JP2002278077A - Projection optical system, manufacturing method for projection optical system, and manufacturing method for exposure device and microdevice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection optical system which does not generates exposure unevenness due to periodical waving of the reflecting surface of a deflection member. SOLUTION: A scanning exposure type projection optical system, which forms a pattern image of a mask M on a plate by moving the mask M and a plate P relatively to the projection optical system, has at least one deflection member, and the continuation direction of the periodic waving of the reflecting surface of the deflection member is made to cross the direction orthogonal to the scanning direction of the mask and plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a projection optical system, a method of manufacturing the projection optical system, an exposure apparatus having the projection optical system, and a method of manufacturing a micro device using the exposure apparatus.

[0002]

2. Description of the Related Art In recent years, liquid crystal display panels have been frequently used as display elements for word processors, personal computers, televisions, and the like. A liquid crystal display panel is manufactured by patterning a transparent thin-film electrode on a plate into a desired shape by a photolithography technique. As an apparatus for the photolithography process, a projection exposure apparatus that projects and exposes an original pattern formed on a mask to a photoresist layer on a plate via a projection optical system is used.

In recent years, there has been an increasing demand for a large-sized liquid crystal display panel, and with this demand, it has been desired to enlarge the exposure area in this type of projection exposure apparatus.
Therefore, in order to enlarge the exposure area, a so-called multi-scan type projection exposure apparatus has been proposed. In a multi-scan type projection exposure apparatus, a mask pattern is projected and exposed on a plate while moving the mask and the plate with respect to a projection optical system including a plurality of projection optical modules.

[0004]

In the multi-scanning type projection exposure apparatus configured as described above, the light supplied from the illumination optical system enters each projection optical module via a mask. The light incident on each projection optical module reaches the plate after passing through the lens of each projection optical module.

Some projection optical modules are configured as catadioptric projection optical modules. The optical member constituting such a projection optical module includes a deflecting member such as a surface reflection type prism. The deflecting surface of the deflecting member has a moving direction of a mask and a plate, that is, an arrow shown in FIG. There is a periodic undulation in a direction orthogonal to the scan direction (scanning direction) indicated by S (the scan direction is a direction in which the peak or valley of the undulation extends, and the direction of the undulation is a direction orthogonal to the direction in which the ridge or valley extends) ), Linear exposure unevenness corresponding to the undulation was generated on the plate.

It is an object of the present invention to provide a projection optical system and a method of manufacturing the projection optical system, which can reduce exposure unevenness. Another object of the present invention is to provide an exposure apparatus having a projection optical system capable of reducing exposure unevenness. Another object of the present invention is to provide a method for manufacturing a micro device using the exposure apparatus.

[0007]

According to a first aspect of the present invention, in the projection optical system, a mask and a photosensitive substrate are moved relative to the projection optical system so that a pattern image of the mask is formed on the photosensitive substrate. In a scanning exposure type projection optical system to be formed, the projection optical system has at least one deflecting member, and the continuous direction of the undulation having periodicity existing on the deflecting surface of the deflecting member is defined by the mask and the photosensitive substrate. And a direction intersecting a direction orthogonal to the scanning direction.

According to a second aspect of the present invention, there is provided an optical projection system, wherein a pattern image of the mask is formed on the photosensitive substrate by moving the mask and the photosensitive substrate relative to the projection optical system. Projection optical system, wherein the projection optical system has at least two deflecting surfaces, and the phases of periodic undulations present on each of the deflecting surfaces are shifted.

According to the projection optical system of the first and second aspects, it is possible to reduce the variation in focus in the exposure area and the variation in distortion in the exposure area, and the projection optical system has less exposure unevenness. Can be provided.

According to a third aspect of the present invention, a pattern image of the mask is formed on the photosensitive substrate by moving the mask and the photosensitive substrate relative to the projection optical system. In the method for manufacturing a scanning exposure type projection optical system, a step of manufacturing an optical member that contributes to the imaging of the projection optical system, and a step of manufacturing a deflection member that deflects an optical path of the projection optical system, A correcting step of correcting deterioration of optical characteristics due to periodic waviness present on the deflection surface of the deflection member.

According to a fourth aspect of the present invention, in the method of manufacturing a projection optical system, the correcting step includes changing a continuous direction of a periodic undulation existing on the deflection surface of the deflection member in a scanning direction of the mask and the photosensitive substrate. A step of performing processing so as to be in a direction intersecting with a direction orthogonal to.

According to a fifth aspect of the present invention, in the method of manufacturing a projection optical system, the correcting is performed such that a phase of a periodic waviness existing on at least two reflecting surfaces of the deflecting member is shifted. It is characterized by including.

According to the method of manufacturing a projection optical system according to the third to fifth aspects, it is possible to reduce the variation in focus in the exposure area and the variation in distortion in the exposure area, thereby reducing exposure unevenness. A method for manufacturing a projection optical system can be provided.

According to a sixth aspect of the present invention, in the exposure apparatus, the mask and the photosensitive substrate are moved relative to the projection optical system to project and expose the pattern image of the mask onto the photosensitive substrate. In the exposure apparatus of the type, a projection optical system according to claim 1 or 2 is provided as the projection optical system.

According to a seventh aspect of the present invention, there is provided an exposure apparatus for projecting a pattern image of the mask onto the photosensitive substrate by moving the mask and the photosensitive substrate relative to a projection optical system. An exposure apparatus of the type, wherein the projection optical system includes a projection optical system manufactured by the manufacturing method according to any one of claims 3 to 5.

