Plane position detection device, exposure apparatus, device production method, and substrate treatment system

Abstract

To precisely perform alignment of a plane of a photosensitive substrate to an image plane (image formation lane) since a focal depth of a projection optics system is comparatively shallow in an exposure apparatus.SOLUTION: A surface position detection device includes: a light-receiving part having a light-transmitting part for irradiating a plane to be detected with a plurality of beams of detection light smoothly intensity-modulated in a first direction in a plane to be detected by superimposing by oblique incidence to form an irradiation region; a light receiving part where a light-receiving plane is optically conjugated with a plane to be detected, and for receiving a plurality beams of light reflected in a detection region of an irradiation region at different positions of a light receiving plane, and outputting a plurality of photoelectric conversion signals of detection light; and a computing part for computing position information of the plane to be detected on the basis of photoelectric conversion signals of a plurality of beams of detection light. The light-transmitting part has a diffraction grating disposed on a light path of the plurality of beams of detection light, an interference pattern from the diffraction grating in the plurality of beams of detection light forms an intensity modulation in a first direction on the plane to be detected, and the plurality beams of detection light are each modulated in intensity with a function of a same period in the first direction, and have mutually different phases in the first direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In an exposure apparatus 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, the exposure apparatus must accurately align the surface of the photosensitive substrate with the image plane (imaging plane) of the projection optical system. As a device for detecting the surface position of a photosensitive substrate (surface position of an exposed surface) along the optical axis direction of a projection optical system, for example, an oblique incidence type surface position detecting device is known (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2010 / 0231881 Summary of the Invention

[0004] A surface position detecting device according to a first aspect of the present invention is a surface position detecting device for determining position information of a test surface along an axis intersecting the test surface, the surface position detecting device including a light transmitting unit that irradiates the test surface with a plurality of detection lights that are smoothly intensity-modulated in a first direction within the test surface at oblique incidence from a direction having a directional component in the first direction, in a superimposed manner, to form an irradiation area on the test surface, and a light detecting unit whose light receiving surface is disposed at a position optically conjugate with the test surface, and receives the plurality of detection lights reflected from a detection area of ​​the irradiation area, the width of which in the first direction is a predetermined value, at different positions on the light receiving surface, and The optical fiber measuring device includes a light receiving unit that outputs a photoelectric conversion signal of each of the output lights, and a calculation unit that calculates position information of the test surface based on the photoelectric conversion signals of the plurality of detection lights output from the light receiving unit, wherein the light transmitting unit has a diffraction grating arranged in the optical path of the plurality of detection lights, and interference fringes caused by +1st order diffracted light and -1st order diffracted light from the diffraction grating in each of the plurality of detection lights form the intensity modulation in the first direction on the test surface, and on the test surface, the plurality of detection lights are each intensity-modulated in the first direction by functions of the same period, and the phases of the functions in the first direction are different from each other. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a diagram schematically showing the configuration of a surface position detecting device 100 according to a first embodiment. [Figure 2] FIG. 2 is a side view of a portion of the surface position detecting device 100 as viewed from the −Y direction. [Figure 3] FIG. 2 is a top view of a portion of the configuration of the surface position detecting device 100, as viewed from the +Z direction. [Figure 4] FIG. 4 is a diagram showing an example of a detection light splitting member. [Figure 5] 5(a) is a diagram showing an irradiation area IA on the test surface WA, and FIG. 5(b) is a diagram showing the light intensity distribution in the X-axis direction of the irradiation area IA. [Figure 6] 2 is a view of the incident surface 23a of the light-receiving prism 23 as viewed from the direction of the normal to the incident surface 23a. [Figure 7] FIG. 2 is a diagram showing an example of a composite separating member 25. [Figure 8]10 is a diagram showing an image of a P-polarized component of an aperture SL formed on a light receiving surface 29a. FIG. [Figure 9] 10 is a diagram showing an example of the relationship between the position in the Z-axis direction (horizontal axis) of the test surface WA and the photoelectric conversion signal S1b and the photoelectric conversion signal S2b. FIG. [Figure 10] Fig. 10(a) is a perspective view showing another example of a detection light splitting member, and Fig. 10(b) is a view of another example of a detection light splitting member as seen from the light-sending-side first lens 17 side. [Figure 11] 11(a) is a diagram showing the light intensity distribution of the first detection light, the second detection light, and the third detection light on the test surface WA in the surface position detection device of the second embodiment, and FIG. 11(b) is a diagram showing the relationship between the position of the test surface WA in the Z-axis direction (horizontal axis) and the photoelectric conversion signal. [Figure 12] FIG. 10 is a diagram showing an outline of an exposure apparatus 200 according to a third embodiment. [Figure 13] FIG. 10 is a diagram showing an outline of a substrate processing line including a substrate processing system 300 according to a fourth embodiment. [Figure 14] 1 is a diagram showing an overview of a device manufacturing method. DETAILED DESCRIPTION OF THE INVENTION

[0006] In this specification, the term "optically conjugate" means that one surface and another surface are in an imaging relationship via an optical system. In this specification, the term "imaging relationship" refers to a relationship in which light emitted from any one point in one region is focused, via an optical system, within a range approximately equal to the resolution of the optical system, with a point in another region as its center. In this specification, a "sine wave function" refers to a function in which a predetermined constant is added to a sine function (sin) or a cosine function (cos), and all values ​​are non-negative.

[0007] (Surface position detection device of the first embodiment) Fig. 1 is a diagram schematically illustrating the configuration of a surface position detecting device 100 according to a first embodiment. In Fig. 1, the Z axis is set in a direction perpendicular (normal direction) to the surface of a measurement object W (hereinafter also referred to as "test surface") WA placed on the surface position detecting device 100, the X axis is set in a plane perpendicular to the Z axis, i.e., in a plane parallel to the test surface WA, and the Y axis is set in a plane perpendicular to the paper surface of Fig. 1.

[0008] The path of detection light in the surface position detecting device 100 of the first embodiment will now be described. Detection light is supplied to the light introducing section 12 from, for example, a light source 10 via a light guide 11. The wavelength band of the detection light from the light source 10 is, for example, 400 nm to 800 nm, but is not limited thereto. For example, the detection light may be 400 nm or less, for example, around 200 nm, or 800 nm or more in the infrared range, for example, 1200 nm to 1700 nm. The detection light emitted from the light introducing section 12 is irradiated onto the test surface WA via a condenser lens group 13, a diffraction grating plate 14, a light-transmitting-side second lens group 15, a light-transmitting-side first lens group 17, a mirror 18, and the like. The detection light reflected by the test surface WA reaches the light-receiving prism 23 via a mirror 19, a light-receiving-side first lens group 20, a light-receiving-side second lens group 22, and the like. The detection light refracted by light-receiving prism 23 passes through a relay optical system consisting of front lens group 24 and rear lens group 26 and enters polarization splitter prism 27. The detection light is then split into two different polarized components by polarization splitter prism 27, and each of the split detection light beams enters light-receiving surface 29a of light detecting unit 28a and light-receiving surface 29b of light detecting unit 28b. Although each lens group is shown to have only one lens in FIGS. 1 to 3, each lens group may be made up of one or more lenses. The object to be measured W is placed on a stage ST, and the XYZ position of the stage ST is measured by an interferometer or encoder (not shown).

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

[0010] 2 and 3 are diagrams schematically illustrating a portion of the configuration of the surface position detecting device 100 shown in FIG. 1. FIG. 2 is a side view of the configuration from the condenser lens group 13 to the photodetector 28a, viewed from the -Y direction. In FIG. 2, the optical path from the diffraction grating plate 14 to the test surface WA and the optical path from the test surface WA to the light-receiving prism 23 are linearly developed. FIG. 3 is a top view of the configuration from the condenser lens group 13 to the photodetector 28a, viewed from the +Z direction. In FIGS. 2 and 3, the mirrors 18 and 19, the polarization splitter prism 27, and the photodetector 28b are not illustrated. In addition, in FIGS. 2 and 3, the optical axis AX2 is aligned with the optical axis AX3, the optical axis AX4 is aligned with the optical axis AX5, and the optical axis AX6 is aligned with the X-axis direction.

