Surface position detection device, exposure device, device manufacturing method, and substrate processing system

Abstract

To provide a surface position detecting device.SOLUTION: A surface position detecting device comprises: a light transmitting part TS which irradiates a surface to be tested in a superposed manner with a plurality of detection light intensity-modulated in a first direction within a surface to be tested on a surface to be tested at oblique incidence from a detection having a direction component in the first direction, and forms an irradiation region on the surface to be tested; a first light-receiving optical system which forms a first conjugate surface; a second light-receiving optical system which forms a second conjugate surface; a photodetection part in which a light-receiving surface is arranged on the second conjugate surface; an opening member equipped with an opening which is arranged on the first conjugate surface, and allows a plurality of detection light from a detection region to pass through; a light-receiving part RS which receives the plurality of detection light having passed through the opening member at different positions on the light-receiving surface, and outputs a photoelectric conversion signal of the plurality of detection light; and an operation part PU which calculates positional information of the surface to be tested on the basis of the photoelectric conversion signal of the plurality of detection light, where an image of the opening of the opening member is formed on the light-receiving surface, and the width of the opening in the second detection is narrower than the width of a third direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a surface position detection device, an exposure device, a device manufacturing method, and a substrate processing system.

Background Art

[0002] In an exposure device that projects and exposes a pattern formed on a mask onto a photosensitive substrate via a projection optical system, the depth of focus of the projection optical system is relatively shallow, and the exposed surface (surface: transfer surface) of the photosensitive substrate may not be flat. For this reason, in the exposure device, it is necessary to accurately align the surface of the photosensitive substrate with respect to the image plane (imaging plane) of the projection optical system. As a device for detecting the surface position (surface position of the exposed surface) of the photosensitive substrate along the optical axis direction of the projection optical system, for example, an oblique incidence type surface position detection device is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The surface position detection device according to the first aspect of the present invention is a surface position detection device for obtaining position information of the surface to be inspected along an axis intersecting the surface to be inspected. In the surface position detection device, a plurality of detection lights whose intensity is modulated in a first direction within the surface to be inspected on the surface to be inspected are obliquely incident from a direction having a direction component in the first direction and superimposed on the surface to be inspected to form an irradiation region on the surface to be inspected. A light transmitting unit, a first light receiving optical system that forms a first conjugate surface optically conjugate to the surface to be inspected, a second light receiving optical system that forms a second conjugate surface conjugate to the first conjugate surface, a light detection unit whose light receiving surface is disposed on the second conjugate surface, and an aperture member disposed on the first conjugate surface and having an aperture that allows the plurality of detection lights from a detection region where the width in the first direction of the irradiation region is a predetermined value to pass through. The plurality of detection lights that have passed through the aperture member are received at different positions on the light receiving surface, and a light receiving unit that outputs photoelectric conversion signals of the plurality of detection lights respectively, and an arithmetic unit that calculates position information of the surface to be inspected based on the photoelectric conversion signals of the plurality of detection lights output from the light receiving unit. On the surface to be inspected, the plurality of detection lights are intensity-modulated in the first direction by sine wave functions of the same period, the phases of the sine wave functions in the first direction are different from each other, and the width of the detection region in the first direction is shorter than half of the period of the sine wave function 。 The exposure device according to the second aspect of the present invention includes a projection optical system, a substrate stage on which a substrate is placed and moved, and the surface position detection device described above that detects the position of the surface of the substrate as the surface to be inspected. The device manufacturing method according to the third aspect of the present invention includes forming a resist on the surface of the substrate, using the exposure device described above to detect the position of the surface of the resist formed on the surface of the substrate, setting the surface of the resist at a predetermined position in the optical axis direction of the projection optical system, exposing an exposure pattern, developing the resist, and processing the surface of the substrate based on the resist pattern formed by the development. The substrate processing system according to the fourth aspect of the present invention is a substrate processing system for processing a substrate, and includes a first stage on which the substrate is placed, and a measuring device having the surface position detection device described above that measures positions at a plurality of locations on the surface of the substrate in a direction intersecting the surface of the substrate. The substrate placed on the second stage after the measurement by the measuring device ofAn exposure apparatus that performs exposure, and the exposure apparatus performs the exposure while changing a position in a direction intersecting with the surface of the substrate by using at least the measurement result by the measurement apparatus. The device manufacturing method according to the fifth aspect of the present invention includes forming a resist on the surface of the substrate, detecting positions of a plurality of locations on the surface of the resist formed on the surface of the substrate in a direction intersecting with the surface of the substrate by using the substrate processing system described above, and exposing an exposure pattern while changing the position in the direction intersecting with the surface of the substrate of the surface of the resist based on the detected positions of the plurality of locations, and forming a circuit pattern based on the exposure pattern.

Brief Description of the Drawings

[0005]

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Embodiments for Carrying Out the Invention

[0006] In this specification, "optically conjugate" means that one surface and another surface are in an imaging relationship via an optical system. In this specification, the "imaging relationship" means a relationship in which light emitted from an arbitrary point within one region is condensed within a range of the resolution of the optical system centered on a point within another region via the optical system. In this specification, the "sine wave function" means a function in which a predetermined constant is added to the sine function (sin) or the cosine function (cos) and all values are non-negative.

[0007] (Surface Position Detection Device of the First Embodiment) FIG. 1 is a diagram schematically showing the configuration of the surface position detection device 100 of the first embodiment. In FIG. 1, the Z-axis is set in the direction perpendicular (normal direction) to the surface (hereinafter also referred to as the "surface to be inspected") WA of the object W to be measured placed on the surface position detection device 100, the X-axis is set parallel to the paper surface of FIG. 1 within a plane perpendicular to the Z-axis, that is, within a plane parallel to the surface to be inspected WA, and the Y-axis is set perpendicular to the paper surface of FIG. 1.

[0008] The outline of the path of the detection light in the surface position detection device 100 of the first embodiment will be described. Detection light is supplied to the light introduction unit 12, for example, from the light source 10 via the light guide 11. The wavelength band of the detection light from the light source 10 is, for example, from 400 nm to 800 nm, but is not limited thereto. For example, it may be 400 nm or less, for example, in the vicinity of 200 nm, or in the infrared region of 800 nm or more, for example, from 1200 nm to 1700 nm. The detection light emitted from the light introduction unit 12 is irradiated onto the surface to be inspected WA via the condenser lens group 13, the diffraction grating plate 14, the second light transmission-side lens group 15, the first light transmission-side lens group 17, the mirror 18, and the like. The detection light reflected by the surface to be inspected WA reaches the light receiving prism 23 via the mirror 19, the first light receiving-side lens group 20, the second light receiving-side lens group 22, and the like. The detection light refracted by the light receiving prism 23 enters the polarization separation prism 27 via the relay optical system composed of the front-side lens group 24 and the rear-side lens group 26. Then, the detection light is separated into two different polarization components by the polarization separation prism 27, and each of the separated detection lights enters the light receiving surface 29a of the light detection unit 28a and the light receiving surface 29b of the light detection unit 28b. In addition, in FIGS. 1 to 3, only one lens of each lens group is shown, but each lens group may be composed of one or more lenses. The object to be measured W is placed on the stage ST, and the XYZ position of the stage ST is measured by an interferometer or an encoder (not shown).

[0009] In this specification, all or part of the light introduction unit 12, the condenser lens group 13, the diffraction grating plate 14, the second light transmission-side lens group 15, the detection light splitting member 16, the first light transmission-side lens group 17, and the mirror 18 are also collectively referred to as the light transmission unit TS. In this specification, all or part of the mirror 19, the first light receiving-side lens group 20, the cylindrical lens 21, the second light receiving-side lens group 22, the light receiving prism 23, the relay optical system (24, 26), the composite separation member 25, the polarization separation prism 27, and the light detection units 28a, 28b are also collectively referred to as the light receiving unit RS.

[0010] FIG. 2 and FIG. 3 are diagrams schematically showing a partial configuration of the surface position detection device 100 shown in FIG. 1. FIG. 2 is a side view of the configuration from the -Y direction, from the condenser lens group 13 to the light detection unit 28a. In FIG. 2, the optical path from the diffraction grating plate 14 to the surface under inspection WA and the optical path from the surface under inspection WA to the light receiving prism 23 are linearly expanded. FIG. 3 is a top view of the configuration from the +Z direction, from the condenser lens group 13 to the light detection unit 28a. In FIGS. 2 and 3, the illustration of the mirrors 18, 19, the polarization beam splitter prism 27, and the light detection unit 28b is omitted. Also, in FIGS. 2 and 3, the optical axis AX2 is made to coincide with the optical axis AX3, the optical axis AX4 is made to coincide with the optical axis AX5, and the optical axis AX6 is made to coincide with the X-axis direction.

[0011] The light emitted from the light introduction unit 12 enters the condenser lens group 13 and enters the diffraction grating plate 14 generally along the optical axis AX1 of the condenser lens group 13. On the surface of the diffraction grating plate 14, a diffraction grating 14a made of a dielectric film or a metal film is formed. The diffraction grating 14a is a one-dimensional grating as an example, and a substantially rectangular pattern whose longitudinal direction coincides with the Y direction in the figure is arranged at a predetermined period in the direction within the plane of the diffraction grating plate 14 orthogonal to the Y direction. In this example, the diffraction grating 14a selectively generates the +1st order diffracted light DP and the -1st order diffracted light DM.

[0012] The ±1st order diffracted lights DP and DM reflected and diffracted by the diffraction grating plate 14 enter the detection light splitting member 16 through the second lens 15 on the light transmission side. The detection light splitting member 16 is arranged on the pupil plane TP of the light transmission optical system composed of the second lens group 15 on the light transmission side and the first lens group 17 on the light transmission side. Here, the pupil plane TP is a plane where a plurality of light rays incident from the same direction at different positions on the surface under inspection WA gather at substantially one point. Conversely, the light traveling in different directions from one point on the pupil plane TP is incident from the same direction at different positions on the surface under inspection WA. The optical axis AX2 is the optical axis of the second lens group 15 on the light transmission side and the first lens group 17 on the light transmission side, and coincides with the optical axis AX1 of the condenser lens 13 reflected (mirrored) by the diffraction grating plate 14.

