JP2004104028A - Aberration measurement method, aberration correction method, position detection device, exposure device, and device manufacturing method - Google Patents

Abstract

An object of the present invention is to satisfactorily correct aberrations such as CIS in an alignment optical system.
In a state in which an imaging surface of an imaging device is fixed at a predetermined position, an image is taken by an imaging device while illuminating a mark with a plurality of light beams from a light source unit, and each image is taken by a plurality of light beams. The image shift of the mark 4 is measured. Then, the aberration of the alignment optical system is corrected based on the measured shift of the image of the mark.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an aberration measurement method, an aberration correction method, a position detection device, an exposure device, and a device manufacturing method. For example, a pattern formed on an original such as a reticle or a mask is formed on a substrate via a projection optical system. A method for measuring and correcting aberrations of an alignment optical system in an exposure apparatus that performs high-accuracy alignment between an original and a substrate when projecting and exposing the same, and the aberration of the alignment optical system is corrected by applying such a method. The present invention relates to a position detection apparatus and an exposure apparatus, and a device manufacturing method using such an exposure apparatus.
[0002]
[Prior art]
In a reduction projection type exposure apparatus for manufacturing a semiconductor element, a circuit pattern of a reticle (original) as a first object is projected and exposed on a wafer as a second object by a projection lens system (projection optical system). At this time, the alignment mark on the wafer (substrate) is detected by observing the wafer surface using an observation device (detection device) prior to the projection exposure, and the position alignment between the reticle and the wafer is performed based on the detection result. Alignment).
[0003]
The alignment accuracy at this time largely depends on the optical performance of the observation device. For this reason, the performance of the observation device is an important factor in the exposure device. In particular, recently, various exposure apparatuses for manufacturing a highly integrated semiconductor device using a phase shift mask, deformed illumination, and the like have been proposed. In such an exposure apparatus, higher alignment accuracy is demanded.
[0004]
2. Description of the Related Art Conventionally, in an exposure apparatus, the following three methods are mainly used as a method of observing a wafer alignment mark (wafer mark) for obtaining positional information on a wafer surface.
(1) A method of observing a mark using non-exposure light without passing through a projection lens system (off-axis method)
(2) Method of observing a mark through a projection lens system using exposure light (exposure light TTL method)
(3) A method of observing a mark through a projection lens system using non-exposure light (non-exposure light TTL method).
[0005]
The present applicant has proposed an alignment system using a non-exposure light TTL type observation device in Japanese Patent Application Laid-Open No. Hei 3-61802. In the method described in the publication, an optical image of an alignment mark (wafer mark) on a wafer surface is formed on an image sensor such as a CCD camera, and image information obtained from the image sensor is processed to process the wafer mark. Detect the position. Also, in Japanese Patent Application Laid-Open No. 62-232504, the present applicant has formed an optical image of a wafer mark on a CCD camera, binarized image information obtained by the CCD camera, and There has been proposed a position detection device that detects a position of a wafer mark by performing a template matching process using a template for a specific image pattern.
[0006]
[Problems to be solved by the invention]
In general, in optical design, it is possible to correct the aberration of the projection optical system at a specific alignment wavelength (non-exposure light, for example, 633 nm He-Ne laser oscillation light). However, correcting the aberration of the projection optical system at the alignment wavelength is a constraint on the specifications (NA, exposure range) of the projection optical system at the exposure wavelength, and increases the overall length of the projection optical system or increases the number of constituent lenses. Or forced to do so. For this reason, most existing projection optical systems are designed to have an aberration in the alignment optical system including the projection optical system at the alignment wavelength. In particular, CIS, which is one such aberration, has a close relationship with alignment accuracy. CIS is an abbreviation of Chromatic Image Shift as introduced in “Optical Alliance, April, 2001”, and imaging by a difference in wavelength of alignment light caused by inclination of an optical component and a processing error. This is the displacement of the alignment mark image on the surface.
[0007]
In general, CIS measurement is performed by measuring the difference in the imaging position of an alignment mark on the imaging surface obtained for each wavelength. At this time, if the setting position of the imaging surface in the optical axis direction for measuring the CIS is arbitrary, the following problem occurs.
[0008]
(1) When the telecentricity of the chief rays of two alignment signals having different wavelengths is zero (that is, the two rays are parallel), an imaging plane in the optical axis direction when imaging the alignment mark at each wavelength. Are different, the blur amount of the alignment mark image is different between the two wavelengths, and the CIS cannot be measured accurately.
