JP2002334827A - Surface position detector, exposure system and manufacturing method for micro-device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface-place detector in which constitution is simplified while deterioration of detection accuracy can be prevented and which can detect a surface place with high accuracy extending, over the whole surface of the detection region of a wide range. SOLUTION: An incident end 18a of an optical fiber 18 is arranged in the pupil space of a photoreceptive optical system 10b, which has the optical fiber 18 in which luminous flux emitted from an outgoing end 18b, in response to the angle of incidence of luminous flux projected to an incident end 18a is divided, so as to have a fixed relation and in which the quantity of the positional displacement of a surface WS of a wafer W to the imaging surface of a projection optical system PL is converted into variation amount of the angle of luminous flux.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a surface position detecting device,
The present invention relates to an exposure apparatus and a method for manufacturing a micro device. In particular, when manufacturing a semiconductor device, a liquid crystal display device, an imaging device, a thin film magnetic head, and other micro devices by a lithography process, a surface of a substrate on which various micro devices are formed. The present invention relates to a surface position detection device that detects a position of a substrate surface in a direction perpendicular to a substrate, an exposure device including the surface position detection device, and a microdevice manufacturing method using the exposure device.

[0002]

2. Description of the Related Art Semiconductor devices, liquid crystal display devices, imaging devices,
In a photolithography process, which is one of the manufacturing processes of a thin-film magnetic head and other microdevices, an image of a pattern formed on a mask or a reticle (hereinafter, collectively referred to as a mask) is formed by a photolithography process. An exposure apparatus is used which transfers a wafer or a glass plate to which a photosensitive agent such as a resist is applied (hereinafter, these are collectively referred to as a substrate). When development processing is performed on the substrate on which the image of the pattern formed on the mask has been transferred,
A resist pattern according to the transferred pattern is formed on the substrate. Thereafter, various processes such as an etching process and a wiring forming process are performed on the substrate using the resist pattern formed on the substrate as a mask, and a process of forming a pattern corresponding to the mask pattern on the substrate is performed. The photosensitive agent is applied again on the upper surface of the substrate on which the pattern has been formed, and the above process is repeated several times to several tens of times.

As described above, in the photolithography process, an image of a pattern to be formed next is superimposed on a pattern already formed on a substrate and transferred. Therefore, in order to manufacture a device having an intended function, the reticle and the substrate must be aligned with high accuracy. In recent years, patterns have been miniaturized for higher density, lower power consumption, and the like, and accordingly, a high alignment accuracy of, for example, about several tenths to several tenths of the minimum line width is required. .

In addition, as the pattern image formed on the mask is transferred onto the substrate via the projection optical system with the miniaturization of the pattern, the surface of the substrate is accurately aligned with the image plane of the projection optical system. Need to be included. For this purpose, the exposure apparatus includes a surface position detecting device that detects the position of the substrate in the optical axis direction of the projection optical system. FIG. 20 is a side view showing a main configuration of a conventional surface position detecting device and a main configuration of an exposure apparatus related to the surface position detecting device. FIG. 21 is an optical system of the surface position detecting device shown in FIG. FIG. 4 is an optical path diagram showing that is bilateral telecentric. Incidentally, of the members shown in FIG.
The same members as those shown in FIG. In FIG. 20, reference numeral 100 denotes an illumination optical system that includes a light source such as an ArF excimer laser (wavelength: 193 nm) and emits illumination light IL that irradiates the reticle R.

[0005] A pattern of a micro device is formed on the reticle R. When illumination light IL emitted from the illumination optical system 100 is irradiated, an image of the pattern formed on the reticle R is projected on the projection optical system PL. Is transferred to the wafer W via The wafer W is held by suction on a wafer holder 101, and the wafer holder 101 is
Are supported at three support points 103a to 103c provided in the. The wafer stage 102 has an optical axis A of the projection optical system PL.
By tilting the support points 103a to 103c in the X direction by the same ratio to set the surface position of the wafer W, and by tilting the support points 103a to 103c independently of each other, tilting the surface of the wafer W with respect to the optical axis AX. (Leveling).

Reference numeral 110 denotes a surface position detecting device,
An irradiation optical system 110a for irradiating the detection light DL from an oblique direction with respect to the wafer W, and light obtained by irradiating the wafer W with the detection light DL is received and formed into an image on a photoelectric conversion element 123 such as a silicon photodiode. It has a light receiving optical system 110b and a detection system 131 that detects the position of the surface of the wafer W in the optical axis AX direction based on the output signal of the photoelectric conversion element 123. The irradiation optical system 110a includes a light source 111 that supplies white light having a wide wavelength range, such as a halogen lamp.
The light from the light source 111 is converted into a substantially parallel light beam by the condenser lens 112 and enters the deflection prism 113. The deflection prism 113 deflects the substantially parallel light beam from the condenser lens 112 by refracting it.

On the exit surface of the deflecting prism 113, there is provided a light-transmitting-side pattern plate 113a composed of a stripe pattern extending in a direction perpendicular to the plane of the drawing. The light-transmitting-side pattern plate 113a is a transmission-type lattice pattern plate, and is arranged such that a lattice pattern forming surface on which transmission portions and light-shielding portions are alternately provided is on the wafer W side. The light transmitted through the light-transmitting side pattern plate 113a is condensed by the condenser lens 114 and the reflection plate 1
15 and the objective lens 116, the surface of the wafer W is irradiated as detection light DL from an oblique direction at an incident angle に 対 し て with respect to the optical axis AX of the projection optical system PL. The incident angle of the detection light DL is set to about 80 degrees. Here, FIG.
As shown in FIG. 1, the condenser lens 114 and the objective lens 11
6 is a so-called double-sided telecentric optical system, and the magnification of the conjugate point on the wafer W is the same as that of the grating pattern forming surface of the light transmitting side pattern plate 113a. Therefore, since the grid pattern forming surface of the light transmitting side pattern plate 113a has a grid pattern at regular intervals with the longitudinal direction perpendicular to the paper surface in FIG. 20, the image formed on the surface of the wafer W is: As shown in FIG. 22, the pattern becomes a grid pattern at regular intervals with the longitudinal direction set in the Y-axis direction.

FIG. 22 is a perspective view showing an image of the detection light DL formed on the surface of the wafer W. In FIG.
The circle with the symbol WS represents a part of the surface WS of the wafer W for convenience. Reference numeral DA denotes a detection area of the surface position detection device 100, and its shape is a rectangular shape. This detection area DA is set as an irradiation area of the illumination light IL on the wafer W. When the detection light DL is irradiated on the front surface WS of the wafer W via the objective optical system 116 provided in the irradiation optical system 110a, the images SL1 to SL5 of the lattice pattern of the light transmitting side pattern plate 113a are detected in the detection area DA. Form an image. In the example shown in FIG. 22, the image SL3 is formed substantially at the center of the detection area DA, and the images SL are formed at the four corners of the detection area DA.
1, SL2, SL4 and SL5 are imaged, respectively.

Returning to FIG. 20, the detection light DL applied to the surface of the wafer W is reflected by the surface of the wafer W, passes through the objective lens 117, and then enters the vibration mirror 118. The vibrating mirror 118 is driven by a mirror driving system 132,
20 oscillates at a predetermined period T around an axis perpendicular to the paper surface of FIG. 20, and deflects the light passing through the objective lens 117 in the paper surface of FIG. The light passing through the vibrating mirror 118 is incident on the light receiving side pattern plate 120 a formed on the incident surface of the tilt correction prism 120 via the condenser lens 119. The light-transmitting-side pattern plate 11 is provided on the light-receiving-side pattern plate 120a.
3a, a grating pattern similar to that of FIG. 3a is formed.
And forms an image on the photoelectric conversion element 123 via the relay lenses 121 and 122 in order. As shown in FIG. 21, the optical system including the objective lens 117 and the condenser lens 119 and the optical system including the relay lenses 121 and 122 are both side telecentric optical systems.

Further, the light transmitting side pattern plate 113a and the surface of the wafer W, the wafer W
The light receiving side pattern plate 120a, the light receiving side pattern plate 120a, and the photoelectric conversion element 123 are set so as to satisfy the Scheimpflug condition. Here, the conditions for Scheimpflug will be described. FIG. 23 is an explanatory diagram of Scheimpflug conditions. Now, consider the non-parallel A-plane and B-plane shown in FIG. Regarding an optical system that forms an image of a pattern on the surface A on the surface B, that the surface A and the surface B satisfy the Scheimpflug condition means that in the meridional section of the optical system,
If the intersection between the extension of the plane A and the object-side principal plane of the optical system is H, and the intersection of the extension of the plane B and the image-side principal plane of the optical system is H ', the light from the intersection H This means that the distance L to the axis is equal to the distance L 'from the intersection H' to the optical axis.

When the Scheimpflug condition is satisfied, a so-called tilt image relationship is established, and light emitted from an arbitrary point on the A surface is focused on a corresponding point on the B surface. I do. Accordingly, an image of a point on the entire surface on the surface A is formed on the surface B. Therefore, the image of the pattern formed on the light transmitting side pattern plate 113a is accurately formed over the entire surface of the wafer W, and the image of the surface of the wafer W is accurately formed over the entire light receiving side pattern plate 120a. The image of the light receiving side pattern plate 120a is further
The image is accurately formed over the entire detection surface.

Here, while the surface position detecting device having the above-described configuration performs the detecting operation, the vibrating mirror 118 is moved to the position shown in FIG.
It vibrates at a period T in the middle paper. Vibrating mirror 11
The light reflected on the surface of the wafer W due to the vibration of the wafer 8 vibrates with respect to the lattice pattern formed on the light receiving side pattern plate 120a. Is a vibrating mirror 1
It changes in synchronization with the vibration of 18. Therefore, the photoelectric conversion element 123 outputs to the detection system 131 an AC signal whose intensity changes with the oscillation cycle of the oscillation mirror 118. Further, an AC signal having the same cycle and phase as the oscillation cycle T of the oscillation mirror 118 is output from the mirror drive system 132 to the detection system 131, and the detection unit 131 is based on the principle of a so-called photoelectric microscope.
These input AC signals are synchronously detected and a detection output signal is output to main control system 130. This detection output signal is
This is called a so-called S-curve signal, and becomes zero level when the surface of the wafer W is located on the imaging plane of the projection optical system PL.

When the surface of the wafer W is displaced from the imaging plane of the projection optical system PL, the light receiving side pattern plate 120a of the light condensed by the objective lens 117 and the condensing lens 119 is used.
Since the center of vibration with respect to the lattice pattern formed in the photoelectric conversion element 123 changes, the cycle of the AC signal output from the photoelectric conversion element 123 changes. Therefore, when the wafer W is located above the image plane of the projection optical system PL, the detection output signal has a positive level, and when the wafer W is located below the image plane, it has a negative level. Becomes The main control system 130 controls the level of the detection output signal output from the detection system 131,
A control signal is output to the stage drive system 133 to drive the three support points 103a to 103c of the wafer stage 102 so that the surface of the wafer W matches the image plane of the projection optical system PL.

[0014]

As described above, the conventional surface position detecting apparatus 110 vibrates the light reflected on the surface of the wafer W with respect to the lattice pattern formed on the light receiving side pattern plate 120a. It is necessary to provide a scanning device such as a vibration mirror 118 or a polygon mirror for generating a light modulation signal in the light receiving optical system 110b. Since these scanning devices bend the optical axis of the light receiving optical system 110b, there is a problem that the arrangement of each optical member provided in the light receiving optical system 110b is restricted. Although the above-described scanning device may be configured to be provided in the projection optical system 110a,
A similar problem occurs in this configuration.

Further, a driving device for vibrating the vibration mirror 118 or rotating the polygon mirror is required to obtain the above-mentioned light modulation signal, but the vibration mirror 118 and the like are separated from the driving device. And remotely oscillating mirror 11
It is difficult to drive 8 and the like due to the device configuration. Therefore, although a driving device is usually arranged near the position where the oscillating mirror 118 is arranged, this driving device becomes an unnecessary heat source and causes fluctuations of the atmosphere or the like around the optical path to cause a fluctuation in the position of the surface of the wafer W. There is a possibility that the detection accuracy is deteriorated. It is conceivable to provide an exhaust device in order to prevent the influence of heat generation of the driving device. However, such a configuration causes an increase in size and complexity of the surface position detecting device 110, and furthermore, the exhaust device becomes an unnecessary vibration source. There is a fear.

Further, in order to obtain the above-mentioned light modulation signal by the conventional surface position detecting device 110, the light receiving side pattern plate 120a
Of the lattice pattern formed on the wafer W and the light reflected on the surface of the wafer W (reflected light of the images SL1 to SL5 in FIG. 23)
Must satisfy a specific relationship with the swing width. Specifically, the swing width must be half the width of the grid pattern. The wafer W is placed at the detection point where the images SL1 to SL5 are irradiated.
When the surface is roughened, the detection error of the surface position may be deteriorated due to a change in the amount of reflected light. Therefore, in order to prevent such a detection error, it is necessary to increase the irradiation area of the images SL1 to SL5 and average and mitigate the change in the amount of reflected light due to the roughness of the surface of the wafer W or the like. However, the width of the grating pattern is determined by the relationship with the swing width of the light reflected on the surface of the wafer W, and the interval between the grating patterns must be set to be larger than the swing width. Therefore, the size in the width direction of the lattice pattern that can be formed on the light receiving side pattern plate 120a is limited. In order to enlarge the irradiation area of the images SL1 to S15,
There is a problem that the length of the images SL1 to SL5 in the longitudinal direction can only be increased, and the detection points cannot be isotropically enlarged in the surface of the wafer W.