[0013] FIG. 4 is a diagram showing an example of the detection light splitting member 16. FIG. 4(a) is a perspective view showing the detection light splitting member 16, and FIG. 4(b) is a view of the detection light splitting member 16 as seen from the light transmitting side first lens group 17 side. The optical axis AX2 and the Y-axis in FIG. 4 indicate the same directions as the optical axis AX2 and the Y-axis shown in FIGS. 1 to 3. The z1-axis in FIG. 4 indicates a direction orthogonal to the optical axis AX2 and the Y-axis. The detection light splitting member 16 includes, as an example, four prisms 16a to 16d. The prism 16a and the prism 16b are arranged in contact with each other in the Y direction at substantially the same position in the optical axis AX2 direction. The prism 16c and the prism 16d are arranged in contact with each other in the Y direction at a position downstream in the optical path from the prism 16a and the prism 16b in the optical axis AX2 direction. The boundary between the prism 16a and the prism 16b and the boundary between the prism 16c and the prism 16d are on a plane passing through the optical axis AX2 and parallel to the z1-axis.

[0014] Any one of the four prisms 16a to 16d has a thickness in the optical axis AX2 direction that changes according to the position in the z1 direction, and gives a phase difference that changes according to the position in the z1 direction to the light transmitted through it, and deflects the traveling direction of the light transmitted through it by a small angle in the z1 direction. Note that the prism 16a and the prism 16b, and the prism 16c and the prism 16d may not be two separate prisms, but may have different shapes of the incident surface or the exit surface of an integral prism on the +Y side and the -Y side of the optical axis AX2.

[0015] The +1st order diffracted light DP and the -1st order diffracted light DM incident on the detection light splitting member 16 are respectively split into a first detection light DL1 that exits from the prism 16c arranged on the +Y side of the optical axis AX2 at the pupil plane TP, and a second detection light DL2 that exits from the prism 16d arranged on the -Y side of the optical axis AX2. Then, the first detection light DL1 and the second detection light DL2 are deflected from each other by a small angle in the z1 direction.

[0016] Note that it should be noted that both the first detection light DL1 and the second detection light DL2 include the +1st order diffracted light DP and the -1st order diffracted light DM. Further, a diffraction light selection filter that selectively transmits only the +1st order diffracted light DP and the -1st order diffracted light DM may be provided on one side or the other side in the direction of the optical axis AX2 of the detection light splitting member 16. In this case, as the diffraction grating 14a, a diffraction grating that generates diffracted light other than the +1st order diffracted light DP and the -1st order diffracted light DM may be used.

[0017] The first detection light DL1 and the second detection light DL2 are condensed by the light transmitting side first lens group 17, then reflected by the mirror 18 and irradiated onto the surface to be inspected WA, and an irradiation region IA is formed on the surface to be inspected WA. The first detection light DL1 and the second detection light DL2 are lights that pass through positions mutually shifted in the Y direction at the pupil plane TP. Therefore, as shown in FIG. 3, the incident directions of the first detection light DL1 and the second detection light DL2 onto the surface to be inspected WA are generally parallel to the +X direction, but are mutually shifted in the Y direction. The incident angle θ of the detection light onto the surface to be inspected WA (the angle of the incident light with respect to the normal NV of the surface to be inspected WA) is set to a large angle, for example, 80 degrees or more and less than 90 degrees. The optical axis AX3 is the one obtained by reflecting (mirroring) the optical axis AX2 by the mirror 18. Note that the incident angle θ may be less than 80 degrees or may be 90 degrees or more.

[0018] FIG. 5(a) is a diagram showing the irradiation region IA on the surface to be inspected WA, and FIG. 5(b) is a diagram showing the light quantity distribution in the X-axis direction of the irradiation region IA. The solid line indicates the light quantity distribution IDL1 of the first detection light DL1, and the broken line indicates the light quantity distribution IDL2 of the second detection light DL2. The detection region DA shown in FIG. 5 will be described later.

[0019] Since the first detection light DL1 and the second detection light DL2 each consist of two diffracted lights, namely the +1st order diffracted light DP and the -1st order diffracted light DM, the light quantity distribution IDL1 and the light quantity distribution IDL2 both become interference fringes formed by the two diffracted lights. Therefore, as shown in FIG. 5(b), both the light quantity distribution IDL1 and the light quantity distribution IDL2 are distributions intensity-modulated by a sine wave function (sin function) having a predetermined period FX and amplitude in the X direction. In this example, the amplitudes and the X-direction period FX of the respective sine wave functions that modulate the light quantity distribution IDL1 and the light quantity distribution IDL2 are equal.

[0020] The first detection light DL1 and the second detection light DL2 are deflected by a minute angle by the detection light splitting member 16 as described above. Due to this deflection, the phases of the sine wave functions of the light quantity distribution IDL1 and the light quantity distribution ID are shifted by half of the period FX of the sine wave function of the respective intensity modulations. However, since the amount of deviation is small, the first detection light DL1 and the second detection light DL2 are superimposed, that is, almost overlapped, and irradiated on the irradiation region IA on the surface under inspection WA. In other words, the first detection light DL1 and the second detection light DL2 are obliquely incident on the surface under inspection WA from a direction having a direction component in the +X direction and are superimposed to form an irradiation region IA on the surface under inspection WA.

[0021] Therefore, in the irradiation region IA, at any position in the X-axis direction, the sum of the light quantity of the first detection light DL1 and the light quantity of the second detection light DL2 is constant. In other words, the light quantity distributions IDL1 and IDL2 are complementary in the X direction. Also, both the light quantity distributions IDL1 and IDL2 are constant within a predetermined range in the Y direction. The X direction in the plane of the surface under inspection WA may be interpreted as the first direction. Also, the Y direction in the plane of the surface under inspection WA may be interpreted as the second direction.

[0022] Note that the reason for arranging the detection light splitting member 16 on the pupil plane TP is to split the ±1st order diffracted lights DP and DM into the first detection light DL1 and the second detection light DL2 according to the incident direction on the surface under inspection WA regardless of the incident position on the surface under inspection WA. Therefore, the position of the pupil plane TP where the detection light splitting member 16 is arranged does not necessarily have to be a plane where a plurality of light rays incident from the same direction at different positions on the surface under inspection WA accurately converge at one point. That is, as long as it is a position where the first detection light DL1 and the second detection light DL2 can be split according to the incident direction on the surface under inspection WA, it may be a position slightly forward or backward along the optical axis AX2. The same applies to other pupil planes described later.

[0023] The light reflected by the inspection surface WA of the object W to be measured enters the incident surface 23a of the light receiving prism 23 after passing through the mirror 19, the first light receiving lens group 20, the cylindrical lens 21, and the second light receiving lens group 22. The optical axis AX5 is the optical axes of the first light receiving lens 20 and the second light receiving lens 22. The optical axis AX4 is the one obtained by reflecting (mirroring) the optical axis AX5 by the mirror 19.

[0024] The mirror 19, the first light receiving lens group 20, and the second light receiving lens group 22 are arranged at positions symmetric to the mirror 18, the first light transmitting lens group 17, and the second light transmitting lens group 15 with respect to the YZ plane including the center of the irradiation region IA, respectively, and have a symmetric configuration. The incident surface 23a of the light receiving prism 23 is arranged at a position symmetric to the diffraction grating 14a on the diffraction grating plate 14 with respect to the YZ plane including the center of the irradiation region IA.

[0025] FIG. 6 is a view of the incident surface 23a of the light receiving prism 23 as seen from the direction of the normal to the incident surface 23a. An opening (slit) SL, which is a light transmission portion having a longitudinal direction in the Y direction, is formed at or near the intersection with the optical axis AX2 on the incident surface 23a. A light shielding portion OF covered with a light shielding film is formed in a portion of the incident surface 23a other than the opening SL.

[0026] The incident surface 23a is optically conjugated with the inspection surface WA of the object W to be measured through the mirror 19, the first light receiving lens group 20, and the second light receiving lens group 22. That is, the first detection light DL1 and the second detection light DL2 emitted from one point in the inspection surface WA both converge at one point on the incident surface 23a. The x2 axis, which is the in-plane direction of the incident surface 23a, has an imaging relationship with the X axis in the inspection surface WA. That is, any region along the X direction in the inspection surface WA is imaged into a region along the x2 direction in the incident surface 23a. The z2 axis is an axis in a direction orthogonal to the Y axis and the x2 axis.

[0027] The aperture SL selectively transmits only the light reflected from the portion in imaging relationship with the aperture SL in the irradiation region IA on the surface under inspection WA formed on the incident surface 23a, out of the first detection light DL1 and the second detection light DL2. Therefore, a portion of the irradiation region IA on the surface under inspection WA that is in imaging relationship with the aperture SL on the incident surface 23a via the light-receiving side first lens 20, the light-receiving side second lens 22, etc. may be interpreted as the detection region DA as shown in FIGS. 5(a) and 5(b). That is, only the light reflected from the detection region DA on the surface under inspection WA out of the first detection light DL1 and the second detection light DL2 passes through the aperture SL.

[0028] The width of the aperture SL in the x2 direction is the width Swx, and the width in the Y direction is the width Swy. As shown in FIG. 5(a), the width of the detection region DA on the surface under inspection WA in the X direction is the width Dwx, and the width in the Y direction is the width Dwy. The imaging magnification from the surface under inspection WA to the incident surface 23a by the light-receiving side first lens 20 and the light-receiving side second lens 22 coincides with the ratio of the width Swx to the width Dwx and the ratio of the width Swy to the width Dwy. In order to condense the reflected light from the detection region DA with a large width Dwx onto the aperture SL with a narrow width Swx, a cylindrical lens 21 may be provided at or near the pupil plane RP1 of the optical system constituted by the light-receiving side first lens group 20 and the light-receiving side second lens group 22. Here, the pupil plane RP1 is a plane where a plurality of light rays emitted from different positions on the surface under inspection WA in the same direction gather at substantially one point.

[0029] The light-receiving side first lens group 20 and the light-receiving side second lens group 22 may be interpreted as the first light-receiving optical system. The x2 direction in the incident surface 23a may be interpreted as the third direction. Also, the Y direction in the incident surface 23a may be interpreted as the fourth direction. The pupil plane RP1 may be interpreted as the first pupil plane.

[0030] The first detection light beam DL1 and the second detection light beam DL2 that have passed through the opening SL are deflected by a predetermined angle by the refraction action of the light receiving prism 23, and then are emitted from the light receiving prism 23 and enter the front lens group 24 of the relay optical system (24, 26). The optical axis AX6 is the optical axis of the front lens group 24 and the rear lens group 26 of the relay optical system.

