JPH07297101A - Projection aligner - Google Patents

Abstract

PURPOSE:To detect or project a predetermined mark accurately even if a pupil filter is inserted when the mark is observed or projected through a projection optical system. CONSTITUTION:The band ring opening of a shade 25 is illuminated collectively through a cone prism 24 with an illumination light IL2 introduced through an optical fiber 23. The transmitted illumination light is then projected through a condenser lens 26 onto an ISS mark 22 put on a reference mark plate 21. Zero order light transmitted through the ISS mark 22 then passes on the outside of the shade part of a pupil filter 4 in a projection optical system 3 and illuminates an alignment mark 8B on a reticle 1. The illumination light transmitted through the reticle 1 then impinges on a photoelectric conversion element 29 with sufficient quantity of light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection exposure apparatus used, for example, in manufacturing a semiconductor device or a liquid crystal display device in a photolithography process, and more particularly to a reticle alignment or a projection optical system via a projection optical system. It is suitable to be applied to a projection exposure apparatus having a function of measuring the image forming characteristics of the above.

[0002]

2. Description of the Related Art In a photolithography process for manufacturing a semiconductor device, a liquid crystal display device, or the like, a photomask or reticle (hereinafter, "reticle" is used as an example).
There is used a projection exposure apparatus which exposes the image of the pattern (1) on a wafer (or a glass plate etc.) coated with a photoresist through a projection optical system. In such a projection exposure apparatus, an alignment mark formed on a reticle and a wafer stage are formed in order to accurately perform reticle alignment (reticle alignment) with respect to a wafer stage on which a wafer is placed prior to exposure. An alignment system is used that simultaneously observes the reference mark and the projection optical system.

A reference mark FM1 consisting of four linear patterns shown in FIG. 11A is an example of a reference mark on a wafer stage used when performing reticle alignment, and a cross shown in FIG. 11B. The mold alignment mark RM1 is an example of a corresponding mark on the reticle. The reference mark FM1 is used as a reference for positions in the X direction and the Y direction that are orthogonal to each other. in this case,
For example, when the reference mark is observed from above the reticle through the projection optical system by the two-dimensional image sensor, the alignment mark RM1 and the reference mark image FM1P are observed overlapping each other in the observation field of view on the reticle as shown in FIG. To be done. Therefore, for example, when the image pickup signal is read out along the scanning line on the image pickup element corresponding to the scanning line SL parallel to the X axis in FIG. 12A, the signal shown in FIG.
From this signal, the amount of misalignment of the alignment mark RM1 with respect to the reference mark image FM1P in the X direction is obtained. Similarly, the amount of positional deviation in the Y direction is also obtained. The reticle alignment is performed by pushing the positional deviation amount of the alignment mark RM1 thus obtained to a predetermined value.

Further, in the projection exposure apparatus, not only the two-dimensional position of the reticle but also the rotation of the reticle with respect to the coordinate system on the wafer stage (reticle rotation).
Therefore, the so-called stage emission type ISS (Imaging Slit Sense) is used as follows.
The reticle rotation was measured by the r) system. In this case, as shown in FIG. 13A, an ISS mark FM2 having a slit-shaped opening pattern is formed along the Y direction on the wafer stage side, and the ISS mark FM2 is correspondingly formed on the reticle as shown in FIG. 13B. As shown in, a linear pattern-shaped alignment mark RM2 is formed.

At this time, when the wafer stage is scanned in the X direction with the ISS mark FM2 illuminated from the bottom side, a bright ISS mark image FM2P is aligned in the X direction on the reticle as shown in FIG. 14 (a). Move across the mark RM2. Therefore, when the light beam that has passed through the reticle is received and photoelectrically converted, a signal that changes according to the position of the wafer stage in the X direction is obtained, as shown in FIG. The position of the alignment mark RM2 is measured from the position. Further, for example, the second formed on the reticle so as to be separated in the Y direction.
When the position of the alignment mark in the X direction is obtained, the rotation angle of the reticle with respect to the Y axis on the wafer stage is measured from the difference between the positions of the two alignment marks.

Similarly, as the reference mark on the wafer stage side, by using the ISS mark FM3 having a slit-shaped opening pattern along the X axis as shown in FIG. The reticle rotation with respect to is measured, and as shown in FIG.
Using the SS mark FM4, the reticle rotation about the X axis and the Y axis is measured.

In general, in the photolithography process, different layers on the wafer may be exposed by using different projection exposure apparatuses. Therefore, in order to keep the overlay error between the different layers within an allowable range. It is necessary that the distortion of the projection optical system provided in each projection exposure apparatus be within a predetermined allowable range. Therefore, conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 59-94032, an evaluation mark on a test reticle is actually projected onto a wafer through a projection optical system, and a projected mark image is formed. By scanning the light receiving slit on the wafer stage side and measuring the position of the mark image,
I was measuring the distortion of the projection optical system.

[0008]

As described above, in the conventional projection exposure apparatus, the position detection or projection of various marks is performed via the projection optical system. In this regard, recently, by installing an optical filter plate (hereinafter referred to as “pupil filter”) having a predetermined transmittance distribution characteristic and a phase distribution characteristic near the pupil plane (Fourier transform surface) of the projection optical system, a predetermined pattern is obtained. Attempts have been made to improve the imaging performance of the projection optical system during exposure of the. For example, in order to improve the resolution and the depth of focus when exposing an isolated pattern such as a contact hole pattern, a pupil plane of a projection optical system is disclosed, for example, as disclosed in Japanese Patent Application Laid-Open No. 4-179958. It has been found that a light-shielding type pupil filter that shields a circular region near the optical axis may be installed in the vicinity.

FIG. 16A is an explanatory view of the principle of the action of the light-shielding pupil filter. In FIG. 16A, the image of the fine contact hole pattern 2 on the reticle 1 is projected onto the projection optical system 3. The wafer 5 is exposed to light through the above. At this time, on the pupil plane FP of the projection optical system 3, the pupil filter 4 having a circular light shielding portion with a radius r centered on the optical axis is arranged. The pupil filter 4 is, for example, a circular light-shielding film formed on a glass substrate, and only the light-shielding portion is shown in FIG. 16A. When the radius of the pupil of the projection optical system 3 is a, the radius r is 0.8a, for example. In this case, when the reticle 1 is irradiated with the exposure light IL, the diffracted light emitted from the contact hole pattern 2 is projected onto the pupil plane F of the projection optical system 3.
The intensity distribution at P has a relatively large value in the area outside the pupil as shown by the distribution curve 6. Therefore, when the image of the contact hole pattern 2 is formed by simply using the light that passes through the entire pupil, the resolution of the obtained image becomes poor.