Further, when enlarging the entire detection area DA of the surface position detecting device 100, the angle of view (image height) of the detection area DA with respect to the irradiation optical system 110a and the light receiving optical system 110b becomes large. 110a and the light receiving optical system 110b, the detection area D
There is a disadvantage that an imaging characteristic equivalent to the imaging characteristic of the image SL3 at the center of A cannot be obtained at the periphery of the detection area DA. In particular, the detection light DL is applied to the surface WS of the wafer W.
When the detection area DA is to be enlarged in a direction perpendicular to the incident surface of the detection light DL with respect to the wafer W, the objective lenses 116, 117, etc. are enlarged by an amount corresponding to the enlargement. And the problem of aberration becomes significant.

The images SL1 to SL5 in the detection area DA
Deteriorates the imaging accuracy of the surface of the wafer W, so that a difference may occur between the detection accuracy in the central part of the detection area DA and the detection accuracy in the peripheral part. When the surface of the wafer W is adjusted to the image plane of the projection optical system PL based on the detection result, the center of the detection area DA matches the image plane of the projection optical system PL. A problem arises in that the peripheral portion is positioned while being defocused with respect to the imaging plane of the projection optical system PL.

If various aberration correction mechanisms are provided to avoid the above-mentioned problems and problems, the structure of the apparatus becomes complicated and the assembly process of the surface position detecting apparatus 100 becomes complicated. Further, as the device configuration and the manufacturing process become complicated, there is a concern that the assembling accuracy of the surface position detecting device 100 may be reduced. As a matter of course, there is a problem that a decrease in assembly accuracy causes a decrease in detection accuracy.

The present invention has been made in view of the above circumstances, and simplifies the configuration by eliminating a scanning device and a driving device conventionally required for detecting a surface position of a surface to be inspected. In addition, by eliminating the driving device, it is possible to prevent the detection accuracy from deteriorating due to the heat generated from the driving device, and by ensuring good imaging characteristics over the entire detection region over a wide range, A main object of the present invention is to provide a surface position detecting device capable of detecting a surface position with high accuracy over the entire detection area in a wide range.
Further, the present invention includes a surface position detecting device capable of detecting the surface position of the substrate with high accuracy, and performs accurate substrate alignment based on the highly accurate surface position detection result of the surface position detecting device. Another object of the present invention is to provide an exposure apparatus suitable for forming a fine pattern on a substrate. Still another object of the present invention is to provide a method for manufacturing a micro device manufactured by forming a fine pattern using the above exposure apparatus.

[0021]

In order to solve the above-mentioned problems, a surface position detecting device of the present invention provides an irradiation optical system for irradiating a detection surface (WS) with a detection light (DL) from an oblique direction. 10a), a light receiving optical system (10b) for receiving the detection light (DL) through the surface to be detected (WS), and a detection for photoelectrically detecting a light beam received by the light receiving optical system (10b). (20, 63a, 63c, 63d, 77) and a detection system (WS) for detecting the surface position of the surface to be detected (WS) based on the detection results of the detectors (20, 63a, 63c, 63d, 77). 31), the dividing means (18, 40, 50, 50) arranged in the pupil space of the light receiving optical system (10b) to divide the incident light beam.
61a, 61c, 61d, 75a, 75c, 75d) and the dividing means (18, 40, 50, 61a, 61).
c, 61d, 75a, 75c, 75d) are the dividing means (18, 40, 50, 61a, 61) of the incident light beam.
c, 61d, 75a, 75c, 75d) such that the split light flux has a predetermined relationship according to the incident angle to
It is characterized in that the incident light beam is split. In the present invention, the splitting means for splitting the light flux incident on the splitting means so as to have a predetermined relationship according to the incident angle of the light flux incident on the splitting means is arranged in the pupil space of the light receiving optical system. Here, the pupil space refers to a space to which a Fourier transform plane of an object plane or an image plane of the optical system belongs, or a space to which a position where position information on the object plane or the image plane is converted into angle information belongs. Therefore, when the detection light is applied to the surface to be measured from an oblique direction and the light beam passing through the surface to be detected is received by the light receiving optical system, the information on the position of the surface to be measured is converted into angle information in the pupil space of the light receiving optical system. Is converted. When this light beam enters the splitting means, it is split into a predetermined relationship according to the angle of incidence. Therefore, if the relationship between the split light beams is detected, angle information of the light beam incident on the splitting means is obtained. Since this angle information is obtained by converting information relating to the position of the surface to be measured, the angle information can be obtained from the angle information. Information about the position of the surface can be determined. As described above, according to the present invention, it is possible to obtain information on the position of the surface to be detected only by providing the dividing means in the pupil space of the light receiving optical system. Since no device is required, the configuration of the device can be extremely simplified, and the cost can be reduced. In addition, since the device configuration is simple, the manufacturing process of the surface position detection device can be simplified, and as a result, the assembly accuracy of the surface position detection device does not decrease. Further, conventionally, since a driving device was provided as a heat source, there was a possibility that the accuracy of detecting the position of the surface to be detected might be deteriorated by causing fluctuations of the atmosphere and the like around the optical path.
In the present invention, since the drive device is not required, the detection accuracy is not deteriorated, and the exhaust device for preventing the influence of heat generation is not required, so that the detection accuracy is not deteriorated due to the vibration. In addition, the surface position detecting device of the present invention may be configured such that the dividing means (18, 40, 50, 61a, 61c, 61)
d, 75a, 75c, 75d) split the incident light beam into at least two directions. Also,
In the surface position detecting device according to the present invention, the dividing means may be an optical fiber (18, 61a, 61c, 61d, 75a, 75c,
75d), and is preferably a cylindrical transmissive rod (41) or a quadrangular prism-shaped transmissive rod (43) having a semi-transmissive member (43c) formed at the incident end. According to these inventions, since the dividing means can be realized by various optical members, various device configurations can be obtained. In particular, when an optical fiber is used, the flexibility of the optical fiber makes it possible to increase the degree of freedom of the arrangement of the detector and the like, which is extremely suitable for miniaturizing the outer shape of the surface position detecting device. It is. In addition, the surface position detecting device of the present invention includes a plurality of dividing means (61a, 61c, 61d, 75a, 75a, 61a, 61c, 61d, and 75a) corresponding to each of a plurality of detection points in the irradiated area on the test surface (WS). 75c, 75d)
It is characterized by having. Further, in the surface position detecting device according to the present invention, the light receiving optical system (10b) is arranged such that a rear focal position is substantially equal to the splitting means (18, 40, 50, 61a, 6).
1c, 61d, 75a, 75c, 75d), a first focusing optical system (17, 73) for focusing a light beam from the surface to be measured (WS), and the splitting means (18). , 40, 50, 61a, 61c, 61d, 75
a, 75c, and 75d), and a second focusing optical system (19, 62a, 75b) that focuses the light beams split on the detection surfaces of the detectors (20, 63a, 63c, 63d, 77) in a predetermined relationship.
62c, 62d, 76, 85). Further, the surface position detecting device of the present invention may be configured such that the first
At least one of the focusing optical system (17, 73) and the second focusing optical system (19, 62a, 62c, 62d, 76, 85) is irradiated with the light on the surface to be measured (WS). It is characterized by having a plurality of focusing optical systems (73a to 73e) corresponding to each of a plurality of detection points in the area. According to the present invention, a plurality of focusing optical systems corresponding to each of a plurality of detection points on the surface to be detected are provided, and reflected light from each detection point is received by the corresponding focusing optical system. Can be reduced. As a result, the detection area irradiated with the detection light can be enlarged without causing the detection accuracy to deteriorate due to the influence of the aberration. Further, the surface position detecting device of the present invention is characterized in that the irradiation optical system (10a) projects an image of a predetermined pattern on the surface to be measured (WS). Further, in the surface position detecting device of the present invention, the irradiation optical system (10a) irradiates the test surface (WS) with one image of the predetermined pattern at a time, and the test surface (WS) It is preferable to include a switching unit (80) for switching the image of the pattern irradiated on the surface every time. Further, the surface position detecting device of the present invention is arranged such that the dividing means (18, 40, 50, 61a, 61c, 61d, 75
Preferably, at least one of the incident ends a, 75c, 75d) is arranged at a predetermined angle with respect to the incident light beam. Further, the surface position detection device of the present invention,
The detector (20, 63a, 63c, 63d, 77)
Is a position sensor or an image sensor. When the above-mentioned sensor is used as a detector, the detection system (31) includes the detector (20, 63).
a, 63c, 63d, 77) based on the detection results of the dividing means (18, 40, 50, 61a, 61c, 61).
d, 75a, 75c, 75d) to determine a relative position on the detection surface of the light beam divided by the detection surface (WS).
Or the detector (20, 63)
a, 63c, 63d, and 77) by performing a Fourier transform on the detection results to obtain a spatial frequency.
8, 40, 50, 61a, 61c, 61d, 75a, 7
5c, 75d), the relative position of the light beam split on the detection surface is obtained to detect the surface position of the test surface (WS). Further, the surface position detecting device of the present invention includes the detector (20, 63a, 63c, 63d,
77) is a sensor that sequentially scans the detection surface to obtain the detection result. When this sensor is used as a detector, the detection system (31) is configured so that the detector (20, 63a, 63c, 63
d, 77) based on the detection result.
40, 50, 61a, 61c, 61d, 75a, 75
c, 75d) to determine the relative position of the light flux on the detection surface to detect the surface position of the surface to be detected (WS), or to detect the time-varying detector (20, 63)
a, 63c, 63d, 77) by performing a Fourier transform on the detection results to obtain a time frequency.
8, 40, 50, 61a, 61c, 61d, 75a, 7
5c, 75d), the relative position of the light beam split on the detection surface is obtained to detect the surface position of the test surface (WS). In order to solve the above-mentioned problems, an exposure apparatus according to the present invention includes an exposure apparatus for transferring a pattern formed on a mask (R) to a substrate (W), wherein the substrate stage (3) holding the substrate (W) includes: A surface position detection device (10) for detecting a position of a surface (WS) of the substrate (W) as a position of the surface to be detected, and a detection result of the surface position detection device (10), An adjusting device (3, 4a-4) for adjusting at least one of a position and a posture of the substrate (W) on the substrate stage (3);
c, 30, 32). In order to solve the above problems, an exposure apparatus according to the present invention includes a surface position detection step of detecting a surface position of a surface (WS) of a substrate (W) using a surface position detection device (10) provided in the exposure device. A substrate (W) adjusting step of adjusting at least one of a position and a posture of the substrate (W) on the substrate stage (3) based on a detection result of the surface position detecting step; (R) to irradiate the mask (R)
A transfer step (S26) of transferring the image of the pattern formed on the substrate (W) to the substrate (W), and a developing step (S27) of developing the substrate (W) transferred in the transfer step. And

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a surface position detecting apparatus, an exposure apparatus, and a method for manufacturing a micro device according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG.
FIG. 1 is a front view illustrating a configuration of an exposure apparatus according to a first embodiment of the present invention including a surface position detecting device according to the first embodiment of the present invention. In the present embodiment, a case where an image of a pattern formed on a reticle R as a mask is transferred to a wafer W as a substrate by a step-and-scan method will be described as an example. In the following description, the XYZ rectangular coordinate system shown in FIG.
The positional relationship between the members will be described with reference to a rectangular coordinate system. The XYZ orthogonal coordinate system is set such that the X axis and the Y axis are parallel to the wafer stage 3 as the substrate stage, and the direction in which the Z axis is orthogonal to the wafer stage 3 (the optical axis AX of the projection optical system PL). (Parallel to direction). In the XYZ coordinate system in the figure, the XY plane is actually set to a plane parallel to the horizontal plane, and the Z axis is set vertically upward.

In FIG. 1, reference numeral 1 denotes a KrF excimer laser (wavelength: 248 nm) and an ArF excimer laser (wavelength:
193 nm), an illumination optical system equipped with a light source such as an F ₂ laser (wavelength: 157 nm). The illumination light IL to irradiate the light is emitted.
The light sources provided in the illumination optical system 1 include g-line (436 nm) and i-line (365 nm) emitted from an ultra-high pressure mercury lamp, a metal vapor laser light source, and a YAG laser harmonic generator. A pulsed light source can also be used.

