JPH118193A - Manufacture of semiconductor device with surface inclination detecting apparatus and process thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device provided with a surface inclination detecting apparatus, with which surface inclination can be detected in a short period, and a surface inclination detecting process. SOLUTION: This surface inclination detecting apparatus which detects the inclination of the surface W to be detected against the prescribed reference surface (X-Y plane, for example) is provided with irradiation optical systems 111 to 114, with which a light is applied to the first detection point 101 on the surface W to be detected, reirradiation optical systems 116, 201 to 206 and 117, which lead the light reflected by the first detection point 101 to the second detection point 102 on the surface W to be detected, photoelectric systems 123 and 124 with which the light reflected by the second detection point 102 on the surface W to be detected is condensed on a light receiving surface, and photoelectric detection parts 126 to 128 which photoelectrically detect the displacement of the light received by the above-mentioned light receiving surface. The information of the first detection point 101 and the second detection point 102 can be given to the light projected from the irradiation optical system, and the inclination of the surface to be detected can be computed by the above-mentioned light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface inclination detecting device for detecting the inclination of a surface to be inspected, and more particularly to a surface suitable for detecting the inclination of a substrate such as a large liquid crystal panel or a semiconductor integrated circuit. The present invention relates to a semiconductor device manufacturing method including an inclination detecting device and a surface inclination detecting step.

[0002]

2. Description of the Related Art When determining the inclination of the surface of a substrate in a semiconductor manufacturing apparatus, the displacement of two points on the substrate may be detected by a surface displacement detecting device, and the difference between the two points may be calculated. As a surface displacement detection device for this purpose, an oblique incidence type surface position detection device that irradiates incident light obliquely to the surface of the substrate, detects light obliquely reflected from the substrate, and detects the surface position. Is used. Such surface position detecting devices include, for example, JP-A-56-42205, JP-A-5-129182 and JP-A-5-2020.
No. 4166.

[0003] In particular, the surface displacement detection system described in Japanese Patent Laid-Open No. 5-204166 is suitable for detecting the surface displacement of a large substrate. This surface displacement detection system includes two light sources and two light receiving elements, and the light of each light source is split by a half prism and guided to two detection points for each light source. Light from a point is received by each of the two light receiving elements, and the displacement of each detection point is measured. The two light sources can simultaneously measure displacements at two points by time division of ON and OFF. In this way, two light sources and two light receiving elements can detect displacements of a total of four detection points spread around the large substrate. By calculating the difference in displacement between the facing points for each of the detection points detected in this way, the inclination of the substrate in the direction connecting the points can be obtained.

[0004]

According to the surface inclination detecting apparatus using the above-described surface displacement detecting system, since each detecting point is detected in a time-division manner, all the plurality of detecting points on the surface to be detected are detected. However, it takes time to determine the inclination of the substrate, which is one of the causes of a decrease in throughput. In order to improve this by a similar configuration, a light receiving optical system is required for each detection point, which complicates the configuration, causes major obstacles in design, manufacturing, and consumes excessive labor. Had become.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a surface inclination detecting device capable of detecting a surface inclination in a short time and a device manufacturing method including a surface inclination detecting step.

[0006]

In order to achieve the above object, a surface inclination detecting apparatus according to the first aspect of the present invention, as shown in FIG. 1, for example, detects a test object on a predetermined reference plane (for example, an XY plane). In a surface tilt detection device that detects the tilt of a surface (the surface of a test object W (hereinafter, appropriately referred to as a “test surface W”)), light is irradiated toward a first detection point 101 on the test surface W. Irradiation optical systems 111 to 114; re-irradiation optical systems 116, 201 to 206, and 1 for guiding light reflected at the first detection point 101 to the second detection point 102 on the surface W to be measured.
And 17; detection optical systems 123 and 124 for condensing light reflected from the second detection point 102 on the surface W to be detected on the light receiving surface.
And photoelectric detectors 126 to 128 for photoelectrically detecting the displacement of the received light on the light receiving surface.

With this configuration, it is possible to give information of the first detection point and the second detection point to the light irradiated from the irradiation optical system, and to obtain the inclination of the surface to be detected by the light. Can be.

According to the second aspect of the present invention, in the surface inclination detecting apparatus according to the first aspect, the re-irradiation optical system includes a first detection portion and a normal direction to a reference plane (XY plane) at the detection point. Z
The displacement of the received light corresponding to the difference between the displacement along the axial direction) and the displacement along the normal direction (Z-axis direction) of the reference plane at the second detection point 102 is formed on the light receiving surface. It is configured as follows.

In other words, the displacement of the received light on the light receiving surface changes in the normal direction (Z
(The axial direction) and the second detection point 10
2, the re-irradiation optical system is configured to change in accordance with a difference from the displacement of the test surface W along the normal direction (Z-axis direction) of the reference surface in Step 2. I can do it.

[0010] With this configuration, the re-irradiation optical system includes:
Since the displacement of the received light corresponding to the difference in displacement along the Z-axis direction between the first detection point 101 and the second detection point 102 is formed on the light receiving surface, the first detection point and the second detection point The inclination of the test surface with respect to the direction connecting the points is determined.

In the above-mentioned surface inclination detecting device, the re-irradiation optical system may be such that the surface to be inspected W is displaced in the normal direction (Z-axis direction) of the reference surface. At this time, the re-irradiation optical system which is orthogonal to the incident surface on the reference surface with respect to the principal ray of the light beam incident on the first detection point 101 and is bisected by a predetermined surface including the optical axis of the re-irradiation optical system Is configured to emit the chief ray incident on one of the portions from the one portion of the re-irradiation optical system bisected by the predetermined surface, and to guide the chief ray to the second detection portion. .

With this configuration, the principal ray incident on one part of the re-irradiation optical system divided into two parts by the predetermined surface is emitted from one part and guided to the second part. , The shift of the light beam in the first direction changes in accordance with the difference between the two displacements.

[0013] Also, as described in claim 4, claim 1 is as follows.
In the surface inclination detecting device according to any one of claims 3 to 3, the re-irradiation optical system deflects the light beam reflected at the first detection point 101 to the second detection point 102. , 117 and the first detection point 1
It may be configured to have relay optical systems ALR1 and ALR2 that substantially conjugate the 01 and the second detection point 102.

Further, as described in claim 5, claim 1 is
In the surface inclination detecting device according to any one of claims 4 to 6, the irradiation optical system includes a light-transmitting slit plate 112 having a predetermined pattern, and the light-transmitting slit plate 112 having the predetermined pattern.
A photoelectric transmission unit for projecting light onto the light-receiving slit plate 126; and a photoelectric detector for photoelectrically converting light passing through the light-receiving slit plate 126 disposed on the light-receiving surface. 128; the detecting optical system includes a vibrating mirror 12 that vibrates so that the image of the predetermined pattern formed on the light receiving surface crosses the light receiving slit plate 126.
9 may be provided.

Further, as described in claim 6, in the surface tilt detecting device according to any one of claims 1 to 5, the tilt of the surface W to be detected is determined based on the output from the photoelectric detector. It is preferable to further comprise an arithmetic device for performing the arithmetic.

[0016]

With this configuration, when the surface to be inspected is tilted, the displacements of the first and second detection points move by different displacements in the direction of the Z axis in FIG. 1, for example. As a result, the reflected light incident on the vibrating mirror causes a lateral shift in a direction orthogonal to the incident direction. The amount of light passing through the light receiving slit is determined according to the amount of the lateral shift, and the output of the light receiving element changes according to the movement of the surface to be detected along the Z direction. From the change, the difference in displacement of the test surface can be calculated by the arithmetic device, and the inclination of the test surface can be adjusted.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a semiconductor device, the method comprising: providing an exposure apparatus having the surface inclination detecting device according to any one of the first to sixth aspects; Placing the photosensitive substrate W at the position of the test surface; detecting the inclination of the surface of the photosensitive substrate W by the surface inclination detection device; and detecting the detected surface of the photosensitive substrate W. Based on the slope information of
A step of adjusting the inclination of the photosensitive substrate W; and a step of exposing the surface of the photosensitive substrate W to light.