On the other hand, when the pupil filter 4 is installed on the pupil plane FP, the intensity distribution of the image obtained on the wafer 5 is enlarged in the X direction by the apodization effect, and a diagram 7 (b) shows a curve 7. And the interval from the peak of the image to the first zero becomes short. That is, the resolution is improved,
At the same time, the effect of increasing the depth of focus is also obtained. As described above, when the light-shielding pupil filter 4 is installed on the pupil plane FP of the projection optical system 3, the image forming characteristic of the projection optical system 3 with respect to the contact hole pattern can be improved. However, assuming that the reticle alignment is performed by detecting the reference mark FM1 shown in FIG. 11A via the projection optical system 3 in which the pupil filter 4 is thus inserted,
Most of the light from the reference mark FM1 is blocked by the light blocking portion of the pupil filter 4 to reduce the light amount, and as a result, reticle alignment cannot be performed with high accuracy. Similarly, the ISS mark FM2 shown in FIG.
Even if an attempt is made to guide the light from the ISS mark FM2 to the reticle side through the projection optical system 3 in which the pupil filter 4 is inserted, most of the light from the ISS mark FM2 is blocked by the light blocking portion of the pupil filter 4, and the reticle is blocked. There was an inconvenience that rotation could not be measured with high accuracy.

Similarly, even if an evaluation mark of the test reticle is projected through the projection optical system 3 in order to measure the distortion characteristic of the projection optical system 3 in which the pupil filter 4 is installed, the evaluation mark is not measured. Most of the image-forming light flux of (3) is blocked by the light-shielding portion of the pupil filter 4, and a good image of the evaluation mark cannot be obtained. In view of such a point, the present invention provides a projection exposure apparatus capable of accurately detecting or projecting a predetermined mark when detecting or projecting a predetermined mark via a projection optical system in which a pupil filter is inserted. The purpose is to provide.

[0012]

A projection exposure apparatus according to the present invention is, for example, as shown in FIG. 1, a projection optical system for projecting a pattern of a mask (1) onto a photosensitive substrate (5) with a predetermined image forming characteristic. (3) and a mark detection system for detecting the reference mark (22) arranged on the object plane side or the image plane side of the projection optical system via the projection optical system. An optical system which is arranged on the Fourier transform plane (FP) formed in the image forming optical path of the optical system (3) or a surface in the vicinity thereof, and which has partially different transmission characteristics of the image forming light beam in order to improve the image forming characteristics. It has a correction plate (4), the mark detection system of which is generated from the reference mark (22), and the projection optical system (3).
At least the zero-order light incident on the optical correction plate (4)
To pass through a specific area whose transmission properties are the same,
An illumination system (23-) that illuminates the reference mark (22) with illumination light.
26) and a photoelectric detector (29) for receiving illumination light passing through a specific area on the optical correction plate (4).

In this case, in one example of the optical correction plate (4), the transmission characteristics are made different between the central circular area and the outer annular zone, and the 0th order light is the circular area or the annular zone. It passes through. An example of an illuminating system suitable for this case is, for example, as shown in FIG. 4B, irradiating the reference mark (22a) with the illuminating light so that the 0th-order light passes through the annular zone. To do.

Further, another example of the illumination system has a conversion optical system (26) which brings the reference mark (22) and the predetermined surface (25) into a Fourier transform relationship, and passes through the predetermined surface (25). The illuminating light is defined as a ring zone or at least one local zone decentered from the optical axis of the conversion optical system (26). Further, for example, as shown in FIG. 8, a mask (42)
The illumination optical system (10 to 12, 47) for illuminating the mark may also serve as the illumination system of the mark detection system.

[0015]

According to the projection exposure apparatus of the present invention as described above, for example, as shown in FIG. 1, the optical correction plate (4) shields an area within a predetermined range centered on the optical axis of the projection optical system (3). In the case of the light-shielding type pupil filter, in the illumination system (23 to 26) of the mark detection system, the 0th-order light passing through the reference mark (22) is outside the light-shielding portion of the pupil filter. ), The reference mark (22) is illuminated with illumination light. Thereby, the light generated from the reference mark (22) is received by the photoelectric detector (29) with a sufficient amount of light even after passing through the projection optical system (3), and the reference mark (22) can be accurately detected.

When the optical correction plate (4) has, for example, a circular area having a large transmittance and an annular area having a small transmittance around it, the illumination system (23 to 2) of the mark detecting system.
In 6), the reference mark (22) is illuminated so that the 0th-order light passing through the reference mark (22) passes through a circular region having a high transmittance. As a result, the reference mark (22)
The light generated by the photodetector (29) is received by the photoelectric detector (29) in a sufficient amount even after passing through the projection optical system (3). On the contrary, when the transmittance of the surrounding ring zone is small, the reference mark (22)
By illuminating the reference mark (22) so that the 0th-order light that passes through the ring zone region having a large transmittance,
The reference mark (22) can be accurately detected.

Further, the 0th-order light from the reference mark (22) due to the illumination light from the illumination system of the mark detection system may pass through a ring-shaped region on the Fourier transform plane of the projection optical system (3), for example. There are roughly two ways to do this. First, as shown in FIG. 4B, the illumination efficiency is high when the illumination light is emitted while being inclined with respect to the reference mark (22a). On the other hand, when the light shield plate (25) having a ring-shaped opening is illuminated once and the light transmitted through the light shield plate (25) is applied to the reference mark (22) through the conversion optical system (26), The entire ring-shaped region can be utilized, and the imaging characteristics are improved.

Further, for example, as shown in FIG.
Alternatively, the reference mark (M _ij) Is the mask (4
2) When it is on the side, the light that illuminates the mask (42)
The bright optical system (10 to 12, 47) is the mark detection system.
In some cases, the lighting system can also be used. This allows the whole light
The academic system is simplified.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the projection exposure apparatus according to the present invention will be described below with reference to FIGS. In this example,
In order to perform reticle alignment, ISS (Imaging Sl
The present invention is applied to the case of detecting the position or rotation angle of the reticle through the projection optical system by the itSenser method.