[0011] Light emitted from the light introducing portion 12 enters the condenser lens group 13 and then enters the diffraction grating plate 14 generally along the optical axis AX1 of the condenser lens group 13. A diffraction grating 14a made of a dielectric film or a metal film is formed on the surface of the diffraction grating plate 14. As an example, the diffraction grating 14a is a one-dimensional grating, and approximately rectangular patterns whose longitudinal direction coincides with the Y direction in the figure are arranged at a predetermined period in the in-plane direction of the diffraction grating plate 14, which is perpendicular to the Y direction. In this example, the diffraction grating 14a selectively generates +1st-order diffracted light DP and -1st-order diffracted light DM.

[0012] The ±1st-order diffracted light beams DP and DM reflected and diffracted by the diffraction grating plate 14 enter the detection light splitter 16 via the light-sending second lens 15. The detection light splitter 16 is located on the pupil plane TP of the light-sending optical system, which consists of the light-sending second lens group 15 and the light-sending first lens group 17. The pupil plane TP is the plane where multiple light beams incident from the same direction at different positions on the test surface WA converge to approximately one point. Conversely, light beams traveling in different directions from a single point on the pupil plane TP enter different positions on the test surface WA from the same direction. The optical axis AX2 is the optical axis between the light-sending second lens group 15 and the light-sending first lens group 17, and coincides with the optical axis AX1 of the condenser lens 13 reflected (mirrored) by the diffraction grating plate 14.

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

[0014] The thickness of any one of the four prisms 16a to 16d in the direction of the optical axis AX2 varies depending on the position in the z1 direction, and imparts a phase difference to the light passing through it that varies depending on the position in the z1 direction, thereby deflecting the traveling direction of the light passing through it by a small angle in the z1 direction. Note that prisms 16a and 16b, and prisms 16c and 16d may not be two separate prisms, but may be integrated prisms whose entrance or exit surfaces have different shapes on the +Y and -Y sides of 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 split into a first detection light DL1 that exits from a prism 16c located on the +Y side of the optical axis AX2 at the pupil plane TP, and a second detection light DL2 that exits from a prism 16d located on the −Y side of the optical axis AX2. The first detection light DL1 and the second detection light DL2 are then deflected by a small angle relative to each other in the z1 direction.

[0016] It should be noted that both the first detection light DL1 and the second detection light DL2 contain the +1st-order diffracted light DP and the −1st-order diffracted light DM. Furthermore, a diffracted 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 in the direction of the optical axis AX2 of the detection light splitting member 16. In this case, 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 as the diffraction grating 14a.

[0017] The first detection light DL1 and the second detection light DL2 are collected by the light-sending first lens group 17, reflected by the mirror 18, and irradiated onto the test surface WA, forming an illumination area IA on the test surface WA. The first detection light DL1 and the second detection light DL2 are light beams that pass through positions on the pupil plane TP that are shifted from each other in the Y direction. Therefore, as shown in FIG. 3, the incident directions of the first detection light DL1 and the second detection light DL2 on the test surface WA are generally parallel to the +X direction, but are shifted from each other in the Y direction. The incident angle θ of the detection light on the test surface WA (the angle of the incident light with respect to the normal NV of the test surface WA) is set to a large angle, for example, equal to or greater than 80 degrees and less than 90 degrees. The optical axis AX3 is obtained by reflecting (mirroring) the optical axis AX2 by the mirror 18. The incident angle θ may be less than 80 degrees or equal to or greater than 90 degrees.

[0018] Fig. 5(a) is a diagram showing an irradiation area IA on the test surface WA, and Fig. 5(b) is a diagram showing the light intensity distribution in the X-axis direction of the irradiation area IA. The solid line shows the light intensity distribution IDL1 of the first detection light DL1, and the dashed line shows the light intensity distribution IDL2 of the second detection light DL2. The detection area DA shown in Fig. 5 will be described later.

[0019] Since the first detection light DL1 and the second detection light DL2 are each composed of two diffracted lights, a +1st-order diffracted light DP and a −1st-order diffracted light DM, the light intensity distributions IDL1 and IDL2 are both interference fringes formed by the two diffracted lights. Therefore, as shown in FIG. 5(b), the light intensity distributions IDL1 and IDL2 are both intensity-modulated by a sine function (sin function) having a predetermined period FX and amplitude in the X direction. In this example, the amplitude of the sine function modulating the light intensity distributions IDL1 and IDL2 is equal to the period FX in the X direction.

[0020] As described above, the first detection light DL1 and the second detection light DL2 are deflected by a small angle by the detection light splitter 16. Due to this deflection, the phases of the sine wave functions of the light intensity distribution IDL1 and the light intensity distribution ID are shifted by half the period FX of the sine wave functions of the respective intensity modulations. However, because the amount of deflection is small, the first detection light DL1 and the second detection light DL2 are superimposed, i.e., nearly overlapping, when they are irradiated onto the irradiation area IA on the test surface WA. In other words, the first detection light DL1 and the second detection light DL2 are obliquely incident onto the test surface WA from a direction having a directional component in the +X direction, and are superimposed on each other, forming an irradiation area IA on the test surface WA.

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

[0022] The reason for locating the detection beam splitting member 16 at the pupil plane TP is to split the ±1st-order diffracted beams DP and DM into the first detection beam DL1 and the second detection beam DL2 according to the direction of incidence on the test surface WA, regardless of the position of incidence on the test surface WA. Therefore, the position of the pupil plane TP where the detection beam splitting member 16 is located does not necessarily have to be the plane where multiple light beams incident from the same direction at different positions on the test surface WA converge exactly at one point. In other words, the position may be slightly off along the optical axis AX2 as long as it is a position where the detection beam can be split into the first detection beam DL1 and the second detection beam DL2 according to the direction of incidence on the test surface WA. This also applies to the other pupil planes described below.

[0023] Light reflected by the test surface WA of the measurement object W passes through the mirror 19, the light-receiving side first lens group 20, the cylindrical lens 21, and the light-receiving side second lens group 22, and then enters the incident surface 23a of the light-receiving prism 23. The optical axis AX5 is the optical axis of the light-receiving side first lens 20 and the light-receiving side second lens 22. The optical axis AX4 is 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 in positions symmetrical to the mirror 18, the first light-transmitting lens group 17, and the second light-transmitting lens group 15, respectively, with respect to the YZ plane containing the center of the irradiation area IA, and have a symmetrical configuration. The incident surface 23a of the light-receiving prism 23 is disposed at a position symmetrical to the diffraction grating 14a on the diffraction grating plate 14 with respect to the YZ plane that includes the center of the irradiation area IA.

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

[0026] The incident surface 23a is optically conjugate with the test surface WA of the measurement object W via the mirror 19, the first light-receiving-side lens group 20, and the second light-receiving-side lens group 22. That is, the first detection light DL1 and the second detection light DL2 emitted from a point on the test surface WA are both focused at a single point on the incident surface 23a. The x2 axis, which is an in-plane direction of the incident surface 23a, is in an imaging relationship with the X axis on the test surface WA. That is, an arbitrary region along the X direction on the test surface WA is imaged on a region along the x2 direction on the incident surface 23a. The z2 axis is an axis perpendicular to the Y axis and the x2 axis.

[0027] The opening SL selectively transmits only the light of the first detection light DL1 and the second detection light DL2 reflected by a portion of the illumination area IA on the test surface WA formed on the incident surface 23a that is in an imaging relationship with the opening SL. Therefore, the portion of the illumination area IA on the test surface WA that is in an imaging relationship with the opening SL on the incident surface 23a via the first light-receiving-side lens 20 and the second light-receiving-side lens 22, etc., may be interpreted as the detection area DA, as shown in Figures 5(a) and 5(b). In other words, only the light of the first detection light DL1 and the second detection light DL2 reflected by the detection area DA on the test surface WA transmits through the opening SL.