According to another aspect of the present invention, there is provided an exposure apparatus, comprising: a projection optical system having a plurality of projection optical modules arranged along a predetermined direction to form a partially overlapped exposure area on a photosensitive substrate; An illumination optical system for illuminating the mask on which the pattern is formed, and by moving the mask and the photosensitive substrate relative to the projection optical system, a pattern image of the mask is transferred to the photosensitive substrate. In an exposure apparatus for performing projection exposure, the projection optical module has at least one deflecting member, and scans the mask and the photosensitive substrate in a continuous direction of a periodic undulation existing on a deflecting surface of the deflecting member. And a direction intersecting a direction orthogonal to.

According to a ninth aspect of the present invention, there is provided an exposure apparatus, comprising: a projection optical system having a plurality of projection optical modules arranged along a predetermined direction to form a partially overlapped exposure area on a photosensitive substrate; An illumination optical system for illuminating the mask on which the pattern is formed, and by moving the mask and the photosensitive substrate relative to the projection optical system, a pattern image of the mask is transferred to the photosensitive substrate. In an exposure apparatus for performing projection exposure, the projection optical module has at least two deflecting surfaces, and the phases of the periodic undulations existing on the respective deflecting surfaces are shifted.

According to the exposure apparatus of the sixth to ninth aspects, it is possible to reduce the variation in the focus in the exposure area and the variation in the distortion in the exposure area. The exposure apparatus having the above configuration can be provided.

According to a tenth aspect of the present invention, there is provided a method of manufacturing a micro device, comprising exposing the pattern of the mask to the photosensitive substrate using the exposure apparatus according to any one of the sixth to ninth aspects. And a developing step of developing the exposed substrate.

According to the method of manufacturing a micro device according to the tenth aspect, since the pattern image of the mask can be faithfully formed on the photosensitive substrate, the micro device can be manufactured with high throughput.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, a mask and a plate are moved with respect to an exposure apparatus according to an embodiment of the present invention, that is, a projection optical system including a plurality of catadioptric projection optical modules. A multi-scanning type projection exposure apparatus for projecting and exposing a pattern of a mask on a plate while causing the pattern to be exposed will be described.

FIG. 1 is a perspective view schematically showing the overall configuration of a multi-scan projection exposure apparatus according to an embodiment. FIG. 2 is a diagram schematically showing a configuration of an illumination system in the exposure apparatus of FIG. In FIGS. 1 and 2, the X-axis is set along the direction (scanning direction) in which the mask on which the predetermined circuit pattern is formed and the plate on which the resist is applied are moved. The Y axis is set along a direction orthogonal to the X axis in the plane of the mask, and the Z axis is set along the normal direction of the plate.

The exposure apparatus of the present embodiment is an illumination system for uniformly illuminating a mask M supported in parallel with an XY plane on a mask stage MS (see FIG. 2) via a mask holder (not shown). It has an IL. 1 and 2
As shown in FIG. 1, the illumination system IL includes a light source 1 composed of, for example, an ultra-high pressure mercury lamp. The light source 1 is positioned at a first focal position of an elliptical mirror 2 having a reflection surface formed of a spheroid. Therefore, the illumination light beam emitted from the light source 1 forms a light source image at the second focal position of the elliptical mirror 2 via the reflecting mirror (plane mirror) 3. A shutter (not shown) is disposed at the second focal position.

The divergent light flux from the light source image formed at the second focal position of the elliptical mirror 2 forms an image again via the relay lens system 4. In the vicinity of the pupil plane of the relay lens system 4, a wavelength selection filter 5 (see FIG. 2) that transmits only a light beam in a desired wavelength range is arranged. In the wavelength selection filter 5, light of the g-line (436 nm), light of the h-line (405 nm), and i
The light of the line (365 nm) is simultaneously selected as the exposure light. In the wavelength selection filter 5, for example, g-line light and h-line light can be simultaneously selected, h-line light and i-line light can be simultaneously selected, and further, i-line light can be selected. It is also possible to select only light.

The entrance end 6a of the light guide 6 is arranged near the position where the light source image is formed by the relay lens system 4. The light guide 6 is a random light guide fiber configured by randomly bundling a large number of fiber strands, and has the same number of incident ends 6 as the number of light sources 1 (one in FIG. 1).
a and the same number of emission ends 6b to 6f (five in FIG. 1) as the number of projection optical modules constituting the projection optical system PL (FIG. 2).
Only the emission end 6b is shown). Thus, the light incident on the incident end 6a of the light guide 6 propagates through the inside, and is emitted from the five emission ends 6b to 6f.

The divergent light beam emitted from the light emitting end 6b of the light guide 6 is converted into a substantially parallel light beam by a collimating lens 7b (see FIG. 2), and then enters a fly-eye integrator (optical integrator) 8b. The fly-eye integrator 8b is configured by arranging a large number of positive lens elements vertically and horizontally and densely so that the central axis thereof extends along the optical axis AX. Therefore, the light beam incident on the fly-eye integrator 8b is split into wavefronts by a large number of lens elements, and a secondary light source composed of the same number of light source images as the number of lens elements is formed on the rear focal plane (ie, near the exit plane). I do. That is, a substantial surface light source is formed on the rear focal plane of the fly-eye integrator 8b. Note that the optical integrators (8b to 8b)
f) is not limited to a fly-eye integrator, but includes a diffractive optical element, a micro fly-eye lens composed of an aggregate of minute lens elements, or an internal reflection type rod-shaped integrator (hollow pipe or light pipe, rod-shaped glass rod, etc.) ) May be included.

The light beam from the secondary light source is restricted by an aperture stop 9b (see FIG. 2) arranged near the rear focal plane of the fly-eye integrator 8b, and then enters the condenser lens system 10b. The aperture stop 9b is
It is arranged at a position optically substantially conjugate with the pupil plane of the corresponding projection optical module PM1, and has a variable aperture for defining the range of the secondary light source contributing to illumination. Aperture stop 9b
By changing the opening diameter of this variable opening,
The σ value for determining the illumination condition (the ratio of the aperture of the secondary light source image on the pupil plane to the aperture diameter of the pupil plane of each of the projection optical modules PM1 to PM5 constituting the projection optical system PL) is set to a desired value. I do.