According to this method, the inclination of the photosensitive substrate can be quickly detected, and the inclination of the substrate can be corrected based on the inclination so that the surface of the substrate is orthogonal to the optical axis of the exposure apparatus.

In the present invention, a display device such as a liquid crystal display device, a plasma display panel (PDP),
Semiconductor elements such as SI and imaging elements such as thin-film magnetic heads and CCDs are collectively defined as semiconductor devices.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding members are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a view showing an example in which the surface inclination detecting device according to the present invention is applied to a liquid crystal exposure device. This exposure apparatus includes an auto focus (AF) system and an auto leveling (AL) system, that is, a surface tilt detection device.

In FIG. 1, the present exposure apparatus for a liquid crystal has an illumination optical system 9 and a projection optical system PL, and a reticle R is arranged between them. Regarding the projection optical system PL, on the side opposite to the illumination optical system 9, the XY stage ST on which the substrate W as a test object is mounted at a position conjugate with the reticle, and on the opposite side to the projection optical system PL of the XY stage. A driving device STD for driving is provided. Here, the XYZ three-dimensional coordinates are set as an axis parallel to the optical axis of the projection optical system PL as a Z axis, and orthogonal coordinates in a plane orthogonal to the Z axis as an X axis and a Y axis. The surface of the XY stage ST on which the substrate W is placed is XY
It is almost parallel to the coordinate plane. Typically, the predetermined reference plane of the present invention is an XY coordinate plane or a plane parallel to the XY coordinate plane,
That is, the image plane of the projection optical system PL is used. Therefore, the Z-axis direction is the normal direction of the reference plane in the present invention. In the figure, the lens of the illumination optical system 9 is shown symbolically deformed.

As described above, the illumination optical system 9 illuminates the reticle R on which a predetermined pattern has been formed, so that the pattern image of the reticle R is projected onto the surface of the substrate W as the surface to be inspected via the projection optical system PL. Exposure on top. And
Through this exposure step, a liquid crystal display device can be finally manufactured.

Prior to the above-described exposure process, the position of the surface of the photosensitive substrate W, that is, the displacement and inclination in the Z-axis direction are detected by an autofocus (AF) system and an autoleveling (AL) system described below. In addition, at the same time as the above-mentioned projection exposure process, an auto focus (AF) described below
It is also possible to detect the position and inclination of the surface of the substrate W by a system and an auto-leveling (AL) system.

Referring to FIG. 1, first, the configuration of the AF system will be described. The AF system detects a displacement of an intersection 100 (or an image forming plane of the projection optical system PL) between the surface of the substrate W, which is the surface to be inspected, and the optical axis of the projection optical system PL, and moves the projection optical system PL to the surface W to be inspected. This is a device for focusing on. The AF system incorporated in the liquid crystal exposure apparatus shown in FIG. 1 includes an optical fiber 1 for guiding illumination light from a light source (not shown) such as a halogen lamp.
The zero light exit end is arranged near the side surface of the projection optical system PL with the exit direction parallel to the Z axis. A condenser lens 11 in the optical path from the exit end, and a light-transmitting slit plate 12 having a slit-shaped opening at a position uniformly illuminated by the condenser lens 11 (hereinafter, the same reference numerals are used as appropriate, and a slit formed in the slit plate). Are used like “slit plate 12” and “slit 12”), and a mirror 13 as a deflecting member is arranged in this order. The mirror 13 is inclined so that light from the light transmitting slit plate 12 is obliquely incident on the detection point 100 on the surface of the substrate W. A light transmitting objective lens system 14 is arranged between the mirror 13 and the detection point 100.

Here, when the surface (test surface) of the substrate W as the test object coincides with the reference surface (image forming surface of the projection optical system PL), the light transmission objective lens system 14 It has a function of keeping the light transmitting slit plate 12 and the surface of the substrate W optically conjugate. In addition, the light transmission objective lens system 14 includes a substrate W
It is telecentric with respect to the front side of.

The illumination optical system of the AF system includes the condenser lens 11 and the light transmission objective lens system 14.

Here, the actual pattern for the product formed on the substrate W typically has vertical and horizontal straight lines which are perpendicular to each other as main components. The longitudinal direction of the slit of the light transmitting slit plate 12 is arranged so that the longitudinal direction of the slit image at the detection point 100 does not coincide with such a vertical and horizontal linear direction, for example, at an angle of about 45 degrees. I do. For example, when the substrate W is placed on the XY stage ST with the horizontal and vertical straight lines of the pattern aligned with the directions of the X and Y axes of the coordinates, the longitudinal direction of the slit is set to be equal to the X axis in the XY plane.
It is parallel to the X ₁ axis which forms a 5 degrees. This is because, if the slit image is formed in this way, the brightness of the pattern and the unevenness of the reflectance are averaged to improve the detection accuracy of the surface position. It is to be noted that 45 ° is a desirable angle, but since it is sufficient that the image of the slit is formed across the vertical and horizontal lines of the pattern, an angle other than 90 °, for example, 30 ° or 60 ° Good. This is because the detection points 101, 1
The same applies to 02.

When the detection point 100 is irradiated with light of multiple wavelengths by the irradiation optical system of the AF system, the detection point 100
From the detection point 100 is incident on a detection optical system (23, 24) of an AF system that condenses the reflected light from the detection point 100 on a predetermined light receiving surface.

At this detection point 100, a slit image re-formed by the irradiation optical system of the AF system is formed. Then, the detection optical system (23, 24)
It has a function of re-imaging (relaying) the slit image formed at 0 on the light receiving slit plate 26 arranged on a predetermined light receiving surface.

The surface of the substrate W as a test object (test surface)
Is coincident with the reference plane (the image forming plane of the projection optical system PL), the detection optical system (23, 24) of the AF system includes the detection point 100 and a light receiving slit plate disposed on a predetermined light receiving surface. 26
And are kept optically conjugate.

The detection optical system (23, 24) of the AF system is arranged so that the front focal point is located on the reference surface (the position of the detection point 100 when the surface of the substrate W coincides with the reference surface) with respect to the test surface. The light receiving objective lens system 23 is disposed to collect the reflected light from the detection point 100 on the light receiving slit plate 26, and deflects the light from the light receiving objective lens system 23 (the optical axis of the light receiving objective lens system 23 is Z (Deflecting in a direction parallel to the axis).

The AF detecting optical system (23, 24)
Alternatively, the light receiving objective lens system 23 is configured to be telecentric with respect to both the detection point side (object side) and the light receiving slit plate side (image side).

Further, the detection optical system of the AF system (23, 24)
On the image side, photoelectric detection units 26 to 28 of an AF system for photoelectrically detecting displacement of received light on a predetermined light receiving surface are arranged.

The AF type photoelectric detectors 26 to 28 are arranged on a predetermined light receiving surface and have a predetermined slit-shaped opening, and a light passing through the opening of the light receiving slit plate 26. And a SPD 28 as a photoelectric conversion element (photoelectric detector) for photoelectrically converting the light condensed by the condenser lens 27.

The light receiving slit plate 26 is formed on the light receiving slit plate 26 (light receiving surface) by the longitudinal direction of the slit-shaped opening formed in the light receiving slit plate 26 and the detection optical system (23, 24) of the AF system. Is set so that the longitudinal direction of the slit image formed at the same position coincides with the longitudinal direction.

