispose the negative lens at a position where the cross section of the light beam is small (that is, a position where the effective diameter is small) as close as possible to the object plane.

In the third embodiment of the present invention, in addition to the configuration in which a liquid having a large refractive index is interposed in the optical path between the projection optical system and the image plane, the following conditional expression (4) is satisfied. In conditional expression (4), FS is the minimum effective diameter of the negative lens closest to the first surface in the projection optical system (the effective diameter (diameter) of the object-side optical surface of the negative lens and the effective optical surface of the image side). Effective diameter of the smaller one of the diameters). As described above, NA is the numerical aperture on the image side of the projection optical system, and FA is the maximum effective diameter of the projection optical system.
0.2 <NA × FS / FA <0.6 (4)

  If the upper limit of conditional expression (4) is exceeded, the minimum effective diameter FS of the negative lens becomes too large, and it becomes difficult to satisfy the Petzval sum condition and to correct the curvature of field well. It becomes difficult to correct the aberration related to the image height and the aberration related to the numerical aperture in a balanced manner. On the other hand, if the lower limit of conditional expression (4) is not reached, the maximum effective diameter FA of the projection optical system becomes too large, and the optical system becomes large in the radial direction. In order to exhibit the effect of the present invention more satisfactorily, it is preferable to set the upper limit value of conditional expression (4) to 0.5 and the lower limit value to 0.35. In the projection optical system according to the first and second embodiments described above, it is preferable that the conditional expression (4) is satisfied.

  In the present invention, it is preferable that at least one of the object-side optical surface and the image-side optical surface of the negative lens has an aspherical shape. By introducing an aspherical surface to the negative lens, various aberrations in the projection optical system can be corrected satisfactorily. In the present invention, it is preferable that no positive lens is disposed in the optical path between the negative lens and the object plane, in other words, the negative lens is a lens component disposed closest to the object side. With this configuration, the Petzval sum can be corrected satisfactorily.

  As described above, according to the present invention, while interposing liquid in the optical path between the image plane and ensuring a large effective image-side numerical aperture, aberrations related to the image height and aberrations related to the numerical aperture Can be corrected in a balanced manner, and a projection optical system having good imaging performance can be realized. Therefore, with the exposure apparatus and exposure method of the present invention, high-resolution and faithful projection exposure can be performed using a projection optical system having good imaging performance while ensuring a large effective image-side numerical aperture. .

  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 X axis and the Y axis are set in a direction parallel to the wafer W, and the Z axis is set in a direction orthogonal to the wafer W. More specifically, the XY plane is set parallel to the horizontal plane, and the + Z axis is set upward along the vertical direction.

  As shown in FIG. 1, the exposure apparatus of this embodiment includes, for example, an ArF excimer laser light source that is an exposure light source, and includes an illumination optical system 1 that includes an optical integrator (homogenizer), a field stop, a condenser lens, and the like. ing. Exposure light (exposure beam) composed of ultraviolet pulsed light having a wavelength of 193 nm emitted from the light source passes through the illumination optical system 1 and illuminates the reticle (mask) R. A pattern to be transferred is formed on the reticle R, 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 that has passed through the reticle R forms a reticle pattern at a predetermined reduction projection magnification in an exposure area on a wafer (photosensitive substrate) W coated with a photoresist via an immersion type 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 region on the reticle R. A pattern image is formed in the area (effective exposure area).

  FIG. 2 is a diagram showing the positional relationship between the rectangular still exposure region formed on the wafer and the optical axis of the projection optical system in each example of the present embodiment. In each example of the present embodiment, as shown in FIG. 2, in the circular area (image circle) IF having a radius B around the optical axis AX of the projection optical system PL, the optical axis AX is the center. A rectangular still exposure region ER that is elongated in the X direction is set. Here, the length in the X direction of the still exposure region ER is LX, and the length in the Y direction is LY.

  Accordingly, although not shown, correspondingly, on the reticle R, there is a rectangular illumination area (that is, a static illumination area) having a size and shape corresponding to the static exposure area ER around the optical axis AX. It will be formed. The reticle R is held parallel to the XY plane on the reticle stage 2, and a mechanism for finely moving the reticle R in the X direction, the Y direction, and the rotation direction is incorporated in the reticle stage 2. The reticle stage 2 is measured and controlled in real time by the reticle laser interferometer 4 using the moving mirror 3 provided on the reticle stage 2 in the X direction, the Y direction, and the rotational direction.

  The reticle stage 2 is movable in the scanning direction (Y direction) with respect to the reticle stage surface plate 5. The reticle stage 2 floats with respect to the reticle stage surface plate 5 using, for example, a gas bearing (typically an air pad). The reticle stage 2 holds the reticle R so that the reticle R is positioned closer to the projection optical system PL than the guide surface 6 of the gas bearing. In other words, the interferometer beam directed from the reticle laser interferometer 4 to the movable mirror 3 on the reticle stage 2 is positioned on the projection optical system PL side with respect to the guide surface 6 of the reticle stage 2.

  The wafer W is fixed parallel to the XY plane on the Z stage 7 via a wafer holder (not shown). The Z stage 7 is fixed on an XY stage 8 that moves along an XY plane substantially parallel to the image plane of the projection optical system PL, and the focus position (position in the Z direction) and tilt of the wafer W are tilted. Control the corners. The Z stage 7 is measured and controlled in real time by the wafer laser interferometer 10 using the moving mirror 9 provided on the Z stage 7 in the X direction, the Y direction, and the rotational direction.

  The XY stage 8 is mounted on the base 11 and controls the X direction, Y direction, and rotation direction of the wafer W. On the other hand, a main control system (not shown) provided in the exposure apparatus of the present embodiment adjusts the position of the reticle R in the X direction, Y direction, and rotation direction based on the measurement values measured by the reticle laser interferometer. Do. That is, the main control system transmits a control signal to a mechanism incorporated in the reticle stage 2 and finely moves the reticle stage 2 to adjust the position of the reticle R.

