JP2003332229A - Inspecting substrate, its manufacturing method, method of inspecting position detecting device, and system and method for exposure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspecting substrate with which a position detecting device can be inspected for optical state with respect to, for example, the comatic aberration, optical axis deviation, accuracy evaluation, etc., with high accuracy. <P>SOLUTION: This inspecting substrate used for inspecting the position detecting device for optical state is provided with a first pattern (SP) having a first structural configuration, a second pattern (MP) having a second structural configuration which is different from the first pattern (SP), and correction patterns (CSP and CMP) respectively having the same patterns as the first and second patterns (SP) and (MP). The first, second, and correction patterns (SP), (MP), and (CSP and CMP) are formed by using the same mask. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection substrate, a method for manufacturing an inspection substrate, an inspection method for a position detection device, an exposure apparatus, and an exposure method. The present invention relates to a position detection device mounted on an exposure apparatus used in a lithography process for manufacturing microdevices such as semiconductor devices, image pickup devices, liquid crystal display devices, and thin film magnetic heads.

[0002]

2. Description of the Related Art Generally, when manufacturing a device such as a semiconductor element, a plurality of layers of circuit patterns are formed on a wafer (or a substrate such as a glass plate) coated with a photosensitive material. Therefore, the exposure apparatus for exposing the circuit pattern onto the wafer includes an alignment apparatus for performing relative alignment (alignment) between the mask pattern and each exposure area of the wafer on which the circuit pattern is already formed. It is equipped. In recent years, with the miniaturization of the line width of circuit patterns, highly accurate alignment has been required.

Conventionally, as this type of alignment apparatus,
JP-A-4-65603, JP-A-4-273246
As disclosed in Japanese Unexamined Patent Publication (KOKAI) Publication, an off-axis type image pickup type alignment device is known. The detection system of the alignment device of this imaging system is FIA (Fi
It is also called an eld image alignment system position detector. In the FIA type position detection device, an alignment mark (wafer mark) on a wafer is illuminated with light having a wide wavelength band emitted from a light source such as a halogen lamp. Then, the wafer mark position is detected by forming an enlarged image of the wafer mark on the image pickup element via the image forming optical system and subjecting the obtained image pickup signal to image processing.

[0004]

In the above position detecting device, when coma aberration remains in the image forming optical system, the wafer mark image formed on the image pickup surface is more than that in the case of ideal image forming. Since the position is shifted and detected, a detection error is likely to occur. In addition, the image forming aperture stop is displaced from the optical axis of the image forming optical system due to manufacturing errors or the like (hereinafter referred to as “optical axis deviation”).
In this case, since the wafer mark image is asymmetrically distorted, a detection error is likely to occur.

Therefore, by using an inspection substrate on which a predetermined pattern is formed, the coma aberration and the optical axis shift remaining in the image forming optical system of the position detecting device are inspected, and the image forming optical system is optically determined based on the inspection result. Techniques for adjusting and correcting the detection result are known. However, in the conventional inspection board,
It is impossible to evaluate the accuracy of a so-called position detecting device, for example, the relationship between the defocus amount and the detection accuracy when a wafer mark having an asymmetric low step pattern is detected in the defocused state. The asymmetry referred to here means that, when paying attention to each convex portion and each concave portion of the step mark,
It means that the structure is not symmetrical with respect to the centerline between the edges. For example, the surface may be tilted, one edge may be tilted, or there may be a dent or a groove at a position off the center line. The reason why it is difficult to evaluate a wafer mark formed of such an asymmetrical low step pattern is that the accuracy required for the position measuring device is very small (several nanometers to several tens of nanometers), and the manufacturing error of the test object is small. I mean,
It is difficult to distinguish whether there is an error in the inspection board, and it is difficult to manufacture the inspection board itself.

The present invention has been made in view of the above-mentioned problems, and an inspection substrate capable of highly accurately inspecting the optical state of a position detection device with respect to, for example, coma aberration, optical axis shift, accuracy evaluation, and the like. And a method for manufacturing the same. It is another object of the present invention to provide an inspection method capable of inspecting the optical state of a position detection device with high accuracy using the inspection substrate of the present invention. Furthermore, by using a highly accurate position detection device that is optically adjusted or corrected based on the inspection result obtained by the inspection method of the present invention, for example, the mask and the photosensitive substrate are aligned with high accuracy with respect to the projection optical system. It is an object of the present invention to provide an exposure apparatus and an exposure method capable of excellent exposure.

[0007]

In order to solve the above-mentioned problems, the first invention of the present invention provides a method for manufacturing an inspection substrate used for inspecting an optical state of a position detection device, wherein the inspection substrate is Includes a first pattern having a first structural form and a second pattern having a second structural form different from the first structural form, and the first pattern and the second pattern are the same mask. Provided is a method for manufacturing an inspection substrate, which is characterized by being formed using. In the first invention of the present invention, it is preferable that the inspection substrate further includes a correction pattern having the same pattern as the entire first pattern and the second pattern, and the correction pattern uses the same mask. It is preferably formed.

A second invention of the present invention provides an inspection substrate manufactured by the manufacturing method of the first invention.

According to a preferred aspect of the second invention, the first pattern is a step pattern and the second pattern is a light-dark pattern. Further, the first pattern is a symmetrical pattern in which the line portion and the space portion are formed symmetrically with respect to the pitch direction of the pattern, and the second pattern is such that the line portion and the space portion are asymmetrical with respect to the pitch direction of the pattern. It is preferably an asymmetric pattern formed. Further, the first pattern is a high step pattern in which the step between the protrusion and the recess is set relatively large, and the second pattern is a low step in which the step between the protrusion and the recess is set relatively small. It is preferably a pattern.

According to a third aspect of the present invention, in the inspection substrate used for inspecting the optical state of the position detecting device, the first pattern having the first structural form and the first pattern are provided.
And a correction pattern having the same pattern as the entire first pattern and the second pattern. provide.

According to a preferred aspect of the third invention, the first pattern is a step pattern, the second pattern is a light-dark pattern, and the correction pattern is a step pattern or a light-dark pattern. Further, the first pattern is a symmetrical pattern in which the line portion and the space portion are formed symmetrically with respect to the pitch direction of the pattern, and the second pattern is such that the line portion and the space portion are asymmetrical with respect to the pitch direction of the pattern. It is preferable that the correction pattern is a step pattern or a light-dark pattern in which the line portion and the space portion are formed symmetrically with respect to the pitch direction of the pattern.

According to a preferred aspect of the third invention,
The first pattern is a high step pattern in which the step between the protrusion and the recess is set to be relatively large, and the second pattern is a low step pattern in which the step between the protrusion and the recess is set to be relatively small. The correction pattern is a step pattern in which the step between the convex portion and the concave portion is set to a predetermined size. Further, it is preferable that the first pattern and the second pattern are formed using the same mask. At this time, it is more preferable that the first pattern and the second pattern are simultaneously formed by exposure using the same mask. Further, the correction pattern is the first
It is preferably formed using the mask used for forming the pattern and the second pattern. At this time,
Exposure for forming the first pattern and the second pattern is performed on a first region on the inspection substrate, and the correction pattern is formed on a second region on the inspection substrate different from the first region. More preferably, exposure is performed to form

According to a fourth aspect of the present invention, in the method for inspecting the optical state of the position detecting device, the position of the first pattern and the second pattern are detected by the position detecting device using the inspection substrate of the second invention. A detection step of detecting a position; and an inspection step of inspecting the optical state of the position detection device based on the relative relationship between the position of the first pattern and the position of the second pattern detected in the detection step. An inspection method is provided.