A micro device pattern is formed on the reticle R. When illumination light IL emitted from the illumination optical system 1 is irradiated, an image of the pattern formed on the reticle R is projected on the projection optical system PL. Is transferred to the wafer W via The reticle R is held on a reticle stage (not shown), and is finely movable in the direction of the optical axis AX of the projection optical system PL.
Further, it is configured to be capable of two-dimensional movement and minute rotation in a plane perpendicular to the optical axis AX. The reticle stage is driven by a linear motor, and moves the reticle R in the X-axis direction in the figure in synchronization with the movement of the wafer stage 3. The position of the reticle stage in the XY plane is measured by a laser interferometer (not shown).

On the other hand, the wafer W is held by suction on the wafer holder 2, and the wafer holder 2 is supported by three support points 4 a to 4 c provided on the wafer stage 3. The wafer stage 3 projects and retracts the support points 4a to 4c by the same ratio in the direction of the optical axis AX of the projection optical system PL by the same ratio.
In addition to setting the position of S, the inclination (leveling) of the surface WS of the wafer W with respect to the optical axis AX is set by projecting and retracting the support points 4a to 4c independently of each other. The wafer stage 3 is driven by a linear motor similarly to the reticle stage, and can arbitrarily set the position of the wafer W in the XY plane, and can move the wafer W at a constant speed in the X-axis direction. . The position of wafer stage 3 in the XY plane is measured by a laser interferometer (not shown).

The outputs of the laser interferometer provided on the reticle stage and the laser interferometer provided on the wafer stage 3 are input to a main control system 30 which will be described later. Along with controlling the reticle stage, it outputs a control signal to the stage drive system 32 to control the position of the wafer stage 3 in the XY plane. Incidentally, the wafer stage 3 and the support points 4
a to 4c, the main control system 30, and the stage drive system 32
This corresponds to the adjusting device according to the present invention. Further, the projection optical system P
L is provided with a lens controller (not shown) for controlling optical characteristics such as imaging characteristics to be constant in response to environmental changes such as temperature and atmospheric pressure. The projection lens PL has an optical element such as a plurality of lenses, and the glass material of the optical element is selected from optical materials such as quartz and fluorite according to the wavelength of the illumination light IL. The magnification of the projection optical system PL may be not only a reduction system but also any one of an equal magnification and an enlargement system. However, the present embodiment is assumed to be a reduction system.

[Surface Position Detecting Apparatus According to First Embodiment] Next, the surface position detecting apparatus according to the first embodiment of the present invention provided in the exposure apparatus according to the first embodiment of the present invention will be described in detail. The surface position detection device 10 according to the first embodiment includes:
An irradiation optical system 10a that irradiates the wafer W with the detection light DL from an oblique direction, and a light-receiving element that receives light obtained by irradiating the wafer W with the detection light DL and receives the light.
And a detection system 31 as detection means for detecting the position of the surface WS of the wafer W in the optical axis AX direction based on the output signal of the photoelectric conversion element 20. In the present embodiment, the surface WS of the wafer W corresponds to the test surface according to the present invention. The photoelectric conversion element 20 is, for example, a position sensor that detects a light irradiation position in the detection surface 20a or an image sensor that converts an optical image formed on the detection surface 20a into an image signal. When an image sensor is used as the photoelectric conversion element 20, a CCD
(Charge Coupled Device) or the like is preferably used.

The irradiation optical system 10a includes a light source 11 for supplying white light having a wide wavelength range such as a halogen lamp, a condenser lens 12 for converting the light from the light source 11 into a substantially parallel light beam, and a substantially parallel light beam from the condenser lens 12. A deflection prism 13 having a pattern plate 13a on which a predetermined pattern is formed on an exit surface, a condenser lens 14 for condensing light passing through the deflection prism 13 and the pattern plate 13a, and a condenser lens, while being deflected by refraction. A reflection plate 15 for reflecting and deflecting the light condensed by the light source 14;
It has an objective lens 16 for irradiating as L. In the present embodiment, it is assumed that one small rectangular pinhole is formed in the pattern plate 13a as the predetermined pattern. The incident angle ψ of the detection light DL radiated from the irradiation optical system 10a to the wafer W with respect to the wafer W is set to about 80 degrees.

The optical system composed of the condenser lens 14 and the objective lens 16 is a so-called double-sided telecentric optical system. With the surface WS of the wafer W coincident with the imaging plane of the projection optical system PL, the pattern forming surface of the pattern plate 13a is arranged at a position optically conjugate with the surface WS of the wafer W or at or near the position. Therefore, the pattern formation surface of the pattern plate 13a and the conjugate point on the wafer W have the same magnification over the entire surface. Further, the surface WS of the wafer W is
In the optical system constituted by the condenser lens 14 and the objective lens 16, the surface WS of the wafer W and the pattern forming surface of the pattern plate 13a satisfy the Scheimpflug condition. Is set to Therefore,
The image of the pattern formed on the pattern plate 13a is
Is accurately formed over the entire surface WS. Incidentally, the wafer W
The image irradiated on the surface of the image corresponds to the image of the predetermined pattern in the present invention.

On the other hand, the light receiving optical system 10b is an objective lens 17 as a first converging optical system for converging the reflected light from the wafer W, and a dividing means in which the incident end 18a is arranged in a pupil space of the light receiving optical system 10b. And a condenser lens 19 as a second focusing optical system for focusing a light beam emitted from the emission end 18b of the optical fiber 18 on the detection surface 20b of the photoelectric conversion element 20. The objective lens 17
Is located at the front side of the projection optical system P
When the position coincides with the image plane of L, the detection light Dl is set at the center position of the image irradiated on the wafer W.

The optical fiber 18 has flexibility, and its incident end 18a is disposed in the pupil space of the light receiving optical system 10b as described above. It is preferable to be arranged at the position. Here, the pupil space generally refers to a space to which a Fourier transform plane of an object plane or an image plane of the optical system belongs, or a space to which a position at which position information on the object plane or the image plane is converted into angle information belongs. Say. Further, the incident end 18 of the optical fiber 18
a is disposed so as to be perpendicular to the optical axis AX1 of the light receiving optical system 10b. Thus, the incident end 18a of the optical fiber 18 is arranged at a position corresponding to the Fourier transform plane of the object plane including the object-side focal point of the objective lens 17. Note that the optical fiber 18 may use only one optical fiber or a bundle of a plurality of optical fibers.

The focal point of the condenser lens 19 is disposed at a position on the rear side within or near the detection surface 20 a of the photoelectric conversion element 20. Further, in the present embodiment, it is assumed that the emission end 18b of the optical fiber 18 and the detection surface 20a of the photoelectric conversion element 20 are arranged perpendicular to the optical axis AX2 of the light receiving optical system 10b. Here, the optical fiber 18
It is preferable that the exit end 18b is disposed at the front focal position of the condenser lens 19 or at a position in the vicinity thereof.

When the surface WS of the wafer W matches the image plane of the projection optical system PL, the light reflected by the surface WS of the wafer W is converted by the objective lens 17 into a substantially parallel light beam, and The light enters the optical fiber 18 from the vertical direction 18 a and propagates through the optical fiber 18. At this time, a light beam substantially parallel to the optical axis AX2 is emitted from the emission end 18b of the optical fiber 18. Exit end 18 of optical fiber 18
The light beam emitted from b is converged at a point on the detection surface 20 a of the photoelectric conversion element 20 via the condenser lens 19.

On the other hand, the surface WS of the wafer W is
The optical path of the reflected light in the light receiving optical system 10b when it does not match the image plane of L is as shown in FIGS. FIG. 2 is a diagram showing an optical path of reflected light in the light receiving optical system 10b when the wafer W is displaced from the image forming plane of the projection optical system PL, and FIG. 3 is a perspective view thereof. FIG.
In the figure, W1 indicates a wafer whose surface coincides with the image forming plane of the projection optical system PL, and the optical path in the light receiving optical system 10b of the reflected light of the surface of the wafer W obtained in this state. Is indicated by a broken line. In FIG. 3, the optical fiber 18 is shown in a simplified manner, and the optical axis AX2 is arranged coaxially with the optical axis AX1. When the surface WS of the wafer W matches the imaging plane of the projection optical system PL, the position shown in FIG. 3 is irradiated with the image SL0 of the pattern formed on the pattern plate 13a. The light receiving optical system 1
The optical axis AX1 of 0b is set to pass through the position where the image SL0 is irradiated. However, if the surface WS of the wafer W is shifted with respect to the image forming plane of the projection optical system PL, the pattern plate 1 is shifted to a position shifted from the irradiation position of the image SL0.
An image SL of the pattern formed on 3a is irradiated. As described above, when the surface WS of the wafer W is displaced from the imaging plane of the projection optical system PL, the reflected light from the surface WS of the wafer W passes through the optical path deviated from the optical axis AX1 and enters the objective lens 17. .

Since the reflected light enters the objective lens 17 via an optical path deviated from the optical axis AX1, the light flux passing through the objective lens 17 becomes a light beam having a certain angle with respect to the optical axis AX1. As described above, the incident end 18a of the optical fiber 18
Is arranged so as to be perpendicular to the optical axis AX1, the light beam passing through the lens 17 is incident on the optical fiber 18 at an incident angle corresponding to the amount of displacement of the wafer W. When the light beam enters the incident end 18a of the optical fiber 18 at a certain angle, the optical axis AX is output from the exit end 18b of the optical fiber 18.
A light beam split at a predetermined angle symmetrically with respect to 2 is emitted. Therefore, the emission end 18b of the optical fiber 18
Emits a light beam in a substantially conical shape. When this light beam is condensed by the condensing lens 19, the photoelectric conversion element 20
A circular image Im1 is formed on the detection surface 20a. The diameter of the image Im1 changes according to the amount of displacement of the position of the surface WS of the wafer W from the image forming plane of the projection optical system PL.

Next, the relationship between the amount of displacement of the wafer W and the diameter of the image Im1 formed on the detection surface 20a of the photoelectric conversion element 20 will be quantitatively described. FIG. 4 shows the amount of positional deviation of the wafer W and the image I formed on the detection surface 20 a of the photoelectric conversion element 20.
It is a figure for quantitatively explaining the relationship with m1 diameter. In FIG. 4, the optical fiber 18 is simplified and shown as in FIG. 3, and the optical axis AX2 is changed to the optical axis AX1.
And are arranged coaxially. Now, the surface WS of the wafer W is shifted downward by ΔZ from the imaging plane of the projection optical system PL (−
(Z-axis direction). If the optical path of the reflected light is shifted by Δd with respect to the optical axis AX1 of the light receiving optical system 10b when the detection light DL enters the surface WS of the wafer W in this state, the optical path of the reflected light from the optical axis AX1 Is expressed by the following equation (1). Δd = 2 · ΔZ · sinψ (1)

When the optical path of the reflected light is shifted from the optical axis AX1 by Δd and enters the objective lens 17, the change in the incident angle at the incident end 18a of the optical fiber 18 is represented by Δ
Assuming α, the change amount Δα of the incident angle is as follows (2)
It is expressed by an equation. Δα = tan ⁻¹ (Δd / f1) (2) where f1 is the image focal length of the objective lens 17.
When the change amount of the incident angle of the light beam incident on the incident end 18a of the optical fiber 18 is Δα, the change amount of the output angle of the light beam emitted from the output end 18b of the optical fiber 18 is Δα.
θ. The optical fiber 18 has a predetermined relationship (for example, one-to-one) with the change amount Δα of the incident angle of the light beam at the incident end 18a and the change amount Δθ of the exit angle of the light beam at the output end 18b.
The light beam incident from the incident end 18a is divided and emitted from the exit end 18b so as to satisfy the following relationship. Here, for the sake of simplicity, the description will be made assuming that the optical fiber 18 is an optical fiber that preserves the incident angle of the incident light beam. In this case, the change amount Δα of the incident angle and the change amount , The relationship of Δθ = Δα holds.

From the exit end 18b of the optical fiber 18, the light beam is split and emitted into a substantially conical shape having an apex angle of 2 · Δα. The condenser lens 19 has, for example, one of the projection characteristics shown by the following equations (3) to (5), and converts the light beam split and emitted from the emission end 18b of the optical fiber 18 into a predetermined light. Photoelectric conversion element 20
Is focused on the detection surface 20b. Y = f2 · Δθ (3) Y = f2 · sin (Δθ) (4) Y = f2 · cos (Δθ) (5) where f2 is the image focal length of the condenser lens 19. And
Y is an image I focused on the detection surface 20 a of the photoelectric conversion element 20.
m1 is the angle of view (image height) (corresponding to the distance from the optical axis AX2 in this embodiment).

As described above, since the circular image Im1 is formed on the detection surface of the photoelectric conversion element 20, this image Im1 is formed.
Assuming that the diameter of 1 is φ, the relationship φ = 2 · Y holds between the diameter φ of the image Im1 and the distance Y of the image Im1 from the optical axis AX2. In this way, the relationship between the displacement amount ΔZ of the wafer W and the diameter φ of the image Im1 formed on the detection surface 20a of the photoelectric conversion element 20 can be quantitatively determined. Therefore, if the diameter φ of the image Im1 formed on the detection surface 20a of the photoelectric conversion element 20 is known, the amount of displacement of the wafer W can be obtained.