  Further, the main control system adjusts the focus position (position in the Z direction) and the tilt angle of the wafer W in order to align the surface on the wafer W with the image plane of the projection optical system PL by the auto focus method and the auto leveling method. Do. That is, the main control system transmits a control signal to a wafer stage drive system (not shown), and drives the Z stage 7 by the wafer stage drive system to adjust the focus position and tilt angle of the wafer W. Further, the main control system adjusts the position of the wafer W in the X direction, the Y direction, and the rotation direction based on the measurement values measured by the wafer laser interferometer 10. That is, the main control system transmits a control signal to the wafer stage drive system, and drives the XY stage 8 by the wafer stage drive system to adjust the position of the wafer W in the X direction, the Y direction, and the rotation direction.

  At the time of exposure, the main control system transmits a control signal to a mechanism incorporated in the reticle stage 2 and also transmits a control signal to the wafer stage driving system, and the reticle is transmitted at a speed ratio corresponding to the projection magnification of the projection optical system PL While driving the stage 2 and the XY stage 8, the pattern image of the reticle R is projected and exposed into a predetermined shot area on the wafer W. Thereafter, the main control system transmits a control signal to the wafer stage drive system, and drives the XY stage 8 by the wafer stage drive system, thereby step-moving another shot area on the wafer W to the exposure position.

  In this way, the operation of scanning and exposing the pattern image of the reticle R on the wafer W by the step-and-scan method is repeated. That is, in the present embodiment, the position of the reticle R and the wafer W is controlled using the wafer stage drive system and the wafer laser interferometer 10 or the like, while the short side direction of the rectangular stationary exposure region and the stationary illumination region, that is, the Y direction ( By moving (scanning) the reticle stage 2 and the XY stage 8 along the scanning direction in a synchronous manner, and by moving the reticle R and the wafer W synchronously, a width equal to the long side LX of the static exposure region is formed on the wafer W. And a reticle pattern is scanned and exposed to an area having a length corresponding to the scanning amount (movement amount) of the wafer W.

  FIG. 3 is a diagram schematically showing a configuration between the boundary lens and the wafer in the projection optical system of the present embodiment. In the first example of this embodiment, as shown in FIG. 3A, the optical path between the boundary lens Lb and the wafer W is filled with a liquid Lm such as pure water. In other words, the optical path between the boundary lens Lb, which is the optical member located closest to the image side (wafer W side) among the optical members having refractive power in the projection optical system PL, and the wafer W is a predetermined liquid Lm. Is filled with.

  On the other hand, in the second example of the present embodiment, as shown in FIG. 3B, the plane parallel plate Lp is detachably disposed in the optical path between the boundary lens Lb and the wafer W, and the boundary lens Lb is arranged. And the optical path between the parallel flat plate Lp and the parallel flat plate Lp and the wafer W are filled with a liquid Lm such as pure water. In this case, even if the liquid Lm is contaminated by the photoresist or the like applied to the wafer W, a parallel flat plate (generally an optical member having almost no refractive power) that is interchangeably interposed between the boundary lens Lb and the wafer W. ) The action of Lp can effectively prevent contamination of the image side optical surface of the boundary lens Lb by the contaminated liquid Lm.

  In the step-and-scan type exposure apparatus that performs scanning exposure while moving the wafer W relative to the projection optical system PL, the boundary lens Lb of the projection optical system PL and the wafer W For example, the technique disclosed in International Publication No. WO99 / 49504 or the technique disclosed in Japanese Patent Laid-Open No. 10-303114 can be used to keep the liquid (Lm) in the optical path between the two. .

  In the technique disclosed in International Publication No. WO99 / 49504, the liquid adjusted to a predetermined temperature from the liquid supply device via the supply pipe and the discharge nozzle is filled with the optical path between the boundary lens Lb and the wafer W. The liquid is recovered from the wafer W via the recovery pipe and the inflow nozzle by the liquid supply device. On the other hand, in the technique disclosed in Japanese Patent Application Laid-Open No. 10-303114, the wafer holder table is configured in a container shape so that the liquid can be accommodated, and the wafer W is evacuated at the center of the inner bottom (in the liquid). It is positioned and held by suction. Further, the lens barrel tip of the projection optical system PL reaches the liquid, and the optical surface on the wafer side of the boundary lens Lb reaches the liquid.

  In this embodiment, as shown in FIG. 1, in the optical path between the boundary lens Lb and the wafer W using the water supply / drainage mechanism 12 (in the second example, between the boundary lens Lb and the plane parallel plate Lp). In the optical path and in the optical path between the plane parallel plate Lp and the wafer W), pure water as the liquid Lm is circulated. In this way, by circulating the pure water Lm as the immersion liquid at a minute flow rate, it is possible to prevent the liquid from being altered due to the effects of antiseptic and mildewproofing. In addition, it is possible to prevent aberration fluctuations due to heat absorption of exposure light.