According to a fifth aspect of the present invention, in the method for inspecting the optical state of the position detecting device, the position of the first pattern and the second pattern are detected by the position detecting device using the inspection substrate of the third invention. A detection step of detecting a position, a position of a first correction pattern corresponding to the first pattern of the correction patterns, and a position of a second correction pattern corresponding to the second pattern of the correction patterns; Based on the relative relationship between the position of the first pattern and the position of the second pattern detected in the step, and the relative relationship between the position of the first correction pattern and the position of the second correction pattern detected in the detection step. And an inspection step of inspecting an optical state of the position detecting device.

According to a preferred aspect of the fourth invention and the fifth invention, the detecting step includes a step of detecting the position of each pattern in a plurality of defocus states with respect to the optical system of the position detecting device, and the inspecting step. Includes the step of inspecting the optical state of the position detecting device based on the position of each pattern detected in each defocus state.

According to a preferred aspect of the fourth and fifth inventions, the detecting step is a first detecting step of detecting the position of each pattern using the inspection substrate set in the first orientation. And a second detection step of detecting the position of each pattern using the inspection substrate set in a second direction rotated by 180 degrees from the first direction with respect to the optical axis of the optical system of the position detection device. The inspection step includes a step of inspecting the optical state of the position detection device based on the position of each pattern detected in the first detection step and the position of each pattern detected in the second detection step. .

Further, according to a preferred aspect of the fourth and fifth inventions, in inspecting the coma aberration of the optical system in the position detecting device, in the detecting step, the width of the concave portion is convex along the pitch direction of the pattern. The method includes the step of detecting the position of each pattern using the inspection substrate provided with the first pattern having a step pattern substantially smaller than the width of the portion and the second pattern having a bright-dark pattern.

According to a preferred aspect of the fourth and fifth aspects of the invention, in the inspection of the optical axis shift of the imaging aperture stop with respect to the optical axis of the optical system in the position detecting device, the detecting step is performed with a convex portion. The first pattern having a high step pattern having a relatively large step with the concave portion and the second pattern having a low step pattern having a relatively small step between the convex portion and the concave portion are provided. The step of detecting the position of each pattern using the inspection substrate is included.

Further, according to the preferred embodiments of the fourth and fifth inventions, in the accuracy evaluation of the position detecting device, in the detecting step, a high step pattern in which a step between a convex portion and a concave portion is set to be relatively large. Alternatively, the first pattern having a bright and dark pattern and the first pattern having a low step asymmetric pattern in which the step between the convex portion and the concave portion is set to be relatively small and the line portion and the space portion are formed asymmetrically in the pitch direction of the pattern, respectively. And a step of detecting the position of each pattern using the inspection substrate having two patterns.

According to a sixth aspect of the present invention, there is provided a position detecting device comprising an optical system which is optically adjusted based on the inspection result obtained by the inspection method according to the fourth aspect or the fifth aspect. To do.

According to a seventh aspect of the present invention, there is provided a position detecting device characterized in that the position detection result is corrected based on the inspection result obtained by the inspection method according to the fourth aspect or the fifth aspect.

The eighth invention of the present invention is the sixth invention or the sixth invention for detecting the position of the photosensitive substrate in an exposure device for transferring a predetermined pattern formed on a mask onto the photosensitive substrate. (7) An exposure apparatus comprising the position detection apparatus according to the invention is provided.

According to a ninth aspect of the present invention, in the exposure method for transferring a predetermined pattern formed on a mask onto a photosensitive substrate, the position detecting device according to the sixth aspect or the seventh aspect is used. And an exposure method characterized by detecting the position of the photosensitive substrate.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION In an inspection substrate according to a typical embodiment of the present invention, a first pattern and a second pattern having different structural forms are formed using the same mask. Therefore, the reference distance between the first pattern and the second pattern can be set with high precision according to the design value, and by using the inspection substrate manufactured with high precision, for example, coma aberration, optical axis deviation, and accuracy evaluation. For example, the optical state of the position detection device can be inspected with high accuracy.

Further, in the inspection board according to another typical form of the present invention, the first structure having different structural forms from each other is provided.
In addition to the pattern and the second pattern, a correction pattern having the same pattern as the entire first pattern and the second pattern is formed. Therefore, by correcting the relative position information of the second pattern with respect to the first pattern with the relative position information of the second correction pattern corresponding to the second pattern with respect to the first correction pattern corresponding to the first pattern of the correction patterns, For example, the optical state of the position detection device can be inspected with high accuracy without being affected by the outside of the inspection target such as distortion of the optical system of the position detection device.

In this case, it is preferable that the first pattern, the second pattern and the correction pattern are formed using the same mask. With this configuration, the reference distance between the first pattern and the second pattern and the first correction pattern can be obtained without being affected by the drawing error of the mask for manufacturing the inspection substrate and the aberration of the projection optical system for exposure. It is possible to match the reference distance with the second correction pattern with high accuracy. As a result, it is possible to inspect the optical state of the position detecting device with higher accuracy by using the inspection substrate including the first pattern, the second pattern, and the correction pattern that are manufactured with high accuracy. Further, it is preferable that the same pattern (a region including the first pattern and the second pattern) in one mask is used, and the relative positions of the mask and the inspection substrate are shifted and the pattern is printed by a photolithography process. Further, when the transfer from the mask to the inspection substrate is performed, it is preferable to perform the transfer under a reduction ratio. As a result, the influence of the mask manufacturing error can be reduced. Further, when manufacturing the mask itself, for example, Japanese Patent Laid-Open No. 2001-2001
In order to manufacture a mask disclosed in Japanese Patent Application Laid-Open No. 92103/92 or Japanese Patent Application Laid-Open No. 2001-92104, an exposure apparatus for transferring a circuit pattern to a glass substrate or the like at a reduction ratio is used, and a parent pattern on a parent mask is reduced and transferred. It is preferable to reduce the mask drawing error. At this time, the reduction transfer is repeated a plurality of times (the parent pattern on the parent mask is reduced and transferred to the child mask, the child pattern of the child mask is reduced and transferred to the grandchild mask, and the grandchild pattern of the grandchild mask is reduced and transferred to the great-grandchild mask. It is preferable to further reduce the mask drawing error.

Thus, using the inspection substrate of the present invention,
For example, the optical state of the position detecting device can be inspected with high accuracy with respect to coma aberration, optical axis shift, accuracy evaluation, and the like. Therefore, the mask and the photosensitive substrate are accurately aligned with the projection optical system by using a highly accurate position detection device that is optically adjusted or corrected based on the inspection result obtained by the inspection method of the present invention. Therefore, good exposure can be performed.

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram schematically showing a configuration of an exposure apparatus equipped with a position detection device that is an inspection target of an optical state using an inspection substrate according to an embodiment of the present invention. Further, FIG. 2 is a diagram schematically showing a configuration of a wafer mark formed on a wafer which is an object whose position is to be detected by the position detecting device shown in FIG.

In this embodiment, the present invention is applied to an FIA type position detecting device for detecting the position of a photosensitive substrate in an exposure device for manufacturing a semiconductor element. In FIG. 1, the Z axis is parallel to the optical axis AX0 of the projection optical system PL of the exposure apparatus, and the X axis is parallel to the paper surface of FIG. 1 in the plane perpendicular to the Z axis. In the vertical plane, the Y-axis is set in the direction perpendicular to the paper surface of FIG.

The illustrated exposure apparatus includes an exposure illumination system IL for illuminating a reticle R as a mask (projection original plate) with appropriate exposure light. The reticle R is supported on the reticle stage 30 substantially parallel to the XY plane, and a circuit pattern to be transferred is formed in its pattern area PA. The light transmitted through the reticle R reaches the wafer W as a photosensitive substrate via the projection optical system PL, and a pattern image of the reticle R is formed on the wafer W.

The wafer W is supported on the Z stage 32 via the wafer holder 31 substantially parallel to the XY plane. The Z stage 32 is a stage control system 3
4 is configured to be driven in the Z direction along the optical axis AX0 of the projection optical system PL. Z stage 32
Is further supported on the XY stage 33. XY
The stage 33 is also controlled by the stage control system 34.
It is configured to be two-dimensionally driven in an XY plane perpendicular to the optical axis AX0 of the projection optical system PL.