[0031] Note that when the first detection light beam DL1 and the second detection light beam DL2 pass through the opening SL having a relatively narrow width Swx in the X2 direction, they are diffracted, and since the traveling directions spread in the Z direction, it becomes impossible to distinguish between the +1st order diffracted light beam DP and the -1st order diffracted light beam DM. Therefore, in FIG. 2, the light after passing through the opening SL is shown as the first detection light beam DL1. Also, in FIG. 2 viewed from the -Y direction, since the second detection light beam DL2 is displayed overlapping the first detection light beam DL1, the illustration is omitted.

[0032] A composite separation member 25 is disposed on the pupil plane RP2 with respect to the incident surface 23a by the front lens group 24. Here, the pupil plane RP2 is a plane on which a plurality of light rays emitted from different positions on the incident surface 23a in the same direction converge at substantially one point. Details of the composite separation member 25 will be described later.

[0033] The first detection light beam DL1 and the second detection light beam DL2 emitted from the composite separation member 25 enter the polarization separation prism 27 via the rear lens group 26 of the relay optical system. Among the first detection light beam DL1 and the second detection light beam DL2, the P polarization component travels straight through the polarization separation prism 27 and forms an image of the P polarization component of the opening SL on the light receiving surface 29a on the light detection unit 28a. On the other hand, among the first detection light beam DL1 and the second detection light beam DL2, the S polarization component is reflected by the polarization separation prism 27 and forms an image of the S polarization component of the opening SL on the light receiving surface 29b on the light detection unit 28b.

[0034] Note that the opening SL is formed on the incident surface 23a of the light receiving prism 23 that is largely inclined from the plane perpendicular to the optical axis AX6. However, as shown in FIG. 2, since the optical path length inside the light receiving prism 23 changes with respect to the Z direction, the inclination of this image plane is corrected. As a result, the image of the opening SL is formed to coincide with the light receiving surface 29a arranged perpendicular to the optical axis AX6. That is, the light receiving prism 23 may also be interpreted as an image plane inclination correction member. Note that the rotation direction centered on the optical axis AX6 of the polarization separation prism 27 is set so that the P-polarized light and S-polarized light with respect to the polarization separation surface 27a of the polarization separation prism 27 coincide with the P-polarized light and S-polarized light with respect to the test surface WA.

[0035] The detection light received and photoelectrically converted on the light receiving surfaces 29a and 29b of the photodetection units 28a and 28b outputs a photoelectric conversion signal of the detection light from the photodetection units 28a and 28b and inputs it to the arithmetic unit PU. The arithmetic unit PU may be a computer device equipped with a CPU and a memory. Details of the photodetection units 28a and 28b and the image of the opening SL formed on their light receiving surfaces 29a and 29b will be described later.

[0036] FIG. 7 is a diagram showing an example of the composite separation member 25. In FIG. 7, for easy understanding, the optical axis AX6 is represented parallel to the X axis as shown in FIGS. 2 and 3. FIG. 7(a) shows a cross-sectional view in the XY plane passing through the optical axis AX6 of the composite separation member 25, and FIG. 7(b) shows a cross-sectional view in the XZ plane passing through the optical axis AX6 of the composite separation member 25. Functionally, the composite separation member 25 is divided into a light separation member 25a on the incident side and a spectroscopic member 25b on the emission side along the optical axis AX6.

[0037] On the incident side of the optical separation member 25a, a first block 251 disposed on the +Y side of the optical axis AX6 and a second block 252 disposed on the -Y side of the optical axis AX6 are arranged. The incident surfaces of the first block 251 and the second block 252 are surfaces rotated in different directions about a rotation axis parallel to the Z axis with respect to a plane orthogonal to the optical axis AX6. The same applies to the exit surfaces of the first block 251 and the second block 252. The shape of the incident surface of the third block 253 matches the shape of the exit surfaces of the first block 251 and the second block 252. The exit surface of the third block 253 is a plane perpendicular to the optical axis AX6.

[0038] As a result, the optical separation member 25a refracts (deflects) the light incident from the +Y side of the optical axis AX6 and the light incident from the -Y side of the optical axis AX in different directions. It is preferable that the first block 251 and the second block 252 and the third block 253 are formed of materials having different refractive indices from each other.

[0039] Since the composite separation member 25 is disposed on the pupil plane RP2, as shown in FIG. 3, the light incident from the +Y side of the optical axis AX6 is the first detection light DL1, and the light incident from the -Y side of the optical axis AX6 is the second detection light DL2. Then, the light that is mutually deflected by a minute angle in the Y direction on the pupil plane RP2 is formed at positions mutually shifted in the Y direction on the light receiving surfaces 29a and 29b.

[0040] The spectroscopic member 25b on the emission side is a prism in which a fourth block 254 and a fifth block 255, which are two triangular prisms, are arranged with their hypotenuses facing each other. The incident surface of the fourth block 254 matches the exit surface of the third block 253, and the exit surface of the fifth block 255 matches a plane perpendicular to the optical axis AX6. The boundary surface between the fourth block 254 and the fifth block 255 is a surface including the Y-axis direction. The fourth block 254 and the fifth block 255 are formed of materials having different dispersions.

[0041] Therefore, at the interface between the fourth block 254 and the fifth block 255, the light of different wavelengths included in the first detection light DL1 and the second detection light DL2 is refracted at different angles according to the wavelength. As a result, by the spectroscopic member 25b, the first detection light DL1 and the second detection light DL2 are spectroscopically separated, and become detection lights DL1a to DL1c that are mutually deflected at minute angles in the Z direction for each wavelength, and are emitted from the spectroscopic member 25b. Note that the spectroscopic member 25b may be formed of one prism having different refractive powers according to the wavelength.

[0042] Since the composite separation member 25 is disposed on the pupil plane RP2, the light that is mutually deflected at minute angles in the Z direction by the composite separation member 25 is formed at positions mutually shifted in the Z direction on the light receiving surfaces 29a and 29b. Note that in FIG. 7, in order to avoid complexity, the illustration of the second detection light DL2 and the detection lights DL2a to DL2c obtained by spectroscopically separating the second detection light DL2 is omitted.

[0043] FIG. 8 is a diagram showing an image of the P-polarization component of the opening SL formed on the light receiving surface 29a. In FIG. 8, the x3 axis in the in-plane direction of the light receiving surface 29a is in an imaging relationship with the x2 axis in the above-described incident plane 23a. That is, an arbitrary region along the x2 direction of the incident plane 23a is imaged in a region along the x3 direction within the light receiving surface 29a. Note that as described above, the x2 axis, which is the in-plane direction of the incident plane 23a, is in an imaging relationship with the X axis in the surface under inspection WA. Therefore, the x3 axis in the in-plane direction of the light receiving surface 29a is also in an imaging relationship with the X axis in the surface under inspection WA. The z3 axis is an axis in a direction orthogonal to the Y axis and the x3 axis. Note that in FIG. 2, in which the optical path is developed and shown in a straight line, it should be noted that the x3 axis in the in-plane direction of the light receiving surface 29a is described to coincide with the Z axis for convenience.

[0044] The relay optical system including the front lens group 24 and the rear lens group 26 may be interpreted as the second light receiving optical system. The x2 direction in the incident plane 23a may be interpreted as the third direction. Also, the Y direction in the incident plane 23a may be interpreted as the fourth direction. The pupil plane RP2 may be interpreted as the second pupil plane. The x3 direction within the light-receiving surface 29a may be interpreted as the fifth direction. Also, the Y direction within the light-receiving surface 29a may be interpreted as the sixth direction.

[0045] Due to the separation and deflection of the detection light by the composite separation member 25, different wavelength components of the first detection light DL1 and the second detection light DL2 are guided to different positions on the light-receiving surface 29a. Therefore, a plurality of images (IM1a to IM1c and IM2a to IM2c) of the aperture SL are formed on the light-receiving surface 29a. On the light-receiving surface 29a, the images IM1a to IM1c and the images IM2a to IM2c formed apart in the Y direction are images formed by the first detection light DL1 and the second detection light DL2 that are mutually deflected by a minute angle in the Y direction by the light separation member 25a of the composite separation member 25, respectively. The first detection light DL1 and the second detection light DL2 are split by the spectroscopic member 25b into detection lights DL1a to DL1c and detection lights DL2a to DL2c that are mutually deflected by a minute angle in a direction orthogonal to the Y direction for each wavelength. Therefore, the images of the aperture SL formed on the light-receiving surface 29a are also formed at different positions in the x3 direction according to the wavelength.

[0046] The image IM1a is an image formed by the light of the first wavelength among the first detection light DL1, the image IM1b is an image formed by the light of the second wavelength among the first detection light DL1, and the image IM1c is an image formed by the light of the third wavelength among the first detection light DL1. On the other hand, the image IM2a is an image formed by the light of the first wavelength among the second detection light DL2, the image IM2b is an image formed by the light of the second wavelength among the second detection light DL2, and the image IM2c is an image formed by the light of the third wavelength among the second detection light DL2.

[0047] Note that in Fig. 8, for ease of understanding, the first detection light DL1 and the second detection light DL2 include light of three different wavelengths. Therefore, the images IM1a to IM1c formed by the first detection light DL1 and the images IM2a to IM2c formed by the second detection light DL2 are each shown as three. However, the wavelengths of the light included in the first detection light DL1 and the second detection light DL2 are not limited to discrete three wavelengths, and may include four or more different discrete wavelengths. In this case, the number of images IM1a to IM1c formed by the first detection light DL1 and the number of images IM2a to IM2c formed by the second detection light DL2 will be four or more. Also, the wavelengths of the light included in the first detection light DL1 and the second detection light DL2 are not limited to discrete multiple wavelengths, and may be discrete or continuous multiple wavelength bands.

[0048] The light receiving surface 29a photoelectrically converts and outputs the light amounts of these images IM1a to IM1c and IM2a to IM2c, respectively. As an example, the light receiving surface 29a is provided with a plurality of separated photoelectric conversion units, each of which includes a photoelectric conversion unit that encompasses each of the images IM1a to IM1c and IM2a to IM2c. Each photoelectric conversion unit receives the images IM1a to IM1c and IM2a to IM2c, respectively, and photoelectrically converts and outputs the light amount thereof.

[0049] As the light detection unit 28a, a two-dimensional imaging sensor in which minute light receiving pixels are two-dimensionally arranged may be used on the light receiving surface 29a. In this case, for example, one image IM1a is received by a plurality of light receiving pixels. In this case, the light detection unit 28a outputs, as a photoelectric conversion signal, a signal obtained by photoelectrically converting the light amounts of the detection light received by the plurality of light receiving pixels.