[0038] Here, briefly Describing operation of detecting the AF system, the vibrating mirror 24, about an axis parallel to the YX plane by mirror driver 29 to swing (X ₁ axially about an axis parallel to) (vibrations ). Then, the slit image formed on the light receiving slit plate 26 by the light receiving objective lens system 23 crosses the opening of the light receiving slit plate 26 by the action of the vibrating mirror 24. Therefore, SPD
Reference numeral 28 photoelectrically detects the light that has passed through the light receiving slit plate 26 and the condenser lens 27, and calculates the position (detection) of the surface of the substrate W by a synchronous detection method using an arithmetic unit in the controller 51 based on the photoelectric detection signal. (The position of the point 100) is detected.

Incidentally, in the example shown in FIG.
4 shows a method of detecting the position of the surface of the substrate W by synchronous detection, but the present invention is not limited to this method.
For example, the light receiving slit plate 26, the condenser lens 27, and the SPD
28, and electrically connected to the arithmetic unit inside the controller 51 at the position of the slit image (image formation) formed by the detection optical systems 23 to 24 of the AF system (the position where the light receiving slit plate 26 was disposed). It is also possible to detect the average position of the surface of the substrate W using an image pickup device such as a CCD or the like. In this case, the vibration mirror 24 is used as a simple fixed mirror that deflects the optical path.

Next, referring to FIG. 1, the structure of the surface inclination detector (AL type) incorporated in the liquid crystal exposure apparatus will be described. In the figure, a light exit end of an optical fiber 110 for guiding illumination light from a light source such as a halogen lamp (not shown) is disposed near the side surface of the projection optical system PL with the exit direction substantially parallel to the Z axis. I have. A condenser lens 111, a light-sending slit plate 112 having a slit-like opening at a position uniformly illuminated by the condenser lens 111, and a mirror 113 as a deflecting member are arranged in this order in the optical path from the exit end. The mirror 113 is
The light from the light transmitting slit plate 112 is transmitted to the first
Are inclined so as to be obliquely incident on a detection point 101 as a detection point. A light transmitting objective lens system 114 is disposed between the mirror 113 and the detection point 101.

Here, when the surface (test surface) of the substrate W as the test object coincides with the reference surface (image forming surface of the projection optical system PL), the light transmission objective lens system 114 It has a function of keeping the light transmitting slit plate 12 and the surface of the substrate W optically conjugate. Further, the light transmission objective lens 114 is configured to be telecentric with respect to the surface side (first detection point side) of the substrate W.

The optical members from the condenser lens 111 to the light transmission objective lens 114 constitute the AL-system irradiation optical system of the present invention.

A light source (not shown) for supplying light of multiple wavelengths and an optical fiber 110 for guiding light from the light source to the condenser lens 111 constitute a light source unit. Further, in FIG. 1, the condenser lens 111 and the light transmission objective lens system 114 are each shown as one lens, but the condenser lens 111 and the light transmission objective lens system 114 may be constituted by a plurality of lenses. Needless to say.

The light transmitting slit plate 112 is formed so that the longitudinal direction of the slit image at the detection point 101 does not coincide with the vertical and horizontal linear directions of the pattern formed on the substrate W, for example, at an angle of about 45 degrees. X is the longitudinal direction of the slit
Arranged in parallel with _one axis is the detection point 100 described above.
And the slit 12 are the same.

When light of multiple wavelengths is irradiated on the first detection point 101 by the above-described irradiation optical system, the detection point 10
The reflected light from No. 1 is incident on the re-irradiation optical system (116, 201 to 206, 117) of the present invention for guiding the reflected light from the detection point 101 to the second detection point 102 as the second detection point. .

At this detection point 101, an image of the opening of the slit plate 112 in the irradiation optical system of the AL system, that is, a slit image is formed. Then, the re-irradiation optical system (11)
6, 201 to 206, 117) are the first detection points 1
01 to the second detection point 102
It has a function to re-image (relay) the image.

The surface of the substrate W as a test object (test surface)
Is coincident with the reference plane (the imaging plane of the projection optical system PL), the re-irradiation optical system (116, 201 to 206, 11)
7) are the first detection point 101 and the second detection point 1
02 is kept optically conjugate.

The re-irradiation optical system (116, 201-2)
06, 117) are configured such that the longitudinal direction of the slit image formed at the first detection point 101 and the longitudinal direction of the slit image formed at the second detection point 102 match.

Here, the re-irradiation optical system includes a first mirror 116 for reflecting (deflecting) the reflected light from the detection point 101 in a direction substantially parallel to the Z axis, and a reference surface (the substrate W The front focal point is located at the position of the detection point 101 when the surface and the reference plane coincide with each other, and the detection point 1
First relay lens group ALR that collects the reflected light from 01
1 (201, 202) and the AL of the first relay lens
A second mirror 203 for reflecting the light through the R1 direction parallel to the X ₁ (deflection), reflecting the direction substantially parallel to the reflection (deflected) has been again Z-axis light by its second mirror 203 (Deflecting) a third mirror 204, a second relay lens group ALR2 (205, 206) for condensing the light passing through the third mirror 204, and a light passing through the second relay lens group ALR2. A fourth mirror 117 that reflects (deflects) the light toward the second detection point 102.

Here, in the example shown in FIG. 1, the relay optical system of the present invention is composed of two relay lens groups (ALR1 and ALR2) having substantially the same magnification, and as a whole substantially equal It has a double imaging magnification.

First, the first relay lens group ALR1
There are two relay lenses (201, 202), and a pupil P1 is formed between the two relay lenses as shown in FIG. That is, the pupil P1 is connected to the relay lens 2
01 is formed at the rear focal position (or the front focal position of the relay lens 202).

The second relay lens group ALR2 is
There are two relay lenses (205, 206), and a pupil P2 is formed between the two relay lenses as shown in FIG. That is, this pupil P2 is
05 is formed at the rear focal position (or the front focal position of the relay lens 206).

Further, between the first relay lens group ALR1 and the second relay lens group ALR2, due to the light condensing action of the first relay lens group ALR1, as shown in FIG. Image) is formed. When the surface of the substrate W coincides with the reference plane, the position of the intermediate imaging point P is determined by the relay lens 202 (or the first relay lens group AL).
R1) becomes the rear focal position. In other words, at this time,
The position of the intermediate imaging point P is determined by the relay lens 205 (or the second
It is formed at the front focal position of the relay lens group ALR2).

When the surface of the substrate W coincides with the reference surface, the first relay lens group ALR1 moves the front focal position of the first relay lens group ALR1 and the reference surface (the surface of the substrate W and the reference surface). Detection point 10 when surface coincides
1) and the first relay lens group AL
The rear focal position of R1 is set to coincide with the front focal position of the second relay lens group ALR2.

When the surface of the substrate W coincides with the reference plane, the second relay lens group ALR2 moves the rear focal position of the first relay lens group ALR1 and the second relay lens group AL.
The front focal position of R2 coincides, and the rear focal position of the second relay lens group ALR2 and the reference plane (the detection point 10 when the surface of the substrate W and the reference plane coincide with each other) with respect to the test surface.
2).

Therefore, the re-irradiation optical system (116, 20)
1 to 206, 117) are both telecentric with respect to the first detection point side (object side) and the second detection point side (image side).

In FIG. 1, two relay lenses (201, 2) constituting the first relay lens group ALR1 are shown.
02) and the two relay lenses (205, 206) constituting the second relay lens group are each shown as one lens, but it goes without saying that these relay lenses may be composed of a plurality of lenses.

Next, the re-irradiation optical system (11)
6, 201 to 206, 117), when light is irradiated to the detection point 102 as the second detection point, the reflected light from the detection point 102 is reflected light from the detection point 102 to a predetermined light receiving surface. AL-based detection optical system (12
3, 124).