[0028] 5(a), the width of the detection area DA on the test surface WA in the X direction is width Dwx, and the width in the Y direction is width Dwy. The imaging magnification from the test surface WA to the incident surface 23a by the light-receiving-side first lens 20 and the light-receiving-side second lens 22 matches the ratio of the width Swx to the width Dwx and the ratio of the width Swy to the width Dwy. In order to focus the reflected light from the large detection area DA with a width Dwx onto the opening SL with a narrow width Swx, a cylindrical lens 21 may be provided on or near the pupil plane RP1 of the optical system formed 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 multiple light rays emitted in the same direction from different positions on the test surface WA converge at approximately one point.

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

[0030] The first detection light DL1 and the second detection light DL2 that have passed through the opening SL are deflected by a predetermined angle due to the refraction action of the light-receiving prism 23, and then emerge 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] The first detection light DL1 and the second detection light DL2 are diffracted when passing through the opening SL, which has a relatively narrow width Swx in the X2 direction, and their propagation directions expand in the Z direction, making it impossible to clearly distinguish between the +1st-order diffracted light DP and the −1st-order diffracted light DM. Therefore, in FIG. 2, the light after passing through the opening SL is shown as the first detection light DL1. In addition, in FIG. 2 viewed from the −Y direction, the second detection light DL2 is shown overlapping the first detection light DL1, and is therefore not shown.

[0032] A composite separating member 25 is disposed at a pupil plane RP2 relative to the entrance plane 23a formed by the front lens group 24. Here, the pupil plane RP2 is a plane where a plurality of light rays emerging in the same direction from different positions on the entrance plane 23a converge at approximately one point. The composite separating member 25 will be described in detail later.

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

[0034] The aperture SL is formed on the entrance surface 23a of the light-receiving prism 23, which is significantly tilted from a plane perpendicular to the optical axis AX6. However, as shown in FIG. 2, the optical path length inside the light-receiving prism 23 changes in the Z direction, so that this tilt of the image plane is corrected. As a result, the image of the aperture SL is formed to coincide with the light-receiving surface 29a, which is disposed perpendicular to the optical axis AX6. In other words, the light-receiving prism 23 can also be considered as an image plane tilt correction member. The direction of rotation of the polarization splitting prism 27 around the optical axis AX6 is set so that the P-polarized light and S-polarized light relative to the polarization splitting surface 27a of the polarization splitting prism 27 coincide with the P-polarized light and S-polarized light relative to the test surface WA.

[0035] The photoelectric conversion signals of the detected light received by the light receiving surfaces 29a, 29b of the photodetectors 28a, 28b and photoelectrically converted are output from the photodetectors 28a, 28b and input to the processing unit PU, which may be a computer device equipped with a CPU and memory. The details of the light detecting units 28a and 28b and the images of the openings SL formed on the light receiving surfaces 29a and 29b thereof will be described later.

[0036] Fig. 7 is a diagram showing an example of a composite separating member 25. For ease of understanding, Fig. 7 shows the optical axis AX6 parallel to the X axis, similar to Figs. 2 and 3. Fig. 7(a) shows a cross-sectional view of the composite separating member 25 in the XY plane passing through the optical axis AX6, and Fig. 7(b) shows a cross-sectional view of the composite separating member 25 in the XZ plane passing through the optical axis AX6. The composite separating member 25 is functionally divided along the optical axis AX6 into an incident-side light separating member 25a and an exit-side light separating member 25b.

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

[0038] As a result, light separating member 25a refracts (deflects) in different directions light incident on the +Y side of optical axis AX6 and light incident on the -Y side of optical axis AX. First block 251, second block 252, and third block 253 are preferably formed from materials with mutually different refractive indices.

[0039] Since composite separating member 25 is disposed on pupil plane RP2, the light incident on the +Y side of optical axis AX6 is first detection light DL1, and the light incident on the -Y side of optical axis AX6 is second detection light DL2, as shown in Fig. 3. The lights deflected by a small angle relative to each other in the Y direction on pupil plane RP2 are formed at positions shifted from each other in the Y direction on light-receiving surfaces 29a and 29b.

[0040] The exit-side dispersive element 25b is a prism formed by two triangular prisms, a fourth block 254 and a fifth block 255, arranged with their hypotenuses facing each other. The entrance surface of the fourth block 254 coincides with the exit surface of the third block 253, and the exit surface of the fifth block 255 coincides with a plane perpendicular to the optical axis AX6. The boundary surface between the fourth block 254 and the fifth block 255 is a plane that includes the Y-axis direction. The fourth block 254 and the fifth block 255 are formed of materials with different dispersions.

[0041] Therefore, the light beams having different wavelengths contained in the first detection light DL1 and the second detection light DL2 are refracted at different angles depending on the wavelengths at the boundary surface between the fourth block 254 and the fifth block 255. As a result, the first detection light DL1 and the second detection light DL2 are separated by the spectroscopic member 25b, and become detection light beams DL1a to DL1c that are deflected by a small angle relative to each other in the Z direction for each wavelength, and are then emitted from the spectroscopic member 25b. The light separating member 25b may be formed of a single prism having different refractive powers depending on the wavelength.

[0042] Since the composite separating member 25 is disposed at the pupil plane RP2, the light beams deflected by a small angle relative to each other in the Z direction by the composite separating member 25 are formed at positions on the light receiving surfaces 29a and 29b that are shifted relative to each other in the Z direction. In FIG. 7, to avoid complexity, the second detection light DL2 and the detection light DL2a to DL2c obtained by separating the second detection light DL2 are not shown.

[0043] Fig. 8 is a diagram showing an image of the P-polarized 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-mentioned incident surface 23a. That is, an arbitrary region along the x2 direction of the incident surface 23a is imaged in a region along the x3 direction on the light-receiving surface 29a. As described above, the x2 axis, which is the in-plane direction of the incident surface 23a, is in an imaging relationship with the X axis within the test surface WA. Therefore, the x3 axis, which is the in-plane direction of the light-receiving surface 29a, is also in an imaging relationship with the X axis within the test surface WA. The z3 axis is an axis perpendicular to the Y axis and the x3 axis. It should be noted that in FIG. 2, which shows the optical path developed on a straight line, the x3 axis in the in-plane direction of the light receiving surface 29a is drawn to coincide with the Z axis for the sake of convenience.

[0044] The relay optical system consisting of the front lens group 24 and the rear lens group 26 may be interpreted as a second light receiving optical system. The x2 direction in the incident surface 23a may be interpreted as the third direction, and the Y direction in the incident surface 23a may be interpreted as the fourth direction. Pupil plane RP2 may be interpreted as a second pupil plane. The x3 direction within the light receiving surface 29a may be interpreted as the fifth direction, and 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, the 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, and multiple images (IM1a to IM1c and IM2a to IM2c) of the opening SL are formed on the light receiving surface 29a. Images IM1a-IM1c and images IM2a-IM2c formed on light-receiving surface 29a, spaced apart in the Y direction, are respectively images formed by first detection light DL1 and second detection light DL2 deflected by a small angle relative to each other in the Y direction by light separating member 25a of composite separating member 25. First detection light DL1 and second detection light DL2 are separated by light separating member 25b into detection light DL1a-DL1c and detection light DL2a-DL2c, which are deflected by a small angle relative to each other in a direction perpendicular to the Y direction for each wavelength, for each wavelength. Therefore, the image of opening SL formed on light-receiving surface 29a is also formed at different positions in the x3 direction depending on the wavelength.

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

[0047] 8, for ease of understanding, the first detection light DL1 and the second detection light DL2 include light of three different wavelengths, and therefore there are three images IM1a-IM1c generated by the first detection light DL1 and three images IMIM2a-IM2c generated by the second detection light DL2. However, the wavelengths of light included in the first detection light DL1 and the second detection light DL2 are not limited to three discrete wavelengths, and may include four or more discrete wavelengths. In this case, the number of images IM1a-IM1c generated by the first detection light DL1 and the number of images IMIM2a-IM2c generated by the second detection light DL2 will be four or more. Furthermore, the wavelengths of the light contained in the first detection light DL1 and the second detection light DL2 are not limited to a plurality of discrete wavelengths, but may be a plurality of discrete or continuous wavelength bands.