As described above, in the exposure apparatus, the pattern area PA on the reticle R and each exposure area on the wafer W must be optically aligned (aligned) prior to projection exposure. Therefore, the wafer W (wafer alignment mark) having a step pattern as schematically shown in FIG.
WM is formed. The step pattern here means
As shown in FIG. 2, it refers to a stepped pattern, and may have any reflectance on the wafer mark including the convex portion and the concave portion. That is, the case where there is a difference in brightness is also included. Further, it may be formed of a substance other than Si (silicon). Further, a transparent substance such as a resist may be present on the mark. In addition, the case where the concave portion of the step is filled with a transparent material is also included. The position of the wafer mark WM is detected,
As a result, the position detection device of this embodiment is used to detect the position of the wafer W.

Specifically, as the wafer mark WM, X
The X-direction wafer mark WMX as a one-dimensional mark having periodicity in the direction and the Y-direction wafer mark WMY (not shown) as a one-dimensional mark having periodicity in the Y direction are
It is formed on the wafer W. In this embodiment,
As the wafer mark WM, two independent one-dimensional marks each having periodicity in the X and Y directions are adopted, but a two-dimensional mark having periodicity in the X and Y directions can also be adopted. .

The position detecting device according to the present embodiment uses illumination light having a wide wavelength band (for example, 530 nm to 800 n).
m) is provided for supplying the light source 1. As the light source 1, a light source such as a halogen lamp can be used. The illumination light (center wavelength λ) supplied from the light source 1 is incident on the incident end of the light guide 2 such as an optical fiber via a relay optical system (not shown). Illumination light that has propagated through the inside of the light guide 2 and is emitted from its exit end is limited, for example, through an illumination aperture stop 3 having a circular opening (light transmitting portion), and then enters a condenser lens 4. To do.

Illumination light passing through the condenser lens 4 is
The light enters the illumination relay lens 6 via the illumination field stop 5 arranged optically conjugate with the exposure surface of the wafer W which is an object to be illuminated. The illumination light that has passed through the illumination relay lens 6 passes through the half prism 7 and then the first objective lens 8
Incident on. The illumination light that has passed through the first objective lens 8 is reflected downward (in the −Z direction) in the drawing by the reflection surface of the reflection prism 9, and then illuminates the wafer mark WM formed on the wafer W.

As described above, the light source 1, the light guide 2, the illumination aperture stop 3, the condenser lens 4, the illumination field stop 5, the illumination relay lens 6, the half prism 7, the first objective lens 8 and the reflection prism 9 are wafer marks. An illumination system for illuminating the WM is configured. The reflected light (including diffracted light) from the wafer mark WM with respect to the illumination light is incident on the half prism 7 via the reflecting prism 9 and the first objective lens 8. The light reflected by the half prism 7 upward (in the + Z direction) in the drawing forms an image of the wafer mark WM on the index plate 11 via the second objective lens 10.

The light that has passed through the index plate 11 passes through the relay lens system (12, 13) and the XY split half prism 14 is transmitted.
Incident on. Then, the light reflected by the XY branch half prism 14 enters the Y direction CCD 15, and the light transmitted through the XY branch half prism 14 enters the X direction CCD 16. An image forming aperture stop 17 is arranged in the parallel optical path of the relay lens system (12, 13).

As described above, the reflecting prism 9, the first objective lens 8, the half prism 7, the second objective lens 10, the index plate 11, the relay lens system (12, 13), the image forming aperture stop 17 and the half prism 14 are formed. , An imaging optical system for forming a mark image based on the reflected light from the wafer mark WM with respect to the illumination light. Also, C for Y direction
The CD 15 and the X-direction CCD 16 constitute a photoelectric detector for photoelectrically detecting the mark image formed via the imaging optical system.

In this way, mark images are formed on the image pickup surfaces of the Y-direction CCD 15 and the X-direction CCD 16 together with the index pattern image of the index plate 11. CCD 1 for Y direction
Output signals from the 5 and X direction CCDs 16 are supplied to a signal processing system 18. Further, the wafer mark W obtained by signal processing (waveform processing) in the signal processing system 18
The position information of M is supplied to the main control system 35. The main control system 35 sends a stage control signal based on the position information of the wafer mark WM from the signal processing system 18 to the stage control system 3.
Output to 4.

The stage control system 34 appropriately drives the XY stage 33 in accordance with the stage control signal, and the wafer W
Perform alignment. The main control system 35 is supplied with a command for the illumination aperture stop 3 and a command for the imaging aperture stop 17 via input means 36 such as a keyboard. Based on these commands, the main control system 35 drives the illumination aperture stop 3 via the drive system 19,
The imaging aperture stop 17 is driven via the drive system 20. Further, the main control system 35 drives the second objective lens 10 and the relay lens 12. Although the illumination aperture stop 3, the imaging aperture stop 17, the second objective lens 10 and the relay lens 12 are automatically controlled in the present embodiment, these controls may be performed manually.

In this embodiment, the optical state of the position detecting device is inspected using the inspection substrate. FIG. 3 is a diagram schematically showing the basic structure of a pattern formed on the inspection substrate of this embodiment. Referring to FIG. 3, a measurement mark MM including a pair of reference patterns SP and a measurement pattern MP arranged at an intermediate position thereof is formed on the inspection substrate of the present embodiment. Further, a correction mark CM having the same pattern as the entire pair of reference pattern SP and measurement pattern MP is formed in parallel with the measurement mark MM.

That is, the correction mark CM has a pair of correction reference patterns CSP corresponding to the pair of reference patterns SP.
And the corrected measurement pattern CM corresponding to the measurement pattern MP
P and P. Here, the reference pattern SP and the measurement pattern MP have different structural forms from each other. Specifically, as will be described later, the reference pattern SP and the measurement pattern MP have different forms from the viewpoints of the pattern type (step type or bright / dark type), pattern symmetry, step size, and the like. The step type here refers to the type of the step pattern described above. In addition, the light-dark type here means that the line portion and the space portion are formed by using substances having different reflectances. It should be noted that although a slight step is formed between the regions of the two substances when forming the light-dark pattern, those having different reflectances between the line portion and the space portion will be generally referred to as a light-dark pattern.

On the other hand, the correction mark CM has the same pattern type as the reference pattern SP as shown in FIG. 3A, or the measurement pattern MP as shown in FIG. 3B.
It has the same pattern type as. In the measurement mark MM, the pair of reference pattern SP and the measurement pattern MP are formed using the same mask, and the correction mark CM is also formed using the same mask as the measurement mark MM.
The correction mark CM is preferably formed using the same mask pattern as the mask pattern on which the measurement mark MM is formed. As will be described later, the inspection substrate of this embodiment is provided with a plurality of sets of measurement marks MM and correction marks CM.

The method of inspecting the position detecting device using the inspection substrate of this embodiment will be described below. First, in the inspection of the coma aberration of the imaging optical system in the position detection device, a plurality of measurement marks MM and correction marks CM formed on the inspection substrate are used, and a plurality of optical marks are formed along the optical axis of the imaging optical system. In a plurality of defocus states obtained by arranging the inspection substrate at the position in the Z direction (including a focus state in which the object plane of the imaging optical system and the inspection substrate match, if necessary), a pair of reference patterns SP Position, position of measurement pattern MP, position of a pair of correction reference patterns CSP, correction measurement pattern C
The position of MP is detected.