Incidentally, in the diagram shown in FIG.
The case where the detection surface 20a is two-dimensional is illustrated, and if the photoelectric conversion element 20 having the two-dimensional detection surface 20a is used, the diameter φ of the image Im1 formed on the detection surface 20a can be easily detected. Can be. However, detection surface 2
If the position of the intersection of two points included in 0a and orthogonal to the optical axis AX2 and the circular image Im1 can be obtained, the diameter φ of the image Im1 can be detected. Therefore, in addition to the photoelectric conversion element 20 having the two-dimensional detection surface 20a shown in FIG. 3, a photoelectric conversion element having a one-dimensional detection surface orthogonal to the optical axis AX2 can be used.

Further, the image Im1 having a circular shape and a straight line included in the detection surface 20a and orthogonal to the optical axis AX2.
The diameter φ of the image Im1 can also be detected simply by detecting the position of one of the intersections on the detection surface 20a. In this case, when the surface WS of the wafer W matches the imaging plane of the projection optical system PL, the photoelectric conversion element 2
The position of the image formed on the zero detection surface 20a (this image is a point image) within the detection surface 20a is determined in advance as the origin. The diameter φ of the image Im1 can be obtained by doubling the distance between the position of the origin on the detection surface 20a and the position of the one intersection on the detection surface 20a.

The detection result of the photoelectric conversion element 20 is transmitted to the detection system 31.
Is output to The detection system 31 detects the diameter φ of the image formed on the detection surface 20a of the photoelectric conversion element 20 based on the detection result of the photoelectric conversion element 20, and obtains the wafer W with respect to the image forming plane of the projection optical system PL from the above-described relational expression. Amount of deviation WS of surface WS
Calculate Z. That is, the detection system 31 detects the relative position of the light beam split by the optical fiber 18 on the detection surface 20a to detect the surface position of the surface WS of the wafer W. The calculated shift amount ΔZ is transmitted from the detection system 31 to the main control system 3.
Output to 0. The main control system 30 outputs a control signal to the stage drive system 32 in accordance with the shift amount ΔZ output from the detection system 31, and the three support points 4 of the wafer stage 3
a to 4c are driven to align the surface WS of the wafer W with the image plane of the projection optical system PL.

According to the surface position detecting device according to the first embodiment of the present invention described above, the light beams emitted from the exit end 18b have a predetermined relationship according to the incident angle of the light beams incident on the incident end 18a. The optical fiber 18 is divided as described above, and the position shift amount of the surface WS of the wafer W with respect to the image forming plane of the projection optical system PL is converted into a change amount of the angle of the light beam. The incident end 18a of the fiber 18 is arranged. Therefore, the angle of incidence of the light beam incident on the incident end 18a of the optical fiber 18 can be obtained from the relationship between the light beams split and emitted from the emission end 18b, and the incident angle with respect to the image plane of the projection optical system PL can be determined from the incident angle. The shift amount of the surface of the wafer W can be obtained.

As shown in FIG. 20, the light reflected on the surface of the wafer W is conventionally formed on the light receiving side pattern plate 120a in order to detect the amount of deviation of the surface of the wafer from the image forming plane of the projection optical system. It is necessary to provide a scanning device such as a vibrating mirror 118 or a polygon mirror for generating an optical modulation signal by vibrating the generated grating pattern and a driving device for driving the scanning device in the light receiving optical system 110b. However, in the present embodiment, a scanning device and a driving device, which are conventionally required, are not required, and the light receiving optical system 10a includes only the objective lens 17, the optical fiber 18, and the condensing lens 19. The configuration can be extremely simplified and the cost can be reduced. In addition, since the device configuration is simple, the manufacturing process of the surface position detection device 10 can be simplified, and as a result, the assembly accuracy of the surface position detection device 10 does not decrease.

Further, conventionally, since a driving device as a heat source is provided, there is a possibility that fluctuations of the atmosphere around the optical path may be caused to deteriorate the detection accuracy of the position of the surface of the wafer W. Since the drive device is not required, the detection accuracy does not deteriorate, and an exhaust device for preventing the influence of heat generation is not required, so that the detection accuracy does not deteriorate due to vibration. Furthermore, in this embodiment, since the optical fiber 18 having flexibility is used,
The degree of freedom in the arrangement of the condenser lens 19 and the photoelectric conversion element 20 is high, which is extremely suitable for reducing the size of the surface position detection device 10.

[Surface Position Detecting Device According to Second Embodiment] Next, a surface position detecting device according to a second embodiment of the present invention will be described in detail. FIG. 5 is a front view showing a configuration of an exposure apparatus according to a second embodiment of the present invention including the surface position detecting device according to the second embodiment of the present invention. In FIG. 5, the same members as those of the surface position detecting device and the exposure device according to the first embodiment of the present invention shown in FIG. 1 are denoted by the same reference numerals. The surface position detecting device according to the second embodiment of the present invention shown in FIG. 5 differs from the surface position detecting device according to the first embodiment of the present invention shown in FIG. 1 in that the light provided in the light receiving optical system 10b is different. A transmission rod 40 is provided in place of the fiber 18, and an optical axis A of the light receiving optical system 10b is provided.
The point is that the condenser lens 19 and the photoelectric conversion element 20 are arranged so that X2 is coaxial with the optical axis 1.

The transparent rod 40 is made of a glass material such as quartz having a high transmittance over the wavelength range of the detection light DL. Since the transmissive rod 40 has high rigidity unlike the optical fiber 18 included in the surface position detecting device according to the first embodiment, it is disposed so that the optical axis AX2 of the light receiving optical system 10b is coaxial with the optical axis 1. . Permeable rod 4
The zero incident end 40a is arranged in the pupil space of the light receiving optical system 10b, and is arranged at the rear focal position of the objective lens 17 or at a position near the rear focal position. Also, the incident end 4 of the transmissive rod 40
0a is arranged so as to be orthogonal to the optical axis AX1, and the emission surface 40b is arranged so as to be orthogonal to the optical axis AX2. Note that the exit surface 40b of the transmissive rod 40 is preferably disposed at the front focal position of the condenser lens 19 or at a position in the vicinity thereof.

FIG. 6 is a perspective view showing an example of the shape of the transmission rod 40. FIG. 6A is a perspective view of a cylindrical transmissive rod 41 having a circular cross-sectional shape, and FIG. 6B is a perspective view of a rectangular rod-shaped transmissive rod 42 having a rectangular cross-sectional shape. When the transmitting rod 41 shown in FIG. 6A is used as the transmitting rod 40 in FIG. 5, when the surface WS of the wafer W matches the imaging plane of the projection optical system PL, The light beam passing through the objective lens 17 is perpendicularly incident on the incident end 41a of the transmissive rod 41, and the light beam emitted from the exit surface 41b is a light beam parallel to the optical axis AX2. Therefore, the image converged by the condenser lens 19 and formed on the detection surface 20a of the photoelectric conversion element 20 becomes a point image.

On the other hand, when the light beam enters the incident end 41a at a certain angle, it is split at an angle corresponding to the incident angle and emitted from the exit end 41b. At this time, since the cross section of the transmissive rod 41 is circular, the emitted light beam has a conical shape similarly to the light beam emitted from the emission end 18b of the optical fiber 18 of the first embodiment. Therefore, a circular image is formed on the detection surface 20a of the photoelectric conversion element 20. Therefore, if the diameter of the circular image formed on the detection surface 20b is detected, the amount of deviation of the surface WS of the wafer W from the imaging surface of the projection optical system PL can be obtained.

When the transmitting rod 42 shown in FIG. 6B is used as the transmitting rod 40 in FIG. 5, the surface WS of the wafer W matches the image forming plane of the projection optical system PL. Sometimes, the light beam passing through the objective lens 17 is
2 is perpendicularly incident on the incident end 42a of the
Is a light beam parallel to the optical axis AX2.
Therefore, the light is condensed by the condenser lens 19 and
The image formed on the detection surface 20a is a point image. As described above, when the light beam is vertically incident on the incident end of the transmissive rod 40, the image formed on the detection surface 20b of the photoelectric conversion element 20 is a point image regardless of the cross-sectional shape of the transmissive rod 40. Become.

When a light beam enters the incident end 42a at a certain angle, the incident light beam is reflected by the upper surface 42c and the lower surface 42d of the transmissive rod 42. Therefore, the light beam is emitted from the emission end 42b in one direction at an angle corresponding to the angle of incidence on the incidence end 42a. The light beam emitted from the emission end 42b is condensed by the condenser lens 19, and a point image or a short linear image is formed on the detection surface 20a of the photoelectric conversion element 20. When this permeable rod 42 is used, the wafer W
The position of the image formed on the detection surface 20a of the photoelectric conversion element 20 (this image is a point image) within the detection surface 20a when the surface WS of the projection optical system PL coincides with the imaging surface of the projection optical system PL is defined as the origin. If the distance between the origin and the formed point image or short linear image in the detection surface 20a is detected, the wafer W with respect to the image formation surface of the projection optical system PL is obtained.
Of the surface WS can be obtained.

FIG. 6C shows a half prism 4 at the incident end.
It is a perspective view of the transparent rod 43 provided with 3c and having a rectangular prism shape in cross section. In FIG. 6C, a half prism 43c as a semi-transmissive member is provided at the incident end 43a of the transmissive rod 43. Since the half prism 43c is arranged such that the division surface DV is perpendicular to the incident end 43a, the light beam incident perpendicular to the incident end 43a is not affected by the half prism 43c at all. However, when a light beam enters the incident end 43a at a certain angle, a part of the light beam is reflected by the division surface DV, and the remaining light beam passes through the division surface DV. Is done.

When the transmitting rod 43 shown in FIG. 6C is used as the transmitting rod 40 in FIG. 5, the surface WS of the wafer W matches the image forming plane of the projection optical system PL. Sometimes, the light beam passing through the objective lens 17 is
7, the light beam is not reflected in the transmission rod 43 and reaches the exit surface 43b as shown by a solid line in FIG. Therefore, the emission surface 42
The light beam emitted from b is a light beam parallel to the optical axis AX2. FIG. 7 is a diagram illustrating an optical path of a light beam propagating in the transmissive rod 43. Therefore, the image converged by the condenser lens 19 and formed on the detection surface 20a of the photoelectric conversion element 20 becomes a point image.

On the other hand, when a light beam enters the incident end 43a at a certain angle, as shown by a broken line in FIG.
Part of the incident light beam is divided by the split surface D of the half prism 43c.
The light is reflected by V, and the remainder is split by passing through the split surface DV. The split light flux is reflected by the upper surface 43d and the lower surface 43e of the transmissive rod 43, and propagates through the transmissive rod 43 via different optical paths. Therefore, from the exit end 43b, an angle corresponding to the incident angle of the incident end 43a is 2 °.
A light beam is emitted in the direction. The light beam emitted from the emission end 43b is condensed by the condensing lens 19 and becomes two point images or 2 points.
Two short linear images are formed on the detection surface 20 a of the photoelectric conversion element 20. If the distance between two point images or the distance between two short linear images formed on the detection surface 20a of the photoelectric conversion element 20 is detected, the wafer W with respect to the imaging surface of the projection optical system PL is detected.
Of the surface WS can be obtained.

When the transmitting rod 42 shown in FIG. 6B is used as the transmitting rod 40, photoelectric conversion is performed when the surface WS of the wafer W matches the imaging plane of the projection optical system PL. The position of the image formed on the detection surface 20a of the element 20 (this image is a point image) within the detection surface 20a is determined in advance as an origin, and one point image or one short line formed with the origin is formed. The shift amount of the surface WS of the wafer W has been obtained by detecting the distance between the shape image and the detection surface 20a. If this method is used, the position of the origin may fluctuate due to disturbance such as vibration, and thus a detection error may occur. However, when the permeable rod 43 shown in FIG. 6C is used as the permeable rod 40,
The distance between two point images or the distance between two short linear images formed on the detection surface 20a of the photoelectric conversion element 20 is detected, and the shift amount of the surface WS of the wafer W with respect to the imaging plane of the projection optical system PL is detected. Of the detection surface 20 due to disturbance such as vibration.
Even if a is displaced, a detection error hardly occurs.

As described above, according to the surface position detecting device according to the second embodiment of the present invention, similarly to the surface position detecting device according to the first embodiment, the configuration of the device can be extremely simplified, and the cost can be reduced. It can also be converted. Also,
Since the device configuration is simple, the manufacturing process of the surface position detection device 10 can also be simplified, and as a result, the assembly accuracy of the surface position detection device 10 does not decrease. Further, the detection accuracy is not deteriorated due to the fluctuation of the atmosphere or the like around the optical path, and an exhaust device for preventing the influence of heat generation is not required, so that the detection accuracy is not deteriorated due to the vibration.

[Surface Position Detecting Apparatus According to Third Embodiment] FIG. 8 is a front view showing the structure of an exposure apparatus according to a third embodiment of the present invention including a surface position detecting apparatus according to the third embodiment of the present invention. . In FIG. 8, the same members as those of the surface position detecting device and the exposure device according to the second embodiment of the present invention shown in FIG. 5 are denoted by the same reference numerals.
The surface position detecting device according to the third embodiment of the present invention shown in FIG. 8 differs from the surface position detecting device according to the second embodiment of the present invention shown in FIG. A half prism 50 is provided in place of the sex rod 40.