In each example of the present embodiment, the aspherical surface is along the optical axis from the tangential plane at the apex of the aspherical surface to the position on the aspherical surface at the height y, where y is the height in the direction perpendicular to the optical axis. When the distance (sag amount) is z, the apex radius of curvature is r, the cone coefficient is κ, and the n-th aspherical coefficient is C _n , the following equation (a) is expressed. In each embodiment, the lens surface formed in an aspherical shape is marked with * on the right side of the surface number.

z = (y ² / r) / [1+ {1− (1 + κ) · y ² / r ² } ^1/2 ]
+ C ₄ · y ⁴ + C ₆ · y ⁶ + C ₈ · y ⁸ + C ₁₀ · y ¹⁰
+ C ₁₂ · y ¹² + C ₁₄ · y ¹⁴ + ... (a)

[First embodiment]
FIG. 4 is a diagram showing a lens configuration of the projection optical system according to the first example of the present embodiment. Referring to FIG. 4, the projection optical system PL according to the first example includes, in order from the reticle side, the first lens group G1 and the first positive refractive power arranged adjacent to the image side of the first lens group G1. A second lens group G2, a third lens group G3 having negative refractive power disposed adjacent to the image side of the second lens group G2, and a positive refractive power disposed adjacent to the image side of the third lens group G3. The fourth lens group G4, the aperture stop AS disposed adjacent to the image side of the fourth lens group G4, and the fifth lens group having positive refractive power disposed adjacent to the image side of the aperture stop AS. G5 is provided.

  The first lens group G1 includes, in order from the reticle side, a plane parallel plate P1, a biconcave lens L1 (first lens) with an aspheric concave surface facing the wafer side, and a negative meniscus with a concave surface facing the reticle side. A lens L2 (first meniscus lens), a positive meniscus lens L3 (second meniscus lens) with an aspheric concave surface facing the reticle side, and a positive meniscus lens L4 (first meniscus lens L with an aspheric concave surface facing the reticle side) 3 meniscus lens) and a positive meniscus lens L5 (fourth meniscus lens) having a concave surface facing the reticle side.

  The second lens group G2 includes, in order from the reticle side, a positive meniscus lens L6 (second lens) having a convex surface facing the reticle side, a positive meniscus lens L7 having a convex surface facing the reticle side, and an aspheric surface on the wafer side. And a positive meniscus lens L8 having a concave surface. The third lens group G3 includes, in order from the reticle side, a negative meniscus lens L9 (front negative lens) with a convex surface facing the reticle side, and a negative meniscus lens L10 (third lens) with an aspheric concave surface facing the wafer side. And a biconcave lens L11 having an aspherical concave surface facing the wafer side, and a negative meniscus lens L12 (rear negative lens) having an aspherical concave surface facing the reticle side.

  The fourth lens group G4 includes, in order from the reticle side, a positive meniscus lens L13 having an aspheric concave surface facing the reticle side, a biconvex lens L14, a biconvex lens L15, and a negative meniscus lens L16 having a convex surface facing the reticle. And a biconvex lens L17. The fifth lens group G5 includes a biconvex lens L18, a positive meniscus lens L19 having a convex surface facing the reticle, a positive meniscus lens L20 having an aspheric concave surface facing the wafer, and an aspheric shape facing the wafer. A positive meniscus lens L21 having a concave surface and a plano-convex lens L22 (boundary lens Lb) having a flat surface facing the wafer. In addition, an aperture stop AS is disposed in the optical path between the fourth lens group G4 and the fifth lens group G5.

In the first embodiment, the optical path between the boundary lens Lb and the wafer W has a refractive index of 1.435876 with respect to ArF excimer laser light (wavelength λ = 193.306 nm) that is used light (exposure light). Pure water (Lm) is filled. Further, all the light transmitting members (P1, L1 to L22 (Lb)) are made of quartz (SiO ₂ ) having a refractive index of 1.560326 with respect to the used light.

  In the following table (1), values of specifications of the projection optical system PL according to the first example are listed. In Table (1), λ is the center wavelength of the exposure light, β is the size of the projection magnification, NA is the numerical aperture on the image side (wafer side), and B is the radius of the image circle IF on the wafer W (maximum Image height), LX represents a dimension along the X direction of the still exposure region ER (long side dimension), and LY represents a dimension along the Y direction of the still exposure region ER (short side dimension). . The surface number is the order of the surfaces from the reticle side, r is the radius of curvature of each surface (vertical radius of curvature: mm in the case of an aspherical surface), and d is the axial distance between the surfaces, that is, the surface interval (mm). N represents the refractive index with respect to the center wavelength. The notation in Table (1) is the same in the following Table (2).

Table (1)
(Main specifications)
λ = 193.306 nm
β = 1/5
NA = 1.2
B = 11.5mm
LX = 22mm
LY = 6.7mm

(Optical member specifications)
Surface number r dn Optical member (reticle surface) 18.000
1 ∞ 8.000 1.560326 (P1)
2 ∞ 10.157
3 -289.036 12.000 1.560326 (L1)
4 * 418.109 24.539
5 -142.063 46.000 1.560326 (L2)
6 -379.154 11.395
7 * -301.615 50.000 1.560326 (L3)
8 -268.436 9.991
9 * -360.774 57.000 1.560326 (L4)
10 -193.765 1.000
11 -955.213 58.000 1.560326 (L5)
12 -260.000 1.000
13 239.399 56.086 1.560326 (L6)
14 586.319 1.000
15 277.514 45.059 1.560326 (L7)
16 751.369 1.000
17 158.548 52.200 1.560326 (L8)
18 * 203.300 23.358
19 8836.695 14.000 1.560326 (L9)
20 84.328 37.636
21 161.547 17.000 1.560326 (L10)
22 * 143.918 44.176
23 -109.833 12.000 1.560326 (L11)
24 * 147.291 33.877
25 * -278.731 17.398 1.560326 (L12)
26 -10024.728 20.517
27 * -501.401 50.380 1.560326 (L13)
28 -176.064 1.000
29 1583.941 41.018 1.560326 (L14)
30 -532.558 1.000
31 611.973 40.000 1.560326 (L15)
32 -6298.101 1.000
33 728.162 35.217 1.560326 (L16)
34 361.302 14.555
35 534.727 60.000 1.560326 (L17)
36 -1287.947 24.091
37 ∞ 29.039 (AS)
38 400.012 58.812 1.560326 (L18)
39 -1300.388 1.000
40 177.735 57.358 1.560326 (L19)
41 338.034 1.000
42 143.476 54.151 1.560326 (L20)
43 * 362.448 1.000
44 98.976 33.882 1.560326 (L21)
45 * 141.188 1.000
46 124.903 58.494 1.560326 (L22: Lb)
47 ∞ 3.000 1.435876 (Lm)
(Wafer surface)