In this case, in the first set of measurement mark MM and correction mark CM, the reference pattern SP is a bright / dark pattern. Further, in the measurement pattern MP, the width of the concave portion is substantially smaller than the width of the convex portion along the pitch direction (specifically, the width of the convex portion is preferably 5 times or more the width of the concave portion). , A so-called fine groove step pattern. Further, the correction mark CM is a step pattern having the same pattern type as the measurement pattern MP or a bright / dark pattern having the same pattern type as the reference pattern SP. Here, the reference pattern SP, which is a bright and dark pattern, is a pattern that is extremely insensitive to coma aberration, and the measurement pattern MP, which is a step pattern of narrow grooves, is a pattern that is very sensitive to coma aberration.

Thus, in the inspection of the coma aberration of the imaging optical system in the position detecting device, the relative position information X1 (Y1) of the measurement pattern MP with respect to one reference pattern SP in each defocus state and the other reference pattern SP.
Relative position information X2 (Y2) of the measurement pattern MP with respect to
Is the relative position information X3 (Y3) of the correction measurement pattern CMP for one correction reference pattern CSP and the correction measurement pattern CM for the other correction reference pattern CSP.
It is corrected by the relative position information X4 (Y4) of P. Then, the relative position information X1 ′ corrected by the correction mark CM
The coma aberration of the imaging optical system is inspected (measured) based on the average value of (Y1 ') and X2' (Y2 '). At this time, the error component contained in each measurement value of the measurement mark MM and the correction mark CM due to the inspection substrate is very small,
Highly accurate measurement can be performed. Further, if the types of the measurement mark and the correction mark are changed and the measurement is appropriately performed, the adjustment can be performed more reliably. For example, if a plurality of types of measurement marks and correction marks are formed on the inspection substrate, the above measurement can be performed more easily.

In this embodiment, the image forming optical system is optically adjusted based on the inspection result of the coma aberration obtained by using the inspection substrate. In order to adjust the coma aberration of the imaging optical system, it is preferable to move at least a part of the lenses of the second objective lens 10 or the relay lens 12 in the direction perpendicular to the optical axis. Alternatively, by moving at least a part of the lenses in the first objective lens 8 or the relay lens 13 in the direction perpendicular to the optical axis, the low-order coma aberration of the imaging optical system can be adjusted. Further, the method of adjusting the aberration is not limited to the above method and may be another method.
For example, a method of replacing at least a part of the lenses in the first objective lens 8, the second objective lens 10, the relay lens 12, or the relay lens 13 may be used. Further, for example, the position detection result can be corrected based on the inspection result of the coma aberration before or after the optical adjustment of the imaging optical system.

Next, in the inspection of the optical axis shift in the position detecting device, the second set of measurement marks M formed on the inspection substrate.
Using the M and the correction mark CM, the positions of the pair of reference patterns SP, the positions of the measurement pattern MP, the positions of the pair of correction reference patterns CSP, and the correction measurement in a plurality of defocus states (including the focus state as necessary). The position of the pattern CMP is detected.

In this case, in the second set of measurement mark MM and correction mark CM, the reference pattern SP has a relatively large step between the convex portion and the concave portion (for example, λ / 8).
The above is a high step pattern. Also, the measurement pattern MP
Is a low step pattern in which the step between the convex portion and the concave portion is set to be relatively small (for example, λ / 16 or less). here,
As the wavelength λ, λ = 633 nm can be used.
Further, the correction mark CM is a step pattern of the same pattern type as the reference pattern SP and the measurement pattern MP. Here, the reference pattern SP including a high step pattern
Is a pattern that is very insensitive to the optical axis shift, and the measurement pattern MP that is a low step pattern is a pattern that is very sensitive to the optical axis shift.

Thus, in the inspection of the optical axis shift in the position detecting device, the relative position information X of the measurement pattern MP with respect to the pair of reference patterns SP in each defocus state.
1, X2 (Y1, Y2) as a pair of correction reference patterns C
Relative position information X of corrected measurement pattern CMP with respect to SP
Correct with 3, X4 (Y3, Y4). Then, the relative position information X1 ′ (Y
Based on the average value of 1 ') and X2' (Y2 '),
The optical axis shift of the imaging optical system is inspected. As described above, also in the inspection of the optical axis shift in the position detection device, it is possible to perform the inspection with high precision as in the coma aberration measurement. In addition, when performing this inspection, it is also possible to inspect using more marks.

In this embodiment, the image forming optical system is optically adjusted based on the inspection result of the optical axis shift obtained by using the inspection substrate. In order to adjust the optical axis shift of the image forming optical system, it is preferable to finely move the image forming aperture diaphragm 17 through the drive system 20 in the direction perpendicular to the optical axis. In addition, since it is possible to inspect even when there is eclipse in the optical system or when there is dust, in such a case, it is possible to replace the lens and parts. Further, for example, the position detection result can be corrected based on the inspection result of the optical axis shift before or after the optical adjustment of the imaging optical system.

Next, in the accuracy evaluation of the position detecting device, that is, in the evaluation of the relationship between the defocus amount and the detection accuracy when the wafer mark composed of the asymmetrical low step pattern is detected in the defocused state, it is formed on the inspection substrate. A plurality of defocus states (including a focus state as necessary) by using the measured third set of measurement marks MM and correction marks CM
In, the position of the pair of reference patterns SP, the position of the measurement pattern MP, the position of the pair of corrected reference patterns CSP,
The position of the corrected measurement pattern CMP is detected.

In this case, in the third set of measurement marks MM and correction marks CM, the reference pattern SP has a bright / dark pattern or a high step pattern in which the step between the convex portion and the concave portion is set relatively large (for example, λ / 8 or more). Is. Here, the reference pattern SP may be a symmetrical pattern in which the line portion and the space portion are formed symmetrically with respect to the pitch direction of the pattern, or the line portion and the space portion are formed asymmetrically with respect to the pitch direction of the pattern. It may be an asymmetric pattern.

Further, in the measurement pattern MP, the step between the convex portion and the concave portion is set to be relatively small (for example, λ / 16 or less), and the line portion and the space portion are formed asymmetrically with respect to the pitch direction of the pattern. It is a step pattern. Further, the correction mark CM is a bright / dark pattern or a step pattern. Here, the reference pattern SP consisting of a high step pattern is a pattern which is very insensitive to the accuracy evaluation of the asymmetry of the pattern, and the measurement pattern MP consisting of the asymmetric low step pattern is very sensitive to the accuracy evaluation of the pattern asymmetry. It is a pattern.

Thus, in the accuracy evaluation regarding the pattern asymmetry of the position detecting device, the relative position information X1, X2 (Y1, Y2) of the measurement pattern MP with respect to the pair of reference patterns SP in each defocus state is calculated in each defocus state. Relative position information X3, X4 (Y of the correction measurement pattern CMP with respect to the pair of correction reference patterns CSP)
3, Y4) to correct. Then, the relative position information X1 ′ (Y1 ′) and X2 ′ corrected by the correction mark CM
Based on the average value with (Y2 ′), etc., the accuracy of the position detection device is evaluated, and by extension, the defocus amount suitable for detecting the wafer mark having the asymmetric low step pattern is inspected.

In another accuracy evaluation of the position detecting device, that is, in the evaluation of the relationship between the detection accuracy and the pattern form of the wafer mark composed of the asymmetric low step pattern, the fourth set of measurement marks formed on the inspection substrate is used. Using the MM and the correction mark CM and the fifth set of the measurement mark MM and the correction mark CM, the positions of the pair of reference patterns SP and the measurement pattern MP in a plurality of defocus states (including the focus state as necessary). The position, the position of the pair of correction reference patterns CSP, and the position of the correction measurement pattern CMP are detected.

In this case, the fourth set of measurement marks MM and correction marks CM and the fifth set of measurement marks MM and correction marks CM have basically the same structural form as the third set of measurement marks MM and correction marks CM. Have. However, in the fourth set of measurement marks MM and correction marks CM, as an example, all patterns have a pitch of 12 μm and a duty ratio of 1: 1 (the ratio of the width of the line portion to the width of the space portion). Have. On the other hand, in the fifth set of measurement marks MM and correction marks CM, as an example, all the patterns have a pitch of 12 μm as in the fourth set, and unlike the fourth set, the duty ratio (line Ratio of the width of the part and the width of the space part).