At this detection point 102, a slit image re-formed by the re-irradiation optical system (116, 201 to 206, 117) is formed. The AL detection optical system (123, 124) is connected to the second detection point 102.
Has a function of re-imaging (relaying) the slit image formed on the light receiving slit plate 126 disposed on a predetermined light receiving surface.

The surface of the substrate W as the object to be inspected (surface to be inspected)
Is coincident with the reference plane (the imaging plane of the projection optical system PL), the AL detection optical system (123, 124) is arranged on the second detection point 102 and a predetermined light receiving surface. The light receiving slit plate 126 is kept optically conjugate with the light receiving slit plate 126.

AL detection optical system (123, 124)
Are arranged such that the front focal point is located on a reference plane (the position of the detection point 102 when the surface of the substrate W coincides with the reference plane) with respect to the test surface, and the reflected light from the detection point 102 is received by the light receiving slit. Receiving objective lens system 12 condensing on plate 126
3 and a vibrating mirror 124 that deflects light from the light receiving objective lens system 123 (deflects the optical axis of the light receiving objective lens system 123 in a direction parallel to the Z axis).

The AL detection optical system (123, 12
4) Alternatively, the light receiving objective lens system 123 is both telecentric with respect to the second detection point side (object side) and the light receiving slit plate side (image side).

The AL detection optical system (123, 12)
On the image side 4), an AL-based photoelectric detector (126 to 128) for photoelectrically detecting the displacement of the received light on a predetermined light receiving surface is arranged.

AL type photoelectric detector (126 to 128)
A light receiving slit plate 126 disposed on a predetermined light receiving surface and having a predetermined slit-shaped opening, a condensing lens 127 for condensing light passing through the opening of the light receiving slit plate 126, SP as a photoelectric conversion element (photoelectric detector) for photoelectrically converting the light condensed by the optical lens 127
D128.

The light receiving slit plate 126 is formed on the light receiving slit plate 126 (light receiving surface) by the longitudinal direction of the slit-shaped opening formed in the light receiving slit plate 126 and by the AL-based photoelectric detectors (126 to 128). Is set so that the longitudinal direction of the slit image formed at the same position coincides with the longitudinal direction.

In FIG. 1, each of the light receiving objective lens system 123 and the condenser lens 127 is shown as one lens, but the light receiving objective lens system 123 and the condenser lens 127 are composed of a plurality of lenses. It goes without saying that you can do it.

Here, the detection operation of the AL system will be briefly described.
Provoking swinging (vibration) to (axis line parallel to the X ₁ axis direction) about an axis parallel to the YX plane by. Then, the slit image formed on the light receiving slit plate 126 by the light receiving objective lens system 123 crosses the opening of the light receiving slit plate 126 by the action of the vibrating mirror 124. Therefore, the SPD 128 photoelectrically detects the light that has passed through the light receiving slit plate 126 and the condenser lens 127, and, based on the photoelectrically detected signal, calculates the inclination of the surface of the substrate W by a synchronous detection method using an arithmetic unit in the controller 51 described later. (The difference between the detection points 101 and 102) is detected.

Incidentally, in the example shown in FIG.
24, a method of detecting the position of the surface of the substrate W by synchronous detection is shown, but the method is not limited to this. For example, the light receiving slit plate 126 and the condenser lens 127
And the SPD128 are removed, and the AL-based detection optical system (1
23, 124) formed by the slit image (imaging)
Position (the position where the light receiving slit plate 126 was arranged)
It is also possible to detect the average position of the surface of the substrate W by using an image pickup device such as a CCD electrically connected to an arithmetic unit inside the controller 51. In this case, the vibration mirror 124 is used as a simple fixed mirror that deflects the optical path.

Next, the operation of the present embodiment will be described with reference to FIG. The pattern in the frame shown by the broken line on the reticle R illuminated via the illumination system 9 is projected onto the surface of the plate substrate W placed at a position conjugate with the reticle R by the lens PL of the projection optical system. Is done. At this time, the displacement of the surface of the substrate W is measured by the AF system, so that the substrate W
Is moved in parallel in the Z direction, adjusted to a predetermined position, and the surface (exposure surface) of the substrate W is set at right angles to the optical axis of the projection optical system PL based on the tilt angle of the substrate W detected by the AL system. To start the exposure.

The XY stage driving device STD is driven in accordance with the detection value of the surface position detecting device (AF system) to
Controller 5 for adjusting the height of stage ST in the Z direction
1 is provided, receives a signal from the SPD 28,
A control signal is sent to the XY stage drive STD. Similarly, the controller 51 includes a surface inclination detecting device (AL
In accordance with the detected value of the system), it drives the drive unit STD is adapted to adjust the X ₁ direction of the slope of the XY stage ST. The controller 51 also receives a signal from SPD128, is configured to include a computing device for calculating a difference between the displacement detection point 101 and 102 (X ₁ direction tilt).
Then, based on the calculation, the XY stage driving device ST
Send a control signal to D.

Here, the operation of the AF system will be described first with reference to FIG. The light from a light source (not shown) is
The light is captured by the condenser lens 11
Illuminate the light-sending slit plate 12 via the. The illuminated slit plate 12 forms an image at a detection point 100 on the substrate W via the light transmission objective lens system 14 of the AF system. Further, the reflected light reflected at the detection point 100 is transmitted to the slit 12 on the light receiving slit plate 26 by the light receiving objective lens system 23 of the AF system disposed opposite to the light transmitting objective lens system 14 of the AF system.
Is re-imaged.

Here, since the mirror 16 is a vibrating mirror, the re-formed image of the slit 12 is
6 Swinged back and forth across the top. That is, light is received using the principle of a photoelectric microscope. The light passing through the light receiving slit 26 is condensed on a photoelectric conversion element 28 such as an SPD via a condenser lens 27. In this way, the height of the detection point 100 (usually the projection center or shot center of the substrate) on the surface of the substrate W is detected by the AF system.

Next, the operation of the AL system will be described. AF described above
As in the system, light from a light source (not shown) is
The light is taken into the surface inclination detection system by 0, and the light illuminates the leveling light transmission slit plate 112 via the condenser lens 111. Illuminated slit plate 112
Is connected to the substrate W through the AL-type light transmission objective lens system 114.
An image is formed at the upper detection point 101 (first detection point of the present invention). Further, the formed slit image is reflected at the detection point 101, and is formed by a first relay lens group ALR1 and a second relay lens group ALR2 arranged so as to face the AL light transmission objective lens system 114. The image is re-imaged at the detection point 102 (the second detection point of the present invention).

Further, the slit image reflected at the detection point 102 is reflected by the vibrating mirror 124 via the AL-system light-receiving objective lens system 123, and is reflected by the light-receiving slit plate 12.
An image is formed on the light-receiving surface of the surface of No. 6. Light receiving slit 126
Is transmitted to a photoelectric conversion element 128 such as an SPD by a condenser lens 127.

The reason why the vibrating mirror is used here is to detect the phase detection method based on the principle of a so-called photoelectric microscope. The controller 51 includes the light receiving element 28,
The electric signal output from 128 is transmitted to mirror driving device 29,
129 performs phase detection at the oscillation frequency of the mirrors 24 and 124.

FIGS. 2 and 3 are a plan view as viewed from the projection optical system PL side in FIG. 1 and a side view in the direction of arrow AA in FIG. 1, respectively. In FIG. 2, the exposure field of the projection optical system PL is indicated by a broken line. In FIG. 2, the slit is shown to have been projected at a 45-degree direction (X ₁ axial direction) with respect to the exposure field. This is because the influence of the pattern is considered for a liquid crystal panel having many vertical and horizontal patterns, as in the case of the AF system. The substrate W may be square as shown in FIG. 1 or round as shown in FIG. In FIG. 3, the projection optical system PL is cut off along the two-dot chain line and is omitted.