(Aspheric data)
4 sides κ = 0
C ₄ = −1.625771 × 10 ⁻⁷ C ₆ = 1.2555 × 10 ⁻¹¹
C ₈ = −3.07027 × 10 ⁻¹⁶ C ₁₀ = 7.666963 × 10 ⁻²⁰
C ₁₂ = 1.14963 × 10 ⁻²⁴ C ₁₄ = −2.88921 × 10 ⁻²⁹

7 surfaces κ = 0
C ₄ = −6.13062 × 10 ⁻⁸ C ₆ = −1.39452 × 10 ⁻¹²
C ₈ = 5.77862 × 10 ⁻¹⁷ C ₁₀ = 2.82753 × 10 ⁻²¹
C ₁₂ = 1.20992 × 10 ⁻²⁶ C ₁₄ = 1.87431 × 10 ⁻²⁹

9 faces κ = 0
C ₄ = −7.10088 × 10 ⁻⁹ C ₆ = 5.88664 × 10 ⁻¹³
C ₈ = −2.0652 × 10 ⁻¹⁷ C ₁₀ = 4.27442 × 10 ⁻²³
C ₁₂ = 2.17682 × 10 ⁻²⁶ C ₁₄ = −3.69737 × 10 ⁻³¹

18 faces κ = 0
C ₄ = −6.74764 × 10 ⁻⁸ C ₆ = 6.03787 × 10 ⁻¹⁴
C ₈ = 4.331057 × 10 ^-17 C ₁₀ = -3.185512 × 10 ^-22
C ₁₂ = −9.02118 × 10 ⁻²⁶ C ₁₄ = 2.00953 × 10 ⁻³⁰

22 planes κ = 0
C ₄ = −2.51712 × 10 ⁻⁸ C ₆ = −8.25906 × 10 ⁻¹³
C ₈ = −3.685505 × 10 ⁻¹⁶ C ₁₀ = −8.48572 × 10 ⁻²⁰
C ₁₂ = 3.30008 × 10 ⁻²⁴ C ₁₄ = −2.325505 × 10 ⁻²⁷

24 surfaces κ = 0
C ₄ = −2.15633 × 10 ⁻⁸ C ₆ = −1.09744 × 10 ⁻¹¹
C ₈ = 3.666796 × 10 ⁻¹⁶ C ₁₀ = 6.35582 × 10 ⁻²⁰
C ₁₂ = −8.74901 × 10 ⁻²⁴ C ₁₄ = 3.18697 × 10 ⁻²⁸

25 faces κ = 0
C ₄ = −5.33358 × 10 ⁻⁸ C ₆ = 4.004143 × 10 ⁻¹²
C ₈ = 1.10606 × 10 ⁻¹⁶ C ₁₀ = −5.3299 × 10 ⁻²¹
C ₁₂ = 9.333840 × 10 ⁻²⁵ C ₁₄ = −6.995389 × 10 ⁻²⁹

27 faces κ = 0
C ₄ = 2.667326 × 10 ⁻⁸ C ₆ = −1.34879 × 10 ⁻¹²
C ₈ = −8.669404 × 10 ⁻¹⁸ C ₁₀ = 4.25084 × 10 ⁻²¹
C ₁₂ = −2.33302 × 10 ⁻²⁵ C ₁₄ = 6.669907 × 10 ⁻³⁰

43 planes κ = 0
C ₄ = 3.997342 × 10 ⁻⁸ C ₆ = −6.46461 × 10 ⁻¹³
C ₈ = 3.882604 × 10 ⁻¹⁷ C ₁₀ = −6.40537 × 10 ⁻²²
C ₁₂ = 9.32020 × 10 ⁻²⁷ C ₁₄ = 6.662826 × 10 ⁻³¹

45 faces κ = 0
C ₄ = 4.24423 × 10 ⁻⁸ C ₆ = 6.75841 × 10 ⁻¹²
C ₈ = −1.02309 × 10 ⁻¹⁶ C ₁₀ = 5.03154 × 10 ⁻²¹
C ₁₂ = 5.2224 × 10 ⁻²⁴ C ₁₄ = −5.1158 × 10 ⁻²⁸

(Values for conditional expressions)
F1 = 632.7 mm
F3 = −37.6 mm
F5 = 113.1mm
L = 1250 mm (length along the optical axis from reticle R to wafer W)
NA = 1.2
WD = 18mm
FA = 331.2 mm (object-side surface of the biconvex lens L18)
FS = 127.9 mm (object-side surface of the biconcave lens L1)
(1) F1 / L = 0.51
(2) F5 / F3 = −0.33
(3) NA × WD / FA = 0.065
(4) NA × FS / FA = 0.463

  FIG. 5 is a diagram showing transverse aberration in the first example. In the aberration diagrams, Y indicates the image height. As is apparent from the aberration diagram of FIG. 5, in the first embodiment, a very large image-side numerical aperture (NA = 1.2) and a relatively large still exposure region ER (22 mm × 6.7 mm) are secured. In spite of this, it can be seen that the aberration is well corrected for the excimer laser light having a wavelength of 193.306 nm.

[Second Embodiment]
FIG. 6 is a diagram showing a lens configuration of the projection optical system according to the second example of the present embodiment. Referring to FIG. 6, the projection optical system PL according to the second example includes a first lens unit G1 and a first lens unit having positive refractive power arranged adjacent to the image side of the first lens unit G1 in this order from the reticle side. A second lens group G2, a third lens group G3 having negative refractive power disposed adjacent to the image side of the second lens group G2, and a positive refractive power disposed adjacent to the image side of the third lens group G3. The fourth lens group G4, the aperture stop AS disposed adjacent to the image side of the fourth lens group G4, and the fifth lens group having positive refractive power disposed adjacent to the image side of the aperture stop AS. G5 is provided.