FIG. 1 shows a projection exposure apparatus of this embodiment,
In FIG. 1, a reticle 1 is an original plate for a contact hole pattern, an original pattern of contact hole patterns is formed in a predetermined array in a pattern area of the reticle 1, and two alignments are provided in the vicinity of the pattern area in the X direction. Marks 8A and 8B are formed. The alignment marks 8A and 8B are cross-shaped light-shielding patterns formed in the glass substrate portion (transmissive portion) as shown in FIG.

When exposing the pattern of the reticle 1,
Exposure light IL1 (i-line of a mercury lamp, excimer laser light, or the like) from a light source for exposure (not shown) enters the fly-eye lens 10 and a large number of secondary surfaces formed on the exit surface of the fly-eye lens 10. The exposure light from the light source illuminates the pattern area of the reticle 1 via the mirror 11 and the condenser lens 12. Under the exposure light, the image of the pattern in the pattern area of the reticle 1 through the projection optical system 3 is
Each shot area of the wafer 5 held on the wafer stage 13 is exposed.

On the Fourier transform surface (pupil surface) FP of the projection optical system 3 with respect to the pattern forming surface of the reticle 1, a light-shielding type which shields light in a circular area having a predetermined radius with the optical axis AX of the projection optical system 3 as the center. The pupil filter 4 is arranged. The pupil filter 4 is formed by forming a light-shielding portion having a predetermined radius around the optical axis AX on the glass substrate, but FIG. 1 shows only the light-shielding portion. The image of the contact hole pattern is projected and exposed on the wafer 5 with a high resolution and a deep depth of focus by the pupil filter 4. Although not shown, an aperture stop is arranged on the pupil plane FP, and the outer radius of the imaging light flux passing through the pupil plane FP is defined by the aperture stop.

Here, the Z axis is taken parallel to the optical axis AX of the projection optical system 3, and the orthogonal coordinate system of a two-dimensional plane perpendicular to the Z axis is defined as X.
Assuming the axis and the Y-axis, the wafer stage 13 is composed of an XY stage for positioning the wafer 5 in an XY plane perpendicular to the Z-axis, a Z stage for adjusting the position of the wafer 5 in the Z-axis direction, and the like. . Further, a movable mirror 14 is fixed to the end of the wafer stage 13, and the X coordinate and Y coordinate of the wafer stage 13 are constantly measured by the movable mirror 14 and a laser interferometer 15 installed outside, and the measured coordinates are measured. Is supplied to the main control system 16 and the calculation unit 17. The main control system 16 controls the moving coordinates of the wafer stage 13 via the wafer stage driving unit 18 based on the measured coordinates.

Further, a projection optical system 19 for projecting a slit pattern image laterally of the projection optical system 3 obliquely with respect to the optical axis AX to a predetermined measurement point in the exposure field of the projection optical system 3.
And the reflected light from the measurement point is received to re-image the slit pattern image, and a focus signal corresponding to the amount of deviation of the re-imaged position from the reference position is generated to generate the main control system 16 An autofocus sensor including a light receiving system 20 for supplying the In this case, calibration is performed so that the focus signal becomes 0 in the state where the measurement point matches the image forming plane (best focus plane) of the projection optical system 3, and the value of the focus signal From this, for example, the amount of positional deviation (defocus amount) of the exposure surface of the wafer 5 from the best focus surface can be detected.

Further, a reference mark plate 21 made of a glass substrate is fixed near the wafer 5 on the wafer stage 13, and the ISS mark 22 is formed on the surface of the reference mark plate 21.
Are formed. At the time of reticle alignment, the surface of the reference mark plate 21 is set at the same height as the image forming plane of the projection optical system 3 by using an auto focus sensor. I
As shown in FIG. 3, the SS mark 22 includes an X-axis slit mark 22a and an X-axis slit mark 22a formed in the light-shielding film and long in the Y direction.
It is a cross-shaped opening pattern composed of Y-axis slit marks 22b that are long in the direction, and the size of the reference mark 22 is about the same as the size of the projection image of the alignment mark 8A or 8B by the projection optical system 3.

In FIG. 1, in the present embodiment, a stage emission type illumination system for illuminating the ISS mark 22 and the alignment mark 8B (or 8A) from the bottom surface side of the reference mark plate 21 is provided. When the position or the rotation angle of the reticle is detected using this illumination system, the exposure light IL1 is emitted from the exposure light source (not shown) via the optical fiber 23.
Illumination light IL2 having the same wavelength as is guided. Optical fiber 23
The illumination light IL2 emitted from the light source is converted into a luminous flux distributed in a substantially annular shape by the cone prism 24 and is incident on the light shielding plate 25.

FIG. 3 shows the stage emission type illumination system shown in FIG. 1. In FIG. 3, the light shielding plate 25 has an optical axis (the optical axis AX of the projection optical system 3 shown in FIG. 1) of the illumination system. Parallel axes)
A ring-shaped opening 25a is formed around the center. The illumination light IL3 emitted from the ring-shaped opening 25a is passed through the condenser lens 26 and the ISS mark 22 on the reference mark plate 21.
Is irradiated to the bottom of the. At this time, the illumination light emitted from the optical fiber 23 by the action of the cone prism 24 efficiently illuminates the ring-shaped opening 25a of the light shielding plate 25, and the surface on which the ring-shaped opening 25a is formed and the ISS mark 22. The forming surface has a Fourier transform relationship with respect to the condenser lens 26. Therefore, the distribution of the 0th-order light emitted from the ISS mark 22 is conically inclined about the optical axis of the illumination system.

Further, returning to FIG. 1, when the ISS mark 22 matches the image plane of the projection optical system 3, the formation surface of the ISS mark 22 and the pupil plane FP of the projection optical system 3 are Fourier transformed. Therefore, the pupil plane FP (the arrangement surface of the pupil filter 4) and the arrangement surface of the light shielding plate 25 are conjugate with each other. Therefore, in this embodiment, the inner radius of the ring-shaped aperture 25a of the light blocking plate 25 is set equal to the radius of the conjugate image of the light blocking portion of the pupil filter 4 on the light blocking plate 25, and the outer radius of the ring-shaped aperture 25a is set to the pupil. It is set equal to the radius of the aperture stop (not shown) on the surface FP. In other words, the conjugate image of the ring-shaped aperture 25a on the pupil plane FP of the projection optical system 3 overlaps with the region on the pupil plane FP through which the image-forming light flux can pass (that is, the transmission part of the pupil filter 4). Therefore, all the illumination light (zero-order light) that passes through the ISS mark 22 as it is passes through the area between the light blocking portion of the pupil filter 4 and the aperture stop on the pupil plane FP of the projection optical system 3, and the reticle 1 Head to the side.