The light beam passing through the condenser lens system 10b illuminates the mask M on which a predetermined transfer pattern is formed in a superimposed manner. Similarly, the other exit end 6c of the light guide 6
The divergent light fluxes emitted from the light source
c to 7f, fly eye integrators 8c to 8f,
Aperture stops 9c to 9f and condenser lens system 10
The mask M is illuminated in a superimposed manner through c to 10f. In other words, the illumination system IL
A plurality (five in FIG. 1 in total) of trapezoidal regions arranged in the direction are illuminated.

FIG. 3 is a view showing a plurality of trapezoidal regions arranged on the mask M in the Y direction. As shown in this figure, a direction perpendicular to the scanning direction indicated by the arrow F1 (hereinafter, referred to as a direction F1).
Trapezoidal image planes Ia to Ie of a plurality of projection optical modules arranged in a zigzag pattern along the “scan orthogonal direction” are formed. Here, the rectangular portion at the center of each of the image planes Ia to Ie is a part that does not contribute to the formation of a partially overlapped exposure area, and the triangular parts at both ends of each of the image planes Ia to Ie are partially formed. Is the part that contributes to

In the above-described example, the illumination light from one light source 1 is equally divided into five illumination lights via the light guide 6 in the illumination system IL. Various modifications are possible without being limited to the number. That is, two or more light sources are provided as needed, and the illumination light from the two or more light sources is equally divided into a required number (the number of projection optical modules) of illumination light via a light guide having good randomness. You can also.
In this case, the light guide has the same number of entrance ends as the number of light sources, and has the same number of exit ends as the number of projection optical modules.

The light from each illumination area on the mask M is divided into a plurality (five in FIG. 1) of projection optical modules PM1 to PM5 arranged in the Y direction so as to correspond to each illumination area.
The light enters the projection optical system PL composed of PM5. Here, the configuration of each of the projection optical modules PM1 to PM5 is the same as each other.

Hereinafter, the configuration of each projection optical module will be described with reference to FIG. In addition, also in FIG.
The X axis is set along a direction (scanning direction) in which the mask on which a predetermined circuit pattern is formed and the plate coated with the resist are moved, and the Y axis is set along a direction orthogonal to the X axis in the plane of the mask. The Z-axis is set along the normal direction of.

The projection optical module shown in FIG. 4 includes a first imaging optical system K1 for forming a primary image of a mask pattern based on light from a mask M, and a normalization of the mask pattern based on light from the primary image. A second imaging optical system K2 for forming a normal image (secondary image) on the plate P. In the vicinity of the position where the primary image of the mask pattern is formed, a field stop FS that defines the field of view (illumination area) of the projection optical module on the mask M and the projection area (exposure area) of the projection optical module on the plate P Is provided.

The first image forming optical system K1 is connected to the mask M by -Z
A first right-angle prism PR1 having a first reflecting surface inclined at an angle of 45 ° with respect to the mask surface (XY plane) so as to reflect light incident along the direction in the −X direction is provided. Further, the first imaging optical system K1 includes a first right-angle prism P
In order from the R1 side, a first refractive optical system G having a positive refractive power
1P and a first concave reflecting mirror M1 having a concave surface facing the first right-angle prism PR1. The first refractive optical system G1P and the first concave reflecting mirror M1 are arranged along the X direction, and constitute a first catadioptric optical system HK1 as a whole. First
Light incident on the first right-angle prism PR1 from the catadioptric optical system HK1 along the + X direction is reflected by the second reflection surface inclined at an angle of 45 ° with respect to the mask surface (XY plane).
It is reflected in the Z direction.

On the other hand, the second imaging optical system K2 is provided on the plate surface (XY plane) so that light incident along the -Z direction from the second reflection surface of the first right-angle prism PR1 is reflected in the -X direction. A second right-angle prism PR2 having a first reflection surface inclined at an angle of 45 ° is provided. Also, the second
The imaging optical system K2 includes, in order from the second right-angle prism PR2 side, a second refractive optical system G2P having a positive refractive power, and a second concave reflecting mirror M2 having a concave surface facing the second right-angle prism PR2 side.
And The second refractive optical system G2P and the second concave reflecting mirror M2 are arranged along the X direction, and constitute the second catadioptric optical system HK2 as a whole. From the second catadioptric optical system HK2 along the + X direction, the second right-angle prism PR2
Incident on the plate surface (XY plane surface)
The light is reflected in the −Z direction by the second reflecting surface inclined at an angle of 5 °.

In this embodiment, a mask-side magnification correcting optical system Gm is provided in the optical path between the first catadioptric system HK1 and the second reflecting surface of the first right-angle prism PR1, and the second catadioptric system is provided. A plate-side magnification correcting optical system G is provided in the optical path between the optical system HK2 and the second reflecting surface of the second right-angle prism PR2.
p is attached. Further, a focus correction optical system Gf is provided in the optical path between the second reflection surface of the second right-angle prism PR2 and the plate P. Further, a photodetector PD for detecting illumination light (exposure light) transmitted through the second concave reflecting mirror M2 is provided behind the second concave reflecting mirror M2. Note that the photodetector PD may be arranged behind the first concave reflecting mirror M1.

As described above, the pattern formed on the mask M is illuminated by the illumination light (exposure light) from the illumination system IL with substantially uniform illuminance. Light traveling along the -Z direction from the mask pattern formed in each illumination area on the mask M is deflected by 90 degrees by the first reflection surface of the first right-angle prism PR1, and then along the -X direction. The light enters the first catadioptric optical system HK1.