[0048] The light receiving surface 29a photoelectrically converts the light quantities of these images IM1a-IM1c and IMIM2a-IM2c, respectively, and outputs the converted light quantities. As an example, the light receiving surface 29a is provided with a plurality of separate photoelectric conversion units, each of which covers one of the images IM1a-IM1c and IMIM2a-IM2c. Each photoelectric conversion unit receives the corresponding image IM1a-IM1c and IMIM2a-IM2c, photoelectrically converts the light quantities, and outputs the converted light quantities.

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

[0050] When a two-dimensional image sensor is used as the light detection unit 28a, the resolution of the light receiving surface 29a in the x3 direction is improved, and the first detection light DL1 and the second detection light DL2 can be separated and received with higher precision. This makes it possible to use light having a continuous spectrum as the first detection light DL1 and the second detection light DL2. By making the width in the x3 direction of each of the multiple images IM1a to IM1c, IMIM2a to IM2c 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 dispersed and received with even higher precision.

[0051] The light detection section 28b has the same configuration as the light detection section 28a, and therefore its description will be omitted. Furthermore, the image of the S-polarized component of the opening SL formed on the light receiving surface 29b is similar to the image of the P-polarized component of the opening SL formed on the light receiving surface 29a described above, and therefore description thereof will be omitted.

[0052] The measurement principle of the surface position detecting apparatus 100 of the first embodiment will be described below. As described above, the light intensity distributions IDL1 and IDL2 shown in FIG. 5B are formed on the test surface WA by irradiation with the first detection light DL1 and the second detection light DL2. Both the first detection light DL1 and the second detection light DL2 are incident from a direction tilted by an incident angle θ in the −X direction with respect to the normal NV of the test surface WA. Therefore, when the test surface WA moves up and down in the Z direction in FIG. 1, the light intensity distributions IDL1 and IDL2 shift as a whole in the X direction while maintaining their distribution shapes. When the test surface WA moves in the +Z direction, the light intensity distributions IDL1 and IDL2 shift in the −X direction.

[0053] On the other hand, the detection area DA shown in FIG. 5(b) is the area where the first detection light DL1 and the second detection light DL2 reflected from 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 first light-receiving-side lens 20 and the second light-receiving-side lens 22. However, because the optical axis AX5 of the first light-receiving-side lens 20 is tilted in the +X direction with respect to the normal NV of the test surface WA, when the test surface WA moves up and down in the Z direction in FIG. 1, the position of the detection area DA also shifts in the X direction on the test surface WA. When the test surface WA moves in the +Z direction, the detection area DA shifts in the +X direction. That is, as the test surface WA moves in the Z direction, the positional relationship in the X direction between the light intensity distributions IDL1 and IDL2 shown in FIG. 5(b) and the detection area DA changes.

[0054] The light intensity of each image IM1a-IM1c of the opening SL formed by the first detection light DL1 on the light receiving surface 29a is proportional to the sum of the light intensity of the first detection light DL1 within the detection area DA. Furthermore, the light intensity of each image IM2a-IM2c of the opening SL formed by the second detection light DL2 on the light receiving surface 29a is proportional to the sum of the light intensity of the second detection light DL2 within the detection area DA. Therefore, the light intensity of each image IM1a-IM1c and IM2a-IM2c varies with the change in the position of the test surface WA in the Z direction. Note that, unlike many conventional surface position detection devices, the positions of each image IM1a-IM1c and IM2a-IM2c on the light receiving surface 29a do not vary even if the position of the test surface WA in the Z direction changes.

[0055] 9 is a diagram showing, as an example, the relationship between the position (horizontal axis) in the Z-axis direction on the test surface WA and the photoelectric conversion signal S1b of image IM1b due to the second wavelength component of the first detection light DL1 and the photoelectric conversion signal S2b of image IM2b due to 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 intensity distributions IDL1 and IDL2 on the test surface WA that are sinusoidal functions whose amplitude is equal to the period FX and whose phase is shifted by half the period FX. Therefore, the photoelectric conversion signals S1b and S2b are both signals that have the same period FZ and amplitude A1 with respect to the position in the Z-axis direction on the test surface WA and are shifted by half the period FZ, as expressed by the following equations (1) and (2):

[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 at which the photoelectric conversion signal S1b is at its maximum and the photoelectric conversion signal S2b is at its minimum. Zb shown in Fig. 9 is located close to Za on the +Z side of Za, and is the Z position of the test surface WA at which the photoelectric conversion signal S1b is at its minimum and the photoelectric conversion signal S2b is at its maximum.

[0057] The calculation unit PU calculates the Z position Zt of the test surface WA, which is located at any 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 calculation based on equations (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] If the width Dwx of the detection area DA in the X direction is set shorter than half the period FX of the light intensity distributions IDL1 and IDL2 in the X direction, the fluctuations of the photoelectric conversion signals S1b and S2b when the test surface WA moves in the Z direction can be increased, thereby further improving the detection accuracy.

[0059] In conventional surface position detection devices, the Z position of the test surface is detected by irradiating the test surface with detection light at an oblique incidence to form an irradiation area with a predetermined width in the X direction, and detecting the position of the center of gravity of the light amount in the X direction of the irradiation area. Therefore, if there is a change in reflectance in the X direction within the irradiation area of ​​the test surface, the change in reflectance will change the position of the center of gravity of the light amount of the irradiation area, resulting in a detection error.

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

[0061] On the other hand, in the surface position detection device of the first embodiment, the detected Z position Zt of the test surface WA is hardly affected by changes in the reflectance of the detection area DA. When the reflectance of the detection area DA changes, the photoelectric conversion signals S1b and S2b both increase or decrease with the same proportional coefficient in response to the change in the reflectance of the detection area DA. This is because even if (S2t - S1t) in equation (3) increases by a factor of α due to a change in the reflectance of the detection area DA, A1 in equation (3), i.e., (S2t + S1t) / 2 in equation (4), also increases by a factor of α, and therefore Zt calculated from equation (3) does not change. That is, the surface position detecting device 100 of the first embodiment can realize a highly accurate surface position detecting device that is less susceptible to fluctuations in the reflectance of the test surface WA.

[0062] In the above, since the light intensity distribution IDL1 of the first detection light DL1 and the light intensity distribution IDL2 of the second detection light DL2 irradiated onto the test surface WA are sinusoidal functions of X, the calculation unit PU calculated the detection position Zt based on equation (3) which includes an arccosine function.

[0063] However, if the light intensity distributions IDL1 and IDL2 are not sinusoidal functions but are other functions, the calculation unit PU may calculate the detection position Zt based on the inverse function of the other functions. Therefore, the light intensity distribution IDL1 of the first detection light DL1 and the light intensity distribution IDL2 of the second detection light DL2 irradiated onto the test surface WA are not limited to sinusoidal functions with respect to X, and may be other functions.

[0064] However, the light intensity distributions IDL1 and IDL2 must be smooth at least in the portion corresponding to the detection area DA. If the light intensity distributions IDL1 and IDL2 are not smooth, that is, if the light intensity distributions change in a manner that is not differentiable in the X direction at any position, it will be difficult to calculate the detection position Zt with high accuracy from the value S1t of the photoelectric conversion signal S1b and the value S2t of the photoelectric conversion signal S2b. Note that "smooth" may also be defined as a function having a continuous differential coefficient (derivative) within a certain interval (i.e., not bending). The light intensity distributions IDL1 and IDL2 being smooth in the portion corresponding to the detection area DA may also be defined as a function that, when fitting the light intensity distributions IDL1 and IDL2 to a certain function, has a continuous differential coefficient in the portion corresponding to the detection area DA.

[0065] Furthermore, if the light intensity distributions IDL1 and IDL2 are sinusoidal functions as described above, the calculation unit PU can calculate the detection position Zt using a general arccosine function or arcsine function, thereby simplifying the configuration of the calculation unit PU.