In FIG. 1, most of the 0th-order light that has passed through the ISS mark 22 and the diffracted light generated from the ISS mark 22 are on the pupil plane FP of the projection optical system 3 outside the light shielding portion of the pupil filter 4. After passing through the area, the projection optical system 3
ISS mark 22 on the pattern formation surface of reticle 1 by
Form an image of. The illumination light thus generated from the ISS mark 22 and transmitted through the reticle 1 is reflected by the mirror 27 for bending the optical path, and then is condensed on the light receiving surface of the photoelectric conversion element 29 via the condenser lens 28. . A detection signal obtained by photoelectrically converting the light received by the photoelectric conversion element 29 is supplied to the calculation unit 17. In the calculation unit 17, for example, the ISS mark 22 is calculated from the X coordinate or the Y coordinate of the wafer stage 13 when the supplied detection signal has the minimum value.
The X-coordinate or the Y-coordinate at which the image of (1) matches the alignment mark 8B is obtained and supplied to the main control system 16 (details will be described later).

Next, an example of the operation when performing reticle alignment in this embodiment will be described. In FIG.
First, with the exposure light IL1 blocked, the reticle 1 is roughly positioned and fixed on the reticle holder 9. After that, in a state where the illumination light IL2 is emitted from the optical fiber 23, the wafer stage 13 is operated to operate the fiducial mark plate 21.
The upper ISS mark 22 is moved to the + X direction side with respect to the position conjugate with the alignment mark 8B of the reticle 1. The illumination light (0th-order light, diffracted light, etc.) that has passed through the ISS mark 22 passes around the light-shielding portion of the pupil filter 4 in the projection optical system 3 to the + X direction side of the alignment mark 8B of the reticle 1 and the ISS mark. Connect 22 images.

In this state, the wafer stage 13 is scanned in the -X direction (first measurement direction), and the photoelectric conversion element 29 receives the illumination light generated from the ISS mark 22 and passing through the projection optical system 3 and the reticle 1. Then, the calculation unit 17 monitors the detection signal. By scanning the wafer stage 13, the IS
X-axis slit mark 22a of the S mark 22 (see FIG. 3)
When is aligned with the long light-shielding portion of the alignment mark 8B in the Y direction, the X-axis slit mark 22a is shielded by the alignment mark 8B, so that the amount of light received by the photoelectric conversion element 29 is small. The calculation unit 17 holds the X coordinate of the wafer stage 13 at this time as the X coordinate of the alignment mark 8B and supplies it to the main control system 16.

Similarly, by scanning the wafer stage 13 in the Y-direction, the Y-coordinate of the wafer stage 13 when the Y-axis slit mark 22b of the ISS mark 22 coincides with the long light-shielding portion of the alignment mark 8B in the X-direction is obtained. can get. A light receiving system (not shown) is also arranged above the alignment mark 8A of the reticle 1 in FIG. 1, and this light receiving system is used to move the wafer stage 13 when the image of the ISS mark 22 matches the alignment mark 8A. The X and Y coordinates are measured. The rotation angle of the reticle 1 is also measured from the coordinates of these two points. By aligning the coordinates of the alignment marks 8A and 8B measured in this way with predetermined reference coordinates, the reticle 1 is aligned.

In this case, in this embodiment, the ISS mark 2
The 0th-order light passing through 2 intersects the optical axis of the stage emission type illumination system at a predetermined angle. Since the optical axis of the stage emission type illumination system and the optical axis AX of the projection optical system 3 are parallel to each other, the 0th-order light from the ISS mark 22 is also at a predetermined angle with respect to the optical axis AX of the projection optical system 3. You will cross. The predetermined angle is substantially equal to the diffraction angle corresponding to the light shielding portion of the pupil filter 4 suitable for the contact hole pattern of the size to be projected by the projection optical system 3. That is, I
The 0th order light from the SS mark 22 is the pupil plane FP of the projection optical system 3.
In, the light passes through the peripheral portion of the light shielding portion of the pupil filter 4 (transmission portion of the pupil filter 4) and is not shielded by the light shielding portion of the pupil filter 4. As a result, the 0th-order light having a large amount of light from the ISS mark 22 passes through the projection optical system 3, so that the image of the ISS mark 22 formed on the pattern formation surface of the reticle 1 is sufficiently bright. Becomes Therefore, when the photoelectric conversion element 29 receives the light that has been generated from the ISS mark 22 and has passed through the projection optical system 3 and the reticle 1, the light is shielded when the ISS mark 22 is shielded by the alignment mark 8B on the reticle 1. The amount of change in the light amount when the ISS mark 22 does not occur becomes large, and the coordinates when the ISS mark 22 matches the alignment mark 8B can be measured with a high SN ratio and with high accuracy.

Further, in this embodiment, the illumination light IL2 emitted from the optical fiber 23 has the axially symmetric cone prism 24.
It is radiated intensively into the ring-shaped opening 25a in the light shielding plate 25 via. Therefore, there is also an advantage that the utilization efficiency of the illumination light IL2 guided by the optical fiber 23 is high. In addition,
In the first embodiment, the ring-shaped opening 25a in the light shield plate 25 is formed.
Of the pupil filter 4 on the pupil plane FP of the projection optical system 3.
Although it has the same size as the area conjugate with the transmissive area around the light-shielding portion, the inner radius of the ring-shaped opening 25a may be made somewhat smaller than the radius of the conjugate image of the light-shielding portion of the pupil filter 4. Or, it may be made wider to some extent. Further, the outer radius of the ring-shaped aperture 25a may be made somewhat wider or narrower than the radius of the conjugate image of the aperture stop on the pupil plane FP. In this case, the size of the annular opening 25a is
By making the area on the pupil plane FP of the projection optical system 3 that is conjugate with the transmissive portion around the pupil filter 4 higher, the higher order diffracted light emitted from the ISS mark 22 surrounds the light shielding portion of the pupil filter 4. The ISS
The resolution of the image of the mark 22 is increased.

Further, in the first embodiment, the illumination light is inclined by the light shielding plate 25. However, for example, the exit end of the optical fiber 23 is formed into a ring shape, and this exit end is the front focal plane of the condenser lens 26. You may arrange. Thereby, the cone prism 24 and the light shielding plate 25 can be omitted, and the configuration is simplified. Although the ISS mark is a cross-shaped two-dimensional mark in the above embodiment, a one-dimensional mark having a slit-shaped opening may be used as shown in FIGS. 4 (a) and 4 (b). In this case, the configuration of the stage emission type illumination system is also changed accordingly.