The light incident on the first catadioptric optical system HK1 passes through the first dioptric optical system G1P to the first concave reflecting mirror M1.
Reach The light reflected by the first concave reflecting mirror M1 again enters the second reflecting surface of the first right-angle prism PR1 along the + X direction via the first refractive optical system G1P. -Z is deflected by 90 ° on the second reflecting surface of the first right-angle prism PR1.
The light traveling along the direction forms a primary image of the mask pattern near the field stop FS. The lateral magnification of the primary image in the X direction is +1 times, and the lateral magnification in the Y direction is -1 times.

The light that has traveled along the -Z direction from the primary image of the mask pattern is deflected by 90 degrees by the first reflecting surface of the second right-angle prism PR2, and then is subjected to the second catadioptric optical system along the -X direction. The light enters the system HK2. The light incident on the second catadioptric optical system HK2 reaches the second concave reflecting mirror M2 via the second refracting optical system G2P. At this time, a part of the incident light passes through the second concave reflecting mirror M2 and is detected by the photodetector PD disposed on the rear side. The outputs of the photodetectors PD1 to PD5 of each of the projection optical modules PM1 to PM5 are supplied to one control unit CT common to each of the projection optical modules PM1 to PM5. The control unit CT drives and controls the mask-side magnification correction optical system Gm via the first drive unit Dm, and drives and controls the plate-side magnification correction optical system Gp via the second drive unit Dp. To drive and control the focus correction optical system Gf.

The light reflected by the second concave reflecting mirror M2 passes through the second refracting optical system G2P again and travels along the + X direction in the second direction.
The light enters the second reflection surface of the right-angle prism PR2. Deflected by 90 ° at the second reflecting surface of the second right-angle prism PR2-
The light that has traveled along the Z direction forms a secondary image of the mask pattern in a corresponding exposure area on the plate P.
Here, the lateral magnification of the secondary image in the X direction and the lateral magnification in the Y direction are both +1 times. That is, the mask pattern image formed on the plate P via each projection optical module is an equal-size erect image, and each projection optical module constitutes an equal-size erect system.

A part of the light reflected by the plate P is detected by the photodetector PD via the second refractive optical system G2P and the second concave reflecting mirror M2. In the above-described first catadioptric optical system HK1, the first concave reflecting mirror M1 is arranged near the rear focal position of the first dioptric system G1P. Be telecentric. Also in the second catadioptric optical system HK2, since the second concave reflecting mirror M2 is arranged near the rear focal position of the second dioptric optical system G2P, it is almost telecentric on the field stop FS side and the plate P side. Becomes As a result, each projection optical module
The optical system is telecentric on almost both sides (the mask M side and the plate P side).

Thus, a plurality of projection optical modules PM
Light passing through the projection optical system PL composed of 1 to PM5 forms a mask pattern image on a plate P supported in parallel to the XY plane via a plate holder on a plate stage PS. That is, as described above,
Since each of the projection optical modules PM1 to PM5 is configured as an equal-length erecting system, a plurality of trapezoidal exposure areas arranged in the Y direction on the plate P, which is a photosensitive substrate, so as to correspond to each illumination area. In this case, an equal-size erect image of the mask pattern is formed.

Incidentally, the mask stage MS is provided with a scanning drive system (not shown) having a long stroke for moving the stage along the X direction which is the scanning direction. Further, a pair of alignment driving systems (not shown) for moving the mask stage MS by a minute amount along the Y direction which is a scanning orthogonal direction and rotating the mask stage MS around the Z axis by a minute amount are provided. And
The position coordinates of the mask stage MS are measured by a laser interferometer MIF using a movable mirror, and the position is controlled.

A similar drive system is provided for the plate stage PS. That is, a scanning drive system (not shown) having a long stroke for moving the plate stage PS in the X direction, which is the scanning direction, moves the plate stage PS by a very small amount in the Y direction, which is the scanning orthogonal direction. In addition, a pair of alignment driving systems (not shown) for rotating the Z-axis by a very small amount around the Z-axis are provided. The position coordinates of the plate stage PS are measured by a laser interferometer PIF using a movable mirror, and the position is controlled.

Further, as means for relatively positioning the mask M and the plate P along the XY plane,
A pair of alignment systems AL are arranged above the mask M. As alignment system AL, for example, mask M
Mask alignment mark and plate P formed on top
An alignment system of a method of obtaining a relative position with respect to a plate alignment mark formed thereon by image processing can be used.

In this way, the operation of the scanning drive system on the mask stage MS side and the scan drive system on the plate stage PS allows the mask M and the plate P to be moved to the projection optical system PL composed of a plurality of projection optical modules PM1 to PM5. By integrally moving in the same direction (X direction), the entire pattern area on the mask P becomes the plate P
Transfer (scanning exposure) is performed on the entire upper exposure area. In addition,
The shape and arrangement of the plurality of trapezoidal exposure regions and the shape and arrangement of the plurality of trapezoidal illumination regions are described in detail in, for example, Japanese Patent Application Laid-Open No. 7-183212, and redundant description is omitted. I do.

Next, a method of manufacturing a catadioptric projection optical module provided in the multi-scan projection exposure apparatus according to the embodiment (see FIG. 1) will be described with reference to FIG.

First, the projection optical modules PM1 to PM5
In step S10, an optical member such as a lens that contributes to image formation is manufactured among the optical members constituting the projection optical modules PM1 to PM5. The deflection members such as the prisms PR1 and PR2 are manufactured (step S11).