Thus, in the accuracy evaluation regarding the pattern form of the wafer mark, the fourth mark is obtained in each defocus state.
Measurement pattern MP for a pair of reference patterns SP detected using a set of measurement marks MM and correction marks CM
Relative position information X1, X2 (Y1, Y2) of the correction measurement pattern CMP for the pair of correction reference patterns CSP.
The relative position information X3, X4 (Y3, Y4) is corrected.
Further, in each defocus state, relative position information X1, X2 (Y1, Y2) of the measurement pattern MP with respect to the pair of reference patterns SP detected using the fifth set of measurement marks MM and correction marks CM is used as a pair of correction references. The correction is performed using the relative position information X3, X4 (Y3, Y4) of the correction measurement pattern CMP with respect to the pattern CSP.

Then, the corrected relative position information X1 'obtained by using the fourth set of measurement marks MM and correction marks CM.
(Y1 ′) and X2 ′ (Y2 ′) and the corrected relative position information X1 ″ (Y1 ″) and X2 ″ (Y2 ″) obtained by using the fifth set of measurement marks MM and correction marks CM. An appropriate duty ratio (pattern form) of a wafer mark having an asymmetric low step pattern is inspected.

In this way, the optical state of the position detecting device can be inspected with high accuracy, for example, with respect to coma aberration, optical axis shift, accuracy evaluation, etc., using the inspection substrate of this embodiment. As a result, a reticle (mask) R and a wafer (photosensitive layer) are projected onto the projection optical system PL by using a highly accurate position detection device that is optically adjusted or corrected based on the inspection result obtained by the inspection method of the present embodiment. It is possible to perform excellent exposure by accurately aligning the substrate (W) with W.

Particularly, in the inspection substrate of this embodiment, the pair of reference patterns SP and the measurement patterns MP are transferred and formed on the measurement marks MM using the same mask.
Therefore, one of the reference pattern SP and the measurement pattern M
The reference distance from P and the reference distance between the other reference pattern SP and the measurement pattern MP can be set with high accuracy according to design values. As a result, the optical state of the position detection device can be inspected with high precision using the inspection substrate manufactured with high precision.

Further, in the inspection substrate of this embodiment, the correction mark CM having the same pattern as the pair of reference pattern SP and measurement pattern MP is formed in parallel with the measurement mark MM. Therefore, the relative position information X of the measurement pattern MP with respect to the pair of reference patterns SP
1, X2 (Y1, Y2) is a pair of correction reference patterns CS
Relative position information X of the corrected measurement pattern CMP with respect to P
By correcting with 3, 3, X4 (Y3, Y4), the optical state of the position detecting device can be inspected with high accuracy without being affected by the outside of the inspection object such as the distortion of the imaging optical system.

Further, in the inspection substrate of this embodiment, the measurement mark MM and the correction mark CM are formed by transferring the same pattern of the same mask to different regions on the substrate. Therefore, the transferred two mark shapes are exactly the same, and are not affected by the drawing error of the mask for manufacturing or the aberration of the projection optical system for exposure.
The reference distance between the pair of reference patterns SP and the measurement pattern MP and the reference distance between the pair of corrected reference patterns CSP and the corrected measurement pattern CMP can be matched with high accuracy. As a result, the optical state of the position detection device can be inspected with higher accuracy by using the inspection substrate including the measurement mark MM and the correction mark CM which are manufactured with high precision.

By the way, in the above-described embodiment, after the position of each pattern is detected using the inspection substrate, the position of each pattern is determined by rotating the inspection substrate 180 degrees with respect to the optical axis of the imaging optical system. It is preferable to detect again. With this method, the influence of the pattern manufacturing error on the inspection substrate can be reduced by the averaging effect, and the optical state of the position detection device can be inspected with higher accuracy.

In the above embodiment, the correction mark C
Although the optical state of the position detecting device is inspected by using the inspection substrate in which M is formed in parallel with the measurement mark MM, the correction mark CM is not always necessary, and the inspection mark in which only the measurement mark MM is formed is used. The substrate can also be used to inspect the optical state of the position detection device. In this case, the relative position information X of the measurement pattern MP with respect to one of the reference patterns SP
1 (Y1) and the relative position information X2 (Y2) of the measurement pattern MP with respect to the other reference pattern SP are used to inspect the optical state of the position detection device.

Further, in the above-described embodiment, the measurement mark M is composed of the pair of reference patterns SP and one measurement pattern MP.
Although M is formed, the present invention is not limited to this, and it is also possible to form the measurement mark MM with at least one reference pattern SP and at least one measurement pattern MP. Specifically, the measurement mark MM may be formed by one reference pattern SP and one measurement pattern MP, or one reference pattern SP and a pair of measurement patterns MP.
May form the measurement mark MM, or the plurality of reference patterns SP and the plurality of measurement patterns MP may form the measurement mark M.
M may be formed. Further, it is possible to form a large number of types of marks on the inspection substrate, and it is possible to improve accuracy by performing measurement using a larger number of measurement patterns.

Next, a method of manufacturing the inspection substrate according to this embodiment will be described. FIG. 4 is a diagram illustrating a method of forming the reference pattern SP having a high step and the measurement pattern MP having a low step with the same mask. In the present embodiment, the high step reference pattern SP and the low step measurement pattern MP
In order to manufacture the optical axis deviation inspection substrate on which is formed by using the same mask, as shown in FIG. 4A, chromium oxide (CrO ₂ ) is formed on a test wafer TW made of silicon, for example.
A film 41 is applied, and a resist 42a is formed on the chromium oxide film 41.
Apply. Instead of the chromium oxide film 41, for example, a silicon nitride (SiN) film can be used.

Next, as shown in FIG. 4B, a basic pattern exposure for the reference pattern SP and the measurement pattern MP is performed using an exposure device such as a stepper using a mask, and the resist 42a is developed (removed). ) And the chromium oxide film 41 are dry-etched. Further, as shown in FIG. 4C, by removing the resist 42a, basic patterns for the reference pattern SP and the measurement pattern MP are formed in the chromium oxide film 41.

Next, as shown in FIG. 4D, a resist 42b is applied on the chromium oxide film 41. After that, FIG.
As shown in (e), only the reference pattern area in which the reference pattern SP is to be formed is exposed, and the resist 42b in this reference pattern area is removed. Further, FIG. 4 (f)
As shown in FIG. 5, a recess (for example, a depth of 150 nm) 43 for the reference pattern SP is formed on the test wafer TW by etching using the chromium oxide film 41 in the reference pattern region as a mask.

Next, as shown in FIG. 4G, after the remaining resist 42 is removed, the concave portion for the measurement pattern MP is formed using the chromium oxide film 41 in the measurement pattern region where the measurement pattern MP is to be formed as a mask. (For example, depth 8
5 nm) 44 is formed on the test wafer TW by etching, and the concave portion 4 for the reference pattern SP is formed using the chromium oxide film 41 in the reference pattern region as a mask.
3 deeper (eg depth 150 + 85 = 235n
m) Etch.

Finally, as shown in FIG. 4H, the surface of the test wafer TW is subjected to CMP (chemical mechanical plan).
arisation) method to flatten the surface to obtain a high step (for example, 1
70 nm) reference pattern SP and low step (for example, 2
A measurement pattern MP of 0 nm) is formed. Thus, in the manufacturing method of the present embodiment, the optical axis deviation inspection substrate on which the high-level difference reference pattern SP and the low-level measurement pattern MP are formed is manufactured using the same mask.

FIG. 5 is a diagram for explaining a method of forming the light-dark type reference pattern SP and the step-type measurement pattern MP with the same mask. In the present embodiment, in order to manufacture the coma aberration inspection substrate on which the light-dark type reference pattern SP and the fine groove step type measurement pattern MP are formed using the same mask, as shown in FIG. A chromium oxide film 51 is applied on the TW, and a resist 52a is applied on the chromium oxide film 51.