[0050] When a two-dimensional imaging sensor is used as the light detection unit 28a, the resolution of the light receiving surface 29a in the x3 direction is improved, so that the first detection light DL1 and the second detection light DL2 can be spectroscopically received with higher precision. As a result, light having a continuous spectrum can be used as the first detection light DL1 and the second detection light DL2. By making the width of each of the plurality of images IM1a to IM1c and IM2a to IM2c in the x3 direction on the light-receiving surfaces 29a and 29b narrower than the width in the Y direction, the first detection light DL1 and the second detection light DL2 can be spectroscopically received with higher accuracy.

[0051] Note that since the light detection unit 28b has the same configuration as the above-described light detection unit 28a, the description thereof is omitted. Also, regarding the image of the S-polarization component of the opening SL formed on the light-receiving surface 29b, it is the same as the image of the P-polarization component of the opening SL formed on the light-receiving surface 29a described above, so the description thereof is omitted.

[0052] Hereinafter, the measurement principle in the surface position detection device 100 of the first embodiment will be described. As described above, by irradiating the first detection light DL1 and the second detection light DL2, the light quantity distributions IDL1 and IDL2 shown in FIG. 5(b) are formed on the surface to be inspected WA. The first detection light DL1 and the second detection light DL2 are both incident from a direction inclined by an incident angle θ in the -X direction with respect to the normal line NV of the surface to be inspected WA. Therefore, when the surface to be inspected WA moves up and down in the Z direction of FIG. 1, the light quantity distributions IDL1 and IDL2 shift in the X direction as a whole while maintaining their distribution shapes. If the surface to be inspected WA moves in the +Z direction, the light quantity distributions IDL1 and IDL2 shift in the -X direction.

[0053] On the other hand, the detection area DA shown in FIG. 5(b) is an area indicating that the first detection light DL1 and the second detection light DL2 reflected in the detection area DA pass through the opening SL on the incident surface 23a of the light receiving prism 23. That is, the detection area DA is in an imaging relationship with the opening SL via the light receiving side first lens 20, the light receiving side second lens 22, and the like. However, since the optical axis AX5 of the light receiving side first lens 20 is inclined in the +X direction with respect to the normal line NV of the surface to be inspected WA, when the surface to be inspected WA moves up and down in the Z direction of FIG. 1, the position of the detection area DA also shifts in the X direction on the surface to be inspected WA. If the surface to be inspected WA moves in the +Z direction, the detection area DA shifts in the +X direction. That is, as the surface to be inspected WA moves in the Z direction, the X-directional positional relationship between the light quantity distributions IDL1 and IDL2 shown in FIG. 5(b) and the detection area DA changes.

[0054] The light quantity of each of the images IM1a to IM1c of the opening SL by the first detection light DL1 on the light receiving surface 29a is proportional to the sum of the light quantities of the first detection light DL1 in the detection area DA. Also, the light quantity of each of the images IM2a to IM2c of the opening SL by the second detection light DL2 on the light receiving surface 29a is proportional to the sum of the light quantities of the second detection light DL2 in the detection area DA. Therefore, the light quantities of the images IM1a to IM1c and IM2a to IM2c vary with the variation in the position of the surface to be inspected WA in the Z direction. It should be noted that, unlike many conventional surface position detection devices, the positions of the images IM1a to IM1c and IM2a to IM2c on the light receiving surface 29a do not vary even when the position of the surface to be inspected WA in the Z direction varies.

[0055] FIG. 9 is a diagram showing, as an example, the relationship between the position (horizontal axis) of the test surface WA in the Z-axis direction, the photoelectric conversion signal S1b of the image IM1b by the second wavelength component of the first detection light DL1, and the photoelectric conversion signal S2b of the image IM2b by the second wavelength component of the second detection light DL2. As described above, the first detection light DL1 and the second detection light DL2 have light quantity distributions IDL1 and IDL2 of a sine wave function having the same period FX and amplitude and a phase shift of half of the period FX on the test surface WA. For this reason, both the photoelectric conversion signal S1b and the photoelectric conversion signal S2b are signals represented by the following formulas (1) and (2) having the same period FZ and amplitude A1 with respect to the position of the test surface WA in the Z-axis direction and a phase shift of half of the period FZ.

[0056] S1b = A1+A1×cos{2π(Z-Za) / FZ)}···(1) S2b = A1-A1×cos{2π(Z-Za) / FZ)}···(2) Za is the Z position of the test surface WA where the photoelectric conversion signal S1b is maximum and the photoelectric conversion signal S2b is minimum. Zb shown in FIG. 9 is a position close to Za on the +Z side of Za, and is the Z position of the test surface WA where the photoelectric conversion signal S1b is minimum and the photoelectric conversion signal S2b is maximum.

[0057] The arithmetic unit PU calculates the Z position Zt of the test surface WA at an arbitrary position between Za and Zb from the value S1t of the photoelectric conversion signal S1b and the value S2t of the photoelectric conversion signal S2b by arithmetic operations based on formulas (3) and (4). Zt = Za+FZ×cos-1{(S2t-S1t) / (2×A1)} / 2π···(3) A1 = (S2t+S1t) / 2···(4) cos-1 is the inverse cosine function.

[0058] Note that if the width Dwx in the X direction of the detection region DA is made shorter than half of the period FX in the X direction of the light quantity distributions IDL1 and IDL2, the variations in the photoelectric conversion signal S1b and the photoelectric conversion signal S2b when the test surface WA fluctuates in the Z direction can be increased. As a result, the detection accuracy can be further improved.

[0059] In a conventional surface position detection device, detection light is obliquely incident on a surface to be inspected to form an irradiation region having a predetermined width in the X direction, and the Z position of the surface to be inspected is detected by detecting the position of the center of gravity of the light amount in the X direction of the irradiation region. Therefore, if there is a change in reflectance in the X direction inside the irradiation region of the surface to be inspected, the position of the center of gravity of the light amount of the irradiation region changes due to the change in reflectance, resulting in a detection error.

[0060] For example, in the case of a semiconductor wafer in the process of forming an integrated circuit, the reflectance varies depending on the position of its surface according to the internal structure and the like. Therefore, it has been difficult for a conventional surface position detection device to accurately detect the surface position of a semiconductor wafer surface.

[0061] On the other hand, in the surface position detection device of the first embodiment, the Z position Zt of the surface to be inspected WA to be detected is hardly affected by the change in the reflectance of the detection region DA. When the reflectance of the detection region DA changes, the photoelectric conversion signal S1b and the photoelectric conversion signal S2b both increase and decrease with an equal proportional coefficient with respect to the change in the reflectance of the detection region DA. Even if (S2t - S1t) in Equation (3) becomes α times due to the change in the reflectance of the detection region DA, A1 in Equation (3), that is, (S2t + S1t) / 2 in Equation (4) also becomes α times. Therefore, Zt obtained from Equation (3) does not change. That is, in the surface position detection device 100 of the first embodiment, it is possible to realize a highly accurate surface position detection device that is hardly affected by fluctuations in the reflectance of the surface to be inspected WA.

[0062] Note that in the above, since the light amount distribution IDL1 of the first detection light DL1 irradiated on the surface to be inspected WA and the light amount distribution IDL2 of the second detection light DL2 are sine wave functions with respect to X, the arithmetic unit PU calculates the detection position Zt based on Equation (3) including the inverse cosine function.

[0063] However, when the light quantity distributions IDL1 and IDL2 are other functions than the sine wave function, the calculation unit PU may calculate the detection position Zt based on the inverse function of the other function. Therefore, the light quantity distributions IDL1 of the first detection light DL1 irradiated on the surface to be inspected WA and IDL2 of the second detection light DL2 are not limited to the sine wave function with respect to X, and may be other functions.

[0064] However, at least in the portion corresponding to the detection region DA, the light quantity distributions IDL1 and IDL2 need to be smooth. If the light quantity distributions IDL1 and IDL2 are not smooth, that is, if the light quantity distribution changes in such a way that it is not differentiable in the X direction at an arbitrary position, it becomes difficult to accurately calculate the detection position Zt from the value S1t of the photoelectric conversion signal S1b and the value S2t of the photoelectric conversion signal S2b. Note that smoothness may be defined as the function having a continuous derivative (derived function) within a certain interval (that is, not being bent). That the light quantity distributions IDL1 and IDL2 are smooth in the portion corresponding to the detection region DA may mean that when the light quantity distributions IDL1 and IDL2 are fitted with a certain function, the fitted function has a continuous derivative in the portion corresponding to the detection region DA.

[0065] Note that when the light quantity distributions IDL1 and IDL2 are sine wave functions as described above, the calculation unit PU can calculate the detection position Zt using a general inverse cosine function or inverse sine function, so the configuration of the calculation unit PU can be simplified.

[0066] Note that the calculation unit PU may calculate the converted surface position representing the surface position of the surface to be inspected WA in internal coordinates or the like in the surface position detection device 100, instead of calculating the surface position of the surface to be inspected WA itself as described above. Hereinafter, the surface position and the converted surface position of the surface to be inspected WA are also collectively or individually referred to as the surface position information of the surface to be inspected WA.

[0067] The calculation unit PU may calculate the amplitude A1 from the sum of the value S1t of the photoelectric conversion signal S1b and the value S2t of the photoelectric conversion signal S2b based on Equation (4). In this case, it is further desirable to calculate the amplitude A1 (hereinafter referred to as amplitude A0) for a reference measurement object with a known reflectance of the measurement surface WA before measuring the object W to be measured. Thereby, the calculation unit PU can calculate the reflectance of the measurement surface WA of the object W to be measured from the ratio of the amplitude A1 to the amplitude A0.

[0068] In the above, the description has been made based on the photoelectric conversion signals S1b and S2b of the images IM1b and IM2b formed by the second wavelength component among the first detection light DL1 and the second detection light DL2. However, of course, any pair of images (the pair of image IM1a and image IM2a, the pair of image IM1b and image IM2b, the pair of image IM1c and image IM2c) formed by the first detection light DL1 and the second detection light DL2 in each wavelength component can be used to calculate the position information of the measurement surface WA by the above method. Also, the position information of the measurement surface WA may be calculated respectively using each pair of images formed by the first detection light DL1 and the second detection light DL2 in each wavelength component.

[0069] In the case of a semiconductor wafer in the above-described integrated circuit formation process, etc., the reflectance of the measurement surface WA may vary depending on the wavelength of the detection light according to the internal structure, etc. Therefore, the calculation unit PU may calculate the position information of the measurement surface WA respectively from a pair of images by a plurality of wavelength components in the first detection light DL1 and the second detection light DL2, and perform statistical processing on the calculated plurality of position information to calculate the final position information of the measurement surface WA. Note that the plurality of position information of the measurement surface WA calculated respectively from a pair of images by a plurality of wavelength components may be interpreted as position information elements in order to distinguish them from the final position information of the measurement surface WA.