[0009]
(2) In the case where the telecentricity of the principal ray of two alignment signals having different wavelengths is not zero, if the set position of the imaging surface in the optical axis direction at the time of imaging the alignment mark at each wavelength is different, the CIS is measured. Since the amount includes an error due to the difference in the set position, the amount of CIS cannot be measured accurately.
[0010]
Such a problem occurs not only when using alignment light having two wavelengths but also when using alignment light having more types of wavelengths.
[0011]
SUMMARY OF THE INVENTION The present invention has been made in recognition of the above problems. For example, an aberration measurement method and an aberration correction method suitable for favorably correcting aberration in an alignment optical system, and an alignment optical method using such a method. It is an object of the present invention to provide a position detection device and an exposure device in which system aberration is corrected, and a method for manufacturing a device that can superimpose a fine pattern with high accuracy using such an exposure device.
[0012]
[Means for Solving the Problems]
According to a first aspect of the present invention, a mark is illuminated with a plurality of light beams having different wavelengths from each other via an alignment optical system, and an image of the mark is observed by an imaging device via the alignment optical system. According to the aberration measurement method for measuring the aberration of, the image of the mark is captured by the image sensor by illuminating the mark with each of the plurality of light fluxes, between the images of the mark respectively captured by the plurality of light fluxes It is characterized by including a measuring step of measuring the displacement.
[0013]
Here, the measurement step may be performed with an imaging surface of the imaging device fixed at a predetermined position. The predetermined position is 1) an optimal focus position of the image of the mark when using any one of the plurality of light beams having different wavelengths, or 2) the plurality of light beams having different wavelengths. It is preferable that the average position of the optimal focus position of the image of the mark for each of the plurality of light fluxes when using is used.
[0014]
According to a preferred embodiment of the present invention, it is preferable that the alignment optical system is for a projection exposure apparatus, and the alignment optical system partially includes a projection optical system of the projection exposure apparatus.
[0015]
According to a preferred embodiment of the present invention, it is preferable that the alignment optical system has a parallel plane plate inclined with respect to an optical axis.
[0016]
According to a second aspect of the present invention, a mark is illuminated with a plurality of light beams having different wavelengths from each other via an alignment optical system, and an image of the mark is observed by an image sensor via the alignment optical system. According to the aberration correction method for correcting the aberration of, the image of the mark is captured by the image sensor by illuminating the mark with each of the plurality of light fluxes, between the images of the mark respectively captured by the plurality of light fluxes A measuring step of measuring a shift; and a correcting step of correcting an aberration of the alignment optical system based on the shift of the image of the mark measured in the measuring step.
[0017]
Here, the measurement step may be performed with an imaging surface of the imaging device fixed at a predetermined position. The predetermined position is 1) an optimal focus position of the image of the mark when using any one of the plurality of light beams having different wavelengths, or 2) the plurality of light beams having different wavelengths. It is preferable that the average position of the optimal focus position of the image of the mark for each of the plurality of light fluxes when using is used.
[0018]
According to a preferred embodiment of the present invention, it is preferable that the alignment optical system is for a projection exposure apparatus, and the alignment optical system partially includes a projection optical system of the projection exposure apparatus.
[0019]
According to a preferred embodiment of the present invention, it is preferable that the alignment optical system has a parallel plane plate inclined with respect to an optical axis.
[0020]
A third aspect of the present invention relates to a position detection device including an alignment optical system whose aberration has been corrected by the above-described aberration correction method. Here, it is preferable that the aberration is corrected so that the displacement of the image of the mark is minimized.
[0021]
A fourth aspect of the present invention relates to an exposure apparatus including an alignment optical system whose aberration has been corrected by the above-described aberration correction method. Here, it is preferable that the aberration is corrected so that the displacement of the image of the mark is minimized.
[0022]
A fifth aspect of the present invention relates to a method for manufacturing a device such as a semiconductor device, wherein an exposure step of exposing a substrate coated with a photosensitive agent in a predetermined pattern using the above-described exposure apparatus is provided. And a developing step of developing the agent.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS.