[0066] Note that the calculation unit PU may not calculate the surface position of the test surface WA itself as described above, but may calculate a converted surface position in which the surface position of the test surface WA is expressed using internal coordinates or the like within the surface position detection device 100. Hereinafter, the surface position of the test surface WA and the converted surface position will be referred to collectively or individually as surface position information of the test surface 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 desirable to further calculate the amplitude A1 (hereinafter referred to as amplitude A0) for a reference object whose reflectance of the test surface WA is known before measuring the object W. This allows the calculation unit PU to calculate the reflectance of the test surface WA of the object W from the ratio between the amplitude A1 and the amplitude A0.

[0068] The above description has been based on the photoelectric conversion signals S1b and S2b of the images IM1b and IM2b formed by the second wavelength component of the first detection light DL1 and the second detection light DL2. However, it goes without saying that the position information of the test surface WA can be calculated by the above-described method using any of the pairs of images formed by the first detection light DL1 and the second detection light DL2 at each wavelength component (the pair of images IM1a and IM2a, the pair of images IM1b and IM2b, or the pair of images IM1c and IM2c). Furthermore, the position information of the test surface WA may be calculated using each of the pairs of images formed by the first detection light DL1 and the second detection light DL2 at each wavelength component.

[0069] In the case of semiconductor wafers in the integrated circuit fabrication process described above, the reflectivity of the test surface WA may vary depending on the wavelength of the detection light, depending on the internal structure, etc. Therefore, the calculation unit PU may calculate position information of the test surface WA from pairs of images formed by multiple wavelength components in the first detection light DL1 and the second detection light DL2, and statistically process the calculated multiple pieces of position information to calculate the final position information of the test surface WA. Note that the multiple pieces of position information of the test surface WA calculated from pairs of images formed by multiple wavelength components may be interpreted as position information elements to distinguish them from the final position information of the test surface WA.

[0070] In addition, by performing detection and calculations similar to those described above not only on the image of the P-polarized component received by the light detection unit 28a but also on the image of the opening SL of the S-polarized component received by the light detection unit 28b, multiple positional information elements of the test surface WA can be calculated.

[0071] The calculation unit PU may calculate an average value of the plurality of position information elements as the statistical processing. Alternatively, the calculation unit PU may calculate the reflectance of the test surface WA of the measurement object W at each wavelength from a pair of images of the plurality of wavelength components for each P-polarized component and S-polarized component, and calculate final position information based on the position information elements and reflectance for each polarization and wavelength.

[0072] The calculation unit PU may correct the calculated position information of the test surface WA in the Z direction using information on the Z position of the stage ST measured by an interferometer or encoder (not shown). Alternatively, a control unit (not shown) may control the stage ST to scan in the X and Y directions while detecting the position of the test surface WA in the Z direction, thereby obtaining position information in the Z direction over the entire surface of the test surface WA.

[0073] (Variation 1) In the first embodiment described above, the surface position detecting device 100 detects the position in the Z direction perpendicular to the test surface WA of the measurement object W. However, the position is not limited to the direction perpendicular to the test surface WA, and the position may be detected in a direction intersecting the test surface WA.

[0074] (Variation 2) In the first embodiment, the longitudinal direction of the aperture 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 aperture SL does not necessarily have to coincide with the Y direction. It may be offset by a predetermined angle from the Y direction within the plane of the incident surface 23a, as long as it intersects with the x2 direction in FIG. 6, i.e., the direction that has an imaging relationship with the X direction on the test surface WA. In this case, the longitudinal directions of the images of the aperture SL (IM1a-IM1c, IM2a-IM2c, etc.) formed on the detection area DA on the test surface WA and the light-receiving surfaces 29a and 29b are also offset by a predetermined angle from the Y direction. To address this, the shape of each photoelectric conversion unit on the light-receiving surfaces 29a and 29b may be designed to encompass the images (IM1a-IM1c, IM2a-IM2c, etc.), and the longitudinal direction of the approximately rectangular pattern constituting the diffraction grating 14a may be offset by a predetermined angle from the Y direction.

[0075] In the surface position detecting device 100 of the first embodiment, the light intensity distribution IDL1 of the first detection light DL1 and the light intensity distribution IDL2 of the second detection light DL2 on the test surface WA are both constant within a predetermined range in the Y direction. However, as described above, when the longitudinal direction of the detection area DA is deviated from the Y direction by a predetermined angle, it is preferable that the light intensity distribution IDL1 and the light intensity distribution IDL2 are both constant within a predetermined range in the direction deviated from the Y direction by the predetermined angle.

[0076] As can be understood from the above detection principle, the light intensity distributions IDL1 and IDL2 do not necessarily have to be constant in the Y direction or in a direction rotated by a predetermined angle from the Y direction. In other words, it is sufficient that the sum of the light intensity distributions of the width Dwy of the detection area DA in the Y direction or in a direction rotated by a predetermined angle from the Y direction is constant at each position in the X direction. However, by making both the light intensity distribution IDL1 and the light intensity distribution IDL2 constant within a predetermined range in the Y direction or in a direction rotated a predetermined angle from the Y direction, the influence of fluctuations in reflectance becomes small even when the reflectance of the test surface WA fluctuates significantly in the Y direction, which makes it possible to detect the surface position with even higher accuracy.

[0077] (Variation 3) The first detection light DL1 and the second detection light DL2 do not necessarily have to be incident on the test surface WA 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 slightly different. In this case, by adding an optical component 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 contained in each light, the periods FX in the X direction of the light intensity distributions of the first detection light DL1 and the second detection light DL2 on the test surface WA can be made to match. However, by making the angles of incidence of the first detection light DL1 and the second detection light DL2 equal, there is an advantage in that the addition of such an optical member becomes unnecessary and the optical system can be simplified.

[0078] (Variation 4) The sum of the light intensities of the first detection light DL1 and the second detection light DL2 in the irradiation area IA on the test surface WA 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 photodetectors 28a and 28b. Therefore, the photoelectric conversion sensitivities for the first detection light DL1 and the second detection light DL2 may be easily set separately in the photodetectors 28a and 28b.

[0079] Therefore, for example, even if the light intensity distribution IDL1 due to the first detection light DL1 and the light intensity distribution IDL2 due to the second detection light DL2 are different, photoelectric conversion signals S1a and S1b of equal amplitude can be obtained by adjusting the photoelectric conversion sensitivity of the photodetectors 28a and 28b. However, by keeping the sum of the light intensities of the first detection light DL1 and the second detection light DL2 constant in the irradiation area IA of the test surface WA, it is possible to omit sensitivity adjustment by the light detection units 28a, 28b and the calculation unit PU, thereby simplifying the configuration of the surface position detection device 100.

[0080] (Variation 5) In the surface position detecting device 100 of the first embodiment, a light-shielding portion OF and an opening SL are formed on the incident surface 23a of the light-receiving prism 23, and the opening SL defines a detection area DA on the test surface WA. However, because the test surface WA, the opening SL, and the light-receiving surfaces 29a and 29b are in an imaging relationship (conjugate), the light-receiving area (area where photoelectric conversion is performed) within the light-receiving surfaces 29a and 29b may be limited instead of providing the light-shielding portion OF. That is, the width of each light-receiving area in the x3 direction may be set narrower than its width in the Y direction. Alternatively, if a two-dimensional image sensor is used as the light detection unit 28a, instead of providing the light-shielding portion OF, the calculation unit PU may calculate the surface position of the test surface WA using only photoelectric conversion signals from light-receiving pixels corresponding to the opening SL. That is, the calculation unit PU may calculate the surface position of the test surface WA using photoelectric conversion signals from light-receiving pixels within a range of the two-dimensional image sensor whose width in the x3 direction is narrower than its width in the Y direction. In this case, the composite separating member 25 may be omitted. Alternatively, the detection light from the light source 10 may be monochromatic light.

[0081] (Variation 6) In the surface position detection device 100 of the first embodiment, the detection light splitting member 16 is arranged in the light sending section, but the member that splits the first detection light DL1 and the second detection light DL2 is not limited to the detection light splitting member 16 arranged on the pupil plane TP of the light sending section. For example, the optical system may be configured so that the first detection light DL1 and the second detection light DL2 are formed to overlap each other on the test surface WA, without using the detection light splitting member 16. Furthermore, the detection light splitting member 16 is not limited to the one configured by the above-mentioned multiple prisms, but may be, for example, a split mirror configured by multiple non-parallel reflecting surfaces.

