Surface position detecting apparatus, exposure apparatus, substrate processing system, and device manufacturing method

Abstract

To provide a surface position detector for obtaining the position information of a surface to be inspected along an axis crossing the surface to be inspected.SOLUTION: A position detection device 100 includes a light transmission part TS having a light transmission optical system which irradiates a plurality of detection lights intensity-modulated in a first direction on a surface to be detected WA on the surface to be detected WA in an obliquely incident manner from a direction having a directional component in the first direction, a first light receiving optical system 20, 21 which forms a first conjugate surface optically conjugate with the surface to be detected, an aperture member SL which is disposed on the first conjugate surface and includes a plurality of apertures arranged side by side in a second direction corresponding to the first direction, a second light receiving optical system 22, 23 which forms a second conjugate surface optically conjugate with the first conjugate surface, and a light detection part 28a, 28b having a light receiving surface arranged on the second conjugate surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a surface position detecting apparatus, an exposure apparatus, a substrate processing system, and a device manufacturing method. [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] One aspect of the present invention is a surface position detection device that determines position information of a test surface along an axis intersecting the test surface, the surface position detection device comprising: a light-transmitting unit having a light-transmitting optical system that irradiates a plurality of detection lights that are intensity-modulated in a first direction within the test surface at oblique incidence onto the test surface from a direction having a directional component in the first direction, such that the detection lights are superimposed on the test surface; a first light-receiving optical system that forms a first conjugate plane optically conjugate with the test surface; an aperture member that is arranged on the first conjugate plane and has a plurality of apertures that are arranged side by side in a second direction corresponding to the first direction; a second light-receiving optical system that forms a second conjugate plane optically conjugate with the first conjugate plane; and a light-receiving unit that has a light-receiving surface arranged on the second conjugate plane, and receives the plurality of detection lights that have passed through the apertures at different positions on the light-receiving surface.

[0005] One aspect of the present invention is an exposure apparatus comprising a projection optical system, a substrate stage for placing and moving a substrate, and the above-described surface position detection device for detecting the position of the surface of the substrate as the surface to be inspected.

[0006] One aspect of the present invention is a device manufacturing method including forming a resist on a surface of a substrate, using the above-described exposure apparatus to detect the position of the surface of the resist formed on the surface of the substrate, setting the surface of the resist at a predetermined position in the optical axis direction of the projection optical system, exposing an exposure pattern, developing the resist, and processing the surface of the substrate based on the resist pattern formed by the development.

[0007] One aspect of the present invention is a substrate processing system for processing a substrate, comprising: a first stage on which the substrate is placed; a measurement device having the above-mentioned surface position detection device that measures the positions of multiple points on the surface of the substrate in a direction intersecting the surface; a second stage on which the substrate is placed after the measurement by the measurement device has been completed; and an exposure device that exposes the substrate placed on the second stage, wherein the exposure device performs the exposure while changing the position of the substrate in the intersecting direction using at least the measurement results by the measurement device.

[0008] One aspect of the present invention is a device manufacturing method including: forming a resist on a surface of a substrate; using the above-described substrate processing system to detect the positions of multiple points on the surface of the resist formed on the surface of the substrate in a direction intersecting the surface; exposing an exposure pattern while changing the position of the surface of the resist in a direction intersecting the surface based on the detected positions of the multiple points; and forming a circuit pattern based on the exposure pattern. [Brief explanation of the drawings]