[0024]
First, the mechanism by which CIS occurs will be described. When the parallel plane plate provided as a component of the alignment optical system is tilted, not only the occurrence of astigmatism and coma aberration, but also the alignment mark image captured using alignment light of different wavelengths A shift (CIS) also occurs. The CIS means an image shift caused by the inclination angle α of the plane-parallel plate and the color dispersion action of the glass material as shown in FIG. In FIG. 2, assuming that the refractive indices of the parallel plane plate 17 at wavelengths λ1 and λ2 are N ₁ and N ₂ , respectively, the CIS is expressed by the following equation.
[0025]
CIS = D · (tanα ₂ −tanα ₁ ) cosα
However,
α ₁ = sin ⁻¹ (sin α / N ₁ )
α ₂ = sin ⁻¹ (sin α / N ₂ )
FIG. 2 shows an example in which CIS occurs due to the eccentricity of the optical axis due to the inclination of the part during assembly. However, the CIS also occurs due to a centering error and an angle error in the optical part alone.
[0026]
36 (1997) Pt. 1, No. 12B in "Jpn.J. Appl. Phys. Vol. 36 (1997) Pt. 1, No. 12B", it can be seen that there is a correlation between the offset amount generated in the alignment of the semiconductor exposure apparatus in a certain semiconductor process and the CIS. It has been reported that CIS needs to be adjusted on the order of nanometers. It is very difficult to manufacture each optical component with high precision to minimize CIS and to assemble it without adjustment. In practice, it is necessary to measure the amount of CIS and then respond with an adjustment mechanism. is there.
[0027]
FIG. 1 is a view schematically showing a configuration of a semiconductor exposure apparatus according to a preferred embodiment of the present invention. In FIG. 1, a reticle (original) 1 as a first object is held by a reticle stage 2. The reticle 1 is illuminated with exposure light from an exposure illumination system 30 during exposure. An alignment mark 4 is provided on the surface of a wafer (substrate) 3 as a second object. The projection optical system 5 projects a circuit pattern or the like on the reticle 1 surface onto the wafer 2 surface.
[0028]
The θZ stage 6 performs θ rotation of the wafer 3 placed thereon and focus adjustment (that is, adjustment in the Z direction). The θZ stage 6 is mounted on an XY stage 7 for performing a step operation with high accuracy. On the XY stage 7, an optical square (not shown) serving as a reference for stage position measurement is placed, and the optical square is monitored using a laser interferometer (not shown).
[0029]
In this embodiment, the alignment (alignment) between the reticle 1 and the wafer 3 is performed indirectly by aligning the reticle 1 and the wafer 3 with respect to a reference mark whose positional relationship is required in advance. At this time, after performing the alignment, exposure and development are actually performed, an alignment error (offset) is measured, and an offset process is performed in consideration of the alignment error.
[0030]
A method for detecting the position of the wafer alignment mark 4 arranged on the wafer 3 will be described. The light source unit 8 includes a plurality of light sources having different wavelengths, such as a halogen lamp 22 and a He—Ne laser 21. When the light from the He-Ne laser 21 is used as illumination light, the light source switching mirror 24 having a movable mechanism is retracted to a position where the light from the He-Ne laser 21 is not cut. On the other hand, when the halogen lamp 22 is used as illumination light, a light source switching mirror 24 having a movable mechanism is installed in the optical path, a predetermined wavelength is cut out by the wavelength switching plate 23, and the light source is switched through the mirror 26 and the light source switching mirror 24. The illumination light is led out of the unit 8.
[0031]
A light beam having linearly polarized light emitted from the light source unit 8 passes through a mirror 9, a lens 10, a polarized beam splitter 11 (hereinafter, referred to as a PBS 11), a lens 12, a λ / 4 plate 13, a mirror 25, and the projection optical system 5. Illuminate the alignment mark 4 on the wafer 3. On the other hand, an alignment signal from the wafer alignment mark 4 is transmitted to the detection surface of an image sensor 16 such as a CCD via the projection optical system 5, mirror 25, λ / 4 plate 13, lens 12, PBS 11, lens 14, and correction optical element 15. Is imaged.
[0032]
Next, a method for correcting various aberrations including CIS will be described with reference to FIG. FIG. 3 shows an example of the configuration of the correction optical element 15 in FIG. 1, and an example in which an inverse correction system in the TTL alignment optical system in FIG. 1 is configured by combining three parallel flat plates 18, 19, and 20. Is shown.