The principle by which the difference between the displacements of the detection points 101 and 102 in the Z-axis direction is detected optically will be described with reference to FIGS. FIG. 4 is a perspective view showing only the AL system except for the AF system in FIG. FIG. 4 shows an optical system from the light transmitting slit plate 112 to the light receiving slit plate 126. FIG. 5 is a side view in the direction of the arrow BB in FIG. 4, and arrows are drawn in accordance with the traveling direction of the light beam in FIG. 4. Solid lines indicate re-irradiation optical systems (116, 201 to 20).
6, 117), the principal ray L1 traveling along the optical axis Ax is referred to as a reference ray here. The dotted line indicates the principal ray L2 that has been shifted laterally from the reference ray by moving the detection point 101 in the minus direction (downward) by ΔZ1, and the two-dot chain line indicates that the detection point 102 has shifted by ΔZ2 in the plus direction (upward). The principal ray L3 shifted laterally from the ray is shown.

In FIGS. 4 and 5, the principal ray of the transmitted light (irradiation light) from the AL irradiation optical system (optical member from the light transmission slit plate 112 to the light transmission objective lens system 114). Is shown as L0.

The image of the light transmitting slit plate 112 is formed on the detection point 101 on the substrate W by the light transmitting objective lens system 114. Here, a case is considered where the substrate W has moved in the minus direction (downward in the figure) by ΔZ1 with respect to the reference position as the imaging plane of the projection optical system PL. The solid line on the surface of the substrate W in FIG. 5 is a reference position.
The position of the image on the light receiving slit 126 does not change. Z
The axial direction is the normal direction of the reference plane of the present invention.

Next, assuming that the detection point 101 on the surface of the substrate W is shifted in the negative direction (downward) by ΔZ1 with respect to the reference plane, the principal ray L0 of the light hitting the detection point 101
Is a reflected light beam L2 passing through the optical path indicated by the dotted line in FIGS. Principal ray L2 reflected at detection point 101
Is the reference light L indicated by the solid line in the first mirror 116.
The light is reflected below 1 and enters the relay lens 201. That is, as the detection point 101 moves in the Z minus direction, the principal ray L2 is closer to the substrate W than the reference ray (the re-irradiation optical system (116, 201 to 206, 1
17) into one of the re-irradiation optical systems (116, 201 to 206, 117) divided into two by a predetermined surface including the optical axis Ax. Next, the principal ray L2 intersects (intersects with a predetermined plane) the optical axis Ax at the pupil position P1 of the relay lens 201, and thereafter is reflected by the second mirror 203 via the relay lens 202, and is formed at an intermediate image point. An image of the slit 112 is formed on P.

Slit plate 11 formed at intermediate imaging point P
The principal ray L2 from the second slit image is
At the pupil position P2 of the relay lens 205, intersects (intersects with a predetermined plane) at the pupil position P2, and thereafter, is reflected by the fourth mirror 117 via the relay lens 206 and guided to the detection point 102. I will

Here, assuming that the detection point 102 on the surface of the substrate W is shifted from the reference plane in the plus direction (upward) by ΔZ2, the re-irradiation optical system (116, 201 to 20)
6 and 117), the principal ray L2 emitted from FIGS.
Is a light ray L3 indicated by a two-dot chain line. The principal ray L3 reflected from the detection point 102 is transmitted to the light receiving objective lens system 1
Each of the detection points (101, 10
The displacement of the received light corresponding to the difference in displacement of the test surface along the normal direction of the reference surface in 2) can be formed.

Here, the predetermined surface shown in the examples of FIGS. 4 and 5 corresponds to the first surface when the surface to be detected coincides with the reference position.
The deflection point R1, on the first mirror 116, of the principal ray L1 traveling along the optical axis Ax of the relay lens group (201, 202),
Deflection point R on the second mirror 203 of the principal ray L1 traveling along the optical axis Ax of the first relay lens group (201, 202)
2. Optical axis Ax of the second relay lens group (205, 206)
Deflection point R3 of the principal ray L1 traveling along the third mirror 204 on the third mirror 204, and deflection of the principal ray L1 traveling along the optical axis Ax of the second relay lens group (205, 206) on the fourth mirror 117. This is a plane formed by four points, point R4. Therefore, the predetermined surface shown in FIG.
6, 201-206, and 117), and is a plane orthogonal to the plane of FIG.

For this reason, as shown in FIG. 5, the predetermined surface referred to in the present invention is such that when the surface to be detected is displaced by ΔZ1 or ΔZ2 in the normal direction (Z direction) of the reference surface with respect to the reference surface. ,
The principal plane L0 of the light beam incident toward the first detection point (detection point 101) on the reference plane with respect to the principal ray L0 of the light beam (the principal ray L0 incident on the test surface indicated by the solid line) and the principal ray L0 The plane is formed so as to include the normal line (Z direction) of the reference plane at the intersecting position, that is, perpendicular to the plane of the drawing (that is, the paper surface of FIG. 5).

Therefore, the re-irradiation optical system (116, 201 to 206, 117) shown in FIGS. 4 and 5 is used when the test surface is displaced by ΔZ in the normal direction (Z direction) of the reference surface.
A predetermined plane that is orthogonal to the plane of incidence on the reference plane for the principal ray L0 of the light beam incident on the first detection point 101 and that includes the optical axis Ax of the re-irradiation optical system (116, 201 to 206, 117) Re-irradiation optical system (116, 2
01-206, 117), the principal ray L2 from the first detection point 101 incident on one part of the re-irradiation optical system (15-18) is bisected by its predetermined surface. From the second detection point 102
It leads to the configuration.

The re-irradiation optical system (116, 201)
206 to 117), the displacement of the received light corresponding to the difference in displacement of the test surface along the normal direction of the reference surface at each detection point is formed on the light receiving surface (light receiving slit plate 126). be able to.

Here, the relay lens 201 and the relay lens 202 are preferably arranged so as to be telecentric on both sides. By doing so, the relay lens 20
This is because the lens system 2 and the subsequent lens system are relatively compact.

Further, the magnification need not be equal in each relay lens group, but may be any magnification. After all,
It is sufficient that the magnification is set so as to be equal between the detection points 101 and 102.

Here, the relay lenses 205 and 206 do not need to be arranged so as to be telecentric on both sides, but are preferably telecentric as described above. As described above, the magnification is set to a magnification that is equal between the detection points 101 and 102.

Here, it is desirable that the incident angle (or the reflection angle) on the detection point 101 side and the incident angle (or the reflection angle) on the detection point 102 side be the same, so that the detection point 101 side and the detection point 102 side Is preferably telecentric.

As shown in FIGS. 4 and 5, the principal ray L2 is the first detection point (detection point 101) of the present invention.
And the re-irradiation optical system (116, 201-206,
117) The principal ray L2 incident on one part (on the side of the dotted optical path in the drawing) of the re-irradiation optical system which is bisected by the predetermined plane including the optical axis Ax is bisected by the predetermined plane. The light is emitted from the same side of the re-irradiation optical system as described above and guided to a second detection point (detection point 102). And the substrate W
Is shifted in the Z-axis direction (upward in the figure) by ΔZ2 at the detection point 102, the principal ray L3 advances as shown by a two-dot chain line in the figure and enters the light receiving objective lens system 123. Further, the light beam L3 passing through the objective lens system 123 is reflected by the mirror 124 and is imaged on the light receiving slit 126 at a position deviated from the reference position by Δ. FIG.
An aperture stop 125 is shown between the light receiving slit 126 and the light receiving slit 126.