Next, as shown in FIG. 5B, basic pattern exposure for the reference pattern SP and the measurement pattern MP is performed using a mask to develop (remove) the resist 52a and dry the chromium oxide film 51. Etching is performed. Further, as shown in FIG. 5C, the resist 52a
Are removed, a basic pattern for the reference pattern SP and the measurement pattern MP is formed in the chromium oxide film 51.

Next, as shown in FIG. 5D, a resist 52b is applied on the chromium oxide film 51. After that, FIG.
As shown in (e), only the measurement pattern region in which the measurement pattern MP is to be formed is exposed, and the resist 52b in this measurement pattern region is removed. Furthermore, FIG.
As shown in FIG. 5, the recess 5 for the measurement pattern MP is formed using the chromium oxide film 51 in the measurement pattern region as a mask.
3 is formed on the test wafer TW by etching.

Next, as shown in FIG. 5G, only the chromium oxide film 51 in the measurement pattern region is removed using the remaining resist 52b as a mask. Finally, Fig. 5 (h)
As shown in FIG. 5, the light-dark type reference pattern SP is formed on the test wafer TW by removing the resist 52b remaining in the reference pattern region where the reference pattern SP is to be formed. Thus, in the manufacturing method of the present embodiment, the coma aberration inspection substrate on which the light-dark type reference pattern SP and the fine groove step type measurement pattern MP are formed is manufactured using the same mask.

FIGS. 6 and 7 show an asymmetrical high-stepped reference pattern SP and an asymmetrical low-stepped measurement pattern MP.
FIG. 6 is a diagram illustrating a method of forming the same with the same mask. In the present embodiment, in order to manufacture the substrate for accuracy evaluation inspection on which the asymmetrical high-stepped reference pattern SP and the asymmetrical low-stepped measurement pattern MP are formed using the same mask, as shown in FIG.
, The chromium oxide film 61 is formed on the test wafer TW.
And a resist 62a is applied on the chromium oxide film 61.

Next, as shown in FIG. 6B, the first basic pattern exposure for the reference pattern SP and the measurement pattern MP is performed using a mask, and the resist 62a is developed (removed) and the chromium oxide film 61 is formed. Dry etching is performed. Further, as shown in FIG.
After removing a, a resist 62 is formed on the chromium oxide film 61.
Apply b.

Next, as shown in FIG. 6D, only the measurement pattern region in which the measurement pattern MP is to be formed is exposed,
The resist 62b in this measurement pattern region is removed. Further, as shown in FIG. 6E, the recess 63 for the measurement pattern MP is formed in the test wafer TW by etching using the chromium oxide film 61 in the measurement pattern region as a mask.

Next, as shown in FIG. 6F, a resist 62b is formed on the chromium oxide film 61 in the measurement pattern area.
Apply. In this way, the reference pattern area and the measurement pattern area where the reference pattern SP is to be formed are entirely covered with the resist 62b. Further, as shown in FIG. 6G, the second basic pattern exposure for the reference pattern SP and the measurement pattern MP is performed using a mask, and the resist 62b is developed (removed) and the chromium oxide film 61 is dry-etched. To do.

Next, as shown in FIG. 7A, by removing the resist 62b, basic patterns for the reference pattern SP and the measurement pattern MP are formed in the chromium oxide film 61. Further, as shown in FIG. 7B, a resist 62c is applied on the chromium oxide film 61. After that, as shown in FIG. 7C, only the reference pattern area is exposed and the resist 62c in the reference pattern area is removed. Further, as shown in FIG. 7D, using the chromium oxide film 61 in the reference pattern region as a mask, the recesses 64 and 6 for the reference pattern MP are formed.
5 is formed on the test wafer TW by etching.

Next, as shown in FIG. 7E, after removing the remaining resist 62c, the recess 63 is changed into a stepwise recess 66 by etching using the chromium oxide film 61 in the measurement pattern region as a mask. At the same time, the recesses 64 and 65 are etched deeper using the chromium oxide film 61 in the reference pattern region as a mask. Finally, as shown in FIG. 7F, by removing the chromium oxide film 61, the asymmetric high stepped reference pattern SP and the asymmetrical (stepwise) low stepped measurement pattern MP are formed.

FIG. 8 and FIG. 9 are views for explaining a method of forming the reference pattern SP of the asymmetric light and dark pattern and the measurement pattern MP of the asymmetric low step difference with the same mask. In the present embodiment, as shown in FIG. 8A, in order to manufacture the accuracy evaluation inspection substrate on which the asymmetrical light-dark pattern reference pattern SP and the asymmetrical low-step measurement pattern MP are formed using the same mask, as shown in FIG. A chromium oxide film 81 is applied on the test wafer TW, and a resist 82a is applied on the chromium oxide film 81.

Next, as shown in FIG. 8B, the first basic pattern exposure for the reference pattern SP and the measurement pattern MP is performed using a mask, and the resist 82a is developed (removed) and the chromium oxide film 81 is formed. Dry etching is performed. Further, as shown in FIG.
After removing a, a resist 82 is formed on the chromium oxide film 81.
Apply b.

Next, as shown in FIG. 8D, only the measurement pattern region in which the measurement pattern MP is to be formed is exposed,
The resist 82b in this measurement pattern region is removed. Further, as shown in FIG. 8E, a recess 83 for the measurement pattern MP is formed on the test wafer TW by etching using the chromium oxide film 81 in the measurement pattern region as a mask.

Next, as shown in FIG. 8F, a resist 82b is formed on the chromium oxide film 81 in the measurement pattern area.
Apply. Thus, the entire reference pattern area and the measurement pattern area where the reference pattern SP is to be formed is covered with the resist 82b. Further, as shown in FIG. 8G, the second basic pattern exposure for the reference pattern SP and the measurement pattern MP is performed using a mask, and the resist 82b is developed (removed) and the chromium oxide film 81 is dry-etched. To do.

Next, as shown in FIG. 9A, the resist 82b is removed to form basic patterns for the reference pattern SP and the measurement pattern MP on the chromium oxide film 81. Further, as shown in FIG. 9B, a resist 82c is applied on the chromium oxide film 81. Then, as shown in FIG. 9C, only the measurement pattern region is exposed and the resist 82c in the measurement pattern region is removed. Further, as shown in FIG. 9D, the recess 83 is stepped into a recess 84 by etching using the chromium oxide film 81 in the measurement pattern region as a mask.
Change to.

Next, as shown in FIG. 9E, by removing the chromium oxide film 81 in the measurement pattern region, the measurement pattern MP having an asymmetric (stepwise) and low step appears in the measurement pattern region. Finally, as shown in FIG. 9F, the chromium oxide film 81 in the reference pattern region is removed, so that the asymmetrical bright-dark reference pattern SP appears in the reference pattern region.

FIG. 10 and FIG. 11 show a symmetrical and high stepped reference pattern SP and an asymmetrical low stepped measurement pattern M.
It is a figure explaining the method of forming P with the same mask. In the present embodiment, in order to manufacture the substrate for accuracy evaluation inspection on which the reference pattern SP having the symmetric high step and the measurement pattern MP having the asymmetric low step are formed using the same mask, FIG.
As shown in (a), silicon nitride (SiNx) 91 is formed on a test wafer TW made of, for example, silicon (Si).
And a resist 92 is applied on the silicon nitride film 91.

Next, as shown in FIG. 10B, a mask is used to perform basic pattern exposure for the reference pattern SP and the measurement pattern MP by an exposure device such as a stepper, and the resist 92 is developed. With
Then, dry etching of the silicon nitride film 91 is performed up to the upper portion of the test wafer TW. Further, by removing the resist 92, basic patterns for the reference pattern SP and the measurement pattern MP are formed on the silicon nitride film 91 and the test wafer TW.