[0033]
In the configuration example of FIG. 1, it is assumed that astigmatism in the projection optical system 5 (AS _P), coma (CM _P) occurs in the alignment wavelength. First, in the meridional cross section shown in FIG. 3, a plane-parallel plate 18, the coma aberration is set inclined so as to generate only -CM _P. At this time, CIS is generated together with coma. If the chromatic aberration of magnification occurring in the CIS and the projection optical system 5 occurs in opposite directions, the occurrence of CIS can be suppressed by selecting the thickness, the glass material, and the tilt angle of the plane parallel plate 18.
[0034]
On the other hand, the astigmatism by tilting the plane-parallel plate 18 _{(AS 18)} also so happens, the amount of astigmatism on the sagittal _{section, - (AS P + AS 18} ) / 2 by the plane parallel plate to generate 19 is set. At this time, coma aberration and CIS occur in the sagittal section due to the parallel plane plate 19. Therefore, the same component as the parallel flat plate 19 is set as the parallel flat plate 20 at an inclination angle opposite to that of the parallel flat plate 19.
[0035]
Also plane-parallel plate 20 as in the plane-parallel plate _19, - since _{(AS P + AS 18) /} 2 by astigmatic aberration occurs, the sum of the aberrations generated in the plane parallel plate 20 and a plane parallel plate 19 - (AS _P + aS ₁₈₎ astigmatism can be generated in, thereby canceling the astigmatism generated in the plane parallel plate 18 and the projection optical system _{5 (aS P + aS 18)} , so that there is no astigmatism in the whole Can correct the alignment optical system.
[0036]
Coma aberration and CIS are also generated in the sagittal section by the parallel plane plate 20, but by making the inclination angle of the parallel plane plate 20 reverse to the inclination angle of the parallel plane plate 19, the CIS generated in the parallel plane plate 20 becomes Since the absolute value is equal to the CIS generated by the parallel plane plate 19 and the positive and negative signs have opposite values, it is possible to correct the coma and the CIS generated in the sagittal section.
[0037]
Thus, by using a plane-parallel plate 18, 19, 20 can be generated by the coma, astigmatism and -CM _P of -AS _P, the alignment wavelength generated in the projection optical system 5 Can be inversely corrected.
[0038]
Of course, since three parallel flat plates are inserted into the optical path of the alignment optical system partially including the projection optical system 5, spherical aberration is generated by that amount. In consideration of the spherical aberration, it is necessary to correct the spherical aberration in the entire alignment optical system including the projection optical system 5 at a design stage.
[0039]
When correcting aberrations by the above method, particularly when measuring and adjusting CIS, the position of the alignment mark image on the detection surface of the image sensor 16 is detected, and correction is performed based on the detection result. At this time, as shown in FIG. 4, the installation position of the optical axis AX of the detection surface of the image sensor 16, fixed in the alignment wavelength .lambda.1, the back focus position Bk ₁ of the optical system including the parallel plate 18-20 In advance, the amount of CIS at the alignment wavelengths λ1 and λ2 is measured. Then, the adjustment of the parallel plane plates 18 to 20 and the measurement of the CIS are repeated based on the image signal from the image sensor 16 so as to minimize the CIS. In this case, the installation position of the optical axis AX of the detection surface of the image sensor 16 may be fixed to the position of the back focus position Bk ₂ in the alignment wavelength .lambda.2.
[0040]
Moreover, Bk 1 back focus position in the alignment wavelength _.lambda.1, if the back focus position in an alignment wavelength λ2 and Bk _2, the installation position of the detection surface of the image sensor 16, is the average position of the two back focus (Bk 1 ₊ Bk ₂ ) / 2.
[0041]
Next, a second embodiment of the present invention will be described. In this embodiment, a description will be given of correction of an aberration generated in a manufacturing stage of a semiconductor exposure apparatus including an alignment optical system. When the projection optical system 5 is thoroughly corrected for aberration at the wavelength of exposure light and assembled, the amount of aberration generated at the wavelength of alignment light, which is non-exposure light, increases. Further, various kinds of aberrations occur at the time of adjusting the assembly of the projection optical system 5. Such aberrations include aberrations caused by eccentricity of each lens constituting the projection optical system 5.