First, in the modification of FIG. 4A, the X-axis slit mark 22a that is long in the Y direction is formed on the reference mark plate 21. Then, a condenser lens 26, a light shielding plate 31, a two-divided cone prism 30, and an optical fiber 23 are sequentially arranged below the reference mark plate 21. Two openings 31a and 31b are formed on the light shielding plate 31 symmetrically in the X direction with respect to the optical axis of the illumination system. In this example as well, the surface on which the X-axis slit mark 22a is formed has a Fourier transform relationship with the surface on which the light-shielding plate 31 is formed with respect to the condenser lens 26. Further, when the illumination system of FIG. 4A is arranged in place of the illumination system of the reference mark plate 21 of FIG. 1, the two openings 31 a and 31 b are provided on the pupil plane FP of the projection optical system 3 with the pupil filter 4. Outside the light-shielding part of the aperture and aperture stop (not shown)
It is located in a conjugate area on the light-shielding plate 31 with the transparent area inside.

Then, the illumination light emitted from the optical fiber 23 is divided into two directions by the two-division cone prism 30 and intensively illuminates the openings 31a and 31b of the light shielding plate 31, thereby opening the openings 31a and 31b. The illumination lights IL4 and IL5 that have respectively passed through the condenser lens 26 are emitted so as to intersect the X-axis slit mark 22a.
The 0th-order light and the predetermined diffracted light emitted from the X-axis slit mark 22a reach the reticle 1 through the region outside the light shielding portion of the pupil filter 4 in the projection optical system 3 of FIG.
Further, the light transmitted through the reticle 1 is received by the photoelectric conversion element 29. Then, by scanning the wafer stage 13 in the X direction, the X coordinate when the X-axis slit mark 22a and the alignment mark 8B match each other is detected.

Also in this case, the light from the openings 31a and 31b illuminates the X-axis slit mark 22a at a predetermined angle with respect to the optical axis of the stage emission type illumination system. Therefore,
The 0th-order light of the light that has passed through the X-axis slit mark 22a is not blocked by the light-shielding portion of the pupil filter 4 of the pupil plane FP of the projection optical system 3 and has a sufficient amount of light on the pattern-formed surface of the reticle 1. The image of the mark 22a is formed.
Therefore, the position or rotation angle of the reticle can be accurately measured.

Next, also in the modification of FIG. 4B, the X-axis slit mark 22a is formed on the reference mark plate 21. Then, the condenser lens 33 and the optical fiber 23 are arranged obliquely below the reference mark plate 21, and the exit surface of the optical fiber 23 and the X-axis slit mark 22a are in a substantially Fourier transform relationship with respect to the condenser lens 33. is there. That is,
The optical fiber 23 and the condenser lens 33 are arranged with respect to the normal line of the fiducial mark plate 21 (the axis parallel to the optical axis AX of the projection optical system 3).
The optical axis of the illumination system is composed of a predetermined angle in the X direction (XZ
Inclined (in the plane). The predetermined angle in this case is
The 0th-order light from the X-axis slit mark 22a and either the + 1st-order light or the -1st-order light from the X-axis slit mark 22a are substantially symmetrical with respect to the optical axis AX of the projection optical system 3 in FIG. The incident light and those two lights are the pupil plane F of the projection optical system 3.
It is defined to pass through the transmission part of the pupil filter 4 at P.

In this example, the illumination light emitted from the optical fiber 23 is obliquely applied to the X-axis slit mark 22a as the illumination light IL6 through the condenser lens 33. One of the 0th-order light and the + 1st-order diffracted light or the -1st-order diffracted light emitted from the X-axis slit mark 22a reaches the reticle 1 through the transmission part of the pupil filter 4 in the projection optical system 3 of FIG. Further, the light transmitted through the reticle 1 is converted into the photoelectric conversion element 29.
Is received by. Then, by scanning the wafer stage 13 in the X direction, the X coordinate when the X-axis slit mark 22a and the alignment mark 8B match each other is detected. Even in this case, one of the 0th-order light and the + 1st-order diffracted light or the −1st-order diffracted light emitted from the X-axis slit mark 22a is not blocked by the light-shielding portion of the pupil filter 4 of the pupil plane FP of the projection optical system 3. The image of the mark 22a is formed on the pattern formation surface of the reticle 1 with a sufficient light amount. Therefore, the position or rotation angle of the reticle can be accurately measured.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the present invention is applied to the case where the image plane position (best focus position) of the projection optical system is measured by using the ISS system, and the portion corresponding to FIGS. Are denoted by the same reference numerals and detailed description thereof will be omitted. In addition, this embodiment is disclosed in
The present invention is also applied to the focusing device disclosed in Japanese Patent Laid-Open No. 262624.

FIG. 5 shows the projection exposure apparatus of this embodiment.
In FIG. 5, in the light-shielding film outside the pattern region of the reticle 34 held on the reticle holder 9 (the region where the original image pattern of the contact hole pattern is formed), a linear opening pattern that is long in the Y direction is formed. An alignment mark 35 is formed. Further, an X-axis slit mark 22a is formed on the reference mark plate 21 on the wafer stage 13.

An illumination system similar to that shown in FIG. 4A is arranged at the bottom of the X-axis slit mark 22a, but in FIG. 5, polarizing plates 36A and 36B are arranged on the light shielding plate 31. The points are different. In this case, the illumination light IL2 emitted from the optical fiber 23 has a random polarization state.
Illuminates the two openings 31a and 31b (see FIG. 6) in the light shielding plate 31 in a concentrated manner via the two-division cone prism 30. As shown in FIG. 6, a polarizing plate 36 having polarization directions orthogonal to each other so as to cover the openings 31a and 31b.
A and 36B are arranged. In this embodiment, the polarization beam splitter 38 is used as described later, but the linearly polarized state of the illumination light that has passed through the polarizing plate 36A is S polarization with respect to the polarizing beam splitter 38, and the polarizing plate 36B.
The linearly polarized state of the illumination light that has passed through is the P-polarized state with respect to the polarization beam splitter 38.