Here, for example, the detection point 102 is also the detection point 10
Consider a case in which the reference position is shifted downward by ΔZ1 of the same amount as 1. In this case, as can be seen from FIG. 5, the principal ray L2 indicated by the dotted line follows the same optical path as the reference ray L1 indicated by the solid line in the AL detection optical system.
No change occurs in the position of the image of the slit 112 formed on the light receiving slit plate 126. That is, since the detection points 101 and 102 are displaced by the same amount, no inclination occurs after all, so that the position of the image of the slit 112 does not change.

As described above, the relay lens group A having the same magnification or the like is used.
LR1, ALR2 and mirrors 116, 117, 203, 2
By using 04, the height of the detection point 102 based on the detection point 101 can be detected.

That is, when viewed from the reference height, Δ is
It is determined by the following equation: Δ = 2 × sin θ × (ΔZ 1 −ΔZ 2) × β. Here, θ is the incident angle of the light beam, β is the detection point 102 of the light receiving objective lens system 123 and the light receiving slit 1
It is a magnification between 26. Is typically between 70 and 80
Degrees.

As described above, according to this embodiment, the height difference between two points can be obtained, so that the tilt component of the substrate W can be detected.

In FIG. 1, the focal point of the projection optical system PL is set by detecting the difference between the displacement of the detection point 101 and the displacement of the detection point 102 and the displacement of the detection point 100, and correcting the inclination of the surface. It becomes possible to do.

FIG. 6 shows another embodiment of the present invention. In the above embodiment, the detection points 100, 101, 102
However, since there are three points arranged on a straight line, the inclination of the surface in a direction orthogonal to the straight line cannot be set. However, in the embodiment shown in FIG. 6, in addition to the above-described surface tilt detection device, another surface tilt having detection points 104 and 105 in a direction orthogonal to a straight line connecting the detection points of the surface tilt detection device is provided. A detection device is arranged. Therefore, the four detection points 101, 102, 103, and 104 are arranged on the substrate W so as to be located at the vertices of a square, and the tilt angles of the substrate W in all directions can be obtained.

In this case, the points on the diagonal line of the square, that is, two points (101
And 102, 104 and 105), the substrate is tilted and controlled so that Δ becomes zero, the height is obtained at the center detection point 100, and the substrate is moved and controlled in the Z direction. The inclination of the substrate W can be corrected.

According to this configuration, the displacement of the detection point at the center of the shot or the difference between the displacements of the two points sandwiching the center of the shot can always be measured, so that the tilt component of the substrate W can be measured without delay. Can be detected.

FIG. 7 shows still another embodiment. This is an embodiment used when the detection field is relatively small, and is an embodiment in which the intermediate imaging position P of the relay system in the previous embodiment is not provided.

In the figure, a condenser lens 111 and a condenser lens 111 are provided in an optical path (parallel to the Z-axis) of illumination light from a light source 110A such as a halogen lamp.
A light transmitting slit plate 112 having a slit-shaped opening at a position where illumination is performed more uniformly, and a mirror 11 serving as a deflecting member
3 are arranged in this order. The mirror 113 transmits the light from the light transmission slit 112 to the detection point 101 on the surface of the substrate W.
A is obliquely incident on A. Mirror 1
13 and a detection point 101, a light transmitting objective lens system 11
4 are arranged so that the light transmitting slit plate 112 and the detection point 101 are conjugate. The illumination optical system of the present invention includes the above-described components from the condenser lens 111 to the light transmission objective lens system 114.

The longitudinal direction of the image of the slit at the detection point 101A is arranged so as to make an angle of, for example, 45 degrees with the vertical and horizontal linear directions of the pattern formed on the substrate W as in the previous embodiment. ing.

In the traveling direction of the light beam reflected at the detection point 101A, the relay lens 206 deflects the light beam ahead of the relay lens 206 in a direction perpendicular to the main light beam in the plane of incidence of the main light beam on the detection point 101A. A mirror 203A is disposed, and a mirror 204A is disposed at the top of the deflected mirror in the figure, and further deflects the optical axis in parallel with the optical axis of the relay lens 201, and deflects the light beam to the detection point 102A on the substrate. Is configured to be obliquely incident. A relay lens 206 is disposed between the mirror 204A and the detection point 102A, so that the detection point 101A and the detection point 102A are conjugate.

A light receiving objective lens system 123 and a deflecting mirror 124A are arranged in this order in the direction of the light reflected at the detection point 2, so that the optical path is deflected parallel to the Z axis. Behind the deflected optical path, a light receiving element 12 such as a CCD is provided.
8A is located at a position conjugate with the detection point 102 (when focused).

Also, the image of the slit 112 is
In A, the slit plate 112 is arranged so that the longitudinal direction is perpendicular to the optical axis, and the detection point 1
The components of the optical system described above are arranged such that the image of the slit at 02A is parallel to the image at the detection point 101A at intervals in the direction perpendicular to the longitudinal direction so that the longitudinal direction is parallel.

In this system, the slit plate 112, the light receiving element 128A, and the detection points 101A and 102A are arranged so as to satisfy the tilt relationship and the Scheimpflug condition.

In the present embodiment, the image sensor 128A is used as a light receiving element. However, similar to the previous embodiment,
A method of a photoelectric microscope using a vibrating mirror may be used.

In such a configuration, the image of the slit 112 of the slit plate illuminated by the light of the light source 110A through the condenser lens 111 is converted to a deflecting mirror 113.
Then, the light obliquely enters the detection point 101A via the light transmission objective lens system 114, and is imaged at that point.

The light reflected at the detection point 101A is reflected by the mirrors 203 and 204 via the relay lens 201, and again via the relay lens 206.
A is re-imaged on A.

Here, the relay lens is an equal-magnification relay lens, and is arranged so that the detection point 101A and the detection point 102A are telecentric on both sides. The light reflected at the detection point 102A passes through a light-receiving objective lens system 123 to an image sensor 1 such as a CCD, a line sensor, or a TDI.
An image is formed on 28A. By detecting the position of the image of the slit 112 with the image sensor 128A, the detection point 101 is detected.
The difference between the displacement of A and the detection point 102A in the Z-axis direction is detected.

With such an arrangement, a great advantage is obtained in the design space. Figure 6 shows such a system.
By arranging a plurality of pieces as shown in (1), it is possible to obtain the height difference between two diagonal points, obtain the inclination angle of the substrate W, and correct it.

Of course, if there is an advantage in arrangement, both AL systems as shown in FIGS. 7 and 4 may be arranged in one apparatus. Further, in the present embodiment, the image pickup device 128A is used as a light receiving device, but as described above,
A method of a photoelectric microscope using a vibrating mirror may be used.

Next, another embodiment will be described with reference to FIGS. In the present embodiment, the first detection point and the second detection point of the present invention each include a plurality of detection points. The displacement of the test surface at the plurality of detection points at the first and second detection points is added by the auxiliary re-irradiation optical system, and the difference between the added values can be obtained. . Therefore, since the inclination of the test surface is obtained using the average of the displacements of the plurality of detection points,
The displacement detection error due to local conditions at each detection location is reduced.

The surface displacement detecting device shown in FIG.
A light transmitting slit plate 312 having a slit-shaped opening at a position where the light is uniformly illuminated using light from a light source (not shown) as in the device described with reference to FIG.
13 are arranged in this order in the Z-axis direction. Mirror 3
Reference numeral 14 is inclined so that light from the light transmitting slit plate 312 is obliquely incident on a detection point 301 on the surface of the substrate W. Between the mirror 313 and the detection point 301, a light transmission objective lens system 314 is connected to the light transmission slit plate 312 and the detection point 3.
And 01 are conjugated.