The entrance end of the half prism 50 is disposed in the pupil space of the light receiving optical system 10b, and the objective lens 17
Is located at or near the rear focal position. Further, at least the incident end of the half prism 50 has the optical axis AX.
1 are arranged orthogonal to each other. The half prism 50 is provided to split the light beam into two directions according to the incident angle of the light beam incident on the incident end. Although the half prism 43c is also provided at the incident end 43a of the transmissive rod 43 shown in FIGS. 6C and 7, the light beam is split into two directions according to the incident angle of the light beam incident on the incident end. For this purpose, only the half prism 50 is sufficient. The split surface of the half prism 50 is formed orthogonal to the incident end similarly to the split surface DV of the half prism 43c. Therefore, when the light beam is incident perpendicular to the incident end, the light beam passes through the half prism 50 without being divided,
The image condensed by the condenser lens 19 and formed on the detection surface 20a of the photoelectric conversion element 20 is a point image.

The wafer W with respect to the image plane of the projection optical system PL
Of the half prism 5 due to the displacement of the surface WS
When the light is incident on the incidence end at 0 at a certain angle, a part of the incident light beam is reflected by the split surface of the half prism 50, and the rest is split by transmitting through the split surface, and is divided according to the incident angle at the incident end. Light beams are emitted in two directions at angles. The emitted light flux is condensed by the condenser lens 19, and two point images are formed on the detection surface 20 a of the photoelectric conversion element 20. If the distance between the two point images formed on the detection surface 20a of the photoelectric conversion element 20 is detected, the shift amount of the surface WS of the wafer W with respect to the imaging plane of the projection optical system PL can be obtained. According to the present embodiment, the first embodiment and the second embodiment
The same effects as in the embodiment can be obtained.

[Modifications of Surface Position Detecting Apparatus According to First to Third Embodiments] Next, modifications of the surface position detecting apparatuses according to the first to third embodiments of the present invention will be described. FIG. 9 is a diagram for explaining a modification of the surface position detecting device according to the first to third embodiments. In any of the surface position detecting devices according to the first to third embodiments of the present invention described above, the surface WS of the wafer W is
When the optical axis AX2 coincides with the image plane of L, the optical fiber 18 (see FIG. 1), the transmitting rod 40 (see FIG. 5) and the half prism 50 (see FIG. Are emitted, and a point image is formed on the detection surface of the photoelectric conversion element 20. On the other hand, when the position of the surface WS of the wafer W is displaced with respect to the imaging plane of the projection optical system PL, for example, in the case of the first embodiment, the detection surface 20a of the photoelectric conversion element 20 The diameter φ of the formed image Im1 changes according to the amount of deviation of the surface WS of the wafer W from the image plane of the projection optical system PL.

Therefore, the position of the surface W of the wafer W and the image Im
The relationship between 1 and the diameter φ is as shown in FIG.
In FIG. 9A, the position where the position of the surface of the wafer W becomes 0 is a position where the surface of the wafer W coincides with the imaging plane of the projection optical system PL. As shown in FIG. 9A, when the position of the surface WS of the wafer W matches the imaging plane of the projection optical system PL, only one point image is formed on the detection surface 20a. The diameter of the image Im1 is minimized. And
The diameter of the image Im1 formed on the detection surface 20a increases as the amount of deviation of the position of the surface WS of the wafer W from the imaging plane of the projection optical system PL increases.

The position of the surface WS of the wafer W is determined by the projection optical system P
When it is shifted upward (+ Z-axis direction) by ΔZ with respect to the image plane of L, the magnitude of the incident angle of the light beam incident on the incident end of the optical fiber 18 and the image plane of the projection optical system PL When the light beam is shifted downward by ΔZ (−Z-axis direction), the incident angle of the light beam incident on the incident end of the optical fiber 18 becomes the same. Accordingly, in both cases, the diameter φ of the image Im1 formed on the detection surface 20a of the photoelectric detector 20 is the same. Although the amount of displacement of the surface WS can be determined, the wafer WS
It is impossible to determine whether the detection plane L is shifted upward or downward.

Therefore, the optical fiber 1 is moved with respect to the optical axis AX1.
Instead of being arranged so that the incident end 18a of the optical fiber 8 is vertical, as shown in FIG.
8b is arranged so as to form an angle δ with the optical axis AX1. The angle δ is appropriately set based on the detection range of the surface position detection device 10 (the range in which the amount of shift is detected). When the incident end 18a of the optical fiber 18 is arranged as shown in FIG.
Surface WS coincides with the image plane of projection optical system PL and optical axis A
Even when a light beam parallel to X1 is incident, the incident angle of this light beam with respect to the incident end 18a of the optical fiber 18 is δ, and therefore, as shown in FIG.
A circular image having a certain diameter Φ1 is formed on the detection surface 20a. Further, since the diameter of the image formed on the detection surface 20a changes not only by the amount of displacement of the projection optical system PL from the image formation surface but also by the direction of displacement of the wafer W, the diameter of the image changes on the detection surface 20a. The position of the surface W of the wafer W with respect to the projection optical system PL can be uniquely obtained from the diameter of the formed image. The matters described by taking the first embodiment as an example can be applied to the second embodiment and the third embodiment.

[Surface Position Detecting Device According to Fourth Embodiment] Next, a surface position detecting device according to a fourth embodiment of the present invention will be described in detail. FIG. 10 is a front view showing a configuration of an exposure apparatus according to a fourth embodiment of the present invention including the surface position detecting device according to the fourth embodiment of the present invention. In FIG. 10, the same members as those of the surface position detecting device and the exposure device according to the first embodiment of the present invention shown in FIG. 1 are denoted by the same reference numerals. The surface position detecting device according to the first embodiment of the present invention described with reference to FIG.
A rectangular pattern SL, SL0 is irradiated as a detection light DL at one point on the surface WS of the wafer W by arranging a pattern plate 13a in which minute rectangular pinholes are formed within 0a (FIG. 3). The surface position detecting apparatus according to the present embodiment is different from the surface position detecting apparatus according to the present embodiment in that a plurality of images are irradiated on the surface WS of the wafer W as detection light DL to set a plurality of detection points.

A plurality of images of the surface WS of the wafer W are detected by the detection light D
In order to irradiate the light as L, the surface position detection device of the present embodiment uses a pattern plate 13b in which rectangular transmission parts arranged in a grid are formed instead of the pattern plate 13a provided in the first embodiment. It is provided in the irradiation optical system 10a.
In the present embodiment, there are five patterns (light-transmitting portions) formed on the pattern plate 13b, and images of these patterns are formed as images SL1 to SL5 in the detection area DA shown in FIG. And

Further, in the first embodiment, the optical fiber 18 and the converging point are set in the light receiving optical system 10b with respect to one detection point (point irradiated with the rectangular image SL0) set on the surface WS of the wafer W. Although the optical lens 19 and the photoelectric conversion element 20 are provided, the present embodiment is different in that an optical fiber, a condenser lens, and a photoelectric conversion element as a dividing unit are provided for each of a plurality of detection points. The optical fiber 61a, the condenser lens 62a, and the photoelectric conversion element 63a shown in FIG.
Is provided for a detection point to which the image SL4 is irradiated, and includes a fiber 61c, a condenser lens 62c, and a photoelectric conversion element 6.
3c is provided for a detection point irradiated with the image SL3, and the fiber 61d, the condenser lens 62d, and the photoelectric conversion element 63d are provided for a detection point irradiated with the image SL1. In addition, the optical fiber, the condenser lens, and the photoelectric conversion element provided for the detection point irradiated with the image SL2 and the image SL5 are not shown.

The optical fibers 61a, 61c and 61d have the same function as the optical fiber 18 described in the first embodiment, and are provided for the same purpose as the optical fiber 18.
The condenser lenses 62a, 62c, and 62d are also provided for the same purpose as the condenser lens 19 described in the first embodiment, and the photoelectric detectors 63a, 63c, and 63d are similar to the photoelectric detector 20 of the first embodiment. It is provided for the purpose of. Also,
A fixed mirror 60 for bending the optical axis AX1 is provided in the light receiving optical system 10b of FIG. The fixed mirror 60 can be omitted when the optical axis AX1 does not need to be bent due to the configuration of the surface position detecting device 10.

When the surface WS of the wafer W coincides with the image plane of the projection optical system PL, the detection point at which the image SL3 is irradiated is set on the optical axis AX1 of the light receiving optical system 10b.
The incident end of the optical fiber 61c is disposed perpendicular to the optical axis AX1 bent by the fixed mirror 60. On the other hand, since the detection points irradiated with the images SL1, SL2, SL4, and SL5 are not arranged on the optical axis AX1 of the light receiving optical system 10b, the surface WS of the wafer W matches the image plane of the projection optical system PL. Also, the reflected light from these detection points
The light enters the objective lens 17 via an optical path outside X1, and forms an angle with the optical axis AX1 in the pupil space in the light receiving optical system 10b. This angle corresponds to the displacement of the detection point on the surface of the wafer W. Surface WS of wafer W
In order to eliminate a detection error caused by an angle in the pupil space that occurs in a state where is coincident with the imaging plane of the projection optical system PL,
The incident ends of the optical fibers 61a, 61d and the like other than the optical fiber 61c are arranged so as to be perpendicular to the traveling direction of the light beam having a certain angle with respect to the optical axis AX1.

If the surface WS of the wafer W does not match the projection optical system PL, a circular image having a diameter corresponding to the amount of displacement of each detection point is converted into a photoelectric conversion element 63a, 63.
C, 63, etc. are formed on the detection surface. Photoelectric conversion element 63
The detection results of a, 63c, 63, etc. are output to the detection system 31, and based on the detected diameter of each circular image, the amount of deviation from the imaging plane of the projection optical system PL at each detection point, and thus the wafer W The posture of the surface WS (such as the inclination with respect to the optical axis AX) is calculated. The calculated shift amount is output to the main control system 30. The main control system 30 outputs a control signal to the stage drive system 32 according to the shift amount of each detection point output from the detection system 31 to drive the three support points 4 a to 4 c of the wafer stage 3. By controlling at least one of the position or posture of the surface WS of the wafer W in the Z-axis direction, the surface WS of the wafer W is adjusted to the image plane of the projection optical system PL.

According to the surface position detecting device according to the fourth embodiment of the present invention described above, the structure of the device can be simplified and the wafer W can be formed in the same manner as the surface position detecting device according to the first embodiment. By setting a plurality of detection points on the front surface WS, it is possible to obtain the shift amounts at the plurality of detection points at once. Further, as in the first to third embodiments, the device configuration is simple, so that the manufacturing process of the surface position detecting device 10 can be simplified, and as a result, the assembling accuracy of the surface position detecting device 10 can be reduced. There is no drop. Furthermore,
The detection accuracy does not deteriorate due to the fluctuation of the atmosphere around the optical path, and the exhaust device for preventing the influence of heat generation is not required. Therefore, the detection accuracy does not deteriorate due to the vibration.

In this embodiment, the surface W of the wafer W is
In order to detect the position of S, the light reflected on the surface of the wafer W is vibrated with respect to the lattice pattern formed on the light receiving side pattern plate 120a (see FIG. 20) as in the related art, and the light modulation signal You don't need to get Therefore, since the degree of freedom of the pattern shape formed on the pattern plate 13b provided in the irradiation optical system 10a is high, the image S irradiated on each detection point is high.
The shapes of L1 to SL5 can be set more freely than before. As a result, the number of detection points in the surface of the wafer W can be isotropically increased, so that it is possible to prevent the detection error of the surface position from being deteriorated due to the roughness of the surface of the wafer W.

[Surface Position Detecting Apparatus According to Fifth Embodiment] FIG. 11 is a front view showing the configuration of an exposure apparatus according to a fifth embodiment of the present invention including a surface position detecting apparatus according to the fifth embodiment of the present invention. . In FIG. 11, the same members as those of the surface position detecting device and the exposure device according to the fourth embodiment of the present invention shown in FIG. 10 are denoted by the same reference numerals. The surface position detecting device according to the fourth embodiment of the present invention described with reference to FIG. 10 uses the condensing lens 14 and the objective lens 16 to convert the image of the pattern formed on the pattern This embodiment is different from the first embodiment in that a lens array 70 is provided instead of the condenser lens 14 and a lens array 72 is provided instead of the objective lens 16.

Lenses corresponding to the respective detection points set on the surface WS of the wafer W are formed on the lens arrays 70 and 72. That is, the lens array 70 is located between the pattern plate 13b and the reflection plate 15, and is formed with lenses so that each image of the pattern formed on the pattern plate 13b passes through each lens. Similarly, the lens array 72 is provided with lenses formed between the reflector 15 and the surface WS of the wafer W such that each image of the pattern formed on the pattern plate 13b passes through each lens. ing. Note that an optical path length correction member 71 for correcting the optical path length of each pattern image of the pattern plate 13b between the pattern plate 13b and the surface WS of the wafer W is provided between the reflection plate 15 and the lens array 72. Is provided. The optical path length correction member 71 is made of, for example, glass or the like, and the thickness thereof is set according to the difference in the optical path length of each image.