[0082] (Surface position detection device of second embodiment) Next, a surface position detecting device 100a according to a second embodiment will be described. However, since the surface position detecting device 100a according to the second embodiment has most of the same features as the surface position detecting device 100 according to the first embodiment, only the differences will be described below, and the common features will not be described. In a surface position detecting device 100a of the second embodiment, a detection light splitting member 161 shown in FIG. 10(a) is used instead of the detection light splitting member 16 in the first embodiment shown in FIG. 4(a).

[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 light-sending-side first lens 17 side. The optical axis AX2 and Y axis in Fig. 10 are the same as the optical axes AX2 and Y axes 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 z1, and three prisms 16f to 16h that are arranged in contact with each other in the Y direction at positions spaced apart from prism 16e downstream on the optical path in the optical axis AX2 direction.

[0084] The three prisms 16f to 16h are arranged in contact with one another in the Y direction, with their boundaries parallel to the z1 direction, and their thicknesses in the optical axis AX2 direction varying differently depending on the position in z1. As a result, the detection light splitting member 161 splits the detection light in the Y direction at the pupil plane TP into three detection lights: a first detection light DL10, a second detection light DL20, and a third detection light DL30. The detection light splitting member 161 then 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 light intensity distributions IDL10, IDL20, IDL30 of the first detection light DL10, the second detection light DL20, and the third detection light DL30 on the test surface WA in the surface position detecting apparatus 100a of the second embodiment. By appropriately setting the deflection amount 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 intensity distributions IDL10, IDL20, and IDL30 are shifted from each other by 1 / 3 of the intensity modulation period FX2.

[0086] The detection light splitting member 161 splits the detection light into three detection lights—first detection light DL10, second detection light DL20, and third detection light DL30—in the Y direction at the pupil plane TP of the light sending unit. Therefore, in the surface position detection device 100a of the second embodiment, the light splitting member 25a of the composite splitting member 25 disposed on the pupil plane RP2 of the light receiving unit also splits the detection light into three lights in the Y direction of the pupil plane RP2. Specifically, a new block whose entrance and exit surfaces are both perpendicular to the optical axis AX6 is added between the first block 251 and the second block 252 of the light splitting member 25a shown in FIG. 7(b). The shape of the entrance surface of the third block 253 is then adjusted to match the shapes of the exit surfaces of the first block 251, the second block 252, and the new block.

[0087] As a result, images of the opening SL due to the first detection light DL10, the second detection light DL20, and the third detection light DL30 are formed on the light receiving surfaces 29a and 29b, respectively, separated in the Y direction. 11(b) is a diagram showing, as an example, the relationship between the position (horizontal axis) in the Z-axis direction of the test surface WA and the photoelectric conversion signal S10b of image IM10b due to the second wavelength component of the first detection light DL10, the photoelectric conversion signal S20b of image IM20b due to the second wavelength component of the second detection light DL20, and the photoelectric conversion signal S30b of image IM30b due to the second wavelength component of the third detection light DL30. The photoelectric conversion signal S10b, the photoelectric conversion signal S20b, and the photoelectric conversion signal S30b are all signals expressed by the following equations (5) to (7), which have the same period FZ and amplitude A2 with respect to the position in the Z-axis direction of the test surface WA, but are shifted in phase by ⅓ 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 on the test surface WA at which the photoelectric conversion signal S10b is at its maximum. Zd shown in Fig. 11(b) is a position spaced apart from Zc by a period FZ2 on the +Z side.

[0089] The calculation unit PU calculates candidates (Zu1 to Zu3) for Z position Zu of the test surface WA located at any position between Za and Zb by calculation based on equations (8) to (11) 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. 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] Due to the properties of the inverse cosine function, candidates Zu1 to Zu3 for the Z position Zu are obtained as two values ​​each in the range from Zc to Zd, but the calculation unit PU selects the values ​​that roughly match and performs the averaging process of equation (12) to calculate the Z position Zu of the test surface WA. Zu = (Zu1+Zu2+Zu3) / 3···(12) In the second embodiment as well, if the width Dwx of the detection area DA in the X direction is made shorter than half the period FX2 in the X direction of the light intensity distributions IDL10 to IDL30, the fluctuation from the photoelectric conversion signal S10b to the photoelectric conversion signal S30b when the test surface WA moves in the Z direction can be increased, thereby further improving the detection accuracy.

[0091] In the second embodiment, light intensity distributions IDL10, IDL20, and IDL30, each with a phase difference of 1 / 3 of the intensity modulation period FX2, are formed on the test surface WA, and therefore the photoelectric conversion signals S10b to S30b also change as so-called three-phase signals with respect to the Z position of the test surface WA. As a result, the position of the test surface WA can be detected over a wider Z range (from Zc to Zd) than in the first embodiment.

[0092] In the above, the photoelectric conversion signals S10b, S20b, and S30b of the second wavelength component in the first detection light DL10 to the third detection light DL0 have been explained, but as in the first embodiment, the position of the test surface WA can be calculated using the photoelectric conversion signals of each wavelength component of each detection light DL10 to DL30.

[0093] Furthermore, by performing the same detection and calculation as described above on not only the image of the P-polarized component received by the photodetector 28a but also the image of the opening SL of the S-polarized component received by the photodetector 28b, it is possible to calculate a plurality of position information elements of the test surface WA. The method of calculating the final position information of the test surface WA from the calculated plurality of position information elements is the same as the method in the first embodiment described above. The configurations described in the modifications of the first embodiment may be applied to the surface position detection device of the second embodiment with appropriate necessary modifications.

[0094] (Effects of the first embodiment, the second embodiment, and each modification) (1) The surface position detecting device 100, 100a of the first embodiment, the second embodiment, and each modified example described above, in the surface position detecting device 100 that obtains position information of the test surface WA along an axis (Z axis) that intersects with the test surface WA, includes a light sending unit TS that irradiates the test surface WA with a plurality of detection lights (DL1, DL2, etc.) that are smoothly intensity-modulated in a first direction (X direction) within the test surface WA at an oblique incidence from a direction having a directional component in the first direction, superimposing the light onto the test surface WA, thereby forming an irradiation area IA on the test surface WA, and light receiving surfaces 29a, 29b, 29c, 29d, 29e, 29f, 29g, 29h ... 9b has light detection units 28a, 28b arranged at a position optically conjugate with the test surface WA, and is equipped with a light receiving unit RS that receives multiple detection light beams (DL1, DL2, etc.) reflected by a detection area DA within the irradiation area IA, which has a predetermined width Dwx in the first direction, at different positions on the light receiving surfaces 29a, 29b and outputs photoelectric conversion signals of the multiple detection light beams (DL1, DL2, etc.), and a calculation unit PU that calculates position information of the test surface WA based on the photoelectric conversion signals of the multiple detection light beams output from the light receiving unit RS. This configuration makes it possible to realize a highly accurate surface position detecting device 100 that is less susceptible to fluctuations in the reflectance of the test surface WA.

[0095] (2) By keeping the light intensity of each of the multiple detection beams (DL1, DL2, etc.) constant in the second direction intersecting with the first direction (X direction) in the illumination area IA, the reflectance of the test surface WA is less affected by fluctuations in reflectance even when the reflectance fluctuates significantly in the direction intersecting with the first direction. As a result, the surface position can be detected with even higher accuracy. (3) By keeping the sum of the light intensities of the multiple detection light beams (DL1, DL2, etc.) in the detection area DA on the test surface WA constant along the first direction (X direction), the reflectance of the detection area DA can be easily calculated from the sum of the photoelectric conversion signals (S1b, S2b, etc.) of the multiple detection light beams received and photoelectrically converted by the photodetectors 28a and 28b. Then, by reflecting the calculated reflectance in the calculation of the surface position of the detection area DA, it is possible to detect the surface position with even higher accuracy.