[0009] [Figure 1]1 is a schematic diagram showing an example of the configuration of a surface position detecting device 100 according to a first embodiment. [Figure 2] 1 is a side view of a part of the configuration of a surface position detecting device 100 according to a first embodiment, as viewed from the −Y direction. [Figure 3] 1 is a top view of a part of the configuration of a surface position detecting device 100 according to a first embodiment, as viewed from the +Z direction. [Figure 4] 2 is a perspective view showing an example of the configuration of a detection light dividing member 16 according to the first embodiment. FIG. [Figure 5] 2 is a diagram showing an example of the configuration of a detection light splitting member 16 according to the first embodiment, as viewed from the light-sending-side first lens group 17 side. FIG. [Figure 6] Figure 6(a) shows the detection light incident on the test surface WA, Figure 6(b) shows the irradiation area IA on the test surface WA, and Figure 6(c) shows the light intensity distribution in the X-axis direction of the irradiation area IA. [Figure 7] 1 is a view of an incident surface 22a of a light-receiving prism 22 according to the first embodiment, viewed from the direction of the normal to the incident surface 22a. [Figure 8] 3 is a diagram showing an example of a pupil splitting prism 24 and a spectral prism 25 according to the first embodiment. FIG. [Figure 9] 10 is a diagram showing an image of a P-polarized component of a slit SL formed on a light receiving surface 29a according to the first embodiment. FIG. [Figure 10] 3 is a diagram showing an example of the configuration of a light introducing portion end surface 120 of a light introducing portion 12 according to the first embodiment. FIG. [Figure 11] 10 is a diagram showing the passage position in the X direction on the pupil plane TP of diffracted light generated by the diffraction grating 14a according to the first embodiment, relative to wavelength. FIG. [Figure 12] 10 is a diagram showing the X-direction passage position of diffracted light generated by the diffraction grating 14a according to the first embodiment on the pupil plane TP relative to wavelength, with a light-blocking region by the diaphragm 161 superimposed thereon. [Figure 13] 10 is a diagram showing a light-blocking region in a direction in which the detection light splitting member 16 is viewed from the light-sending-side second lens group 15 according to the first embodiment. FIG. [Figure 14]FIG. 10 is a schematic diagram showing an example of the configuration of an exposure apparatus 200 according to a second embodiment. [Figure 15] FIG. 10 is a schematic view showing an example of the configuration of a substrate processing line including a substrate processing system 300 according to a third embodiment. [Figure 16] FIG. 10 is a diagram illustrating an overview of a device manufacturing method according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] (First embodiment) Hereinafter, the embodiments will be described in detail with reference to the drawings. In this embodiment, "optically conjugate" means that one surface and another surface are in an imaging relationship via an optical system. In this embodiment, "imaging relationship" means that light emitted from an arbitrary point in one region is focused via the optical system within a range that is approximately the resolution of the optical system, with a point in another region as its center. In this embodiment, a "sine wave function" is 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.

[0011] 1 is a schematic diagram showing an example of the configuration of a surface position detection device 100 according to this embodiment. The surface position detection device 100 includes a light source 10, a light guide 11, a light-transmitting unit TS, a light-receiving unit RS, and a processing unit PU. The light-transmitting unit TS includes a light introducing unit 12, a condenser lens group 13, a diffraction grating plate 14, a light-transmitting-side second lens group 15, an aperture 161, a detection light splitter 16, a light-transmitting-side first lens group 17, and a mirror 18. The light-receiving unit RS includes a mirror 19, a light-receiving-side first lens group 20, a light-receiving-side second lens group 21, a light-receiving prism 22, a front lens group 23, a pupil-splitting prism 24, a light-splitting prism 25, a rear lens group 26, a polarizing beam splitter 27, a light detector 28a, and a light detector 28b.

[0012] In addition, a three-dimensional Cartesian coordinate system (XYZ coordinate system) is shown in the drawings as appropriate. In the XYZ Cartesian coordinate system, the direction of the Z axis is perpendicular (normal direction) to the test surface WA. The test surface WA is the surface of the measurement object W placed on the surface position detection device 100. The direction of the Z axis is upward on the paper surface of FIG. 1. The direction of the X axis is parallel to the paper surface of FIG. 1 in a plane parallel to the test surface WA. The direction of the X axis is rightward on the paper surface of FIG. 1. The direction of the Y axis is perpendicular to the paper surface of FIG. 1 in a plane parallel to the test surface WA. The direction of the Y axis is from the front to the back on the paper surface of FIG. 1.