Further, in the surface position detecting device according to the fourth embodiment shown in FIG. 10, the reflected light from the surface WS of the wafer W is received by the objective lens 17, but in this embodiment, the objective lens is The difference is that a lens array 73 is provided instead of 17. The lens array 73 has a wafer W
(A plurality of focusing optical systems) corresponding to each of the detection points set on the surface WS. Also,
The optical axis of each lens formed in the lens array 73 is set to be parallel to the optical axis AX1, and is set so as to pass substantially the center of each of the detection points SL1 to SL5 set on the surface WS of the wafer W. .

FIG. 12 is a view showing a state in which an image is radiated onto the surface of the wafer W via the lens array 72, and the reflection from the surface of the wafer W is received by the lens array 73. In the example shown in FIG. 12, five lenses 72a to 72e are formed in a lattice shape in the lens array 72, and five lenses 73a to 73e are similarly formed in a lattice shape in the lens array 73. Also, as can be seen from FIG.
Lenses 72a to 72e formed in lens array 72 and lenses 73a to 73e formed in lens array 73
Are the detection points of the wafer W (in FIG. 12, the image SL1
(The center of the position where the image SL5 is irradiated). In FIG. 12, the lens array 7
The hatched portions other than the second lenses 72a to 72e and the hatched portions other than the lenses 73a to 73e of the lens array 73 are irradiated with the detection light DL when the detection points are set as illustrated. Or, it is a portion not used for receiving reflected light. Incidentally, a lens may be formed in these portions.

Returning to FIG. 11, in the present embodiment, optical fibers 75a, 75c, and 75d are provided instead of the optical fibers 61a, 61c, and 61d in FIG.
The difference is that a lens array 76 is provided instead of 62c and 62d, and a photoelectric conversion element 77 is provided instead of the photoelectric conversion elements 63a, 63c and 63d. The optical fiber 75a is at the detection point where the image SL1 is irradiated, the optical fiber 75c is at the detection point where the image SL3 is irradiated, and the optical fiber 75d is the image S.
L4 is provided corresponding to each of the detection points to be irradiated. In FIG. 11, the optical fibers provided for the detection points irradiated with the images SL2 and SL5 are not shown.

The basic functions of the optical fibers 75a, 75c and 75d are the same as those of the optical fibers 61a and 61 shown in FIG.
This is the same as 1c, 61d and the like. However, in this embodiment, the reflected light from each detection point set on the surface WS of the wafer W is received by each lens formed in the lens array 73, and the fourth embodiment shown in FIG. Unlike the above, when the surface WS of the wafer W coincides with the image plane of the projection optical system PL, the reflected light from each detection point is parallel to the optical axis AX1 in the pupil space, so that each optical fiber 75a, The incident ends of 75c, 75d, etc. are arranged so as to be orthogonal to the optical axes of the corresponding lenses formed in the lens array 73. In addition, between the lens array 73 and the incident surface of the optical fibers 75a, 75c, 75d, etc., each detection point set on the surface WS of the wafer W and the optical fiber 7
An optical path length correction member 74 for correcting the optical path length of the reflected light between the incident surfaces such as 5a, 75c, and 75d is provided. The optical path length correction member 74 is made of, for example, glass or the like, and its thickness is set according to the difference in the optical path length of each reflected light.

As in the lens array 73, lenses (a plurality of focusing optical systems) corresponding to the respective detection points set on the surface WS of the wafer W are formed in the lens array 76. Further, each lens formed in the lens array 76 is set so that its optical axis is balanced with each other. The emission ends of the optical fibers 75a, 75c, 75d and the like are arranged so as to be orthogonal to the optical axes of the lenses formed in the lens array 76. The photoelectric conversion element 77 is a position sensor that detects a light irradiation position on the detection surface 77a or an image sensor that converts an optical image formed on the detection surface 77a into an image signal, similarly to the photoelectric conversion element 20. The difference is that the surface 77a is divided into a plurality of detection regions corresponding to the respective detection points set on the front surface WS of the wafer W. That is, the aforementioned photoelectric conversion element 2
0a detects the position of the light incident on the detection surface 20a within the detection surface 20a.
The difference is that the position of the light incident on a in each detection area is detected. Each detection area provided in the detection surface 77 a of the photoelectric conversion element 77 is disposed at a rear focal position of each lens formed in the lens array 76.

The image of the pattern formed on the pattern plate 13b passes through the lens array 70 via different lenses, and further passes through the lens array 7 via different lenses.
Then, the light is irradiated to each of the detection points SL1 to SL5 on the wafer W after passing through the wafer W. Also, the reflected light from each detection point is converted to each detection point SL
The light passes through the lens array 73 via lenses provided corresponding to 1 to SL5, and further passes through optical fibers 75a, 75c, 75d provided for the respective detection points SL1 to SL5. Thereafter, the optical fibers 75a, 75c, 75
The light emitted from the emission end such as d is detected at each of the detection points SL1 to SL
The light is focused by passing through a lens array 76 via a lens provided corresponding to L5, and the photoelectric conversion element 77
An image is formed in each detection area provided on the detection surface 77a. The image formed in each detection area is a circular image whose diameter changes in accordance with the amount of misalignment of the surface WS of the wafer W with respect to the projection optical system PL. The photoelectric conversion element 77 detects the diameter of an image formed in each detection area and outputs a detection result to the detection system 31. The detection system 31 calculates a shift amount at each detection point based on the detection result output from the photoelectric conversion element 77. In the example shown in FIG. 11, an example in which both the micro lens arrays 73 and 76 are provided has been described.
One of these may be configured as the objective lens 17 or the condenser lens 19 shown in FIG.

According to the fifth embodiment of the present invention described above, the irradiation optical system 10a is provided with the lens arrays 70 and 72 in which a plurality of lenses are formed, and each of the detection points on the wafer W is irradiated. Each of the images SL1 to SL5 is a lens array 7
0 and 72 different lenses, so that the detection area is smaller than that of a conventional surface position detection apparatus that irradiates an image on the wafer W using the condenser lens 114 and the objective lens 116 (see FIG. 20). Image SL3 at central part of DA
And the imaging characteristics of the image in the peripheral portion can be made substantially the same. Further, in the present embodiment, a lens array 73 in which a plurality of lenses are formed in the light receiving optical system 10b.
Is provided so that the reflected light from each detection point passes through a different lens of the lens array 73, so that the influence of aberration can be reduced. As a result, the detection area D
A Detecting area D while ensuring good imaging characteristics over the entire surface
A can be enlarged, so that a wide detection area DA
The surface position can be detected with high accuracy over the entire surface.

According to the present embodiment, the irradiation optical system 1
Since it is not necessary to provide various aberration correction mechanisms for correcting the residual aberration of the light receiving optical system 10a and the light receiving optical system 10b, the apparatus configuration is simplified, and the assembly process of the surface position detection apparatus 10 is also simplified. As a result, the surface position detecting device 10
Of the assembling accuracy is not reduced, and the detection accuracy is not deteriorated. Further, similarly to the fourth embodiment, since the degree of freedom of the pattern shape formed on the pattern plate 13b is high,
The shapes of the images SL1 to SL5 irradiated to each detection point can be set more freely than before. As a result, the number of detection points in the surface of the wafer W can be isotropically increased, so that it is possible to prevent the detection error of the surface position from being deteriorated due to the roughness of the surface of the wafer W.

[Modifications of Surface Position Detecting Device According to Fourth and Fifth Embodiments] Next, modifications of the surface position detecting devices according to the fourth and fifth embodiments of the present invention will be described.
In the above-described fourth embodiment, the incident end of the optical fiber 61c is arranged so as to be perpendicular to the optical axis AX1 bent by the fixed mirror 60, and the optical fibers 61a, 61d and the like other than the optical fiber 61c are arranged. Is arranged such that its entrance end is perpendicular to the traveling direction of a light beam having an angle with respect to the optical axis AX1 in the pupil space of the light receiving optical system 10b. In the above-described fifth embodiment, the optical fibers 75a and 75a are perpendicular to the optical axis of each lens formed on the lens array 73.
c, 75d and other incident ends are arranged.

In the above arrangement, as shown with reference to FIG. 9, an upward (+)
It is possible to detect the amount of displacement of the projection optical system PL with respect to the imaging plane when it is displaced by the same amount in the Z-axis direction) or in the downward direction (-Z-axis direction). It cannot be detected. In order to solve this problem, the incident end of at least one optical fiber such as the optical fibers 61a, 61c, 61d or the optical fibers 75a, 75d.
The incident ends of at least one optical fiber such as c and 75d may be arranged so as to form a certain angle with respect to the optical axis or the traveling direction of the light beam as shown in FIG.

[Surface Position Detecting Apparatus According to Sixth Embodiment] FIG. 13 is a front view showing the structure of an exposure apparatus according to a sixth embodiment of the present invention including a surface position detecting apparatus according to the sixth embodiment of the present invention. . In FIG. 13, the same members as those of the surface position detecting device and the exposure device according to the first embodiment of the present invention shown in FIG. 1 are denoted by the same reference numerals. The surface position detecting device according to the sixth embodiment of the present invention shown in FIG. 13 is different from the surface position detecting device according to the first embodiment of the present invention shown in FIG. 1 in that a pattern plate 13c is used instead of the pattern plate 13a. The difference is that a rotating pattern plate 80 as switching means is provided between the pattern plate 13 and the condenser lens 14.

On the pattern plate 13c, three rectangular patterns (light transmitting portions) are formed in the direction along the X axis within the pattern forming surface. Therefore, images of this pattern are detected at three detection points set on the wafer W by the detection light DL.
Irradiated as The rotating pattern plate 80 includes a rotating shaft 81.
It is configured to be rotatable around. FIG. 14 is a top view of the rotating pattern plate 80. As shown in FIG. 14, a light shielding portion 82 is provided on the rotating pattern plate 80, and the rotating pattern plate 80
The openings 83 to 85 are formed so that the distance from the center varies depending on the rotation angle of. Each of the openings 83 to 85 is formed at a position where an image of a pattern formed on the pattern plate 13c passes. Therefore, the rotating pattern plate 80 transmits only one of the image of the pattern formed on the pattern plate 13c according to the rotation angle.

In the present embodiment, while detecting the position of the surface WS of the wafer W, only one pattern image is irradiated onto the surface WS of the wafer W at a time, and the rotating pattern plate 8
The image of the pattern is irradiated on different detection points according to the rotation angle of 0. Light reflected from different detection points enters the light receiving optical system 10b in a time-series manner. Objective lens 17
Is set so as to pass through any of the detection points. Therefore, even when the surface WS of the wafer W matches the imaging plane of the projection optical system PL, the optical axis AX1 is not The reflected light forms an angle with the optical axis AX1 in the pupil space of the light receiving optical system 10b. Therefore, the image formed on the detection surface of the photoelectric conversion device 20 changes in time series as shown in FIG.

FIG. 15 shows a detection surface 20a of the photoelectric conversion element 20 provided in the surface position detection device according to the sixth embodiment of the present invention.
FIG. 6 is a diagram showing a time-series change of an image formed in FIG. Now, in the surface WS of the wafer W, three detection points are X
The objective lens 17 is arranged at equal intervals in the axial direction.
It is assumed that the optical axis AX1 is set to pass through the center detection point. When the surface of the wafer W is coincident with the image plane of the projection optical system PL, the reflected light from the center detection point is perpendicularly incident on the incident end 18a of the optical fiber 18, but other detections are performed. Light reflected from the point enters the incident end 18a of the optical fiber 18 with the same incident angle.
Therefore, the image formed on the detection surface 20a of the photoelectric conversion element 20 changes in a time series as shown in FIG.
In FIG. 15, the image Im11 is due to the reflected light from the center detection point, and the images Im10 and Im12
Is due to the reflected light at each of the other detection points.

As shown in FIG. 15A, when the surface WS of the wafer W coincides with the detection surface of the projection optical system PL, the image Im11 becomes a point image. The diameter of the image Im10 and the diameter of the image Im12 due to the reflected light are the same. On the other hand, when the surface WS of the wafer W is displaced from the detection surface of the projection optical system, the detection surface 20
The image formed on a in FIG. 15 (b) or FIG.
It changes as shown in FIG. FIG. 15B shows that the surface of the wafer W is upward (+ Z) from the reference plane of the projection optical system PL.
FIG. 15C shows an image formed in time series on the detection surface 20b when the wafer W is shifted in the (axial direction), and FIG. 15C shows that the surface of the wafer W is downward (−Z axis) from the reference surface of the projection optical system PL. 2 shows an image formed in time series on the detection surface 20b when the image is shifted in the direction (i.e., direction). In FIGS. 15B and 15C, an image formed when the surface WS of the wafer W matches the detection surface of the projection optical system is shown by a broken line for comparison.