Next, processing such as polishing of the reflection surface (deflection surface) of the deflection member is performed (step 12). Here, the polishing of the reflection surface of the deflecting member is performed using a polishing apparatus. FIG. 6 is a diagram illustrating a state in which the prisms PR1 and PR2, which are deflection members, are being polished by the polishing apparatus. In FIG. 6, an XYZ coordinate system is adopted.

In FIG. 6, prisms PR1 and PR2
Are mounted on a stage 21 movable in the XY directions. The drive unit 22 that moves the stage 21 in the X and Y directions is controlled by the control unit 20.
When the stage 21 is moved by the drive unit 22, the XY
In order to detect a position in the direction, a detection unit 30 including an encoder, an interferometer, and the like is provided on the stage 21. The detection signal from the detection unit 30 is transmitted to the control unit 20.

The polishing plate 23 is attached to one end of a rotating shaft 25 via a holding portion 24, and is rotatable about the Z direction in the figure. At the other end of the rotating shaft 25,
A motor 26 controlled by the control unit 20 is attached. Bearing 27 that rotatably supports rotating shaft 25
Is provided so as to be movable in the Z direction with respect to a supporting portion 28 fixed to a main body (not shown). This support part 20
, A motor 29 controlled by the control unit 20 is attached.
The polishing plate 23 moves along the Z direction. The holding unit 24 holding the polishing plate 23
Is provided with a sensor (not shown) for detecting the contact pressure between the polishing plate 23 and the prisms PR1 and PR2, and the output from this sensor is transmitted to the control unit 20.

Next, the operation of the polishing apparatus shown in FIG. 6 will be briefly described. First, the control unit 20 moves the stage 21 via the driving unit 22 in the XY directions while rotating the polishing plate 23. Let it. That is, the polishing plate 23 is
1 and PR2 to move along the XY directions along the processing surfaces PR1a and PR2a. At this time, the prism PR
The polishing amount of the workpiece surfaces PR1a and PR2a of the workpieces 1 and PR2 is determined by the contact pressure between the workpiece surfaces PR1a and PR2a and the polishing plate 23 and the residence time of the polishing plate 23. Therefore,
Using this polishing apparatus, the polishing surfaces 23 of the prisms PR1 and PR2 are polished by reciprocating the polishing plate 23 in the scanning direction of the mask M and the plate P, that is, in the X direction. Due to this polishing, undulations having continuous periodicity are formed on the processing surfaces PR1a and PR2a of the prisms PR1 and PR2 in a direction intersecting a direction orthogonal to the scanning direction of the mask M and the plate P.

The polishing direction by the polishing apparatus is a direction in which undulations having continuous periodicity are formed in a direction crossing a direction orthogonal to the scanning direction of the mask M and the plate P, that is, the scanning of the mask M and the plate P. Any direction other than the direction orthogonal to the direction may be used.

Next, the projection optical modules PM1 to PM5 are assembled by assembling the optical members produced in step S10 and contributing to the image and the deflection members produced in step S11 and processed in step S12 (step S12). S13).

Next, the positions and inclinations of the optical member and the deflecting member which contribute to the image formation, the distance between the optical member and the deflecting member, and the like are adjusted (step S14). Next, the aberration of the projection optical module is measured (Step S15). That is, the aberration of the projection optical module is measured using a wavefront aberration measuring device (not shown). Note that the aberration measurement in step S15 is performed using the test reticle on which the test pattern is formed, using the above-described steps S13 and S13.
The pattern image of the test reticle may be actually exposed and transferred to the plate via the projection optical module assembled and adjusted in 14, and the test pattern image transferred on the substrate may be observed by an observation device such as an electron microscope.

Next, it is determined whether or not the aberration measured in step S15 is within an allowable range.
(Step S16) If the value is not within the allowable range, the process returns to Step S14, where the projection optical module P
The optical characteristics are adjusted so that the residual aberration of M1 to PM5 is reduced. On the other hand, when the aberration measured in step S16 is within the allowable range, the manufacture of the projection optical modules PM1 to PM5 ends.

The pattern of the mask while moving the mask and the plate with respect to the multi-scan type projection exposure apparatus described with reference to FIGS. 1 to 4, ie, the projection optical system including a plurality of catadioptric projection optical modules. Is a device having a plurality of catadioptric projection optical modules manufactured by the method shown in FIG. Therefore, it is possible to reduce the variation in focus in the exposure area and the variation in distortion in the exposure area, thereby reducing exposure unevenness on the plate.

Next, another manufacturing method of the catadioptric projection optical module provided in the multi-scan projection exposure apparatus according to the embodiment will be described with reference to FIG.

First, the projection optical modules PM1 to PM5
In step S20, an optical component such as a lens contributing to image formation is manufactured in the optical members constituting the projection optical modules PM1 to PM5, and surface reflection for deflecting an optical path in the optical members constituting the projection optical modules PM1 to PM5 is performed. A deflection member such as a prism is manufactured (step S21).

Next, processing such as polishing of the reflection surface (deflection surface) of the deflection member is performed (step 22). Here, the polished surfaces PR1a and PR2a of the prisms PR1 and PR2 as the deflecting members are polished by using the above-described polishing apparatus (see FIG. 6). That is, using this polishing apparatus, the polishing plate 23 is reciprocated in the direction orthogonal to the scanning direction of the mask M and the plate P, that is, in the Y direction, to polish the processing surfaces of the prisms PR1 and PR2.

As shown in FIG. 8, when the processing surface (reflection surface) of the prism PR1 is A and B, and the processing surface (reflection surface) of the prism PR2 is C and D, respectively, the prism PR
The phase of the periodic undulation existing on the surface A to be processed and the phase of the undulating periodicity existing on the surface B to be processed of the prism PR1 have the same period, and exist on the surface C to be processed of the prism PR2. The phase of the periodic undulation and the phase of the periodic undulation existing on the processing surface D of the prism PR2 have the same period, and the phase of the periodic undulation existing on the processing surface A of the prism PR1 and the prism P
R2 is processed so that the phase of the waviness having periodicity existing on the processing surface C is shifted by １ ／ period.