Next, as shown in FIG. 10C, silicon oxide (SiO ₂ ) is embedded in the pattern portion formed on the silicon nitride film 91 and the test wafer TW, and the silicon nitride film 91 is formed on the pattern portion. Silicon oxide film 9
3 is formed. Further, as shown in FIG. 10D, the silicon oxide film 93 is planarized by the CMP method until the surface of the silicon nitride film 91 is visible. And FIG.
As shown in (e), the silicon nitride film 91 is peeled off.

Next, as shown in FIG. 10F, a polysilicon (PolySi) film 94 is formed on the test wafer TW and the silicon oxide film 93. Further, on the polysilicon (PolySi) film 94, tungsten silicide (W
Si) film 95 is formed. Finally, in the reference pattern region, the polysilicon film 94 and the tungsten silicide film 95 are peeled off.

Since the silicon oxide film 93 has a light-transmitting property, a reference pattern SP as a symmetrical high step pattern defined by the concavo-convex pattern formed on the upper portion of the test wafer TW is obtained in the reference pattern region by dry etching. To be On the other hand, the tungsten silicide film 95
Has no light transmission property, so that an uneven pattern formed on the surface of the tungsten silicide film 95 is obtained in the measurement pattern region. Here, the silicon oxide film 9
The surface of No. 3 is asymmetrically deformed by the CMP method, and the concavo-convex pattern formed on the surface of the tungsten silicide film 95 is also asymmetrical. As a result, the measurement pattern M as an asymmetrical low step pattern is asymmetrical in the measurement pattern area.
P is obtained.

Although the tungsten silicide film 95 as an opaque film is formed on the polysilicon film 94 in FIG. 10, a modification in which the tungsten silicide film 95 is not used as shown in FIG. 11 is also possible. In the modification of FIG. 11, the polysilicon film 94 functions as an opaque film, and illumination light of a relatively small wavelength (for example, 530 nm to 700).
nm) is effective.

Although the wafer mark is epi-illuminated in the above-described embodiment, the present invention is not limited to this, and the present invention can be applied to a position detecting device that transmits and illuminates the wafer mark. Further, in the above-described embodiment, different CCDs are used for the X-direction mark detection and the Y-direction mark detection.
Is used, but one CCD detects X direction mark and Y
Both the direction mark detection and the direction mark detection may be performed.

Further, in the above-mentioned embodiment, the present invention is applied to the position detecting device provided with the image forming optical system for forming the image based on the light from the wafer mark, but the present invention is not limited to this. The present invention can also be applied to a position detection device that is generally provided with an optical system that guides light from a wafer mark.

Further, in the exposure apparatus according to the above-described embodiment, ultraviolet light having a wavelength of 100 nm or more, such as g-line, i-line, and deep-ultraviolet (DUV) light such as KrF excimer laser, ArF excimer is used as the illumination light for exposure. Laser and F
Vacuum ultraviolet (VUV) such as ₂ lasers (wavelength 157 nm)
Light can be used. Note that instead of the excimer laser, for example, wavelengths of 248 nm, 193 nm, 157 nm
Alternatively, a harmonic of a solid-state laser such as a YAG laser having an oscillation spectrum may be used. Also,
A single-wavelength laser in the infrared or visible range emitted from a DFB semiconductor laser or a fiber laser is amplified by a fiber amplifier doped with erbium (or both erbium and ytterbium), and is then irradiated with ultraviolet light using a nonlinear optical crystal. A harmonic wave whose wavelength is converted to light may be used.

Of course, in the above embodiment, the wavelength of the exposure illumination light is not limited to 100 nm or more.
For example, to expose a pattern of 70 nm or less, S
EUV (Extreme Ultra Vio) in the soft X-ray region (for example, a wavelength region of 5 to 15 nm) using an OR or a plasma laser as a light source.
let) light is generated and its exposure wavelength (for example, 1
3.5 nm) based on all reflection reduction optical system,
Further, an EUV exposure apparatus using a reflective mask has been developed. In this apparatus, it is conceivable that the mask and the wafer are synchronously scanned and exposed by scanning using arc illumination, and such an apparatus is also included in the scope of application of the present invention. In an EUV exposure apparatus or the like, it is preferable that the stage drive system is a magnetic levitation linear actuator and the chuck system also uses an electrostatic adsorption method, assuming that the chamber is evacuated. In an optical exposure apparatus of 100 nm or more, a vacuum may be used for the stage drive system or suction by airflow.

By the way, as the projection optical system, not only a reduction system but also a unity magnification system or an enlargement system (for example, an exposure apparatus for manufacturing a liquid crystal display) may be used. Further, the present invention can be applied to a proximity type scanning exposure apparatus, such as an X-ray exposure apparatus that moves a mask and a wafer integrally relative to an arcuate illumination region where X-rays are irradiated. Further, the present invention can be applied to an EB (electron beam) exposure apparatus that performs pattern transfer using an electron beam instead of the above-described radiant light. Further, not only an exposure apparatus used for manufacturing a semiconductor element, but also an exposure apparatus for transferring a device pattern onto a glass plate, which is used for manufacturing a display including a liquid crystal display element, and a device used for manufacturing a thin film magnetic head. The present invention can be applied to an exposure device that transfers a pattern onto a ceramic wafer, an exposure device that is used for manufacturing an image pickup device (CCD, etc.), and the like. The present invention can also be applied to an exposure apparatus that transfers a circuit pattern onto a glass substrate, a silicon wafer, or the like in order to manufacture a reticle or a mask.

Further, although the position of the photosensitive substrate in the exposure apparatus is detected in the above-described embodiment, the position of the object mark formed on a general object to be detected is not limited to this. Detection, for example, JP-A-6-58
730, JP-A-7-71918, and JP-A-1
The present invention can also be applied to the overlay accuracy measuring device and the inter-pattern dimension measuring device disclosed in, for example, 0-1222814, JP-A-10-122820, and JP-A-2000-258119.

[0100]

As described above, in the inspection substrate of the present invention, since the first pattern and the second pattern having different structural forms are formed using the same mask, the first pattern and the second pattern are formed. The reference distance between the two patterns can be set with high accuracy according to the design value. As a result, it is possible to highly accurately inspect the optical state of the position detection device with respect to, for example, coma aberration, optical axis shift, accuracy evaluation, and the like, using the inspection substrate manufactured with high accuracy.

Further, in the inspection substrate of the present invention, in addition to the first pattern and the second pattern having different structural forms, a correction pattern having the same pattern as the entire first pattern and the second pattern is formed. There is. As a result, by correcting the relative position information of the second pattern with respect to the first pattern with the relative position information of the correction pattern, the position can be detected without being affected by the non-inspection object such as the distortion of the optical system of the position detecting device. The optical state of the detection device can be inspected with high accuracy.

As described above, the mask and the photosensitive substrate are highly accurately arranged with respect to the projection optical system by using the highly accurate position detecting device which is optically adjusted or corrected based on the inspection result obtained by the inspection method of the present invention. Good exposure can be performed by aligning with.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of an exposure apparatus including a position detection device that is an inspection target in an optical state using an inspection substrate according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a structure of a wafer mark formed on a wafer which is an object whose position is to be detected by the position detecting device shown in FIG.

FIG. 3 is a diagram schematically showing a basic structure of a pattern formed on the inspection substrate of the present embodiment.

FIG. 4 is a diagram illustrating a method of forming a high-level reference pattern SP and a low-level measurement pattern MP with the same mask.

FIG. 5 is a diagram illustrating a method of forming a light-dark type reference pattern SP and a fine groove step type measurement pattern MP with the same mask.

FIG. 6 is a first diagram illustrating a method of forming a reference pattern SP having an asymmetric high step and a measurement pattern MP having an asymmetric low step with the same mask.