As shown in FIGS. 15B and 15C, the surface W of the wafer W with respect to the image forming plane of the projection optical system PL
If there is a displacement of S, the image Im11 due to the reflected light from the center detection point is not a point image but a circular image having a certain diameter. Further, the diameters of the images Im10 and Im12 due to the reflected light from the detection points other than the center detection point also change according to the positional shift amount of the wafer W, but the wafer W is shifted upward or shifted downward. The direction of the change (whether the diameter becomes larger or smaller) differs depending on whether or not the change is made. If the wafer W is shifted upward, the image Im
Although the diameter of the image Im12 increases as the diameter of the image 10 decreases, the reverse is true when the wafer W is shifted downward. Therefore, by detecting the magnitude relationship between the diameters of the images Im10 and Im12 due to the reflected light from the detection points other than the center detection point, is the wafer WS shifted upward with respect to the detection surface of the projection optical system PL? Alternatively, it can be determined whether the position is shifted downward.

In the sixth embodiment described above, only one of the detection points on the wafer W is irradiated with the pattern image by rotating the rotating pattern plate 80 provided in the irradiation optical system 10a. In addition, the detection point to which the image is radiated is temporally switched. However, the rotating pattern plate 8
Since it is necessary to provide a rotating device (not shown) for rotating 0, the rotating device may become an unnecessary vibration source or heat source, and the detection accuracy may be deteriorated. In order to prevent this deterioration in detection accuracy, a liquid crystal panel is provided in place of the rotating pattern plate 80, and only one of the images of the pattern formed on the pattern plate 13c is transmitted at a time, and It is preferable to perform driving for changing an image in time series. The positions of the rotating pattern plate 80 and the liquid crystal panel are determined by the pattern plate 13 a and the condenser lens 14.
The position is not limited to this, and may be any position as long as the optical path between the light source 11 and the surface WS of the wafer W can be arranged. Also, without disposing the rotating pattern plate 80 or the liquid crystal panel,
A plurality of light emitting diodes are provided as the light source 11 corresponding to each of the patterns formed on the pattern plate 13c, and by switching these light emitting diodes, only one of the detection points is irradiated with an image of the pattern, and time is reduced. Alternatively, the detection point to which the image is irradiated may be switched.
In the above embodiment, the wafer W
Although the case where three detection points are set has been described above as an example, the present invention can be applied to a case where five detection points are set in the same manner as in the fourth embodiment and the fifth embodiment. In this case, when the rotating pattern plate 80 is used,
In order to irradiate only one pattern image at a time on the surface WS of the wafer W and irradiate the pattern image to different detection points according to the rotation angle of the rotating pattern plate 80, the rotating pattern plate 80 It is necessary to appropriately change the opening to be formed in accordance with the position of the detection point.

According to the above-described surface position detecting device according to the sixth embodiment of the present invention, the configuration of the irradiation optical system 10a of the surface position detecting device according to the first embodiment of the present invention is changed only by a slight change. Without complicating the configuration of the light receiving optical system 10b, a plurality of detection points can be set on the surface WS of the wafer W, and the shift amounts at the plurality of detection points can be obtained at one time. Further, similarly to the first embodiment, the device configuration is simple, so that the manufacturing process of the surface position detection device 10 can be simplified, and the detection accuracy can be reduced without lowering the assembly accuracy of the surface position detection device 10. No deterioration occurs.

[Surface Position Detecting Device According to Another Embodiment] The surface position detecting device according to the first to sixth embodiments of the present invention and the modification of the surface position detecting device according to the first to fifth embodiments of the present invention. Although an example has been described, the above embodiments may be combined. For example, the optical fibers 61a, 61c, 61d used in the fourth embodiment (FIG. 10)
Optical fiber 75a used in the fifth embodiment,
75c and 75d (see FIG. 11) and the optical fiber 18 (see FIG. 13) used in the sixth embodiment,
The transmissive rod 40 used in the embodiment (see FIG. 5) or the half prism 50 used in the third embodiment (see FIG. 8)
Reference).

In the first to third and sixth embodiments, the optical fiber 18 (see FIGS. 1 and 13) is used.
), The light beam emitted from the exit end of the transmissive rod 40 (see FIG. 50) or the exit end of the half prism 50 (see FIG. 8) for focusing on the detection surface 20a of the photoelectric conversion element 20 in a predetermined relationship. In the fourth embodiment, as shown in FIG. 10, each of the optical fibers 61a, 61c,
The condensing lenses 62a, 62c, 62d, etc. are used to converge the light beams emitted from the light emitting devices 61d, etc. on the photoelectric conversion elements 63a, 63c, 63d, etc. in a predetermined relationship. , 62c, 6
A prism system may be used instead of 2d. As this prism system, a biprism 85 shown in FIG. 16 can be used. FIG. 16 is a diagram illustrating a configuration example using a biprism as the second focusing optical system. Biprism 85 shown in FIG. 16 is a prism 85 having the same apex angle.
a, 85b are attached to each other.

In each of the embodiments described above, the photoelectric conversion element 20, the photoelectric conversion elements 63a, 63c, 63d
Or an image Im formed on the detection surface of the photoelectric conversion element 77
1 is detected, and the amount of displacement of the wafer W with respect to the imaging plane of the projection optical system PL is determined based on the detection result. However, instead of directly obtaining the diameter Φ of the image Im1 from the detection result of the photoelectric conversion element 20 or the like, the diameter Φ of the image Im1 is obtained by performing Fourier transform on the detection result of the photoelectric conversion element 20 or the like and obtaining the spatial frequency of the image Im1. May be requested.

FIG. 17 is a diagram for explaining a process of obtaining the diameter Φ of the image Im1 formed on the detection surface 20a by performing Fourier transform on the detection result of the photoelectric conversion element 20. FIG.
As shown in (a), a circular image I is formed on the detection surface 20a.
Consider the case where m1 is formed. Now, FIG.
It is assumed that the signal intensity indicating the detection result along the line AA in (a) has three peak values as shown in FIG. In FIG. 17B, the positions P1, P2
Is assumed to be due to the image Im1, and the peak value of the signal intensity appearing at the position P3 is due to light other than the image Im1, such as stray light.

The photoelectric conversion element 2 as in the above-described embodiment
When the diameter Φ of the image Im1 is directly obtained from the detection result such as 0, the detection surface 10a of the image of the light beam incident on the detection surface 20a
From the relative position within Therefore, the image Im1
If there is any other light incident on the detection surface 20a, there is a possibility that, for example, the distance between the position P3 and the position P2 is erroneously detected as the diameter Φ of the image Im1. Here, it is assumed that the spatial frequency characteristic shown in FIG. 17C is obtained when the detection result of the photoelectric conversion element 20 shown in FIG. 17B is Fourier-transformed. In FIG. 17C, the spatial frequency ν1 is the spatial frequency related to the distance between the position P1 and the position P2, and the spatial frequency ν2
Is the spatial frequency related to the distance between the position P2 and the position P3, and the spatial frequency ν3 is the spatial frequency related to the distance between the position P1 and the position P3.

Normally, since the light intensity of stray light or the like is lower than the light intensity of the image Im1, the spatial frequencies ν2 and ν3 generated due to the peak value of the light intensity appearing at the position P3 in FIG.
Is smaller than the amplitude of the Fourier component of the spatial frequency ν1 caused by the peak values of the light intensity appearing at the positions P1 and P2. Therefore, erroneous detection can be prevented by comparing the amplitudes of Fourier components obtained by Fourier transforming the detection result of the photoelectric conversion element 20.

The photoelectric conversion element 20, the photoelectric conversion element 6
As 3a, 63c, 63d, or the like, or the photoelectric conversion element 77, a sensor that sequentially scans a detection surface and obtains a detection result can be used. As a method for scanning the detection surface, for example, a scanning member having a slit formed in front of the detection surface is arranged, and the scanning member is moved relatively to the detection surface for scanning. For example, the slit formed in the scanning member is shown in FIG.
Scanning is performed along the line AA shown in FIG. When such a sensor is used, a detection result that changes over time is output from the sensor. Therefore, the detection system 31 is formed on the detection surface from the difference in time when the signal intensity of the detection result becomes high by associating the detection result output from the sensor that changes with time and the position in the detection surface of the sensor. Image I
The diameter φ of m1 can be detected, and the amount of deviation of the surface WS of the wafer W from the imaging plane of the projection optical system PL can be determined based on the detection result.

In the case of using a sensor for sequentially detecting the above-described detection surface to obtain a detection result, the detection system 31 further performs Fourier transform on the detection result output from the sensor and changes over time to obtain a frequency characteristic. If the diameter Φ of the image Im1 is detected by comparing the amplitudes of the Fourier components obtained by Fourier transform, erroneous detection can be prevented even when light other than the image Im1 enters the detection surface 20a.

When the pattern formed on the reticle R is transferred to the wafer W using the exposure apparatus having the surface position detecting device of the embodiment described above, first, the reticle R on which the device pattern is formed is placed on a reticle stage (not shown). To adjust the position of the mask M. Next, a reference pattern formed on a reference member (not shown) formed on the wafer stage 3 and a mark (not shown) for position measurement formed on the reticle R are simultaneously observed through the projection optical system PL. The center (center of exposure) of the projected image of the device pattern formed on the reticle R is determined. After the wafer W is placed on the wafer holder 2, the position of the wafer W in the XY plane is measured using an alignment sensor (not shown), and the surface position detecting device 10 described above is used.
Is used to detect the position of the surface WS of the wafer W (surface position detecting step).

The detection result of the alignment sensor and the detection result of the surface position detecting device 10 are output to the main control system 30.
The main control system 30 moves the wafer W in the XY plane via the stage drive system 32 based on the detection result of the alignment sensor, and performs alignment of the partitioned area (shot area) set on the wafer W, Surface position detection device 10
Based on the detection result, at least one of the position of the surface WS of the wafer W in the Z-axis direction and the attitude of the wafer W is adjusted (substrate adjustment step). Then, while the illumination light IL is irradiating the reticle R, the main control system 30 synchronously moves the reticle stage and the wafer stage 3 to sequentially device patterns formed on the reticle R via the projection optical system PL. Transfer to the shot area of the wafer W (transfer step).

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be freely modified within the scope of the present invention. For example, in the above embodiment, the step-and-scan type exposure apparatus has been described as an example, but the present invention is also applicable to a step-and-repeat type exposure apparatus. The light source of the illumination optical system of the exposure apparatus according to the present embodiment includes g-line (436 nm), i-line (365 nm), and Kr emitted from an extra-high pressure mercury lamp.
Laser light emitted from an F excimer laser (248 nm), an ArF excimer laser (193 nm), or an F ₂ laser (157 nm) has been used. it can. For example,
When an electron beam is used, thermionic emission type lanthanum hexaborite (LaB ₆ ), tantalum (T
a) can be used.

Further, in the above embodiment, the images SL1 to SL illuminated on the surface WS of the wafer W from the surface position detecting device 10 are used.
Although the longitudinal direction of L5 is set in a direction parallel to the Y axis, the longitudinal direction is substantially 45 degrees with respect to the X axis direction and the Y axis direction.
It is preferable to irradiate an image forming a degree angle. Usually, since the pattern formed on the wafer W is mainly composed of vertical and horizontal straight lines perpendicular to each other, a pattern having a longitudinal direction in the X-axis direction and a pattern having a longitudinal direction in the Y-axis direction are formed on the wafer W. Are formed in large numbers. Here, by irradiating so that the longitudinal direction of the image to be irradiated does not coincide with such a vertical and horizontal linear direction,
Brightness and darkness due to the pattern and non-uniformity of the reflectance can be averaged to improve the detection accuracy of the surface position. Note that X
It is desirable that the angle between the axis and the axis is 45 degrees. However, 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 degrees, for example, 30 degrees or 60 degrees. There may be.

Next, an embodiment of a method of manufacturing a micro device using an exposure apparatus according to an embodiment of the present invention in a lithography process will be described. FIG. 18 shows a micro device (a semiconductor chip such as an IC or an LSI, a liquid crystal panel,
FIG. 9 is a diagram showing a flowchart of a manufacturing example of a CD, a thin-film magnetic head, a micromachine, and the like). As shown in FIG.
First, in step S10 (design step), a function / performance design of the micro device (for example, a circuit design of a semiconductor device) is performed, and a pattern design for realizing the function is performed. Subsequently, in step S11 (mask manufacturing step), a mask (reticle) on which the designed circuit pattern is formed is manufactured. On the other hand, step S
At 12 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.

Next, in step S13 (wafer processing step), using the mask and the wafer prepared in steps S10 to S12, an actual circuit or the like is formed on the wafer by lithography or the like as described later. . Next, in step S14 (device assembly step), device assembly is performed using the wafer processed in step S13. Step S14 includes, as necessary, steps such as a dicing step, a bonding step, and a packaging step (chip encapsulation).
Finally, in step S15 (inspection step), inspections such as an operation confirmation test and a durability test of the microdevice manufactured in step S14 are performed. After these steps, the microdevice is completed and shipped.