  The first lens group G1 includes, in order from the reticle side, a plane parallel plate P1, a biconcave lens L1 (first lens) with an aspheric concave surface facing the wafer side, and a negative meniscus with a concave surface facing the reticle side. A lens L2 (first meniscus lens), a positive meniscus lens L3 (second meniscus lens) with an aspheric concave surface facing the reticle side, and a positive meniscus lens L4 (first meniscus lens L with an aspheric concave surface facing the reticle side) 3 meniscus lens) and a positive meniscus lens L5 (fourth meniscus lens) having a concave surface facing the reticle side.

  The second lens group G2 includes, in order from the reticle side, a positive meniscus lens L6 (second lens) having a convex surface facing the reticle side, a positive meniscus lens L7 having a convex surface facing the reticle side, and an aspheric surface on the wafer side. And a positive meniscus lens L8 having a concave surface. The third lens group G3 includes, in order from the reticle side, a negative meniscus lens L9 (front negative lens) with a convex surface facing the reticle side, and a positive meniscus lens L10 (third lens) with an aspheric concave surface facing the wafer side. And a biconcave lens L11 having an aspherical concave surface facing the wafer side, and a negative meniscus lens L12 (rear negative lens) having an aspherical concave surface facing the reticle side.

  The fourth lens group G4 includes, in order from the reticle side, a positive meniscus lens L13 having an aspheric concave surface facing the reticle side, a biconvex lens L14, a biconvex lens L15, and a negative meniscus lens L16 having a convex surface facing the reticle. And a biconvex lens L17. The fifth lens group G5 includes, in order from the reticle side, a biconvex lens L18, a positive meniscus lens L19 having a convex surface facing the reticle, a positive meniscus lens L20 having an aspheric concave surface facing the wafer, and a wafer. A positive meniscus lens L21 having an aspherical concave surface on the side, a plano-convex lens L22 (boundary lens Lb) having a flat surface on the wafer side, and a parallel plane plate Lp. An aperture stop AS is disposed in the optical path between the fourth lens group G4 and the fifth lens group G5.

In the second embodiment, ArF excimer laser light (wavelength λ == wave used) is used in the optical path between the boundary lens Lb and the plane parallel plate Lp and the optical path between the plane parallel plate Lp and the wafer W. 193.306 nm) is filled with pure water (Lm) having a refractive index of 1.435876. Further, all the light transmitting members (P1, L1 to L22 (Lb), Lp) are made of quartz (SiO ₂ ) having a refractive index of 1.560326 with respect to the used light. The following table (2) lists the values of the specifications of the projection optical system PL according to the second example.

Table (2)
(Main specifications)
λ = 193.306 nm
β = 1/5
NA = 1.2
B = 11.5mm
LX = 22mm
LY = 6.7mm

(Optical member specifications)
Surface number r dn Optical member (reticle surface) 15.000
1 ∞ 8.000 1.560326 (P1)
2 ∞ 7.826
3 -291.264 12.000 1.560326 (L1)
4 * 471.806 22.511
5 -146.492 45.212 1.560326 (L2)
6 -450.028 13.498
7 * -275.063 49.840 1.560326 (L3)
8 -215.611 4.860
9 * -229.335 57.000 1.560326 (L4)
10 -180.793 1.055
11 -1121.720 56.000 1.560326 (L5)
12 -265.851 1.000
13 297.211 57.623 1.560326 (L6)
14 2594.370 1.000
15 231.673 45.989 1.560326 (L7)
16 487.660 1.000
17 164.455 53.571 1.560326 (L8)
18 * 175.730 22.795
19 1610.329 14.000 1.560326 (L9)
20 85.177 36.772
21 137.356 17.000 1.560326 (L10)
22 * 143.506 42.978
23 -113.461 12.000 1.560326 (L11)
24 * 139.013 37.518
25 * -227.880 15.000 1.560326 (L12)
26 -2054.713 25.776
27 * -458.116 51.583 1.560326 (L13)
28 -174.437 1.001
29 2001.966 41.797 1.560326 (L14)
30 -496.626 1.008
31 700.529 40.327 1.560326 (L15)
32 -1780.444 1.225
33 702.889 44.893 1.560326 (L16)
34 353.567 23.285
35 513.879 60.000 1.560326 (L17)
36 -2515.821 16.536
37 ∞ 16.962 (AS)
38 377.767 59.966 1.560326 (L18)
39 -1475.223 1.039
40 187.464 52.966 1.560326 (L19)
41 354.018 1.010
42 143.854 56.871 1.560326 (L20)
43 * 397.834 1.008
44 101.825 35.237 1.560326 (L21)
45 * 127.741 0.221
46 111.809 47.397 1.560326 (L22: Lb)
47 ∞ 1.000 1.435876 (Lm)
48 ∞ 10.000 1.560326 (Lp)
49 ∞ 2.000 1.435876 (Lm)
(Wafer surface)

(Aspheric data)
4 sides κ = 0
C ₄ = −1.51508 × 10 ⁻⁷ C ₆ = 1.265571 × 10 ⁻¹¹
C ₈ = −1.21587 × 10 ⁻¹⁶ C ₁₀ = 3.83102 × 10 ⁻²⁰
C ₁₂ = 9.16022 × 10 ⁻²⁴ C ₁₄ = −5.119124 × 10 ⁻²⁸