In the traveling direction of the light beam reflected at the detection point 301, the detection point 301 is opposed to the light transmission objective lens system 314.
The relay lens 315 is arranged so that
A mirror 316 for deflecting the optical axis of the relay lens 315 in a direction parallel to X ₁ and a mirror 317 for further deflecting the deflected optical axis toward the detection point 302 on the substrate W are arranged ahead of the mirror 317. Between the detection point 302, a relay lens 318 is arranged.

The detection point 301 and the detection point 302 are conjugate by the relay lens 315 and the relay lens 318.
The detection point 302 is defined such that the longitudinal direction of the slit image at the detection point 302 matches the longitudinal direction of the slit image at the detection point 301.

Further, a relay lens 323 and a mirror 324 are arranged in this order in the traveling direction of the light beam reflected at the detection point 302.

In such a structure, an image is formed on the detection point 301 from the light transmitting slit plate 312 via the relay lens 314. The light reflected here forms a slit image again at the detection point 302 by the relay lens 315, the mirror 316, the mirror 317, and the relay lens 318. Further, the image of the slit reflected at the detection point 302 is emitted again via the relay lens 323 and the mirror 324.

Here, with reference to FIGS. 8 and 9, how the displacements of a plurality of detection points are optically added will be described. FIG. 8 shows the detection point of the first detection point as the detection point 30.
FIG. 3 is a perspective view when there are two points, 1 and a detection point 302.
FIG. 8 illustrates an optical system from the light-sending slit plate 312 to the mirror 324, and an arrow indicating a direction in which the light travels from the light-sending slit plate 312 to the mirror 324 is attached to the principal ray. . The solid line indicates a principal ray L1 traveling along the optical axis Ax of the optical system, and is referred to as a reference ray here. The two-dot chain line indicates the principal ray L2 that has shifted laterally from the reference ray.

Also, in FIGS. 8 and 9, the transmitted light (irradiated light) from the irradiation optical system (optical member from the light transmission slit plate 312 to the light transmission objective lens 314) is shown as a principal ray L0. I have. The auxiliary re-irradiation optical system shown in FIGS. 8 and 9 adds an amount of displacement between the detection point 301 and the detection point 302 by a predetermined amount.
15, 318) and two deflection members (316, 317).

FIG. 9 is a view taken along the line BB ′ of FIG.
An arrow is attached to the direction in which the light beam travels in correspondence with. The image of the light-sending slit 312 is formed by the light-sending objective lens system 314.
The process proceeds to form an image on the detection point 301 on the substrate W.

Here, in FIG. 9, the substrate W moves downward by ΔZ (in the direction normal to the reference plane of the present invention) (in the direction away from the projection optical system PL) with respect to the reference position (indicated by a dotted line). Consider the case. When the light is reflected at the reference position, the position of the slit image of the light transmitting slit plate 312 formed on the light receiving slit plate 326 does not change. next,
If the substrate W is shifted downward by ΔZ, the detection point 3
The light L0 hitting 01 (the position irradiated with light shifts to 301 ') is a light ray L2 indicated by a two-dot chain line in FIG. 8 and a solid line in FIG. The angle at which the light beam L1 is obliquely incident, and the angle θ between the light beam L1 and the optical axis of the projection optical system PL
Is typically about 70-80 degrees.

The light L2 is a space below the reference light L1 in the relay lens 315, that is, a space which is orthogonal to the incident surface of the reference light L1 on the reference surface and is bisected by a predetermined surface including the optical axis Ax of the relay lens 315. (Lower part in the figure), passes through it, intersects with the reference light beam L1 at the pupil position P1 of the relay lens 315, that is, intersects with the predetermined surface. Will also move upward. This light beam L2 is transmitted to the relay lens 318.
, The detection point 30 remains above the reference light beam L1.
2 (the position where the light is irradiated is shifted to 302 ′). The light ray L2 has been emitted to the other part divided by the predetermined surface.

The predetermined surface shown in the examples of FIGS. 8 and 9 is the detection point 301 when the surface to be detected coincides with the reference position, and the auxiliary relay optical system (315, 318) on the mirror 316.
Between the deflection point A of the optical axis Ax, the deflection point B of the optical axis Ax of the auxiliary relay optical system (315 to 318) on the mirror 317, and the detection point 302 when the surface to be measured coincides with the reference position. This is a plane formed by four points.

Therefore, the predetermined surface shown in FIG. 9 includes the optical axis Ax of the auxiliary relay optical system (314, 318).
Is a plane orthogonal to the paper surface of FIG.

Therefore, as shown in FIG. 9, the predetermined surface is such that the surface to be inspected is in the normal direction (Z
When the light beam is displaced by ΔZ in the direction (direction), the principal ray L0 of the light beam incident toward the detection point 310 on the reference surface with respect to the principal ray L0 (the principal ray L0 incident on the test surface indicated by the solid line) and the principal ray L0 Is normal to the reference plane at the position where
Direction), that is, the surface orthogonal to the surface formed in FIG.

As described above, the auxiliary re-irradiation optical system (315 to 318) shown in FIGS. 8 and 9 can be used when the test surface is displaced by ΔZ in the normal direction (Z direction) of the reference surface. The auxiliary re-irradiation optical system (315 to 545) is orthogonal to the incident plane on the reference plane with respect to the principal ray L0 of the light beam incident toward the detection point 301.
318) the principal ray L2 from the first detection point 301 incident on one part of the auxiliary re-irradiation optical system (315 to 318) divided by the predetermined plane including the optical axis Ax, Auxiliary re-irradiation optical system (315-3
18), the light is emitted from the other part and guided to the second detection point 302.

Such an auxiliary re-irradiation optical system (315 to 3
18), two detection points (301, 30)
The light receiving surface (light receiving slit plate 126) of the received light can be formed such that the displacement of the test surface along the normal direction of the reference surface in 2) is added by a predetermined amount.

In FIG. 9, the conversion amount Δ1 in the Z-axis direction at the detection point 302 differs depending on the magnification of the relay optical system, but becomes equal to ΔZ if the magnification is equal. Further, if the detection point 302 similarly shifts downward by ΔZ, the light beam L2 is added by this shift amount and enters the light receiving system objective lens 323.

If the magnification of the relay lens is not the same magnification, the deviation ΔZ of the detection point 1 is multiplied by the magnification of the optical system on the detection point 302 to be ΔZ × β. Is added to the relay lens 323
Moves in a plane conjugate to the detection point 302, which is equivalent to weighting the value of the detection point 301.

Further, the number of relay optical systems may be increased to detect three points on the substrate W.

FIG. 10 shows the light including the information of the sum of the displacements of the test surface at the detection points 301 and 302 when the number of the detection points is two as described above with reference to FIG. 2 shows an optical system combined with the system. The relay lens 323 shown in FIG. 8 corresponds to the relay lens 201 shown in FIG.

In FIG. 10, the mirror 116 is moved to the detection point 302.
Although it is installed between the relay lens 201 and the relay lens 201, it may be installed behind the relay lens 323 as in FIG. 8, that is, between the relay lens 201 and the relay lens 202 in FIG. Further, the mirror 116 (and the mirror 117)
Is for reducing the size of the apparatus, and is unnecessary in terms of function, and may be omitted.

FIG. 11 is a plan view of the apparatus of FIG. 10 as viewed from above in the normal direction of the substrate W. As shown in FIG. 11, two sets of surface displacement detection devices capable of detecting the sum of the displacements of two detection points are provided, one set of which is one vertex on the diagonal of the rectangular exposure field of the substrate. The other equation is provided to detect the sum of the displacements of the detection points 401 and 402 near the other vertex so as to detect the sum of the displacements of the nearby detection points 301 and 302.