[0070] Also, not only for the image of the P-polarized light component received by the photodetector 28a, but also for the image of the aperture SL of the S-polarized light component received by the photodetector 28b, by performing the same detection and calculation as above, a plurality of position information elements of the measurement surface WA can be calculated respectively.

[0071] As the above statistical processing, the arithmetic unit PU may calculate the average value of a plurality of position information elements. Further, for each of the P-polarization component and the S-polarization component, the arithmetic unit PU may calculate the reflectance of the measurement surface WA of the object W to be measured at that wavelength from a pair of images formed by a plurality of wavelength components, and calculate the final position information based on the position information elements for each polarization and wavelength and the reflectance.

[0072] The arithmetic unit PU may correct the calculated position information regarding the Z direction of the measurement surface WA with the information on the Z position of the stage ST measured by an interferometer or an encoder (not shown). Further, while a control unit (not shown) controls the stage ST to scan in the X direction and the Y direction, the position in the Z direction of the measurement surface WA may be detected to obtain the position information regarding the Z direction over the entire surface of the measurement surface WA.

[0073] (Modification 1) In the above first embodiment, the surface position detection device 100 is configured to detect the position in the Z direction perpendicular to the measurement surface WA of the object W to be measured. However, it is not limited to the position in the direction perpendicular to the measurement surface WA, and the position in the direction intersecting the measurement surface WA may be detected.

[0074] (Modification 2) In the first embodiment, the longitudinal direction of the opening SL on the incident surface 23a of the light receiving prism 23 shown in FIG. 6 coincides with the Y direction. However, the longitudinal direction of the opening SL does not necessarily have to coincide with the Y direction, and it may be shifted by a predetermined angle from the Y direction within the plane of the incident surface 23a, and it may be in the x2 direction in FIG. 6, that is, a direction intersecting the direction in imaging relationship with the X direction on the measurement surface WA. In this case, the detection region DA on the measurement surface WA and the images (such as IM1a to IM1c and IM2a to IM2c) of the opening SL formed on the light receiving surfaces 29a and 29b also have their longitudinal directions shifted by a predetermined angle from the Y direction. To cope with this, the shape of each photoelectric conversion unit in the light receiving surfaces 29a and 29b may be set to a shape including each image (such as IM1a to IM1c and IM2a to IM2c), and the longitudinal direction of the above-described substantially rectangular pattern constituting the diffraction grating 14a may be shifted by a predetermined angle from the Y direction.

[0075] In the surface position detection device 100 of the first embodiment, it was assumed that the light quantity distributions IDL1 of the first detection light DL1 and IDL2 of the second detection light DL2 on the surface WA to be inspected are both constant within a predetermined range in the Y direction. However, as described above, when the longitudinal direction of the detection region DA is deviated from the Y direction by a predetermined angle, it is preferable that the light quantity distributions IDL1 and IDL2 are both constant within a predetermined range in the direction deviated from the Y direction by a predetermined angle.

[0076] Note that, as understood from the above detection principle, the light quantity distributions IDL1 and IDL2 do not necessarily have to be constant in the Y direction or the direction rotated by a predetermined angle from the Y direction. That is, it is sufficient that the sum of the light quantity distributions in the width Dwy in the Y direction or the direction rotated by a predetermined angle from the Y direction of the detection region DA is constant at each position in the X direction. However, by making the light quantity distributions IDL1 and IDL2 both constant within a predetermined range in the Y direction or the direction rotated by a predetermined angle from the Y direction, even when the reflectance of the surface WA to be inspected greatly varies in the Y direction, it becomes less susceptible to the influence of the variation in reflectance. As a result, more accurate detection of the surface position can be performed.

[0077] (Modification Example 3) The first detection light DL1 and the second detection light DL2 do not necessarily have to be incident on the surface WA to be inspected at the same incident angle θ. For example, the incident angles of the first detection light DL1 and the second detection light DL2 may be somewhat different. In this case, by adding an optical member such as a prism that adjusts the difference in the incident angles of the +1st order diffracted light DP and the -1st order diffracted light DM included in each, the period FX in the X direction of the light quantity distributions of the first detection light DL1 and the second detection light DL2 on the surface WA to be inspected can be made to coincide. However, by making the incident angles of the first detection light DL1 and the second detection light DL2 equal, there is an advantage that the addition of such an optical member becomes unnecessary and the optical system can be simplified.

[0078] (Modification Example 4) In the irradiation region IA of the surface WA to be inspected, the sum of the light amounts of the first detection light DL1 and the second detection light DL2 does not necessarily have to be constant along the X direction. As described above, the first detection light DL1 and the second detection light DL2 are received at different positions on the light receiving surfaces 29a and 29b of the light detection units 28a and 28b. Therefore, in the light detection units 28a and 28b, the sensitivity of photoelectric conversion to the first detection light DL1 and the second detection light DL2 may be easily set separately.

[0079] Therefore, for example, even if the light amount distribution IDL1 by the first detection light DL1 and the light amount distribution IDL2 by the second detection light DL2 are different, by adjusting the sensitivity of the photoelectric conversion of the light detection units 28a and 28b, photoelectric conversion signals S1a and S1b with equal amplitudes can be obtained. However, by making the sum of the light amounts of the first detection light DL1 and the second detection light DL2 constant in the irradiation region IA of the surface WA to be inspected, the adjustment of the sensitivity by the light detection units 28a and 28b and the arithmetic unit PU can be omitted, and the configuration of the surface position detection device 100 can be simplified.

[0080] (Modification Example 5) In the surface position detection device 100 of the first embodiment, a light shielding portion OF and an opening portion SL are formed on the incident surface 23a of the light receiving prism 23, and the opening portion SL is defined as defining the detection region DA on the surface WA to be inspected. However, since the surface WA, the opening portion SL, and the light receiving surfaces 29a and 29b are in an imaging relationship (conjugate), instead of providing the light shielding portion OF, the light receiving regions (regions where photoelectric conversion is performed) within the light receiving surfaces 29a and 29b may be limited. That is, the width of each light receiving region in the x3 direction may be set to be narrower than the width in the Y direction. Alternatively, when a two-dimensional imaging sensor is used as the light detection unit 28a, instead of providing the light shielding portion OF, the arithmetic unit PU may calculate the surface position of the surface WA using only the photoelectric conversion signals from the light receiving pixels corresponding to the opening portion SL. That is, the arithmetic unit PU may calculate the surface position of the surface WA using the photoelectric conversion signals from the light receiving pixels within a range where the width in the x3 direction is narrower than the width in the Y direction of the two-dimensional imaging sensor. At this time, the composite separation member 25 may be omitted. Alternatively, the detection light from the light source 10 may be monochromatic light.

[0081] (Modification Example 6) In the surface position detection device 100 of the first embodiment, the detection light splitting member 16 is arranged in the light transmitting unit. However, the member that splits the first detection light DL1 and the second detection light DL2 is not necessarily limited to the detection light splitting member 16 arranged on the pupil plane TP of the light transmitting unit. For example, the optical system may be configured such that the first detection light DL1 and the second detection light DL2 are formed to overlap on the surface to be inspected WA without using the detection light splitting member 16. Further, the detection light splitting member 16 is not limited to being composed of the plurality of prisms described above. For example, a splitting mirror composed of a plurality of non-parallel reflecting surfaces may be used.

[0082] (Surface Position Detection Device of the Second Embodiment) Next, the surface position detection device 100a of the second embodiment will be described. However, since most of the surface position detection device 100a of the second embodiment is common to the surface position detection device 100 of the first embodiment described above, only the differences will be described below, and the description of the common points will be omitted. In the surface position detection device 100a of the second embodiment, instead of the detection light splitting member 16 in the first embodiment shown in FIG. 4(a), the detection light splitting member 161 shown in FIG. 10(a) is used.

[0083] FIG. 10(a) is a perspective view showing the detection light splitting member 161, and FIG. 10(b) is a view of the detection light splitting member 161 as seen from the first lens 17 on the light transmitting side. The optical axis AX2 and the Y axis in FIG. 10 are the same as the optical axis AX2 and the Y axis in FIG. 4. The detection light splitting member 161 has a prism 16e whose thickness in the optical axis AX2 direction varies depending on the position of z1, and three prisms 16f to 16h that are arranged in contact with each other in the Y direction at positions downstream from the prism 16e in the optical path direction of the optical axis AX2.

[0084] The three prisms 16f to 16h are arranged in contact with each other in the Y direction, their boundaries are parallel in the z1 direction, and their thicknesses in the optical axis AX2 direction vary differently according to the position of z1. As a result, the detection light splitting member 161 splits the detection light into three detection lights, i.e., a first detection light DL10, a second detection light DL20, and a third detection light DL30, in the Y direction on the pupil plane TP. Then, the detection light splitting member 161 deflects the traveling directions of the first detection light DL10, the second detection light DL20, and the third detection light DL30 by a small angle in the z1 direction.

[0085] FIG. 11(a) is a diagram showing the light quantity distributions IDL10, IDL20, and IDL30 of the first detection light DL10, the second detection light DL20, and the third detection light DL30 on the surface to be inspected WA in the surface position detection device 100a of the second embodiment. By appropriately setting the deflection amounts of the first detection light DL10, the second detection light DL20, and the third detection light DL30 by the detection light splitting member 161, the light quantity distributions IDL10, IDL20, and IDL30 are light quantity distributions shifted from each other by 1 / 3 of the period FX2 of their intensity modulation.

[0086] The detection light splitting member 161 splits the detection light into three detection lights, i.e., a first detection light DL10, a second detection light DL20, and a third detection light DL30, in the Y direction on the pupil plane TP of the light transmitting unit. Therefore, also in the light separation member 25a of the composite separation member 25 disposed on the pupil plane RP2 of the light receiving unit in the surface position detection device 100a of the second embodiment, the detection light is split into three in the Y direction of the pupil plane RP2. Specifically, a new block in which both the incident surface and the emission surface are perpendicular to the optical axis AX6 may be added between the first block 251 and the second block 252 of the light separation member 25a shown in FIG. 7(b). Then, the shape of the incident side surface of the third block 253 may be made to coincide with the shapes of the emission side surfaces of the first block 251, the second block 252, and the new block.