7 surfaces κ = 0
C ₄ = −4.85921 × 10 ⁻⁸ C ₆ = −1.58761 × 10 ⁻¹²
C ₈ = 5.996726 × 10 ⁻¹⁷ C ₁₀ = −1.3031 × 10 ⁻²¹
C ₁₂ = 3.405 × 10 ⁻²⁵ C ₁₄ = 1.9226 × 10 ⁻²⁹

9 faces κ = 0
C ₄ = −1.38171 × 10 ⁻⁸ C ₆ = 7.49006 × 10 ⁻¹³
C ₈ = −1.32207 × 10 ⁻¹⁷ C ₁₀ = 1.0249 × 10 ⁻²¹
C ₁₂ = −5.54396 × 10 ⁻²⁶ C ₁₄ = 1.99316 × 10 ⁻³⁰

18 faces κ = 0
C ₄ = −8.443829 × 10 ⁻⁸ C ₆ = −4.74221 × 10 ⁻¹³
C ₈ = 4.66688 × 10 ⁻¹⁷ C ₁₀ = 1.4706 × 10 ⁻²¹
C ₁₂ = −2.53321 × 10 ⁻²⁵ C ₁₄ = 6.44309 × 10 ⁻³⁰

22 planes κ = 0
C ₄ = −4.03592 × 10 ⁻⁸ C ₆ = 2.53394 × 10 ⁻¹³
C ₈ = −4.81458 × 10 ⁻¹⁶ C ₁₀ = −7.83586 × 10 ⁻²⁰
C ₁₂ = 2.662966 × 10 ⁻²⁵ C ₁₄ = −1.43462 × 10 ⁻²⁷

24 surfaces κ = 0
C ₄ = 7.3218 × 10 ⁻⁹ C ₆ = −1.61879 × 10 ⁻¹¹
C ₈ = 6.049777 × 10 ⁻¹⁶ C ₁₀ = 9.03859 × 10 ⁻²⁰
C ₁₂ = −1.477705 × 10 ⁻²³ C ₁₄ = 6.297793 × 10 ⁻²⁸

25 faces κ = 0
C ₄ = −7.4328 × 10 ⁻⁸ C ₆ = 2.668286 × 10 ⁻¹²
C ₈ = 9.63069 × 10 ⁻¹⁷ C ₁₀ = 7.40959 × 10 ⁻²¹
C ₁₂ = −5.885288 × 10 ⁻²⁵ C ₁₄ = 1.89775 × 10 ⁻²⁸

27 faces κ = 0
C ₄ = 2.665549 × 10 ⁻⁸ C ₆ = −1.30433 × 10 ⁻¹²
C ₈ = −1.42637 × 10 ⁻¹⁷ C ₁₀ = 3.88792 × 10 ⁻²¹
C ₁₂ = -1.98429 × 10 ⁻²⁵ C ₁₄ = 4.497775 × 10 ⁻³⁰

43 planes κ = 0
C ₄ = 4.035959 × 10 ⁻⁸ C ₆ = −8.591919 × 10 ⁻¹³
C ₈ = 4.7222 × 10 ⁻¹⁷ C ₁₀ = −1.03584 × 10 ⁻²¹
C ₁₂ = 1.95201 × 10 ⁻²⁶ C ₁₄ = 5.59774 × 10 ⁻³¹

45 faces κ = 0
C ₄ = 2.667517 × 10 ⁻⁸ C ₆ = 7.991427 × 10 ⁻¹²
C ₈ = 5.19191 × 10 ⁻¹⁷ C ₁₀ = −4.88571 × 10 ⁻²⁰
C ₁₂ = 1.41505 × 10 ⁻²³ C ₁₄ = −1.58974 × 10 ⁻²⁷

(Values for conditional expressions)
F1 = 809.6mm
F3 = -40.0mm
F5 = 111.2mm
L = 1250 mm (length along the optical axis from reticle R to wafer W)
NA = 1.2
WD = 15mm
FA = 331.1 mm (object-side surface of the biconvex lens L18)
FS = 12.5 mm (object-side surface of the biconcave lens L1)
(1) F1 / L = 0.65
(2) F5 / F3 = −0.35
(3) NA x WD / FA = 0.054
(4) NA × FS / FA = 0.454

  FIG. 7 is a diagram showing transverse aberration in the second example. In the aberration diagrams, Y indicates the image height. As is apparent from the aberration diagram of FIG. 7, in the second embodiment, as in the first embodiment, a very large image-side numerical aperture (NA = 1.2) and a relatively large still exposure area ER (22 mm × It can be seen that the aberration is corrected well for the excimer laser light having a wavelength of 193.306 nm despite the fact that 6.7 mm) is secured.

  Thus, in each embodiment, a high image-side numerical aperture of 1.2 is secured for an ArF excimer laser beam having a wavelength of 193.306 nm, and an effective exposure area (stationary exposure) of 22 mm × 6.7 mm is obtained. Area) ER can be secured, and for example, a circuit pattern can be scanned and exposed at a high resolution in a rectangular exposure area of 22 mm × 33 mm.

  Incidentally, in each embodiment, the working distance WD on the object side of the projection optical system PL is set to be smaller than that in a normal exposure apparatus. Specifically, in the first example, the working distance WD on the object side of the projection optical system PL is 18 mm, and in the second example, the working distance WD on the object side of the projection optical system PL is 15 mm. Therefore, in this embodiment, in order to avoid mechanical interference between the mechanism on the reticle stage 2 side and the mechanism on the projection optical system PL side, a digging type reticle stage mechanism as shown in FIG. 1 is adopted. is doing.