FIG. 19 is a diagram showing an example of a detailed flow of step S13 in FIG. 18 in the case of a semiconductor device. In FIG. 19, in step S21 (oxidation step), the surface of the wafer is oxidized. In step S22 (CVD step), an insulating film is formed on the wafer surface. Step S23 (electrode forming step)
In, electrodes are formed on a wafer by vapor deposition. In step S24 (ion implantation step), ions are implanted into the wafer. Each of the above-described steps S21 to S24 constitutes a pre-processing step in each stage of wafer processing, and is selected and executed according to a necessary process in each stage.

In each stage of the wafer process, when the above-mentioned pre-processing step is completed, the post-processing step is executed as follows. In this post-processing step, first, step S
In 25 (resist forming step), a photosensitive agent is applied to the wafer. Subsequently, in step S26 (exposure step: transfer step), the circuit pattern of the mask is transferred to the wafer by the lithography system (exposure apparatus) and the exposure method described above. Next, step S27
In the (development step: development step), the exposed wafer is developed, and in step S28 (etching step), the exposed members other than the part where the resist remains are removed by etching. And step S
In 29 (resist removing step), unnecessary resist after etching is removed. By repeating these pre-processing and post-processing steps, multiple circuit patterns are formed on the wafer.

If the microdevice manufacturing method of the present embodiment described above is used, the above-described exposure apparatus and the above-described exposure method are used in the exposure step (step S26), and the resolution is improved by the illumination light in the vacuum ultraviolet region. In addition, since the exposure amount can be controlled with high accuracy, a highly integrated device having a minimum line width of about 0.1 μm can be produced with a high yield.

In addition to a micro device such as a semiconductor device, a reticle or a mask used in an optical exposure apparatus, an EUV exposure apparatus, an X-ray exposure apparatus, an electron beam exposure apparatus, or the like is manufactured using a mother reticle. The present invention is also applicable to an exposure apparatus that transfers a circuit pattern to a glass substrate, a silicon wafer, or the like. Here, in an exposure apparatus using DUV (deep ultraviolet) or VUV (vacuum ultraviolet) light, a transmission reticle is generally used, and as a reticle substrate, quartz glass, fluorine-doped quartz glass, fluorite, Magnesium fluoride, quartz, or the like is used. In a proximity type X-ray exposure apparatus, electron beam exposure apparatus, or the like, a transmission mask (stencil mask, membrane mask) is used, and a silicon wafer or the like is used as a mask substrate. Such an exposure apparatus is described in WO99
No./34255, WO99 / 50712, WO99 /
66370, JP-A-11-194479, JP-A-2000-12453
And JP-A-2000-29202.

[0110]

As described above, according to the present invention, information relating to the position of the surface to be inspected can be obtained only by providing the pupil space of the light receiving optical system with the dividing means. Since the scanning device and the driving device which have been required become unnecessary, the configuration of the device can be extremely simplified, and the cost can be reduced. Further, since the device configuration is simple, the manufacturing process of the surface position detecting device can be simplified, and as a result, there is an effect that the assembly accuracy of the surface position detecting device is not reduced. Further, conventionally, a driving device as a heat source is provided, which may cause fluctuations of the atmosphere around the optical path, thereby deteriorating the detection accuracy of the position of the surface to be detected. However, this driving device is unnecessary in the present invention. Therefore, the detection accuracy does not deteriorate, and an exhaust device for preventing the influence of heat generation is not required. Therefore, there is an effect that the detection accuracy does not deteriorate due to vibration. According to the present invention,
Since the dividing means can be realized by various optical members, various device configurations can be adopted. Especially when an optical fiber is used, since the optical fiber has flexibility, the degree of freedom of arrangement of the detector and the like can be increased, which is extremely suitable for miniaturizing the outer shape of the surface position detecting device. There is an effect that is. Furthermore, according to the present invention, a plurality of focusing optical systems are provided in accordance with each of the plurality of detection points on the surface to be detected, and reflected light from each detection point is received by the corresponding focusing optical system. The influence of aberration can be reduced. As a result, without deteriorating the detection accuracy due to the influence of aberration,
There is an effect that the detection region irradiated with the detection light can be enlarged.

[Brief description of the drawings]

FIG. 1 is a front view showing a configuration of an exposure apparatus according to a first embodiment of the present invention including a surface position detecting device according to the first embodiment of the present invention.

FIG. 2 is a diagram illustrating an optical path of reflected light in a light receiving optical system when a wafer is displaced from an imaging plane of a projection optical system.

FIG. 3 is a perspective view showing an optical path of reflected light in the light receiving optical system 10b when the wafer W is displaced from an imaging plane of the projection optical system PL.

FIG. 4 is a diagram for quantitatively explaining a relationship between a positional shift amount of a wafer W and a diameter of an image Im1 formed on a detection surface 20a of the photoelectric conversion element 20.

FIG. 5 is a front view showing a configuration of an exposure apparatus according to a second embodiment of the present invention including a surface position detecting device according to the second embodiment of the present invention.

FIG. 6 is a perspective view showing an example of the shape of the permeable rod 40.

FIG. 7 is a diagram showing an optical path of a light beam propagating in a transmissive rod 43.

FIG. 8 is a front view illustrating a configuration of an exposure apparatus according to a third embodiment of the present invention including a surface position detecting device according to the third embodiment of the present invention.

FIG. 9 is a diagram for explaining a modification of the surface position detecting device according to the first to third embodiments.

FIG. 10 is a front view showing a configuration of an exposure apparatus according to a fourth embodiment of the present invention including a surface position detecting device according to the fourth embodiment of the present invention.

FIG. 11 is a front view illustrating a configuration of an exposure apparatus according to a fifth embodiment of the present invention including a surface position detecting device according to the fifth embodiment of the present invention.

FIG. 12 is a diagram illustrating a state in which an image is irradiated onto the surface of a wafer W via a lens array 72, and reflection from the surface of the wafer W is received by a lens array 73.

FIG. 13 is a front view showing a configuration of an exposure apparatus according to a sixth embodiment of the present invention including a surface position detecting device according to the sixth embodiment of the present invention.

14 is a top view of the rotating pattern plate 80. FIG.

FIG. 15 is a diagram showing a time-series change of an image formed on a detection surface 20a of a photoelectric conversion element 20 provided in a surface position detection device according to a sixth embodiment of the present invention.

FIG. 16 is a diagram illustrating a configuration example using a biprism as a second focusing optical system.

FIG. 17 is a diagram for describing a process of obtaining a diameter Φ of an image Im1 formed on a detection surface 20a by performing a Fourier transform on a detection result of the photoelectric conversion element 20.

FIG. 18 is a flowchart illustrating an example of a manufacturing process when manufacturing a micro device.

FIG. 19 is a diagram showing an example of a detailed flow of step S13 in FIG. 18 in the case of a semiconductor device.

FIG. 20 is a side view showing a main part configuration of a conventional surface position detection device and a main part configuration of an exposure apparatus related to the surface position detection device.

21 is an optical path diagram showing that the optical system of the surface position detecting device shown in FIG. 20 is telecentric on both sides.

FIG. 22 shows detection light DL formed on the surface of wafer W
FIG. 3 is a perspective view showing an image of FIG.

FIG. 23 is an explanatory diagram of Scheimpflug conditions.

[Explanation of symbols]

Reference Signs List 3 Wafer stage (substrate stage, adjusting device) 4a-4c Support point (adjusting device) 10 Surface position detecting device 10a Irradiation optical system 10b Light receiving optical system 17 Objective optical system (first focusing optical system) 18 Optical fiber (division means) 19) Condensing lens (second focusing optical system) 20 Photoelectric conversion element (detector) 30 Main control system (adjustment device) 31 Detection system 32 Stage drive system (adjustment device) 40 Transmitting rod (dividing means) 41 Transmission Flexible rod 43 Transmissive lot 43c Half prism (semi-transmissive member) 50 Half prism (dividing means) 61a, 61c, 61d Optical fiber (dividing means) 62a, 62c, 62d Condensing lens (second focusing optical system) 63a , 63c, 63d Photoelectric conversion element (detector) 73 Lens array (first focusing optical system) 73a to 73e Lens (focusing optical system) 75a, 75c, 75d Optical fiber (dividing means) 76 Lens array (second focusing optical system) 77 Photoelectric conversion element (detector) 80 Rotating pattern plate (switching means) 85 Biprism (second focusing optical system) DL Detection light R Reticle (mask) W Wafer (substrate) WS Wafer surface (test surface)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F065 AA01 AA31 BB01 CC19 DD02 DD14 FF04 GG05 GG24 HH12 JJ26 LL01 LL02 LL04 LL12 LL13 LL59 MM03 PP12 5F046 BA03 CC01 CC05 DA14 DB05 DB11 DC12

Claims (19)

[Claims] 1. An irradiation optical system for irradiating a detection light from a diagonal direction to a test surface, a light receiving optical system for receiving the detection light through the test surface, and a light receiving optical system receiving the detection light. In a surface position detecting device having a detector that photoelectrically detects a light beam and a detecting unit that detects a surface position of the surface to be detected based on a detection result of the detector, the detector is disposed in a pupil space of the light receiving optical system. And a splitting means for splitting the incident light flux, wherein the splitting means splits the incident light flux so that the split light flux has a predetermined relationship in accordance with an incident angle of the incident light flux to the splitting means. A surface position detection device characterized by dividing. 2. A surface position detecting device according to claim 1, wherein said dividing means divides the incident light beam into at least two directions. 3. The surface position detecting device according to claim 2, wherein said dividing means is an optical fiber. 4. A surface position detecting device according to claim 2, wherein said dividing means is a cylindrical transparent rod. 5. The surface position detecting device according to claim 2, wherein said dividing means is a quadrangular prism-shaped transmitting rod having a semi-transmitting member formed at an incident end. 6. The apparatus according to claim 1, further comprising a plurality of dividing units corresponding to a plurality of detection points in the irradiated area on the surface to be inspected. Item 8. The surface position detecting device according to Item 1. 7. A first focusing optical system, wherein the light receiving optical system has a rear focal point set substantially at the position of the incident end of the splitting means, and focuses a light beam from the surface to be detected; and the splitting means. 7. A surface position according to claim 1, further comprising: a second focusing optical system that focuses the light beam divided by the above on a detection surface of the detector in a predetermined relationship. Detection device. 8. At least one of the first focusing optical system and the second focusing optical system has a plurality of detection points corresponding to a plurality of detection points in the irradiated area on the surface to be inspected. 8. The surface position detecting device according to claim 7, further comprising a focusing optical system. 9. The surface position detecting device according to claim 1, wherein the irradiation optical system projects an image of a predetermined pattern on the surface to be inspected. 10. A switching means for irradiating only one image of the predetermined pattern at a time on the surface to be inspected at a time and switching the image of the pattern on the surface to be inspected at a time. The surface position detecting device according to claim 9, further comprising: 11. The apparatus according to claim 1, wherein at least one incident end of the splitting unit is disposed at a predetermined angle with respect to the incident light beam. Surface position detection device. 12. The surface position detecting device according to claim 1, wherein the detector is a position sensor or an image sensor. 13. The surface position detection device according to claim 1, wherein the detector is a sensor that sequentially scans a detection surface and obtains the detection result. 14. The method according to claim 1, wherein the detecting unit determines a relative position of the light beam split by the splitting unit on the detection surface based on a detection result of the detector to detect a surface position of the test surface. The surface position detecting device according to any one of claims 1 to 12, wherein 15. The detecting means obtains a spatial frequency by performing a Fourier transform on a detection result of the detector to obtain a relative position on the detection surface of the light beam split by the splitting means, and The surface position detecting device according to claim 1, wherein a surface position of the surface is detected. 16. The detection means obtains a relative position on the detection surface of the light beam split by the splitting means based on a detection result of the detector which changes with time, and determines a surface position of the test surface. 14. The surface position detecting device according to claim 13, wherein the surface position is detected. 17. The detecting means obtains a time frequency by performing a Fourier transform on a detection result of the detector which changes with time, thereby obtaining a relative position on the detection surface of the light beam split by the splitting means. 14. The surface position detecting device according to claim 13, wherein the surface position of the surface to be detected is detected. 18. An exposure apparatus for transferring a pattern formed on a mask onto a substrate, wherein the substrate stage for holding the substrate and a position of a surface of the substrate are detected as a position of the surface to be detected. Item 18. A surface position detecting device according to any one of Items 17, and an adjusting device that adjusts at least one of a position and a posture of the substrate on the substrate stage based on a detection result of the surface position detecting device. An exposure apparatus comprising: 19. A surface position detecting step of detecting a surface position of a surface of a substrate using a surface position detecting device provided in the exposure apparatus according to claim 18, and the substrate is detected based on a detection result of the surface position detecting step. A substrate adjustment step of adjusting at least one of a position and a posture of the substrate on a stage; a transfer step of irradiating an illumination light on the mask to transfer an image of a pattern formed on the mask to the substrate; And a developing step of developing the substrate transferred in the transfer step.