[0087] As a result, images formed by the first detection light DL10, the second detection light DL20, and the third detection light DL30 of the opening SL are separated and formed on the light receiving surfaces 29a and 29b in the Y direction, respectively. FIG. 11(b) is a diagram showing, as an example, the relationship between the position (horizontal axis) of the test surface WA in the Z-axis direction, the photoelectric conversion signal S10b of the image IM10b by the second wavelength component of the first detection light DL10, the photoelectric conversion signal S20b of the image IM20b by the second wavelength component of the second detection light DL20, and the photoelectric conversion signal S30b of the image IM30b by the second wavelength component of the third detection light DL30. The photoelectric conversion signals S10b, S20b, and S30b are all signals represented by the following formulas (5) to (7) with the same period FZ and amplitude A2 with respect to the position of the test surface WA in the Z-axis direction and a phase shift of 1 / 3 of the period FZ.

[0088] S10b = A2+A2×cos{2π(Z-Zc) / FZ2)}···(5) S20b = A2+A2×cos{2π(Z-Zc) / FZ2)-2π / 3}···(6) S30b = A2+A2×cos{2π(Z-Zc) / FZ2)-4π / 3}···(7) Zc is the Z position of the test surface WA where the photoelectric conversion signal S10b is maximum. Zd shown in FIG. 11(b) is a position separated from Zc by a period FZ2 on the +Z side.

[0089] The arithmetic unit PU calculates candidates (Zu1 to Zu3) for the Z position Zu of the test surface WA at an arbitrary position between Za and Zb from the value S10u of the photoelectric conversion signal S10b, the value S20u of the photoelectric conversion signal S20b, and the value S20u of the photoelectric conversion signal S30b by calculations based on formulas (8) to (11). Zu1 = FZ2×[cos-1{(S10u-A2) / A2}] / 2π + Zc···(8) Zu2 = FZ2×[cos-1{(S20u-A2) / A2}+2π / 3] / 2π+ Zc···(9) Zu3 = FZ2×[cos-1{(S20u-A2) / A2}+4π / 3] / 2π+ Zc···(10) A2 = (S10u+S20u+S30u) / 3···(11)

[0090] From the properties of the inverse cosine function, candidates Zu1 to Zu3 for the Z position Zu are each obtained in two values within the range from Zc to Zd. However, the arithmetic unit PU calculates the Z position Zu of the surface WA to be inspected by adopting values that generally match among them and performing the averaging process of Expression (12). Zu = (Zu1 + Zu2 + Zu3) / 3 ··· (12) Also in the second embodiment, when the width Dwx in the X direction of the detection region DA is made shorter than half of the period FX2 in the X direction of the light quantity distribution IDL10 to the light quantity distribution IDL30, the variation from the photoelectric conversion signal S10b to the photoelectric conversion signal S30b when the surface WA to be inspected varies in the Z direction can be increased. As a result, the detection accuracy can be further improved.

[0091] In the second embodiment, since the light quantity distributions IDL10, IDL20, and IDL30 with different phases by one-third of the period FX2 of the intensity modulation are formed on the surface WA to be inspected, the photoelectric conversion signals S10b to S30b also change as so-called three-phase signals with respect to the Z position of the surface WA to be inspected. For this reason, the position of the surface WA to be inspected can be detected in a wider Z range (from Zc to Zd) compared to the first embodiment.

[0092] In the above, the description has been made using the photoelectric conversion signals S10b, S20b, and S30b of the second wavelength component among the first detection light DL10 to the third detection light DL0. However, similar to the first embodiment, the position of the surface WA to be inspected can be calculated using the photoelectric conversion signals of each wavelength component of each detection light DL10 to DL30.

[0093] Also, not only for the image of the P-polarized light component received by the light detection unit 28a, but also for the image of the aperture SL of the S-polarized light component received by the light detection unit 28b, by performing the same detection and calculation as above, a plurality of position information elements of the surface WA to be inspected can be calculated respectively. The method of calculating the final position information of the surface WA to be inspected from the calculated plurality of position information elements is the same as the method in the first embodiment described above. Note that the configurations described in each modification example of the first embodiment above may be applied to the surface position detection device of the second embodiment with appropriate necessary changes.

[0094] (Effects of the First Embodiment, the Second Embodiment, and Each Modification Example) (1) In the surface position detection devices 100 and 100a of the above-described first embodiment, second embodiment, and each modification example, which are surface position detection devices for obtaining position information of the surface to be inspected WA along an axis (Z-axis) intersecting the surface to be inspected WA, a plurality of detection lights (DL1, DL2, etc.) that are smoothly intensity-modulated in a first direction (X-direction) within the surface to be inspected WA on the surface to be inspected WA are obliquely incident on the surface to be inspected WA from a direction having a direction component in the first direction and are superimposed and irradiated to form an irradiation region IA on the surface to be inspected WA. A light transmitting unit TS, and light detection units 28a and 28b having light receiving surfaces 29a and 29b disposed at positions optically conjugate with the surface to be inspected WA. A plurality of detection lights (DL1, DL2, etc.) reflected by a detection region DA in which the width Dwx in the first direction of the irradiation region IA is a predetermined value are received at different positions of the light receiving surfaces 29a and 29b, and a light receiving unit RS that outputs photoelectric conversion signals of the plurality of detection lights (DL1, DL2, etc.) respectively, and an arithmetic unit PU that calculates position information of the surface to be inspected WA based on the photoelectric conversion signals of the plurality of detection lights output from the light receiving unit RS. With this configuration, a highly accurate surface position detection device 100 that is less susceptible to variations in the reflectivity of the surface to be inspected WA can be realized.

[0095] (2) By making the light intensity in a second direction intersecting the first direction (X-direction) constant in the irradiation region IA for each of the plurality of detection lights (DL1, DL2, etc.), even when the reflectivity of the surface to be inspected WA varies greatly in a direction intersecting the first direction, it becomes less susceptible to the influence of the variation in reflectivity. As a result, more accurate detection of the surface position can be performed. (3) By making the sum of the light amounts of the plurality of detection lights (DL1, DL2, etc.) in the detection region DA on the surface to be inspected WA constant along the first direction (X-direction), the reflectivity of the detection region DA can be easily calculated from the sum of the photoelectric conversion signals (S1b, S2b, etc.) of the plurality of detection lights received and photoelectrically converted by the light detection units 28a and 28b. Then, by reflecting the calculated reflectivity in the calculation of the surface position of the detection region DA, more accurate detection of the surface position can be performed.

[0096] (4) On the surface to be inspected WA, a plurality of detection lights (DL1, DL2, etc.) are intensity-modulated in the first direction (X direction) by sine wave functions with the same period FX and the same amplitude, and the phases of the sine wave functions in the first direction are different from each other, so that the configuration of the calculation unit PU can be simplified. (5) By configuring the plurality of detection lights to include a first detection light DL10, a second detection light DL20, and a third detection light DL30 in which the phases of the sine wave functions are different from each other by 1 / 3 of the period FX2, the position on the surface to be inspected WA can be detected over a wider range in the measurement direction (Z direction).

[0097] (6) By making the width Dwx in the first direction (X direction) of the detection region DA shorter than half of the period FX of the sine wave function, the fluctuations in the photoelectric conversion signals S1b, S2b, etc. when the surface to be inspected WA fluctuates in the Z direction can be increased. As a result, the detection accuracy can be further improved. (7) The plurality of detection lights (DL1, DL2, etc.) irradiated by the light transmission unit TS onto the surface to be inspected WA each include a plurality of different wavelengths, and the light receiving unit RS can be configured to include a spectroscopic member 25b that spectroscopically separates each of the plurality of detection lights according to the wavelength and guides them to different positions on the light receiving surfaces 29a, 29b. Further, the photodetection units 28a, 28b output photoelectric conversion signals (S1b, S2b, etc.) for each of the plurality of different wavelengths incident at different positions for each of the plurality of detection lights (DL1, DL2, etc.), and the calculation unit PU can also be configured to calculate the position information of the surface to be inspected WA based on the photoelectric conversion signals (S1b, S2b, etc.) of the plurality of detection lights for each of the plurality of different wavelengths. In this case, since the position of the surface to be inspected WA is detected by the detection lights of a plurality of different wavelengths, the position of the surface to be inspected WA can be detected with higher accuracy. In addition, in the surface position detection device of the first and second embodiments, it is not necessary to obtain the position information of the surface to be inspected WA. As an example, the surface position detection device of the first and second embodiments may measure the spectral reflectance distribution of the surface to be inspected WA without obtaining the position information of the surface to be inspected WA.

[0098] (Exposure apparatus of the third embodiment) FIG. 12 is a diagram showing an overview of the exposure apparatus 200 of the third embodiment. The exposure apparatus 200 of the third embodiment is an exposure apparatus for exposing and transferring an exposure pattern onto a photoresist (resist) PR formed on the surface of a semiconductor wafer or a substrate for a display device (hereinafter collectively referred to as "substrate") WF. The exposure apparatus 200 includes the surface position detection devices 100 and 100a of the above-described first or second embodiment. The surface position detection devices 100 and 100a treat the substrate WF as the object W to be measured described above, and treat the surface of the photoresist formed on the surface of the substrate WF as the surface WA to be inspected described above. In FIG. 12, the directions of the X, Y, and Z axes are such that the direction parallel to the optical axis AXP of the projection optical system 57 is the Z-axis direction.

[0099] The substrate WF carried into the exposure apparatus 200 is placed on a substrate stage 59 movable on the surface plate 61, and is disposed below the surface position detection device 100 by the movement of the substrate stage 59. The control device 70 sends a control signal S5 to move the substrate stage 59 in the XY plane, and causes the surface position detection device 100 to detect the Z-direction position information of a plurality of locations on the surface of the substrate WF. At this time, the Z-direction position information of the substrate stage 59 on which the substrate WF is placed is measured by interferometers 63a and 64b that are integrally held with the surface position detection device 100 via the positions of the reference mirrors 60a and 60b. Further, the XY-direction position of the substrate stage 59 is measured by the interferometer 62 via the position of the reference mirror 60b. The interferometers 63a and 64b may be interpreted as a first measurement unit.

[0100] Information regarding the Z-direction position of the surface of the substrate WF detected by the surface position detection device 100, and the Z-direction position information of the substrate stage 59 are transmitted to the control device 70 as a signal S2. The XY-direction position information of the substrate stage 59 is transmitted to the control device 70 as a signal S3. Based on the signal S2 and the signal S3, map data representing the Z-direction position information with respect to the XY position of the surface of the substrate WF is created in the control device 70.