The phase of the periodic undulation existing on the processing surface A of the prism PR1, the phase of the periodic undulation existing on the processing surface B of the prism PR1, and the phase of the undulation existing on the processing surface C of the prism PR2. The phase of the waviness having periodicity and the phase of the waviness having periodicity existing on the processing surface D of the prism PR2 may be processed so as to be shifted by １ ／ period.

Then, the projection optical module is assembled by assembling the optical member produced in step S20 and contributing to the image, and the deflection member produced in step S21 and processed in step S22 (step S23).

Next, the positions and inclinations of the optical member and the deflecting member which contribute to the image formation, the distance between the optical member and the deflecting member, and the like are adjusted (step S24). Next, the aberration of the projection optical module is measured (Step S25). That is, the aberration of the projection optical module is measured using a wavefront aberration measuring device (not shown). Note that the aberration measurement in step S25 is performed using the test reticle on which the test pattern is formed, using the above-described steps S23 and S23.
The pattern image of the test reticle may be actually exposed and transferred to a plate via the projection optical module assembled and adjusted in 24, and the test pattern image transferred onto the substrate may be obtained by an observation device such as an electron microscope.

Next, it is determined whether or not the aberration measured in step S25 is within an allowable range.
(Step S26) If the value is not within the allowable range, the process returns to Step S24 to adjust the optical characteristics so that the residual aberration of the projection optical module is reduced. On the other hand, when the aberration measured in step S26 is within the allowable range, the manufacture of the projection optical module ends.

Even when the multi-scanning type projection exposure apparatus described with reference to FIGS. 1 to 4 is provided with a plurality of catadioptric projection optical modules manufactured by the method shown in FIG. Variations and variations in distortion within the exposure area can be reduced, and exposure unevenness on the plate can be reduced.
That is, by shifting the phase of the undulation having periodicity existing on the deflection surface of the deflecting member, the influence of the undulation having the periodicity, which appears as the variation in the focus in the exposure area and the variation in the distortion in the exposure area, is reduced. Can be smaller.

In the manufacturing method shown in FIG. 7, due to the processing of the deflecting surface of the prism, the phase of the waviness having periodicity existing on the processing surface A of the prism PR1 and the undulation phase on the processing surface B of the prism PR1. The phase of the periodic undulation has the same period, and the phase of the periodic undulation existing on the processing surface C of the prism PR2 and the prism PR2.
The phase of the undulation having periodicity existing on the processing surface D has the same period, and the phase of the undulation having periodicity existing on the processing surface A of the prism PR1 and the periodicity existing on the processing surface C of the prism PR2. And the phase of the undulation having
Although the period is shifted, a similar effect may be obtained by shifting the position where the prism is installed.
Next, another method of manufacturing the catadioptric projection optical module provided in the multi-scan projection exposure apparatus according to the embodiment will be described with reference to FIG.

First, the projection optical modules PM1 to PM5
In step S30, an optical agent such as a lens that contributes to image formation is manufactured in the optical members constituting the projection optical modules PM1 to PM5, and surface reflection for deflecting an optical path in the optical members constituting the projection optical modules PM1 to PM5. A deflection member such as a prism is manufactured (step S31). In this step S31, a plurality of prisms for the prism PR1,
A plurality of prisms for two are manufactured.

Next, processing such as polishing of the reflection surface (deflection surface) of the deflection member is performed. The processing of the reflecting surface of the deflecting member is performed as shown in FIG.
Is performed using the above-described polishing apparatus (see FIG. 6) in the same manner as in step S22 in the manufacturing method shown in FIG. That is, the process is performed on all of the plurality of prisms manufactured in step S31. Then, the undulation state of each surface of the plurality of polished prisms is measured (step S32).

Next, a prism for the prism PR1 and a prism for the prism PR2 are selected based on the measurement result in step S32 (step S33). Then, the prism PR1 selected in step S33
When the prism PR2 is used, the prism PR1
Then, it is determined whether or not the variation in focus in the exposure area and the variation in distortion in the exposure area caused by the combination of the four reflecting surfaces of the prism PR2 are within the target value (step S35).

Here, the target values of the variation in focus in the exposure area and the variation in distortion in the exposure area are as follows. (Focus variation in exposure area) <(λ / (N
A) ² ) × 1/5 (variation in distortion within exposure area) <0.3
μm (1/10 of the line width) If the value is not within the target value in step S35, the process returns to step S33 and returns to the prism PR1.
Of the prism for the prism PR2 and the prism for the prism PR2 are performed again. On the other hand, if the value is within the target value in step S35, the optical member that contributes to the image produced in step S30 is produced in step S31,
The projection optical module is assembled by assembling the deflection member selected in step S33 (step S3).
6).

Next, the position and inclination of each of the optical member and the deflecting member that contribute to the image formation, the distance between the optical member and the deflecting member, and the like are adjusted (step S37). Next, the aberration of the projection optical module is measured (Step S38).

Next, it is determined whether or not the aberration measured in step S38 is within an allowable range.
(Step S39) If the value does not fall within the allowable range, the process returns to step S37 to adjust the optical characteristics so that the residual aberration of the projection optical module is reduced. On the other hand, if the aberration measured in step S39 is within the allowable range, the manufacture of the projection optical module ends.

Even in the case where the multi-scanning type projection exposure apparatus described with reference to FIGS. 1 to 4 is equipped with the projection optical module manufactured by the method shown in FIG. Can be reduced, and uneven exposure on the plate can be reduced.