  The digging-type reticle stage mechanism of this embodiment includes a reticle stage 2 that holds and moves a reticle (mask) R, and a reticle stage surface plate 5 that movably mounts the reticle stage 2 via a guide surface 6. And an interferometer 4 that irradiates the measurement beam toward the reticle stage 2 in order to measure the position of the reticle stage 2. The interferometer 4 irradiates the measurement beam toward the projection optical system PL rather than the guide surface 6. It is configured as follows. In other words, the reticle stage mechanism of the present embodiment moves the reticle stage 2 to a space opposite to the space to which the projection optical system PL belongs when the space is divided by a plane including the pattern surface of the mounted reticle. The guide surface 6 for this is arrange | positioned. For more detailed configuration and operation of the digging-type reticle stage (mask stage) mechanism, reference can be made to, for example, International Publication No. WO99 / 66542. However, without being limited to the digging type reticle stage mechanism, for example, by adopting a hanging type reticle stage mechanism disclosed in Japanese Patent Publication No. 11-504770, the mechanism and projection on the reticle stage 2 side are projected. Mechanical interference with the mechanism on the optical system PL side can also be avoided.

In the above-described embodiment, pure water is used as the liquid. However, the present invention is not limited to this. For example, H ⁺ , Cs ⁺ , K ⁺ , Cl ⁻ , SO ₄ ²⁻ , PO ₄ ²⁻ are added. Water, isopropanol, glycerol, hexane, heptane, decane, etc. can be used.

  In the above-described embodiment, a normal transmission type mask (having a predetermined light-shielding pattern or phase pattern formed on a light-transmitting substrate) is used. However, the present invention is not limited to this, and a variable pattern generator ( Programmable LCD array (see US Pat. No. 5,229,872), DMD or other programmable mirror array (see US Pat. No. 5,296,891 and US Pat. No. 5,523,193), matrix Self-luminous mask having a shape (array shape) light-emitting point can be used. Such a variable pattern generator has a matrix addressable surface that allows light to pass / reflect / emit only in the addressed region, and the beam is patterned according to the addressing pattern of the matrix addressable surface. Yes. The necessary addressing is performed using suitable electronic means. When such a variable pattern generator is used as a mask (reticle), it becomes easy to bring the matrix addressable surface (pattern surface) of the variable pattern generator close to the projection optical system.

  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. 8 for an example of a technique 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. 8, a metal film is deposited on one lot of wafers. In the next step 302, a photoresist is applied on the metal film on the 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. 9, in a 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 a 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 above-described embodiment, the ArF 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 can also be used. However, when F ₂ laser light is used as exposure light, a fluorine-based liquid such as fluorine-based oil or perfluorinated polyether (PFPE) that can transmit the F ₂ laser light is used as the liquid.

  In the above-described embodiment, the present invention is applied to the immersion type projection optical system mounted on the exposure apparatus. However, the present invention is not limited to this, and other common immersion type projection optical systems are used. The present invention can also be applied to a projection optical system. In the above-described embodiment, the present invention is applied to a refraction type projection optical system. However, the present invention is not limited to this, and the present invention is applied to, for example, a catadioptric projection optical system. You can also.

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 positional relationship of the rectangular-shaped still exposure area | region formed on a wafer in each Example of this embodiment, and the optical axis of a projection optical system. It is a figure which shows roughly the structure between the boundary lens and wafer in the projection optical system of this embodiment. It is a figure which shows the lens structure of the projection optical system concerning the 1st Example of this embodiment. It is a figure which shows the lateral aberration in 1st Example. It is a figure which shows the lens structure of the projection optical system concerning 2nd Example of this embodiment. It is a figure which shows the lateral aberration in 2nd Example. 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

R reticle PL projection optical system Lb boundary lens Lp plane parallel plate Lm pure water (liquid)
W Wafer 1 Illumination optical system 2 Reticle stage 3, 9 Moving mirror 4, 10 Laser interferometer 5 Reticle stage surface plate 6 Guide surface 7 Z stage 8 XY stage 11 Base 12 Water supply / drainage mechanism

Claims (20)