[0096] (4) On the test surface WA, the intensity of multiple detection lights (DL1, DL2, etc.) is modulated in the first direction (X direction) by sinusoidal functions of the same period FX and the same amplitude, and the phases of the sinusoidal functions in the first direction are different from each other, thereby simplifying the configuration of the calculation unit PU. (5) By configuring the multiple detection lights to include the first detection light DL10, the second detection light DL20, and the third detection light DL30, whose sinusoidal function phases differ from each other by 1 / 3 of the period FX2, it is possible to detect the position on the test surface WA over a wider range in the measurement direction (Z direction).

[0097] (6) By making the width Dwx of the detection area DA in the first direction (X direction) shorter than half the period FX of the sine wave function, it is possible to increase the fluctuations of the photoelectric conversion signals S1b, S2b, etc. when the test surface WA moves in the Z direction, thereby further improving the detection accuracy. (7) The light-transmitting unit TS irradiates the test surface WA with multiple detection lights (DL1, DL2, etc.), each containing multiple different wavelengths. The light-receiving unit RS can be configured to include a spectroscopic element 25b that disperses each of the multiple detection lights according to wavelength and directs them to different positions on the light-receiving surfaces 29a, 29b. Furthermore, the light-detecting units 28a, 28b can output photoelectric conversion signals (S1b, S2b, etc.) for multiple different wavelengths incident on different positions for each of the multiple detection lights (DL1, DL2, etc.), and the processing unit PU can calculate position information for the test surface WA based on the photoelectric conversion signals (S1b, S2b, etc.) for the multiple detection lights for the multiple different wavelengths. In this case, the position of the test surface WA can be detected with even greater accuracy because the position of the test surface WA is detected using detection lights with multiple different wavelengths. It should be noted that the surface position detecting devices of the first and second embodiments do not necessarily need to obtain position information of the test surface WA. As an example, the surface position detecting devices of the first and second embodiments may measure the spectral reflectance distribution of the test surface WA without obtaining position information of the test surface WA.

[0098] (Exposure apparatus of the third embodiment) 12 is a diagram showing an outline of an 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 to 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 is equipped with the surface position detection apparatus 100, 100a of the first or second embodiment described above. The surface position detection apparatus 100, 100a treats the substrate WF as the above-mentioned measurement object W, and treats the surface of the photoresist formed on the surface of the substrate WF as the above-mentioned test surface WA. 12, the direction parallel to the optical axis AXP of the projection optical system 57 is taken as the Z-axis direction.

[0099] The substrate WF carried into the exposure apparatus 200 is placed on a substrate stage 59 that is movable on a surface plate 61, and is positioned below the surface position detection device 100 by moving the substrate stage 59. The control device 70 sends a control signal S5 to move the substrate stage 59 within the XY plane, while causing the surface position detection device 100 to detect Z-direction position information of multiple locations on the surface of the substrate WF. At this time, 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 held integrally with the surface position detection device 100, via the positions of reference mirrors 60a and 60b. Furthermore, the XY-direction position of the substrate stage 59 is measured by an interferometer 62, via the position of the reference mirror 60b. The interferometers 63a and 64b may be considered 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 information regarding the Z-direction position of the substrate stage 59 are transmitted as signal S2 to the control device 70. Information regarding the X- and Y-direction position of the substrate stage 59 is transmitted as signal S3 to the control device 70. Based on signals S2 and S3, map data is created in the control device 70 that represents the Z-direction position information relative to the X- and Y-direction positions of the surface of the substrate WF.

[0101] Next, the control device 70 moves the substrate stage 59 in the XY plane so that the substrate WF is positioned below the projection optical system 57, and exposes the resist PR formed on the surface of the substrate WF. The exposure may be a so-called step exposure or a scan exposure. During exposure, the control device 70 controls the substrate stage 59 based on map data that represents the positional information in the Z direction relative to the XY position of the surface of the substrate WF. That is, the control device 70 sends a control signal S4 to the substrate stage 59 to move the substrate stage 59 in the X and Y directions and drive 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. If necessary, the control device 70 slightly rotates (levels) the substrate stage 59 about the Y-axis and X-axis directions.

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

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

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

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

[0106] (Effects of the exposure apparatus of the third embodiment) (8) The exposure apparatus 200 of the third embodiment includes the surface position detecting apparatus 100 of the first or 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. This configuration minimizes measurement errors caused by the reflectance distribution on the surface of the substrate WF, making it possible to measure the surface position of the surface of the substrate WF with high accuracy. As a result, the exposure apparatus of the third embodiment can align the surface of the substrate WF on which the resist PR is formed with respect to the projection optical system 57 with high accuracy, thereby enabling good projection exposure.

[0107] (Substrate Processing System of Fourth Embodiment) 13 is a diagram showing an outline of a substrate processing line including a substrate processing system 300 according to the fourth embodiment. The substrate processing system 300 includes the surface position detecting apparatus 100, 100a according to the first embodiment, the second embodiment, or each of the modifications described above, the exposure apparatus 200 according to the second embodiment described above, and a data holding device 110.

[0108] In the substrate processing system 300, a substrate WF, on whose surface a resist PR has been formed 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 therein on which the substrate WF is placed, and the stage ST moves the substrate WF in a direction within its surface, thereby detecting position information of the surface of the substrate WF across the entire front surface of the substrate WF. The surface position detection device 100 may further measure the reflectance of the surface of the substrate WF. The surface position detection device 100 may also measure the position information and reflectance of the surface of the substrate WF multiple times for each detection wavelength. The position information of the surface of the substrate WF measured by the surface position detecting device 100, and further the reflectance information, is transmitted to the data holding device 110 and temporarily stored therein.

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

[0110] In the substrate processing system 300 of the fourth embodiment, position information of the surface of the substrate WF and also accurate information on the reflectance have already been measured by the surface position detecting device 100. Therefore, the surface position detecting device 100 in the exposure apparatus 200 may be omitted, and a conventional surface position detecting device may be used instead.

[0111] The substrate WF exposed by the exposure apparatus 200 is transported by the transport mechanism 103 to the coater developer 104, where the resist PR on the substrate WF is developed. The substrate WF is then transported by the transport mechanism 105 to the processing apparatus 106. Using the developed resist PR as a mask, i.e., based on the resist pattern PR formed in the resist PR, the surface of the substrate WF or a 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] The substrate processing system 300 of the fourth embodiment described above is equipped with a data holding device 110 that temporarily stores position information and / or reflectance information about the surface of the substrate WF measured by the surface position detection device 100, but this is not limiting. The data holding device 110 may be built into the surface position detection device 100 or into the exposure apparatus 200. Alternatively, the data holding device 110 may be included in a computer or 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 via a network.

[0113] (Effects of the Substrate Processing System of the Fourth Embodiment) (9) A substrate processing system of a fourth embodiment is a substrate processing system 300 for processing a substrate WF, and includes a first stage ST on which the substrate WF is placed, a measurement device having a surface position detection device 100, 100a of the first embodiment, second embodiment, or modified example described above that measures the position of multiple points on the surface of the substrate WF in a direction intersecting the surface (Z direction), and a second stage 59 on which the substrate WF is placed after measurement by the measurement device has been completed, and an exposure apparatus 200 that exposes the substrate WF placed on the second stage 59. The exposure apparatus 200 performs exposure while changing the position of the substrate WF in a direction intersecting the surface, using at least the measurement results from the measurement devices 100, 100a. This configuration minimizes measurement errors caused by the reflectance distribution on the surface of the substrate WF, and enables highly accurate alignment of the surface of the substrate WF on which the resist PR is formed with respect to the projection optical system 57. This makes it possible to form a good exposure pattern on the substrate WF.

[0114] (Device manufacturing method according to the fifth embodiment) A device manufacturing method of the fifth embodiment will be described with reference to Figure 14. The device manufacturing method of the fifth embodiment is a method of manufacturing a device using the exposure apparatus 200 of the third embodiment or the substrate processing system 300 of the fourth embodiment described above. Therefore, please refer to the above descriptions for details of the operation of the exposure apparatus 200 of the third embodiment and the substrate processing system 300 of the fourth embodiment.