Next, another method of manufacturing the catadioptric projection optical module provided in the multi-scan projection exposure apparatus according to the embodiment will be described with reference to FIG. Steps S40 to S45 of this manufacturing method are the same as steps S30 to S35 of the manufacturing method shown in FIG. 9, and steps S47 to S50 of this manufacturing method are the same as those of FIG.
Are the same as steps S36 to S39 of the manufacturing method shown in FIG.

In this manufacturing method, if the variation in the focus in the exposure area and the variation in the distortion in the exposure area are not within the target values,
The reflection surface (deflection surface) of any of the prisms PR1 and PR2 selected in step S43 is reworked, and the focus variation in the exposure area caused by the combination of the reflection surfaces (four surfaces) of the prism PR1 and the prism PR2. ,
The variation in distortion within the exposure area is set to a value within the target value.

Even when the multi-scanning type projection exposure apparatus described with reference to FIGS. 1 to 4 is equipped with the projection optical module manufactured by the method shown in FIG. Can be reduced, and uneven exposure on the plate can be reduced.

The illumination system IL of the exposure apparatus according to the present embodiment
The mask is illuminated (illumination step), and a transfer pattern formed on the mask is scanned and exposed on the photosensitive substrate using the projection optical system PL including the projection optical modules PM1 to PM5 (exposure step), thereby obtaining a microscopic image. Devices (semiconductor elements, liquid crystal display elements, thin-film magnetic heads, etc.) can be manufactured. Hereinafter, 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 shown in FIG. 1 will be described with reference to the flowchart in FIG. Will be explained.

First, in step 301 of FIG.
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 l lot of wafers. Then, step 30
In 3, the image of the pattern on the mask is converted into a projection optical system (projection optical module) using the exposure apparatus shown in FIG. 1.
, Are sequentially exposed and transferred to each shot area on the wafer of the lot. Thereafter, in step 304, the photoresist on the one lot of wafers is developed, and in step 305, etching is performed on the one lot of wafers using the resist pattern as a mask, thereby forming a pattern on the mask. A corresponding circuit pattern is formed in each shot area on each wafer. Thereafter, a device such as a semiconductor element is manufactured by forming a circuit pattern of an upper layer and the like. According to the above-described semiconductor device manufacturing method, a semiconductor device having an extremely fine circuit pattern can be obtained with high throughput.

In the exposure apparatus shown in FIG. 1, 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). Less than,
An example of the technique at this time will be described with reference to the flowchart in FIG. In FIG. 12, in a pattern forming step 401, a so-called photolithography step of transferring and exposing a mask pattern onto a photosensitive substrate (a glass substrate coated with a resist) using the exposure apparatus of the present embodiment is performed. 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 is subjected to various steps such as a developing step, an etching step, and a reticle peeling 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, three colors corresponding to R (Red), G (Green), and B (Blue)
Many sets of dots are arranged in a matrix,
Alternatively, a color filter in which a plurality of sets of three stripe filters of R, G, and B are arranged in the horizontal scanning line direction is formed. Then, after the color filter forming step 402, a cell assembling step 403 is performed. In the cell assembly step 403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern formation step 401, the color filter obtained in the color filter formation step 402, and the like. In the cell assembling step 403, for example, a liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern forming step 401 and the color filter obtained in the color filter forming step 402, and a liquid crystal panel (liquid crystal cell) is formed. ) To manufacture.

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 device, a liquid crystal display device having an extremely fine circuit pattern can be obtained with high throughput.

In the above embodiment, the present invention is applied to a multi-scan type projection exposure apparatus in which each projection optical module has a pair of imaging optical systems, but each projection optical module has one or three projection optical modules. The present invention is also applicable to a multi-scan type projection exposure apparatus having the above-described imaging optical system.

In the above embodiment, the present invention is applied to the multi-scan type projection exposure apparatus in which each projection optical module has a catadioptric imaging optical system. However, the present invention is not limited to this. For example, the present invention can be applied to a multi-scan type projection exposure apparatus having a refraction type image forming optical system.

Further, in the above-described embodiment, an ultra-high pressure mercury lamp is used as a light source, but the present invention is not limited to this, and another appropriate light source can be used. That is, in the present invention, the exposure wavelength is not particularly limited to g-line, h-line, i-line and the like.

In the above-described embodiment, the present invention is described with respect to a multi-scan type projection exposure apparatus which performs scanning exposure while moving a mask and a photosensitive substrate with respect to a projection optical system composed of a plurality of projection optical modules. are doing.
However, the present invention can also be applied to a projection exposure apparatus that performs collective exposure without moving a mask and a photosensitive substrate with respect to a projection optical system including a plurality of projection optical modules. Further, even when the amount of light passing through each projection optical module differs depending on the device pattern, the adjustment can be performed at the in-focus position of the overlapping portion.

[0087]

According to the projection optical system of the present invention, it is possible to reduce a variation in focus in an exposure area and a variation in distortion in an exposure area, and to provide a projection optical system with less exposure unevenness. it can.

Further, according to the method of manufacturing a projection optical system of the present invention, it is possible to reduce the variation in focus in the exposure area and the variation in distortion in the exposure area, and manufacture the projection optical system with less exposure unevenness. A method can be provided.

Further, according to the exposure apparatus of the present invention, there can be provided an exposure apparatus having a projection optical system capable of reducing variations in focus in an exposure area and variations in distortion in an exposure area, and having less exposure unevenness. can do.

Further, according to the method of manufacturing a micro device of the present invention, a pattern image of a mask can be faithfully formed on a photosensitive substrate, so that a micro device can be manufactured with high throughput.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an overall configuration of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a configuration of an illumination system in the exposure apparatus of FIG.