In a projection optical system for forming an image of a first surface on a second surface,
A first lens group disposed in an optical path between the first surface and the second surface;
A second lens group having a positive refractive power arranged continuously on the image side of the first lens group;
A third lens group having a negative refractive power, which is arranged subsequently to the image side of the second lens group;
A fourth lens group having positive refracting power and arranged continuously on the image side of the third lens group;
A fifth lens group having positive refracting power and arranged continuously on the image side of the fourth lens group,
The first lens group includes a biconcave first lens disposed closest to the first surface, a first meniscus lens disposed subsequent to the first lens and having a concave surface facing the object side, A second meniscus lens disposed following the first meniscus lens and having a concave surface facing the object side; a third meniscus lens disposed following the second meniscus lens and having a concave surface directed toward the object side; A fourth meniscus lens arranged following the meniscus lens and having a concave surface facing the object side;
The third lens group includes a front negative lens disposed closest to the object side in the third lens group and having a concave surface facing the image side, and disposed closest to the image side in the third lens group. A rear negative lens with a concave surface,
An aperture stop is disposed between the fourth lens group and the fifth lens group,
The fifth lens group includes an optical member positioned closest to the second surface among optical members having refractive power in the projection optical system,
An optical path between the second surface and the optical member located closest to the second surface in the fifth lens group is filled with a predetermined liquid ,
The numerical aperture on the second surface side of the projection optical system is NA, and the distance along the optical axis between the optical member located closest to the first surface in the projection optical system and the first surface is WD. When the maximum value of the effective diameters of all optical surfaces in the projection optical system is FA,
0.04 <NA × WD / FA <0.08
A projection optical system characterized that you meet the conditions. The second lens group includes a second lens disposed adjacent to the fourth meniscus lens in the first lens group and having a convex surface facing the fourth meniscus lens. Item 4. The projection optical system according to Item 1. The third lens group includes a third lens disposed in an optical path between the front negative lens and the rear negative lens and having a convex surface facing the first surface. 3. The projection optical system according to 1 or 2. 4. The projection optical system according to claim 1, wherein all of the optical members having refractive power in the fifth lens group are positive lenses. 5. When the focal length of the first lens group is F1, and the total length of the projection optical system is L,
0.4 <F1 / L <0.8
The projection optical system according to claim 1, wherein the following condition is satisfied. When the focal length of the third lens group is F3,
−0.4 <F5 / F3 <−0.3
The projection optical system according to claim 5, wherein the following condition is satisfied. The numerical aperture on the second surface side of the projection optical system is NA, the maximum effective diameter of all optical surfaces in the projection optical system is FA, and the optical surface on the first surface side of the first lens is effective. When the smaller effective diameter of the diameter and the effective diameter of the optical surface on the second surface side of the first lens is FS,
0.2 <NA × FS / FA <0.6
The projection optical system according to claim 1, wherein the following condition is satisfied. In a projection optical system for forming an image of a first surface on a second surface,
A first lens group disposed in an optical path between the first surface and the second surface;
A second lens group having a positive refractive power arranged continuously on the image side of the first lens group;
A third lens group having a negative refractive power, which is arranged subsequently to the image side of the second lens group;
A fourth lens group having positive refracting power and arranged continuously on the image side of the third lens group;
A fifth lens group having positive refracting power and arranged continuously on the image side of the fourth lens group,
The first lens group includes a biconcave first lens disposed closest to the first surface, a first meniscus lens disposed subsequent to the first lens and having a concave surface facing the object side, A second meniscus lens disposed following the first meniscus lens and having a concave surface facing the object side; a third meniscus lens disposed following the second meniscus lens and having a concave surface directed toward the object side; A fourth meniscus lens arranged following the meniscus lens and having a concave surface facing the object side;
The third lens group includes a front negative lens disposed closest to the object side in the third lens group and having a concave surface facing the image side, and disposed closest to the image side in the third lens group. A rear negative lens having a concave surface, and a third lens disposed in an optical path between the front negative lens and the rear negative lens and having a convex surface facing the first surface,
An aperture stop is disposed between the fourth lens group and the fifth lens group,
The fifth lens group includes an optical member positioned closest to the second surface among optical members having refractive power in the projection optical system,
An optical path between the second surface and the optical member located closest to the second surface in the fifth lens group is filled with a predetermined liquid,
The numerical aperture on the second surface side of the projection optical system is NA, and the distance along the optical axis between the optical member located closest to the first surface in the projection optical system and the first surface is WD. When the maximum value of the effective diameters of all optical surfaces in the projection optical system is FA,
0.02 <NA × WD / FA <0.08
A projection optical system characterized by satisfying the following conditions . The second lens group includes a second lens disposed adjacent to the fourth meniscus lens in the first lens group and having a convex surface facing the fourth meniscus lens. Item 9. The projection optical system according to Item 8 . 10. The projection optical system according to claim 8, wherein all of the optical members having refractive power in the fifth lens group are positive lenses . When the focal length of the first lens group is F1, and the total length of the projection optical system is L,
0.4 <F1 / L <0.8
The projection optical system according to claim 8, wherein the following condition is satisfied . When the focal length of the third lens group is F3,
−0.4 <F5 / F3 <−0.3
The projection optical system according to claim 11, wherein the following condition is satisfied . The numerical aperture on the second surface side of the projection optical system is NA, the maximum effective diameter of all optical surfaces in the projection optical system is FA, and the optical surface on the first surface side of the first lens is effective. When the smaller effective diameter of the diameter and the effective diameter of the optical surface on the second surface side of the first lens is FS,
0.2 <NA × FS / FA <0.6
The projection optical system according to claim 8, wherein the following condition is satisfied . 14. The optical surface of at least one of the optical surface on the first surface side of the first lens and the optical surface on the second surface side of the first lens has an aspherical shape . The projection optical system according to any one of the above. The projection optical system according to claim 1, which projects an image of a mask pattern set on the first surface onto a photosensitive substrate set on the second surface. An exposure apparatus characterized by that. An illumination system for illuminating the mask, a mask stage for holding and moving the mask, a mask stage surface plate for movably placing the mask stage via a guide surface, and a position of the mask stage An interferometer that irradiates a measurement beam toward the mask stage to measure,
The exposure apparatus according to claim 15, wherein the measurement beam is irradiated to the projection optical system side with respect to the guide surface. An image of a mask pattern set on the first surface via a substrate setting step of setting a photosensitive substrate on the second surface and the projection optical system according to any one of claims 1 to 14. And an exposure step of performing projection exposure on the photosensitive substrate set on the second surface. Illuminating the mask on a mask stage holding the mask movably; and
A mask position measuring step of measuring the position of the mask using a measurement beam of an interferometer,
In the exposure step, the mask stage is moved along the guide surface of the mask stage surface plate, and the projection exposure is performed while moving the photosensitive substrate,
18. The exposure method according to claim 17, wherein in the mask position measurement step, the measurement beam of the interferometer is irradiated to a position closer to the projection optical system than the guide surface of the mask stage surface plate. A substrate setting step of setting a photosensitive substrate on the second surface;
Through the projection optical system according to any one of claims 1 to 14, a mask pattern image set on the first surface is projected and exposed onto the photosensitive substrate set on the second surface. An exposure process;
A developing step for developing the photosensitive substrate;
A device manufacturing method comprising: Illuminating the mask on a mask stage holding the mask movably; and
A mask position measuring step of measuring the position of the mask using a measurement beam of an interferometer,
In the exposure step, the mask stage is moved along the guide surface of the mask stage surface plate, and the projection exposure is performed while moving the photosensitive substrate,
20. The device manufacturing method according to claim 19, wherein, in the mask position measurement step, the measurement beam of the interferometer is irradiated to a position closer to the projection optical system than the guide surface of the mask stage surface plate. .

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