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

[0116] Next, in step S103, the exposure apparatus 200 exposes an exposure pattern onto the resist PR on the substrate WF using the surface position of the resist PR detected by the surface position detection apparatus 100 in step S102. Then, in step S104, the resist PR exposed with the exposure pattern is developed to form a resist pattern. After that, 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 circuit pattern of one layer that constitutes a device is formed on the substrate WF. Therefore, after step S105 is completed, the process moves to the next step, and steps S100 to S105 are repeated again, thereby manufacturing a device (semiconductor integrated circuit, display device, etc.) made up of multiple layers.

[0118] (Effects of the device manufacturing method according to the fifth embodiment) (10) From one perspective, the above-mentioned device manufacturing method includes forming a resist PR on the surface of a substrate WF, using the exposure apparatus 200 of the third embodiment described above to detect the position of the surface of the resist PR formed on the surface of the substrate WF, setting the surface of the resist PR at a predetermined position in the optical axis (AXP) direction of the projection optical system 57 and exposing an exposure pattern, developing the resist PR, and processing the surface of the substrate WF based on the resist pattern PR formed by the development. This configuration minimizes measurement errors caused by the reflectance distribution on the surface of the substrate WF, and enables highly accurate alignment of the surface of the substrate WF on which the resist PR is formed with respect to the projection optical system 57. This makes it possible to form a good exposure pattern on the substrate WF, and ultimately to manufacture high-performance devices.

[0119] (11) From another perspective, the above-described device manufacturing method includes forming a resist PR on the surface of a 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 a direction intersecting the surface using the substrate processing system 300 of the fourth embodiment. Then, the device manufacturing method includes exposing an exposure pattern while changing the positions of the surface of the resist PR in a direction intersecting the surface based on the detected positions of the plurality of points, and forming a circuit pattern based on the exposure pattern. This configuration minimizes measurement errors caused by the reflectance distribution on the surface of the substrate WF, and enables highly accurate alignment of the surface of the substrate WF on which the resist PR is formed with respect to the projection optical system 57. This makes it possible to form a good exposure pattern on the substrate WF, and ultimately to manufacture high-performance devices.

[0120] The present invention is not limited to the above. 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 part of the above aspects. [Explanation of symbols]

[0121] 100, 100a: surface position detection device, 200: exposure device, 300: substrate processing system, TS: light transmitting unit, RS: light receiving unit, PU: calculation unit, W: object to be measured, WA: surface to be measured, 14: diffraction grating plate, 17: first lens on the light transmitting side, 15: second lens on the light transmitting side, 18, 19: mirror, TP: pupil plane, RP1: pupil plane, RP2: pupil plane, AX1 to AX6: optical axis, 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 separation prism 1. Structure of the optical fiber, 28a, 28b: photodetector, 29a, 29b: light receiving surface, ST: stage, 12: light introducing section, 13: condenser lens, 16: detected light splitting member, 25: composite separating member, 25a: light separating member, 25a, 25b: spectroscopic member, IA: irradiation area, DA: detection area, DP: +1st order diffracted light, DM: -1st order diffracted light, DL1, DL10: first detected light, DL2, DL20: second detected light, SL: aperture, IM1a to IM1c, IM2a to IM2c: images, S1a, S1b: photoelectric conversion signals

Claims

1. 1. A surface position detecting device for determining position information of a test surface along an axis intersecting the test surface, a light sending unit that irradiates the test surface with a plurality of detection lights that are smoothly intensity-modulated in a first direction within the test surface at oblique incidence from a direction having a directional component in the first direction, in a superimposed manner, to form an irradiation area on the test surface; a light-receiving unit having a light-receiving surface arranged at a position optically conjugate with the test surface, the light-receiving unit receiving the plurality of detection light beams reflected by a detection region of the irradiation region having a predetermined width in the first direction 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 the light sending unit includes a diffraction grating disposed in the optical paths of the plurality of detection lights, interference fringes due to +1st-order diffracted light and −1st-order diffracted light from the diffraction grating in each of the plurality of detected light beams form the intensity modulation in the first direction on the test surface; a surface position detecting device, wherein the plurality of detection lights are intensity-modulated in the first direction by functions of the same period on the test surface, and the phases of the functions in the first direction are different from each other.

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 second direction intersecting the first direction in the irradiation area.

3. 3. The surface position detection device according to claim 1, The light-transmitting unit irradiates the plurality of detection beams onto the test surface at equal angles with respect to a normal to the test surface.

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

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

6. 6. The surface position detection device according to claim 1, The plurality of detection beams include a first detection beam and a second detection beam, the phases of the functions of which differ from each other by half the period.

7. 6. The surface position detection device according to claim 1, The plurality of detection beams include first detection beam, second detection beam, and third detection beam, the phases of the functions of which differ from each other by 1 / 3 of the period.

8. 8. The surface position detection device according to claim 1, A surface position detection device, wherein the width of the detection area in the first direction is shorter than half the period of the function.

9. 9. The surface position detection device according to claim 1, the light receiving unit comprises: 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 optically conjugate with the first conjugate plane at the conjugate position; and an aperture member that is arranged on the first conjugate plane, has a longitudinal direction in a fourth direction that intersects with a third direction that is in an imaging relationship with the first direction, and has an aperture that 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 the width of 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 the width of 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, with respect to 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 plurality of detection lights on the light receiving surface, the area having a width in a fifth direction that is in an imaging relationship with the first direction and is narrower than a width in 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 light beams, 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 each of the plurality of detection lights according to wavelength and guides the light 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 detecting device according to claim 16 or 17, a surface position detection device, wherein the spectral direction of the spectral 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 detecting device according to claim 16, The spectroscopic member includes a prism having a refractive power that varies depending on the wavelength.

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

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

22. 22. The surface position detecting device according to claim 21, A surface position detection device, wherein the light detection unit has, as the light receiving surface, a first light receiving surface that receives the light of the first polarization component and a second light receiving surface that receives the light of the second polarization component.

23. 23. The surface position detecting device according to claim 21 or 22, the light receiving unit outputs, as the photoelectric conversion signals, a first photoelectric conversion signal corresponding to the light of the first polarization component and a second photoelectric conversion signal corresponding to the light of the second polarization component; 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.

24. 24. The surface position detection device according to claim 1, 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 diffraction grating selectively generates +1st-order diffracted light and -1st-order diffracted light.

26. 26. The surface position detection device according to claim 1, The light sending unit includes a diffracted light selection filter that selectively transmits +1st-order diffracted light and -1st-order diffracted light.

27. 27. 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.

28. 28. The surface position detecting device according to claim 27, a surface position detection device, wherein the light sending unit has a pupil plane; and the detection light splitting member is disposed on the pupil plane and deflects at least one of the plurality of detection lights.

29. 29. The surface position detecting device according to claim 27 or 28, the detection light splitting member includes a plurality of prisms, A surface position detection device, wherein at least one of the plurality of prisms has a thickness of the light sending section in the optical axis direction that changes depending on the position in a seventh direction that intersects with the optical axis direction.

30. a projection optical system; a substrate stage on which a substrate is placed and moved; a surface position detecting device according to any one of claims 1 to 29, which detects the position of the surface of the substrate as the surface to be detected; An exposure apparatus comprising:

31. 31. The exposure apparatus according to claim 30, a first position measurement unit that measures a position of at least a part of the substrate stage in the optical axis direction 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 the 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:

32. forming a resist on a surface of the substrate; using the exposure apparatus according to claim 30 or 31, detecting the position of the 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 the surface of the substrate based on the resist pattern formed by the development; A device manufacturing method comprising:

33. A substrate processing system for processing a substrate, a measurement apparatus including a first stage on which the substrate is placed, and the surface position detection device according to any one of claims 1 to 29, which measures the positions of a plurality of points on a surface of the substrate in a direction intersecting the surface; 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 The exposure apparatus performs the exposure while changing the position of the substrate in the intersecting direction by using at least a measurement result from the measurement apparatus.

34. forming a resist on a surface of the substrate; using the substrate processing system according to claim 33, detecting positions of a plurality of points on the surface of the resist formed on the surface of the substrate in a direction intersecting the surface, and exposing an exposure pattern while changing positions of the surface of the resist in a direction intersecting the surface 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