Returning to FIG. 5, the illumination light IL4 having passed through the polarizing plate 36A and the illumination light IL5 having passed through the polarizing plate 36B.
Is the X-axis slit mark 22a through the condenser lens 26.
The X-axis slit mark 22 is focused so that it intersects with the top.
The 0th-order light and the predetermined diffracted light of the illumination lights IL4 and IL5 emitted from a pass through the outside of the light shielding portion of the pupil filter 4 of the projection optical system 3 and form a conjugate image of the X-axis slit mark 22a on the reticle 34. Tie After being emitted from the X-axis slit mark 22 a, the illumination light that has passed through the projection optical system 3 and the reticle 34 reaches the beam splitter 37 via the condenser lens 12 and the mirror 11, and reaches the beam splitter 37.
The illumination light reflected by is incident on the polarization beam splitter 38. Then, the S-polarized illumination light IL4 is reflected by the polarization beam splitter 38 and enters the light receiving surface of the first photoelectric conversion element 39A, and the P-polarized illumination light IL5 passes through the polarization beam splitter 38 and passes through the second photoelectric conversion element 39A. The light enters the light receiving surface of the conversion element 39B.

The detection signals of the photoelectric conversion elements 39A and 39B are supplied to the arithmetic unit 17A. The X coordinate and the Y coordinate of the wafer stage 13 measured by the laser interferometer 15 are also supplied to the calculation unit 17A, and the calculation unit 17A determines the best focus position of the projection optical system 3 based on the supplied detection signal and coordinates. The information on the best focus position is obtained and supplied to the main control system 16.

Next, an example of the operation for obtaining the best focus position of the projection optical system 3 in this embodiment will be described.
Such an operation is performed by, for example, the projection optical system 19 and the light receiving system 2
It is executed when calibrating the autofocus sensor consisting of 0. First, the wafer stage 1
With the current Z coordinate of the Z stage in 3 as Z ₁ , the wafer stage 13 is driven in a state where the height of the Z stage is fixed and the area of the reticle 34 on which the conjugate image of the alignment mark 35 is projected is projected. The X-axis slit mark 22a on the reference mark plate 21 is set at a position displaced in the + X direction.
After that, in a state where the illumination light IL2 is emitted from the optical fiber 23, the wafer stage 13 is driven to scan the X-axis slit mark 22a in the −X direction, and the detection signals of the photoelectric conversion elements 39A and 39B are monitored.

In this case, one opening 31a of the light shielding plate 31
When the conjugate image of the S-polarized illumination light (including 0th-order light and diffracted light) IL4 emitted from the X-axis slit mark 22a after passing through the optical axis matches the alignment mark 35, photoelectric conversion is performed. Since the detection signal of the element 39A is minimized, the X coordinate X _S1 at that time is stored. In parallel with this, the other opening 31 of the light shielding plate 31
Il5 of P-polarized illumination light (including 0th-order light and diffracted light) emitted from the X-axis slit mark 22a after passing through b
When the conjugate image of the X-axis slit mark 22a according to the above coincides with the alignment mark 35, the detection signal of the photoelectric conversion element 39B becomes the minimum, so the X coordinate X _P1 at that time is stored.

The central light flux of the S-polarized illumination light IL4 emitted from the X-axis slit mark 22a intersects with the normal line of the reference mark plate 21 at a predetermined angle (this is referred to as an angle θ ₁ ), The central light flux of the P-polarized illumination light IL5 emitted from the X-axis slit mark 22a intersects the normal line of the reference mark plate 21 at an angle −θ ₁ . Therefore, Z
Assuming that the coordinate Z ₁ is deviated from the best focus position Z ₀ by ΔZ ₁ , the measured X coordinates X _S1 and X _P1
As shown in FIG. 7, Δ from the original position X ₀
The difference is Z ₁ tan θ ₁ and −ΔZ ₁ tan θ ₁ .

Next, the Z coordinate of the Z stage in the wafer stage 13 is moved to Z ₂ , and the wafer stage 1 is similarly moved.
3 is scanned in the X direction and the detection signals of the photoelectric conversion elements 39A and 39B are monitored to detect the X coordinate X _S2 when the conjugate image of the X axis slit mark 22a by the illumination light IL4 matches the alignment mark 35, And illumination light IL
X-coordinate X _P2 when the conjugate image of the X-axis slit mark 22 a by 5 matches the alignment mark 35 is obtained. Assuming that the Z coordinate Z ₂ is on the opposite side of the Z coordinate Z ₁ with respect to the best focus position Z ₀ , the X coordinate X _S2 and the X coordinate X _P2 are as shown in FIG. 7.

Therefore, in FIG. 7, a straight line 40 passing through (Z ₁ , X _S1 ) and (Z ₂ , X _S2 ) in (Z coordinates, X coordinates) and (Z ₁ , X _P1 ) and (Z The Z coordinate Z ₀ of the intersection with the straight line 41 passing through ( ₂ , X _P2 ) is the best focus position of the projection optical system 3. A method of obtaining such a best focus position is disclosed in JP-A-1-262624.

In this case, in this embodiment, the openings 31a and 31b are provided on the light shielding plate 31, and the light from the X-axis slit mark 22a caused by the light flux passing through the openings 31a and 31b is zero.
The next light passes through the area outside the light blocking portion of the pupil filter 4 on the pupil plane FP of the projection optical system 3. Therefore,
Even when the pupil filter 4 is installed, a bright conjugate image of the X-axis slit mark 22a (including a defocused state) is formed on the reticle 34, and the projection optical system 3 of the projection optical system 3 in which the pupil filter 4 is installed is formed. The best focus position can be measured with high accuracy.

Next, a third embodiment of the present invention will be described with reference to FIGS. The present embodiment applies the present invention to the case where the distortion measurement of the projection optical system is performed. In FIG. 8, the portions corresponding to those in FIG. 1 are designated by the same reference numerals and the detailed description thereof will be omitted. FIG. 8 shows the projection exposure apparatus of this embodiment. In FIG. 8, an evaluation mark M _ij (i = 1, 2, ...; j =) is formed on the reticle holder 9.
1, 2, ...) are regularly formed on the test reticle 42.
Is held. FIG. 10A shows an enlarged view of a part of the evaluation marks M _ij . As shown in FIG. 10A, the evaluation marks M _ij are arranged at a predetermined pitch in the X direction and the Y direction. Moreover, each evaluation mark M _ij is a cross-shaped opening pattern formed in the light-shielding film.