[0042]
As aberration correction in such a manufacturing stage, spherical aberration can be easily corrected. To correct spherical aberration that occurs during the manufacturing stage, for example, at the design stage, a parallel flat plate with an appropriate thickness is designed in an alignment optical system, and the spherical aberration is corrected after measuring the spherical aberration. This can be done by replacing the parallel flat plate with a suitable thickness as possible.
[0043]
In the example of FIG. 3, by changing the inclination angles of the three parallel flat plates 18, 19, and 20, it is possible to correct the aberration that occurs during the manufacturing stage. However, when the inclination angles of the plane-parallel plates 18, 19, and 20 are changed, all of spherical aberration, astigmatism, coma, and CIS change. Therefore, in advance, a plurality of parallel plane plate tilting mechanisms are arranged where sensitivity to various aberrations is different, and multiple parallel plane plates with different thicknesses and glass materials are prepared as replacement parts for each parallel plane plate. After obtaining various amounts of aberration before adjustment, the amount of tilt for each tilt mechanism and an appropriate parallel plane plate are determined, and the alignment optical system is adjusted accordingly (including replacement with an appropriate parallel plane plate). Is preferred. Thereby, all aberrations caused by manufacturing errors can be corrected.
[0044]
The measurement of CIS and the adjustment of CIS are preferably performed by detecting the position of the alignment mark image on the detection surface of the image sensor 16. At this time, as shown in FIG. 4, the installation position of the optical axis AX direction of the detection surface of the image pickup element 16, fixed in the alignment wavelength .lambda.1, the back focus position Bk ₁ of the optical system including the parallel plate 18-20 In this state, it is preferable to measure the amount of CIS at the alignment wavelengths λ1 and λ2 in that state, and repeat the adjustment and measurement based on the image signal from the image sensor 16 so that the CIS is minimized. In this case, the installation position of the optical axis AX of the detection surface of the image sensor 16 may be fixed to the position of the back focus position Bk ₂ in the alignment wavelength .lambda.2.
[0045]
Alternatively, assuming that the back focus position at the alignment wavelength λ1 is Bk ₁ and the back focus position at the alignment wavelength λ2 is Bk ₂ , the installation position of the detection surface of the image sensor 16 is, for example, the average position of two back focuses (Bk ₁ + Bk ₂ ) / 2.
[0046]
In the first and second embodiments described above, the correction of the CIS and the like is realized by disposing the correction optical element 15 in the alignment optical system. The adjustment can be performed by decentering or rotating some of the components of the alignment optical system.
[0047]
As described above, according to the preferred embodiment of the present invention, coma aberration, astigmatism, CIS, etc., generated in the projection optical system 5 when using light beams of a plurality of different wavelengths as exposure light as alignment light. Are measured in a state where the imaging surface of the image sensor 16 is fixed at a predetermined position, and the various aberrations are adjusted by the correction optical element 15 based on the measurement result so as to minimize the various aberrations. Correction can be made well.
[0048]
According to the exposure apparatus having such an alignment optical system, the position information of the alignment mark provided on the wafer surface can be detected with high accuracy, and the relative alignment between the reticle and the wafer can be performed with high accuracy. Thus, a highly integrated device can be easily manufactured.
[0049]
In particular, according to the preferred embodiment of the present invention, coma aberration, astigmatism, CIS, etc. generated in the projection optical system can be satisfactorily corrected. The change in chromatic aberration near the alignment fundamental wavelength, which has been described above, can be greatly reduced. As a result, a remarkable effect that a high-precision alignment can be performed by obtaining a good alignment signal while easily designing the projection optical system can be obtained.
[0050]
Next, a description will be given of a semiconductor device manufacturing process using an exposure apparatus whose aberration has been corrected by the above method. FIG. 5 is a diagram showing a flow of the entire semiconductor device manufacturing process. In step 1 (circuit design), the circuit of the semiconductor device is designed. In step 2 (mask fabrication), a mask is fabricated based on the designed circuit pattern. On the other hand, in step 3 (wafer manufacturing), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is referred to as a pre-process in which an actual circuit is formed on the wafer by lithography using the above-described mask and wafer. The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer produced in step 4, and assembly such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). Process. In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).