FIG. 7 is a second diagram illustrating a method of forming a reference pattern SP having an asymmetric high step and a measurement pattern MP having an asymmetric low step with the same mask.

FIG. 8 is a first diagram illustrating a method of forming a reference pattern SP of an asymmetric light and dark pattern and a measurement pattern MP of an asymmetric low step difference with the same mask.

FIG. 9 is a second diagram illustrating a method of forming a reference pattern SP having an asymmetric light-dark pattern and a measurement pattern MP having an asymmetric low step with the same mask.

FIG. 10 is a diagram illustrating a first method of forming a symmetric, high-level reference pattern SP and an asymmetric, low-level measurement pattern MP with the same mask.

FIG. 11 is a diagram illustrating a second method of forming a reference pattern SP having a symmetric high step and a measurement pattern MP having an asymmetric low step with the same mask.

[Explanation of symbols]

1 halogen lamp 2 light guide 3 Illumination aperture stop 5 Illumination field diaphragm 7 Half prism 8 First objective lens 9 Reflective prism 10 Second objective lens 11 Indicator board 14 XY branch half prism 15,16 CCD 17 Imaging aperture stop 18 Signal processing system 30 reticle stage 31 Wafer holder 32 Z stage 33 XY stage 34 Stage control system 35 Main control system 36 keyboard SP reference pattern MP measurement pattern MM measurement mark CM correction mark Illumination system for exposure R reticle PA pattern area PL projection optical system W wafer WM wafer mark

Claims (23)

[Claims] 1. A method of manufacturing an inspection substrate used for inspecting an optical state of a position detection device, wherein the inspection substrate has a first pattern having a first structural form, and the first structural form. And a second pattern having a second structural form different from the above, wherein the first pattern and the second pattern are formed using the same mask. 2. The inspection substrate further comprises a correction pattern having the same pattern as the entire first pattern and the second pattern, and the correction pattern is formed using the same mask. The method for manufacturing an inspection substrate according to claim 1. 3. An inspection substrate manufactured by the manufacturing method according to claim 1. 4. The inspection board according to claim 3, wherein the first pattern is a step pattern, and the second pattern is a light-dark pattern. 5. The first pattern is a symmetric pattern in which a line portion and a space portion are formed symmetrically with respect to a pitch direction of the pattern, and the second pattern has a line portion and a space portion with respect to the pitch direction of the pattern. The inspection board according to claim 3, wherein each of the inspection boards has an asymmetric pattern formed asymmetrically. 6. The first pattern is a high step pattern in which the step between the protrusion and the recess is set relatively large, and the second pattern is set in the step where the step between the protrusion and the recess is relatively small. The inspection substrate according to claim 3, wherein the inspection substrate has a low step pattern. 7. An inspection board used for inspecting an optical state of a position detection device, comprising: a first pattern having a first structural form; and a second structural form different from the first structural form. An inspecting substrate, comprising: a second pattern having the same; and a correction pattern having the same pattern as the entire first pattern and the second pattern. 8. The inspection substrate according to claim 7, wherein the first pattern is a step pattern, the second pattern is a light-dark pattern, and the correction pattern is a step pattern or a light-dark pattern. . 9. The first pattern is a symmetrical pattern in which line portions and space portions are formed symmetrically with respect to the pitch direction of the pattern, and in the second pattern, line portions and space portions are related to the pitch direction of the pattern. The asymmetric pattern formed asymmetrically, respectively, and the correction pattern is a step pattern or a light-dark pattern in which the line portion and the space portion are formed symmetrically with respect to the pitch direction of the pattern, respectively. Inspection board. 10. The first pattern is a high step pattern in which the step between the protrusion and the recess is set relatively large, and the second pattern is set in the step where the step between the protrusion and the recess is relatively small. The inspection board according to claim 7, wherein the correction pattern is a step pattern in which the step between the convex portion and the concave portion is set to a predetermined size. 11. The inspection substrate according to claim 7, wherein the first pattern and the second pattern are simultaneously formed by exposure using the same mask. 12. The correction pattern is formed on a region different from the region on the inspection substrate on which the first pattern and the second pattern are formed by an exposure different from the exposure using the same mask. The inspection substrate according to claim 11, wherein the inspection substrate is formed. 13. A method for inspecting an optical state of a position detecting device, wherein the position of the first pattern and the first pattern are detected by the position detecting device using the inspection substrate according to any one of claims 3 to 6. A detection step of detecting the positions of the two patterns; and an inspection step of inspecting the optical state of the position detection device based on the relative relationship between the positions of the first pattern and the positions of the second pattern detected in the detection step. An inspection method comprising: 14. A method for inspecting an optical state of a position detecting device, comprising: using the inspection substrate according to claim 7, the position detecting device using the inspection substrate; A detection step of detecting the positions of two patterns, the position of the first correction pattern corresponding to the first pattern of the correction patterns, and the position of the second correction pattern corresponding to the second pattern of the correction patterns; A relative relationship between the position of the first pattern and the position of the second pattern detected in the detecting step, and a relative relationship between the position of the first correction pattern and the position of the second correction pattern detected in the detecting step. An inspection step of inspecting an optical state of the position detection device based on a relationship. 15. The detecting step includes a step of detecting the position of each pattern in a plurality of defocus states with respect to the optical system of the position detecting device, and the inspecting step includes a step of detecting each pattern in each defocus state. The inspection method according to claim 13 or 14, comprising a step of inspecting an optical state of the position detection device based on a position. 16. The first detecting step of detecting the position of each pattern using the inspection substrate set in a first direction, and the detecting step with respect to an optical axis of an optical system of the position detecting device. A second detection step of detecting the position of each pattern using the inspection substrate set in a second orientation that is rotated by 180 degrees from the first orientation, wherein the inspection step is the first detection step. 16. The method according to claim 13, further comprising a step of inspecting an optical state of the position detecting device based on the detected position of each pattern and the position of each pattern detected in the second detecting step. Inspection method described in paragraph. 17. In the inspection of the coma aberration of the optical system in the position detecting device, the detecting step has a step pattern in which the width of the concave portion is substantially smaller than the width of the convex portion along the pitch direction of the pattern. 14. The step of detecting the position of each pattern using the inspection substrate having the first pattern and the second pattern having a bright-dark pattern.
17. The inspection method according to any one of 1 to 16. 18. A high step pattern in which the step between the convex portion and the concave portion is set to be relatively large in the inspection of the optical axis shift of the imaging aperture stop with respect to the optical axis of the optical system in the position detecting device. The first pattern having
A step of detecting a position of each pattern using the inspection substrate having the second pattern having a low step pattern in which a step between the convex portion and the concave portion is set to be relatively small is included. Item 17. The inspection method according to any one of Items 13 to 16. 19. In the accuracy evaluation of the position detecting device, in the detecting step, the first pattern having a high step pattern or a bright / dark pattern in which the step between the convex portion and the concave portion is set to be relatively large, and the convex portion Each of the inspection substrates is provided with the second pattern having a low step asymmetric pattern in which the step difference from the recess is set to be relatively small and the line and space portions are formed asymmetrically with respect to the pitch direction of the pattern. 17. The method according to claim 13, further comprising the step of detecting the position of the pattern.
Inspection method described in paragraph. 20. A position detecting device comprising an optical system which is optically adjusted based on an inspection result obtained by the inspection method according to any one of claims 13 to 19. 21. A position detection device, which corrects a position detection result based on an inspection result obtained by the inspection method according to claim 13. 22. The position detecting device according to claim 20, wherein the position detecting device detects the position of the photosensitive substrate in an exposure device for transferring a predetermined pattern formed on a mask onto the photosensitive substrate. An exposure apparatus comprising: 23. An exposure method for transferring a predetermined pattern formed on a mask onto a photosensitive substrate, using the position detecting device according to claim 20 or 21.
An exposure method comprising detecting the position of the photosensitive substrate.