Returning to FIG. 8, opening patterns 44a and 44b (see FIG. 10B) are formed on the reference mark plate 43 on the wafer stage 13. As shown in an enlarged view in FIG. 10B, the opening pattern 44a is a slit-shaped opening pattern that is long in the Y direction, and the opening pattern 44b is a slit-shaped opening pattern that is long in the X direction. Then, the width of the contour of the projected image of the evaluation mark M _ij on the test reticle 42 onto the wafer stage 13 is determined by the opening pattern 44a.
And 44b are set to be substantially equal to the width.

In FIG. 8, a condenser lens 45 and a photoelectric conversion element 46 are sequentially arranged at the bottom of the reference mark plate 43, and the light passing through the opening pattern on the reference mark plate 43 is converted by the condenser lens 45 into the photoelectric conversion element. It is condensed on the light receiving surface of 46. The detection signal output from the photoelectric conversion element 46 is supplied to the calculation unit 17B. The X-coordinate and the Y-coordinate of the wafer stage 13 measured by the laser interferometer 15 are also supplied to the calculation unit 17B, and the calculation unit 17B calculates the distortion of the projection optical system 3 based on the supplied information.

A turret plate 47 is rotatably arranged on the exit surface of the fly-eye lens 10 by a drive motor 48. The arrangement surface of the turret plate 47 has a Fourier transform relationship with the pattern formation surface of the test reticle 42, and the arrangement surface of the turret plate 47 is the same as the pupil surface of the projection optical system 3 (the arrangement surface of the pupil filter 4). It is conjugate.

FIG. 9 shows the pattern of the turret plate 47. In FIG. 9, the turret plate 47 is provided with an illumination system aperture stop 49 having a ring-shaped aperture 49a and a normal circular aperture 50a at substantially equal angular intervals. The illumination system aperture stop 50, the illumination system aperture stop 51 having a ring-shaped aperture having a narrower zone width than the ring-shaped aperture 49a, and the circular aperture 50a.
Illumination system aperture stop 52 having a smaller circular aperture, illumination system aperture stop 53 having a so-called modified light source method having four circular apertures, and illumination system aperture stop 54 having two circular apertures.
Are formed. In this case, the ring-shaped aperture 49a of the illumination system aperture stop 49 is set to the same size as the conjugate image on the turret plate 47 of the transmission part of the pupil filter 4 on the pupil plane of the projection optical system 3 in FIG. There is.

In the present embodiment, when measuring the distortion of the projection optical system 3, the illumination system aperture stop 49 is set on the exit surface of the fly-eye lens 8 in FIG. 8, and the annular aperture of the illumination system aperture stop 49 is set. The entire surface of the test reticle 42 is illuminated by the exposure light IL7 that has passed through. As a result, the images of all the evaluation marks M _ij on the test reticle 42 are projected onto the wafer stage 13 side. In this state, when the wafer stage 13 is driven to scan the reference mark plate 43 in the X and Y directions, the opening pattern 44a forms an image of the X axis mark portion (slit portion long in the Y direction) of the evaluation mark M _ij. When they match, and when the opening pattern 44b matches the image of the Y-axis mark portion of the evaluation mark M _ij , the amount of light received by the photoelectric conversion element 46 reaches a peak. X coordinate and Y of image of _ij
The coordinates can be obtained. The distortion of the projection optical system 3 can be measured by comparing the coordinates thus obtained with the designed coordinates when the projection optical system 3 has no distortion.

At this time, in this embodiment, since the illumination optical system for illuminating the exposure reticle for illuminating the test reticle 42 is also used, the structure of the optical system is simple. Further, since the test reticle 42 is illuminated through the illumination system aperture stop 49 having a ring-shaped aperture, 0 from the evaluation mark M _ij on the test reticle 42.
The next light and the predetermined diffracted light pass through the area (transmission portion) outside the light shielding portion of the pupil filter 4 on the pupil surface of the projection optical system 3 and reach the reference mark plate 43 side. Therefore, since the photoelectric conversion element 46 can receive the 0th-order light having a large light amount, the coordinates of the image of each evaluation mark M _ij can be accurately measured, and the distortion of the projection optical system 3 in which the pupil filter 4 is mounted can be accurately measured. Can be measured.

Although the ISS mark 22, the alignment mark 8B, the evaluation mark M _ij , the opening pattern 44a and the like are used in each of the above-mentioned embodiments, the darkness (or transmission / non-transmission) of these marks or patterns is used. It is needless to say that a mark or pattern in which) is inverted may be used. Further, in addition to the use of each of the above-described embodiments, by using a mark formed on a reference mark plate (for example, 21) on the wafer stage 13, various TTL (through the lens) type alignments are performed. The detection center of the system,
Baseline measurement is also performed to find the difference (baseline) from the actual exposure position. Even in this case, the illumination light for illuminating the mark is tilted with respect to the optical axis of the projection optical system 3 so that even if a pupil filter is arranged in the vicinity of the pupil plane of the projection optical system, the base can be accurately measured. Line measurement is performed.

Next, as a pupil filter for improving the imaging characteristics of a fine isolated pattern such as a contact hole pattern, not only the above-mentioned light-shielding type pupil filter but also Japanese Patent Application No. 4-263521. Issue, Japanese Patent Application No. 4-271
No. 723, a so-called SFINCS-type pupil filter that reduces coherence between the transmitted light in the central portion and the transmitted light in the peripheral portion near the pupil plane of the projection optical system, and 1991. Spring Society of Applied Physics, Proceedings 29
For example, there is a so-called Super FLEXS type pupil filter, which is disclosed in a-ZC-8, 9 and which reverses the phase of the transmitted light in the central portion and the transmitted light in the peripheral portion of the pupil plane of the projection optical system. Even when such a pupil filter is installed near the pupil plane of the projection optical system, when observing the mark through the projection optical system or when projecting the measurement mark through the projection optical system. , The pupil filter may prevent good imaging.

Therefore, even in such a case, the tilt angle of the illumination light for illuminating the mark to be observed or projected is adjusted so that the 0th-order light from the mark is near the pupil plane of the projection optical system. By allowing an area having a large transmittance and a substantially constant phase distribution in the pupil filter to observe, the mark can be observed or projected well. Further, as a pupil filter for improving resolution and depth of focus when exposing a relatively dense periodic pattern such as a line-and-space pattern, a proceedings 12a-ZF-7 of the Autumn Applied Physics Society of 1991, and In 1992 Spring Society of Applied Physics, Proceedings 30p-NA-5 and the like, a pupil filter in which the transmittance is changed between a circular region centered on the optical axis and a ring-shaped region around it is also proposed. When using a filter of such a type that the transmittance of the central portion is made smaller than the transmittance of the peripheral portion in such a pupil filter, the marks are observed through the projection optical system, or the projection optical system is changed. When the measurement mark is exposed via the pupil filter, the pupil filter may interfere with good image formation.