[0101] Subsequently, the control device 70 moves the substrate stage 59 within the XY plane so that the substrate WF is disposed below the projection optical system 57, and exposes the resist PR formed on the surface of the substrate WF. The exposure may be so-called step exposure or scan exposure. At the time of exposure, the control device 70 controls the substrate stage 59 based on map data representing the position information in the Z direction with respect to the XY position on the surface of the substrate WF. That is, the control device 70 sends a control signal S4 to the substrate stage 59, moves the substrate stage 59 in the XY directions, and drives the substrate stage 59 in the Z direction so that the surface of the substrate WF within the exposure field of the projection optical system 57 coincides with the image plane of the projection optical system 57. As necessary, the control device 70 slightly rotates (levels) the substrate stage 59 about the Y-axis direction and the X-axis direction as rotation centers.

[0102] The position of the substrate stage 59 in the Z direction during exposure is measured by interferometers 58a and 58b that are integrally held with the projection optical system 57 via the positions of the reference mirrors 60a and 60b, and is transmitted to the control device 70 as a signal S1. The position of the substrate stage 59 in the XY directions during exposure is measured by the interferometer 62 via the position of the reference mirror 60b, and is transmitted to the control device 70 as a signal S3. The interferometers 58a and 58b may be interpreted as a second measurement unit.

[0103] The control device 70 controls the substrate stage 59 during exposure based on the map data representing the position information in the Z direction with respect to the XY position on the surface of the substrate WF described above, the signal S1, and the signal S3. In the above-described exposure operation, illumination light from the exposure light source 50 irradiates the original plate (mask pattern) drawn on the mask 52 via the illumination optical system 51. As a result, an image of the original plate is projected onto the resist PR on the substrate WF via the projection optical system 57, and an exposure pattern is exposed on the resist PR.

[0104] When the exposure operation is a scanning exposure, during the exposure operation, the mask 52 and the substrate WF scan relative to the projection optical system 57 synchronously. For this scanning, the mask 52 is placed on the mask stage 53, and the mask stage 53 is movable in the X direction on the mask surface plate 54. The position of the mask stage 53 is measured by the mask interferometer 56 via the position of the mask reference mirror 55. When the exposure operation is a step exposure, during one-shot exposure, the substrate stage 59 is stationary, and between each shot, the substrate stage 59 moves a predetermined distance in the X direction or the Y direction.

[0105] The projection optical system 57 may be a so-called immersion optical system in which a liquid is disposed between the projection optical system 57 and the substrate WF. Alternatively, the exposure apparatus 200 may be not limited to an apparatus that performs exposure with light or ultraviolet rays, but may be an apparatus that performs exposure with an electron beam or an X-ray. The interferometers 58a, 58b, 63a, 63b, 62 are not limited to interferometers, and may be encoders for position measurement.

[0106] (Effect of the exposure apparatus of the third embodiment) (8) The exposure apparatus 200 of the third embodiment includes the surface position detection apparatus 100 of the first embodiment or the second embodiment as an apparatus for detecting the Z-direction position of the surface of the substrate WF on which the resist PR is formed. With this configuration, measurement errors due to the reflectance distribution on the surface of the substrate WF can be suppressed to a small level, and the surface position of the surface of the substrate WF can be measured with high precision. As a result, in the exposure apparatus of the third embodiment, the surface of the substrate WF on which the resist PR is formed can be accurately aligned with respect to the projection optical system 57, and thus good projection exposure can be performed.

[0107] (Substrate processing system of the fourth embodiment) FIG. 13 is a diagram showing an outline of a substrate processing line including the substrate processing system 300 of the fourth embodiment. The substrate processing system 300 includes the surface position detection apparatuses 100, 100a of the first embodiment, the second embodiment, or each modification described above, the exposure apparatus 200 of the second embodiment described above, and the data holding apparatus 110.

[0108] In the substrate processing system 300, a substrate WF having a resist PR formed on its surface by a coater developer (track system) 104 is transported by a transport mechanism 101 to a surface position detection device 100. The surface position detection device 100 has a stage ST for placing the substrate WF inside it. As the stage ST moves the substrate WF in the direction within its surface, position information on the surface of the substrate WF is detected across the front surface of the substrate WF. The surface position detection device 100 may further measure the reflectivity of the surface of the substrate WF. Also, the surface position detection device 100 may measure a plurality of pieces of position information and reflectivity of the surface of the substrate WF for each detection wavelength. The position information on the surface of the substrate WF measured by the surface position detection device 100, or further the reflectivity information, is transmitted to a data holding device 110 and temporarily stored.

[0109] The substrate WF whose surface position has been detected by the surface position detection device 100 is transported by a transport mechanism 102 to an exposure device 200. The position information on the surface of the substrate WF or further the reflectivity information stored in the data holding device 110 is also transmitted to the exposure device 200. In the exposure device 200, the position of the surface of the substrate WF is detected using the position information on the surface of the substrate WF measured by the surface position detection device 100 or further the reflectivity information. Then, the exposure device 200 operates a substrate stage 59 to align the surface of the substrate WF with the image plane of a projection optical system 57, and exposes an exposure pattern onto the resist PR on the surface of the substrate WF.

[0110] Note that in the substrate processing system 300 of the fourth embodiment, accurate position information on the surface of the substrate WF or further reflectivity information has already been measured by the surface position detection device 100. Therefore, the surface position detection device 100 inside the exposure device 200 may be omitted, and instead, a conventional surface position detection device may be used.

[0111] The substrate WF exposed by the exposure apparatus 200 is conveyed to the coater-developer 104 by the conveyance mechanism 103, and the resist PR on the substrate WF is developed by the coater-developer 104. Thereafter, the substrate WF is conveyed to the processing apparatus 106 by the conveyance mechanism 105. Using the developed resist PR as a mask, that is, based on the resist pattern PR formed in the resist PR, the surface of the substrate WF or the film formed on the surface of the substrate WF is processed (etched, ion-implanted, etc.) by the processing apparatus 106. Therefore, the substrate processing system 300 can form a circuit pattern based on the exposure pattern exposed on the resist PR on the substrate WF and manufacture a device.

[0112] In the substrate processing system 300 of the above-described fourth embodiment, it is provided with the data holding device 110 that temporarily stores the position information of the surface of the substrate WF measured by the surface position detection device 100 or further the reflectance information, but it is not limited thereto. The data holding device 110 may be built in the surface position detection device 100, or may be built in the exposure apparatus 200. Alternatively, the data holding device 110 may be included in a computer or a storage device that manages a device factory such as a semiconductor factory where the surface position detection device 100 and the exposure apparatus 200 are installed and is connected to the surface position detection device 100 and the exposure apparatus 200 by a network.

[0113] (Effect of the substrate processing system of the fourth embodiment) (9) The substrate processing system of the fourth embodiment is a substrate processing system 300 that targets the substrate WF, and includes a first stage ST on which the substrate WF is placed, and the measurement device having the surface position detection devices 100, 100a of the above-described first embodiment, second embodiment, or modification example that measures the positions in the direction (Z direction) intersecting the surface at a plurality of locations on the surface of the substrate WF, and a second stage 59 on which the substrate WF after the measurement by the measurement device is placed, and an exposure apparatus 200 that exposes the substrate WF placed on the second stage 59. Then, the exposure apparatus 200 performs exposure while changing the position in the direction intersecting the surface of the substrate WF using at least the measurement results by the measurement devices 100, 100a. With this configuration, measurement errors caused by the reflectance distribution on the surface of the substrate WF can be suppressed to a small level, and the surface of the substrate WF on which the resist PR is formed can be accurately aligned with respect to the projection optical system 57. As a result, a good exposure pattern can be formed on the substrate WF.

[0114] (Device Manufacturing Method of the Fifth Embodiment) The device manufacturing method of the fifth embodiment will be described with reference to FIG. 14. The device manufacturing method of the fifth embodiment is a method for manufacturing a device using the exposure apparatus 200 of the above-described third embodiment or the substrate processing system 300 of the fourth embodiment. Therefore, for details of the operations of the exposure apparatus 200 of the third embodiment and the substrate processing system 300 of the fourth embodiment, refer to the above description.

[0115] In step S100, a film made of a dielectric, metal, or semiconductor is formed on the surface of the substrate WF (semiconductor wafer or substrate for display device). Next, in step S101, a photoresist (resist) PR is formed on the film formed in step S100. Then, in step S102, the position of the surface of the resist PR formed on the surface of the substrate WF is detected using the surface position detection device 100 included in the exposure apparatus 200 of the above-described third embodiment or the substrate processing system 300 of the fourth embodiment.

[0116] Next, in step S103, the exposure apparatus 200 uses the position of the surface of the resist PR detected by the surface position detection device 100 in step S102 to expose an exposure pattern onto the resist PR on the substrate WF. Then, in step S104, the resist PR exposed with the exposure pattern is developed to form a resist pattern. Thereafter, in step S105, using the resist pattern as a mask, processing such as etching or ion implantation is performed on the film formed on the substrate WF or the surface of the substrate WF.

[0117] Through the above steps S100 to S105, a single layer of circuit pattern constituting the device is formed on the substrate WF. Therefore, after the completion of step S105, the process proceeds to the next step, and by repeating steps S100 to S105 again, a device (such as a semiconductor integrated circuit or a display device) composed of multiple layers can be manufactured.

[0118] (Effect of the device manufacturing method of the fifth embodiment) (10) From one perspective, the above-described device manufacturing method includes forming a resist PR on the surface of the substrate WF, detecting the position of the surface of the resist PR formed on the surface of the substrate WF using the exposure apparatus 200 of the above-described third embodiment, setting the surface of the resist PR at a predetermined position in the direction of the optical axis (AXP) of the projection optical system 57 and exposing the exposure pattern, developing the resist PR, and processing the surface of the substrate WF based on the resist pattern PR formed by the development. With this configuration, it is possible to greatly suppress the measurement error caused by the reflectance distribution on the surface of the substrate WF and accurately align the surface of the resist PR on the substrate WF with respect to the projection optical system 57. As a result, a good exposure pattern can be formed on the substrate WF, and thus a high-performance device can be manufactured.

[0119] (11) From another perspective, the above-described device manufacturing method includes forming a resist PR on the surface of the substrate WF and detecting the positions of a plurality of points on the surface of the resist PR formed on the surface of the substrate WF in the direction intersecting the surface using the substrate processing system 300 of the fourth embodiment. Then, it includes exposing the exposure pattern while changing the position of the surface of the resist PR in the direction intersecting the surface based on the detected positions of the plurality of points, and forming a circuit pattern based on the exposure pattern. With this configuration, it is possible to significantly reduce the measurement error caused by the reflectance distribution on the surface of the substrate WF and accurately align the surface of the substrate WF on which the resist PR is formed with respect to the projection optical system 57. As a result, a good exposure pattern can be formed on the substrate WF, and ultimately, a high-performance device can be manufactured.