That is, the detecting device shown in FIG. 11 includes an irradiation optical system (314) for irradiating the first detection point 301,
A first auxiliary re-irradiation optical system (31) for adding the sum of displacements at the second detection point 301 and the second detection point 302 to the detection light.
5 to 318), a re-irradiation optical system (ALR1, ALR2) for giving the difference in displacement between the second detection point 302 and the third detection point 401 to the detection light, and the third detection point 40
A second auxiliary re-irradiation optical system (415-418) for giving the sum of the displacement between the first and fourth detection points 402 to the detection light;
A detection optical system (123) for condensing the detection light from the fourth detection point 402 onto a predetermined light receiving surface (a light receiving slit plate 126 (not shown)).

In FIG. 11, the irradiation optical system is represented by the light transmission objective lens system 314, and the detection optical system is represented by the light reception objective lens system 123.

With such a configuration, the sum of the displacement of the test surface at the detection points 301 and 302 at the first detection point and the sum of the displacement of the test surface at the detection points 401 and 402 at the second detection point Is required. Therefore, local conditions at each detection point of one detection point are relaxed by averaging, and an accurate inclination of the surface to be detected is obtained.

In order to weight the first detection point 301 and the second detection point 302, the first auxiliary re-irradiation optical system (315 to 318) has two detection points (301, 301). The displacement of the received light along the normal direction of the reference surface at 302) is formed on the light receiving surface (the light receiving slit plate 126, not shown) such that the displacement of the received light is added by a predetermined amount. May be. Also, in order to weight the third detection point 401 and the fourth detection point 402, a second auxiliary re-irradiation optical system (415-418)
Is a light receiving surface (not shown light receiving slit) that adds a predetermined amount of displacement of the test surface along the normal direction of the reference surface at two detection points (401, 402). It may be configured to be formed on the plate 126).

As described above, the inclination of the photosensitive substrate W is detected by using the surface inclination detecting device according to each embodiment of the present invention, and based on the detected inclination (the amount of inclination, etc.) of the photosensitive substrate W. An exposure method (optical lithography process) that adjusts the inclination (the amount of inclination, etc.) of the photosensitive substrate W and exposes the pattern of the reticle R on the photosensitive substrate W via the projection optical system PL provides a high throughput. A good liquid crystal display device can be manufactured even under the condition. The present invention is not limited to manufacturing a liquid crystal display device by a photolithography process, but includes a display device such as a plasma display panel (PDP), a semiconductor device such as an LSI, a thin film magnetic head, and an imaging device such as a CCD. Can be manufactured.

When manufacturing a semiconductor device including a liquid crystal display device, the pattern of the reticle R is projected onto the projection optical system P.
Exposure step of exposing through L (optical lithography step)
Is not limited to being performed after the step of detecting the position of the photosensitive substrate W by the surface tilt detection device, but may be performed simultaneously with the step of detecting the position of the photosensitive substrate W by the surface tilt detection device. .

[0141]

As described above, according to the present invention, the difference between the displacement of the second detection point with respect to the first detection point is obtained optically by receiving one detection light. The inclination between them can be easily detected, and even when there are a plurality of inclination detection systems, each detection system can be independently detected without control by time division or the like, and the throughput can be improved. Further, by using the exposure apparatus provided with the above-described surface tilt detection device of the present invention, a good semiconductor device can be manufactured even under a high throughput.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a projection exposure apparatus according to an embodiment of the present invention, in which one set of a surface inclination detecting device and one set of an automatic focusing device are incorporated.

FIG. 2 is a plan view of the substrate shown in FIG. 1 from between the projection optical system and the substrate.

FIG. 3 is a side view in the direction of arrow AA in FIG. 1;

FIG. 4 is a perspective view of the surface displacement detection device according to the present invention, which shows the surface inclination detection device of FIG. 1 extracted.

FIG. 5 is a side view in the direction of arrow BB in FIG. 4;

FIG. 6 is a plan view of another embodiment of the present invention, in which a set of surface inclination detecting devices is added to the case of FIG. 2;

FIG. 7 is a side view of a surface inclination detecting device according to still another embodiment of the present invention.

FIG. 8 is a perspective view of a surface displacement detection device that can calculate a sum of displacements of detection points.

FIG. 9 is a side view in the direction of the arrow BB ′ in FIG. 8;

FIG. 10 is a perspective view showing a configuration of a surface inclination detecting device according to an embodiment of the present invention in which the surface displacement detecting device of FIG. 8 is incorporated.

11 is a schematic plan view of the apparatus of FIG.

[Explanation of symbols]

11, 111 Condenser lens 12, 112, 312 Light transmitting slit 14, 114, 314 Light transmitting objective lens system 15, 315 Light receiving system objective lens 16, 116, 117, 203, 204 Mirror 26, 126 Light receiving slit 29, 129 Mirror drive Device 51 Controller 100, 101, 102, 104, 105 Detection point 201, 202, 205, 206, 318 Relay lens 301, 302, 401, 402 Detection point P Intermediate imaging point P1, P2 Pupil ST XY stage STD XY stage drive Equipment W Substrate R Reticle PL Projection optical system

Claims (7)

[Claims] 1. A surface inclination detecting device for detecting an inclination of a test surface with respect to a predetermined reference surface;
An irradiation optical system for irradiating light toward the detection point; a re-irradiation optical system for guiding light reflected at the first detection point to a second detection point on the test surface; A detection optical system for condensing the light reflected from the second detection point on the light receiving surface; and a photoelectric detection unit for photoelectrically detecting the displacement of the received light on the light receiving surface; Surface tilt detector. 2. The re-irradiation optical system according to claim 1, wherein the displacement along the normal direction of the reference plane at the first detection point and the displacement along the normal direction of the reference plane at the second detection point. The surface inclination detecting device according to claim 1, wherein a displacement of the received light corresponding to a difference from the displacement is formed on the light receiving surface. 3. The re-irradiation optical system according to claim 1, wherein, when the test surface is displaced in the normal direction of the reference surface, the re-irradiation optical system includes a principal ray of a light beam incident on the first detection point on the reference surface. The principal ray incident on one portion of the re-irradiation optical system, which is orthogonal to the incident surface and is bisected by a predetermined surface including the optical axis of the re-irradiation optical system, is bisected by the predetermined surface. The surface inclination detecting device according to claim 1, wherein the device is configured to emit light from the one portion of the re-irradiation optical system and guide the light to the second detection point. 4. A re-irradiation optical system, comprising: a deflecting member for deflecting a light beam reflected at the first detection point to the second detection point; and a first detection point and the second detection point. And a relay optical system that substantially conjugates the following. 4. The surface inclination detecting device according to claim 1, wherein: 5. The irradiation optical system includes: a light transmitting slit plate having a predetermined pattern; and a light transmitting objective lens system for projecting the predetermined pattern onto the first detection point; Has a light-receiving slit plate disposed on the light-receiving surface, and a photoelectric detector that photoelectrically converts light passing through the light-receiving slit plate; the detection optical system is provided on the light-receiving surface. 5. The surface inclination detecting device according to claim 1, further comprising: a vibrating mirror that vibrates so that an image of the pattern crosses the light receiving slit plate. 6. 6. The apparatus according to claim 1, further comprising an arithmetic unit that calculates an inclination of the surface to be inspected based on an output from the photoelectric detection unit. Surface tilt detector. 7. A step of providing an exposure apparatus including the surface inclination detecting device according to claim 1, and a photosensitive substrate at a position of the surface to be detected of the surface inclination detecting device. Mounting the photosensitive substrate; detecting the inclination of the surface of the photosensitive substrate by the surface inclination detecting device; and determining the inclination of the photosensitive substrate based on the detected inclination information of the surface of the photosensitive substrate. Adjusting; and exposing the surface of the photosensitive substrate to light; a method for manufacturing a semiconductor device.