Therefore, even in such a case, the tilt angle of the illumination light for illuminating the mark of the observation target or the projection target is adjusted so that the 0th-order light from the mark is near the pupil plane of the projection optical system. By allowing the region having high transmittance in the pupil filter to pass therethrough, the mark can be observed or projected well. As described above, the present invention is not limited to the above-described embodiments, and various configurations can be taken without departing from the gist of the present invention.

[0063]

According to the projection exposure apparatus of the present invention, the 0-order light generated from the reference mark has the same transmission characteristic on the optical correction plate near the pupil plane of the projection optical system by the illumination system of the mark detection system. The fiducial mark is illuminated so that it passes through a certain area. Therefore, there is an advantage that the light from the reference mark can be sufficiently received and the reference mark can be accurately detected (observed) through the projection optical system provided with the optical correction plate (pupil filter or the like).

When the optical correction plate has different transmission characteristics in the central circular area and the outer annular area, it is emitted from the illumination system and then passes through the reference mark. By allowing the next light to pass through the circular area or the annular area, the reference mark can be accurately detected. In this case, if the illumination system irradiates the reference mark with the illumination light inclined such that the 0th-order light passes through the ring zone region, the illumination efficiency is high.

On the other hand, the illumination system has a conversion optical system that makes the reference mark and the predetermined surface a Fourier transform relationship.
When defining the illumination light passing through the predetermined surface in the ring zone area or at least one local area decentered from the optical axis of the conversion optical system, adjust the passage area of the illumination light on the predetermined surface. This makes it possible to easily set the passage area of the 0th-order light that has passed through the reference mark to a desired area.

Further, when the illumination optical system for illuminating the mask also serves as the illumination system for the mark detecting system, the entire optical system is simplified.

[Brief description of drawings]

FIG. 1 is a partially cutaway block diagram showing a first embodiment of a projection exposure apparatus according to the present invention.

FIG. 2 is an alignment mark 8A on the reticle 1 of FIG.
And FIG. 8B is a plan view showing 8B.

FIG. 3 is an enlarged perspective view showing a configuration of a stage emission type illumination system of FIG.

FIG. 4A is a first stage emission type illumination system of FIG.
FIG. 4B is a perspective view showing a modified example of FIG. 3B, and FIG. 6B is a perspective view showing a second modified example of the stage emission type illumination system of FIG.

FIG. 5 is a partially cutaway block diagram showing a projection exposure apparatus according to a second embodiment of the present invention.

6 is an enlarged plan view showing the positional relationship between the light shielding plate 31 and the polarizing plates 36A and 36B of FIG.

FIG. 7 is an explanatory diagram for measuring the best focus position of the projection optical system 3 in the projection exposure apparatus of FIG.

FIG. 8 is a partially cutaway block diagram showing a projection exposure apparatus according to a third embodiment of the present invention.

9 is an enlarged view showing the shapes of illumination system aperture stops 49 to 54 formed on the turret plate 47 of FIG.

10A is an enlarged plan view showing a part of the evaluation mark in FIG. 8, and FIG. 10B is an enlarged plan view showing an opening pattern formed on the reference mark plate 43 in FIG.

FIG. 11 is an enlarged plan view showing reference marks and alignment marks used in conventional reticle alignment.

FIG. 12 is an explanatory diagram of the principle of position detection when the mark of FIG. 11 is used.

FIG. 13 is an enlarged plan view showing a stage emission type ISS mark and a corresponding alignment mark used in conventional reticle rotation measurement.

FIG. 14 is an explanatory view of the principle of position detection when the mark of FIG. 13 is used.

FIG. 15 is an enlarged plan view showing another example of a conventional ISS mark.

16A is an explanatory view showing an image formation state by a projection optical system in which a conventional pupil filter is inserted, and FIG. 16B is an enlarged view showing an intensity distribution of a projected image by the projection optical system.

[Explanation of symbols]

1,34 Reticle 3 Projection optical system 4 Pupil filter 5 Wafer 8A, 8B Alignment mark 9 Reticle holder 13 Wafer stage 15 Laser interferometer 16 Main control system 17, 17A, 17B Computational unit 22 ISS mark 23 Optical fiber 24 Axisymmetric cone Prism 25, 31 Light-shielding plate 26, 33 Condensing lens 29, 39A, 39B Photoelectric conversion element 30 Divided cone prism 35 Alignment mark M _ij Evaluation mark 42 Test reticle 44a, 44b Opening pattern

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03F 9/00 H

Claims (5)

[Claims] 1. A projection optical system for projecting a pattern of a mask on a photosensitive substrate with a predetermined image forming characteristic, and a reference mark arranged on the object plane side or the image plane side of the projection optical system. In a projection exposure apparatus provided with a mark detection system for detecting through, a Fourier transform surface formed in an image forming optical path of the projection optical system, or a surface in the vicinity thereof, for improving the image forming characteristics. Has an optical correction plate in which the transmission characteristics of the image forming light beam are partially different; the mark detection system corrects at least the 0th order light of the light generated from the reference mark and incident on the projection optical system. An illumination system that illuminates the reference mark with illumination light so as to pass through a specific region having the same transmission characteristics on the plate, and a photoelectric detector that receives the illumination light that passes through the specific region on the optical correction plate. And having Projection exposure apparatus. 2. The optical correction plate is configured so that the transmission characteristic is different between a circular region at the center and an annular region outside thereof,
The projection exposure apparatus according to claim 1, wherein the next light passes through the circular area or the annular area. 3. The projection system according to claim 2, wherein the illumination system illuminates the illumination light with an inclination with respect to the reference mark so that the zero-order light passes through the ring zone region. Exposure equipment. 4. The conversion system for converting the reference mark and the predetermined surface into a Fourier transform relationship, and the illumination light for passing the illumination light through the predetermined surface into a ring zone or a light of the conversion optical system. 4. The projection exposure apparatus according to claim 3, further comprising an optical member that defines at least one local area decentered from the axis. 5. The projection exposure apparatus according to claim 1, 2 or 3, wherein an illumination optical system for illuminating the mask also serves as an illumination system for the mark detection system.