FIG. 3 is a diagram for explaining an image plane of a projection optical module constituting the projection optical system.

FIG. 4 is a view schematically showing a configuration of each projection optical module constituting a projection optical system in the exposure apparatus of FIG. 2;

FIG. 5 is a flowchart for explaining a method of manufacturing a catadioptric projection optical module provided in the multi-scan projection exposure apparatus according to the embodiment.

FIG. 6 is a configuration diagram of a polishing apparatus for processing a deflecting member of a catadioptric projection optical module provided in the multi-scan projection exposure apparatus according to the embodiment.

FIG. 7 is a flowchart for explaining a method of manufacturing a catadioptric projection optical module provided in the multi-scan projection exposure apparatus according to the embodiment.

FIG. 8 is a diagram for explaining a deflection member of a catadioptric projection optical module provided in the multi-scan projection exposure apparatus according to the embodiment.

FIG. 9 is a flowchart for explaining a method of manufacturing a catadioptric projection optical module provided in the multi-scan projection exposure apparatus according to the embodiment.

FIG. 10 is a flowchart for explaining a method of manufacturing a catadioptric projection optical module provided in the multi-scan projection exposure apparatus according to the embodiment.

FIG. 11 is a flowchart showing 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.

FIG. 12 is a flowchart showing a technique for obtaining a liquid crystal display element as a micro device by forming a predetermined pattern on a plate using the exposure apparatus of the present embodiment.

FIG. 13 is a view for explaining the direction of a periodic undulation existing on the deflection surface of the deflection member.

[Explanation of symbols]

 Reference Signs List 1 light source 2 elliptical mirror 3 reflecting mirror 4 relay lens system 6 light guide 8 fly-eye integrator 9 aperture stop 10 condenser lens system M mask PL projection optical system PM1 to PM5 projection optical module P plate Gm, Gp magnification correction optical system Gf focus Correction optics LC lens control room

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H045 AF12 CB17 CB35 DA02 2H087 KA21 TA01 TA02 2H097 GB00 LA12 5F046 AA11 BA05 CB03 CB05 CB10 CB12 CB25 DA13

Claims (10)

[Claims] 1. A scanning exposure type projection optical system for forming a pattern image of the mask on the photosensitive substrate by moving a mask and a photosensitive substrate relative to the projection optical system, wherein the projection optical system The system has at least one deflecting member;
A projection optical system, wherein a continuous direction of the undulation having periodicity existing on the deflection surface of the deflection member is set to a direction intersecting a direction orthogonal to a scanning direction of the mask and the photosensitive substrate. 2. A scanning exposure type projection optical system for forming a pattern image of the mask on the photosensitive substrate by relatively moving a mask and a photosensitive substrate with respect to the projection optical system, A projection optical system, wherein the system has at least two deflecting surfaces, and the phases of periodic waviness present on each of the deflecting surfaces are shifted. 3. A method for manufacturing a scanning exposure type projection optical system, wherein a pattern image of the mask is formed on the photosensitive substrate by moving a mask and a photosensitive substrate relative to the projection optical system. A step of manufacturing an optical member that contributes to the imaging of the projection optical system; a step of manufacturing a deflection member that deflects an optical path of the projection optical system; and a periodicity existing on a deflection surface of the deflection member. A correction step of correcting deterioration of optical characteristics due to undulation. 4. The correcting step is such that a continuous direction of the waviness having a periodicity existing on the deflection surface of the deflection member is a direction intersecting a direction orthogonal to a scanning direction of the mask and the photosensitive substrate. 4. The method of manufacturing a projection optical system according to claim 3, further comprising a step of performing processing. 5. The projection according to claim 3, wherein the correcting step includes a step of performing processing so as to shift a phase of a periodic waviness existing on at least two deflecting surfaces of the deflecting member. Optical system manufacturing method. 6. A scanning exposure type exposure apparatus for projecting and exposing a pattern image of the mask onto the photosensitive substrate by moving a mask and a photosensitive substrate relative to a projection optical system. An exposure apparatus comprising the projection optical system according to claim 1 or 2 as a system. 7. A scanning exposure type exposure apparatus for projecting and exposing a pattern image of the mask onto the photosensitive substrate by moving a mask and a photosensitive substrate relative to a projection optical system, wherein: An exposure apparatus comprising a projection optical system manufactured by the manufacturing method according to any one of claims 3 to 5 as a system. 8. A projection optical system having a plurality of projection optical modules arranged along a predetermined direction to form a partially overlapped exposure area on a photosensitive substrate, and illuminates a mask on which a predetermined pattern is formed. An exposure optical system for projecting and exposing a pattern image of the mask onto the photosensitive substrate by relatively moving the mask and the photosensitive substrate with respect to the projection optical system. The optical module has at least one deflecting member, and a direction intersecting a continuous direction of the undulation having periodicity existing on the deflecting surface of the deflecting member with a direction orthogonal to a scanning direction of the mask and the photosensitive substrate. An exposure apparatus characterized in that: 9. A projection optical system having a plurality of projection optical modules arranged along a predetermined direction to form a partially overlapped exposure area on a photosensitive substrate, and a mask having a predetermined pattern formed thereon. An exposure optical system for projecting and exposing a pattern image of the mask onto the photosensitive substrate by relatively moving the mask and the photosensitive substrate with respect to the projection optical system. An exposure apparatus, wherein the optical module has at least two deflecting surfaces, and the phases of periodic undulations present on each of the deflecting surfaces are shifted. 10. An exposure step of exposing the pattern of the mask to the photosensitive substrate using the exposure apparatus according to claim 6, and a developing step of developing the exposed substrate. And a method for manufacturing a micro device.