[0051]
FIG. 6 is a diagram showing a detailed flow of the wafer process. Step 11 (oxidation) oxidizes the wafer's surface. Step 12 (CVD) forms an insulating film on the wafer surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor deposition. Step 14 (ion implantation) implants ions into the wafer. In step 15 (resist processing), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the above-described exposure apparatus to transfer a circuit pattern onto a wafer. Step 17 (development) develops the exposed wafer. In step 18 (etching), portions other than the developed resist image are removed. Step 19 (resist stripping) removes unnecessary resist after etching. By repeating these steps, multiple circuit patterns are formed on the wafer.
[0052]
【The invention's effect】
According to the present invention, it is possible to satisfactorily correct aberration in the alignment optical system.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a projection exposure apparatus including an alignment optical system using a non-exposure light TTL method.
FIG. 2 is a diagram illustrating a mechanism in which CIS occurs.
FIG. 3 is a diagram illustrating a correction optical system.
FIG. 4 is a diagram showing a correction optical system.
FIG. 5 is a diagram showing a device manufacturing method.
FIG. 6 is a diagram showing a device manufacturing method.
[Explanation of symbols]
Reference Signs List 1 reticle 2 reticle stage 3 wafer 4 alignment mark 5 projection optical system 6 θZ stage 7 XY stage 8 light source unit 9, 25, 26 mirror 10, 12, 14 lens 11 PBS
13 λ / 4 plate 15 Correcting optical element 16 Imaging means 17, 18, 19, 20 Parallel plane plate 21 He-Ne laser 22 Halogen lamp 23 Wavelength switching plate 24 Light source switching mirror 30 Illumination system

Claims (13)

A plurality of light beams having different wavelengths illuminate a mark through an alignment optical system, an image of the mark is observed by an image sensor through the alignment optical system, and an aberration measuring method for measuring aberration of the alignment optical system is used. So,
A measurement step of illuminating the mark with each of the plurality of light beams, capturing an image of the mark with the image sensor, and measuring a shift between the images of the mark respectively captured with the plurality of light beams. Aberration measurement method. The measurement step is performed in a state where the imaging surface of the imaging element is fixed at an optimal focus position of the image of the mark when one of the plurality of light beams having different wavelengths is used. The method for measuring aberration according to claim 1. When the plurality of light beams having different wavelengths from each other are used, the measurement step is performed in a state where the imaging surface of the image sensor is fixed at an average position of an optimal focus position of the mark image for each of the plurality of light beams. 2. The aberration measurement method according to claim 1, wherein: 2. The aberration measuring method according to claim 1, wherein the alignment optical system is for a projection exposure apparatus, and the alignment optical system partially includes a projection optical system of the projection exposure apparatus. 2. The aberration measuring method according to claim 1, wherein the alignment optical system has a plane parallel plate inclined with respect to an optical axis. A mark is illuminated through an alignment optical system with a plurality of light beams having different wavelengths from each other, an image of the mark is observed by an image pickup device through the alignment optical system, and an aberration correction method for correcting aberration of the alignment optical system. So,
A measurement step of illuminating the mark with each of the plurality of light beams, capturing an image of the mark with the image sensor, and measuring a shift between the images of the mark each captured with the plurality of light beams;
A correction step of correcting the aberration of the alignment optical system based on a shift between the images of the marks measured in the measurement step,
An aberration correction method comprising: The measurement step is performed in a state where the imaging surface of the imaging element is fixed at an optimal focus position of the image of the mark when one of the plurality of light beams having different wavelengths is used. The aberration correction method according to claim 6. When the plurality of light beams having different wavelengths from each other are used, the measurement step is performed in a state where the imaging surface of the image sensor is fixed at an average position of an optimal focus position of the mark image for each of the plurality of light beams. The aberration correction method according to claim 6, wherein the correction is performed. 7. The aberration correction method according to claim 6, wherein the alignment optical system is for a projection exposure apparatus, and the alignment optical system partially includes a projection optical system of the projection exposure apparatus. The aberration correction method according to claim 6, wherein the alignment optical system has a parallel flat plate inclined with respect to an optical axis. A position detection device comprising an alignment optical system whose aberration has been corrected by the aberration correction method according to claim 6. An exposure apparatus comprising: an alignment optical system whose aberration has been corrected by the aberration correction method according to claim 6. A method of manufacturing a device, comprising:
Using the exposure apparatus according to claim 12, an exposure step of exposing the substrate coated with a photosensitive agent in a predetermined pattern,
A developing step of developing a photosensitive agent on the substrate;
A method for manufacturing a device, comprising:

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