[0120] The present invention is not limited to the above content. Other aspects conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. This embodiment may combine all or some of the above-described aspects.

Explanation of Reference Numerals

[0121] 100, 100a: Surface position detection device, 200: Exposure device, 300: Substrate processing system, TS: Light transmitting unit, RS: Light receiving unit, PU: Arithmetic unit, W: Object to be measured, WA: Surface to be inspected, 14: Diffraction grating plate, 17: First lens on the light transmitting side, 15: Second lens on the light transmitting side, 18, 19: Mirrors, TP: Pupil plane, RP1: Pupil plane, RP2: Pupil plane, AX1 - AX6: Optical axes, 20: First lens on the light receiving side, 22: Second lens on the light receiving side, 23: Light receiving prism, 24: Front lens group, 26: Rear lens group, 27: Polarization beam splitter prism, 28a, 28b: Light detection units, 29a, 29b: Light receiving surfaces, ST: Stage ST, 12: Light introduction unit 12, 13: Condenser lens, 16: Detection light splitting member, 25: Composite separation member, 25a: Light separation member 25a, 25b: Spectral member, IA: Irradiation region, DA: Detection region, DP: +1st order diffracted light, DM: -1st order diffracted light, DL1, DL10: First detection light, DL2, DL20: Second detection light, SL: Aperture, IM1a - IM1c, IM2a - IM2c: Images, S1a, S1b: Photoelectric conversion signals

Claims

1. 1. A surface position detection apparatus for determining position information of a test surface along an axis intersecting the test surface, comprising: a light sending unit that irradiates the test surface with a plurality of detection lights, each of which is intensity-modulated in a first direction within the test surface, from a direction having a directional component in the first direction in a superimposed manner at an oblique incidence to the test surface, thereby forming an irradiation area on the test surface; a first light-receiving optical system that forms a first conjugate plane that is optically conjugate with the test surface; a second light-receiving optical system that forms a second conjugate plane that is conjugate with the first conjugate plane; a light detection unit whose light-receiving surface is disposed on the second conjugate plane; and a light-receiving unit that is disposed on the first conjugate plane and has an aperture member that has an aperture for passing the plurality of detection light beams from a detection region in the irradiation region that has a predetermined width in the first direction, the light-receiving unit receiving the plurality of detection light beams that have passed through the aperture member at different positions on the light-receiving surface and outputting photoelectric conversion signals of the plurality of detection light beams, a calculation unit that calculates position information of the test surface based on photoelectric conversion signals of the plurality of detection lights output from the light receiving unit; Equipped with On the test surface, the plurality of detection lights are intensity-modulated in the first direction by sine wave functions of the same period, and the phases of the sine wave functions in the first direction are different from each other; A width of the detection region in the first direction is shorter than half the period of the sine wave function. Surface position detection device.

2. 2. The surface position detection device according to claim 1, A surface position detection device, wherein each of the plurality of detection lights has a constant light intensity in a fourth direction intersecting the first direction in the irradiation area.

3. 3. The surface position detection device according to claim 1, The light sending unit irradiates the test surface with the plurality of detection lights at equal angles relative to a normal to the test surface in the detection region.

4. 4. The surface position detection device according to claim 1, A surface position detection device, wherein a sum of the light amounts of the plurality of detection lights in the detection region is constant along the first direction.

5. 5. The surface position detection device according to claim 1, A surface position detection device, wherein, on the test surface, the plurality of detection lights are intensity-modulated in the first direction by the sine wave function having the same amplitude.

6. 6. The surface position detection device according to claim 5, The plurality of detection beams include a first detection beam and a second detection beam, the phases of the sine wave functions of which differ from each other by half the period.

7. 6. The surface position detection device according to claim 5, a surface position detection device, the plurality of detection beams including a first detection beam, a second detection beam, and a third detection beam, the phases of the sine wave functions of which differ from each other by ⅓ of the period;

8. 8. The surface position detection device according to claim 1, a surface position detection device in which an image of the opening of the opening member is formed on the light receiving surface, and a width of the opening in a second direction that is in an image-forming relationship with the first direction is narrower than a width of the opening in a third direction that intersects with the second direction on the light receiving surface.

9. 9. The surface position detection device according to claim 1, The aperture of the aperture member is in an imaging relationship with the detection area.

10. 10. The surface position detection device according to claim 9, The second light receiving optical system has a light separating member that causes the plurality of detection lights incident on the light receiving unit via the detection region to be incident on different positions on the light receiving surface.

11. 11. The surface position detection device according to claim 10, The light separating member is disposed on a pupil plane of the second light receiving optical system.

12. 12. The surface position detection device according to claim 9, A surface position detection device, wherein a width in a fifth direction that is in an imaging relationship with the first direction of the plurality of detection lights on the light receiving surface is narrower than a width in a sixth direction that intersects with the fifth direction on the light receiving surface.

13. 13. The surface position detection device according to claim 9, A surface position detection device, wherein the second light receiving optical system has an image plane tilt correction member that makes the second conjugate plane perpendicular to the optical axis of the second light receiving optical system, for the first conjugate plane that is inclined with respect to the optical axis of the second light receiving optical system.

14. 9. The surface position detection device according to claim 1, The calculation unit calculates position information of the test surface using photoelectric conversion signals of an area of ​​the multiple detection light beams on the light receiving surface, the width of which in a fifth direction that is in an imaging relationship with the first direction is narrower than the width of a sixth direction that intersects with the fifth direction.

15. 15. The surface position detection device according to claim 1, the calculation unit includes a reflectance calculation unit that calculates a reflectance in the detection region on the test surface based on an intensity distribution of the detection light on the test surface and photoelectric conversion signals of the plurality of detection lights, The calculation unit calculates position information of the test surface based on the calculated reflectance.

16. 16. The surface position detection device according to claim 1, the plurality of detection lights irradiated by the light sending unit onto the test surface each include a plurality of different wavelengths, the light receiving unit includes a spectroscopic member that separates the plurality of detection lights according to wavelength and guides them to different positions on the light receiving surface, the light detection unit outputs a photoelectric conversion signal for each of the plurality of different wavelengths incident at the respective different positions for each of the plurality of detection light beams; The calculation unit calculates position information of the test surface based on photoelectric conversion signals of the plurality of detection light beams for each of the plurality of different wavelengths.

17. 17. The surface position detection device according to claim 16, the calculation unit calculates position information elements of the test surface for each of the plurality of different wavelengths based on photoelectric conversion signals of the plurality of detection light beams for each of the plurality of different wavelengths, and calculates position information of the test surface by statistically processing the calculated position information elements for each of the plurality of different wavelengths.

18. 18. The surface position detection device according to claim 16, a spectral direction of the light beam emitted by the spectroscopic member is a fifth direction that is in an image-forming relationship with the first direction on the light receiving surface.

19. 19. The surface position detection device according to claim 16, The spectroscopic member includes a plurality of prisms having different dispersions.

20. 20. The surface position detection device according to claim 1, The light receiving unit is provided with a polarization separation member that separates the received detection light into a first polarization component and a second polarization component different from the first polarization component.

21. 21. The surface position detection device according to claim 20, The light detection unit includes a first light receiving surface that receives light of the first polarization component as the light receiving surface; a second light receiving surface that receives the second polarized light component.

22. 22. The surface position detection device according to claim 20, the light receiving unit outputs, as the photoelectric conversion signal, a first photoelectric conversion signal corresponding to the first polarization component of light and a second photoelectric conversion signal corresponding to the second polarization component of light; The calculation unit calculates position information of the test surface using the first photoelectric conversion signal and the second photoelectric conversion signal from the light receiving unit.

23. 23. The surface position detection device according to claim 1, the light sending unit includes a diffraction grating disposed in optical paths of the plurality of detection light beams, A surface position detection device, wherein interference fringes caused by a plurality of diffracted light beams from the diffraction grating in each of the plurality of detection light beams form the intensity modulation in the first direction on the test surface.

24. 24. The surface position detection device according to claim 23, A surface position detection device, wherein the plurality of detection light beams travel in different directions from the surface of the diffraction grating.

25. 25. The surface position detection device according to claim 1, The light sending unit includes a detection light splitting member that splits incident light to generate the plurality of detection lights.

26. 26. The surface position detection device according to claim 25, The light sending unit has a pupil plane, The detection light splitting member is disposed on the pupil plane and deflects at least one of the plurality of detection light beams.

27. A projection optical system; a substrate stage on which a substrate is placed and moved; a surface position detection device according to claim 1 , which detects the position of a surface of the substrate as the test surface; An exposure apparatus comprising:

28. 28. The exposure apparatus according to claim 27, a first position measurement unit that measures a position of at least a part of the substrate stage in a direction along an optical axis of the projection optical system at a position where the substrate placed on the substrate stage faces the surface position detection device; a second position measurement unit that measures a position of at least a part of the substrate stage in the optical axis direction at a position where the substrate placed on the substrate stage faces the projection optical system; An exposure apparatus comprising:

29. forming a resist on a surface of the substrate; using the exposure apparatus according to claim 27 or 28, detecting a position of a surface of the resist formed on the surface of the substrate, setting the surface of the resist to a predetermined position in the optical axis direction of the projection optical system, and exposing an exposure pattern; developing the resist; processing a surface of the substrate based on the resist pattern formed by the development; A device manufacturing method comprising:

30. A substrate processing system for processing a substrate, comprising: a measurement apparatus having a first stage on which the substrate is placed, and the surface position detection device according to any one of claims 1 to 26, which measures positions of a plurality of points on a surface of the substrate in a direction intersecting the surface of the substrate; an exposure apparatus including a second stage on which the substrate is placed after the measurement by the measurement apparatus has been completed, the exposure apparatus exposing the substrate placed on the second stage; Equipped with A substrate processing system in which the exposure apparatus performs the exposure while changing a position in a direction intersecting the surface of the substrate, using at least a measurement result by the measurement apparatus.

31. forming a resist on a surface of the substrate; using the substrate processing system according to claim 30, detecting positions of a plurality of points on a surface of the resist formed on the surface of the substrate in a direction intersecting with the surface of the substrate, and exposing an exposure pattern while changing positions of the surface of the resist in a direction intersecting with the surface of the substrate based on the detected positions of the plurality of points; forming a circuit pattern based on the exposure pattern; A device manufacturing method comprising:

Images