[0013] The surface position detecting device 100 is a surface position detecting device that determines position information of the test surface WA along an axis (Z-axis) that intersects with the test surface WA. An overview of the path of detection light in the surface position detecting device 100 will be described. Detection light is supplied to a light introducing section 12 from 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 to this. The wavelength band of the detection light may be, for example, 400 nm or less, for example, around 200 nm, or may be in the infrared range of 800 nm or more, for example, 1200 nm to 1700 nm.

[0014] The detection light emitted from the light introducing section 12 is irradiated onto the test surface WA via the condenser lens group 13, the diffraction grating plate 14, the light-transmitting-side second lens group 15, the aperture 161, the detection light splitter 16, the light-transmitting-side first lens group 17, and the mirror 18. The detection light reflected from the test surface WA reaches the light-receiving prism 22 via the mirror 19, the light-receiving-side first lens group 20, and the light-receiving-side second lens group 21. The detection light refracted by the light-receiving prism 22 passes through the front lens group 23, the pupil-splitting prism 24, the spectroscopic prism 25, and the rear lens group 26 and enters the polarizing beam splitter 27. The polarizing beam splitter 27 then splits the detection light into two differently polarized components. The split detection light then enters the light-receiving surface 29a of the light detecting section 28a and the light-receiving surface 29b of the light detecting section 28b. The front lens group 23 and the rear lens group 26 form a relay optical system.

[0015] 2 and 3 are diagrams showing part of the configuration of the surface position detecting device 100 according to this embodiment. FIG. 2 is a side view of the configuration from the diffraction grating plate 14 to the light detecting unit 28a as 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 22 are linearly developed. FIG. 3 is a top view of the configuration from the diffraction grating plate 14 to the light detecting unit 28a as viewed from the +Z direction. Mirrors 18 and 19, the polarizing beam splitter 27, and the light detecting unit 28b are not shown in FIGS. 2 and 3. 2 and 3, the optical axis AX2 coincides with the optical axis AX3, the optical axis AX4 coincides with the optical axis AX5, and the optical axis AX6 coincides with the X-axis direction.

[0016] Although each lens group is shown to have only one lens in FIGS. 1 to 3, each lens group may be made up of two 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).

[0017] Light emitted from the light introducing section 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. The light is obliquely incident on the diffraction grating plate 14 from a direction having a directional component in the X direction. The diffraction grating plate 14 is disposed in the optical path between the light introducing section 12 and the detection light splitting member 16. The diffraction grating plate 14 has a diffraction grating 14a formed on its surface, the diffraction grating 14a being made of a dielectric film or a metal film. The diffraction grating 14a is, for example, a one-dimensional grating, and has approximately rectangular patterns whose longitudinal direction coincides with the Y direction in the figure, arranged at a predetermined period in the in-plane direction of the diffraction grating plate 14 perpendicular to the Y direction. In this embodiment, the diffraction grating 14a selectively generates +1st-order diffracted light DP1 and −1st-order diffracted light DM1.

[0018] The diffracted light reflected and diffracted by the diffraction grating plate 14 is incident on the aperture 161 via the light-sending-side second lens group 15. The diffracted light may include 0th-order diffracted light and 3rd-order and higher diffracted light in addition to +1st-order diffracted light DP1 and −1st-order diffracted light DM1. The aperture 161 blocks the 0th-order diffracted light and 3rd-order and higher diffracted light generated by the diffraction grating 14a. The configuration for blocking by the aperture 161 will be described in detail later.

[0019] The diaphragm 161 is disposed on the pupil plane TP of the light-sending optical system. The light-sending optical system is composed of a light-sending-side second lens group 15 and a light-sending-side first lens group 17. Here, the pupil plane TP is a plane where multiple light rays incident from the same direction at different positions on the test surface WA converge at approximately one point. In other words, light rays traveling in different directions from a single point on the pupil plane TP are incident from the same direction at different positions on the test surface WA.

[0020] The +1st-order diffracted light DP1 and the −1st-order diffracted light DM1 emitted from the diaphragm 161 are incident on the detection light splitting member 16. The detection light splitting member 16 is arranged closer to the test surface WA than the diaphragm 161 arranged on the pupil plane TP, and is arranged in close proximity to the diaphragm 161.

[0021] Optical axis AX1 is the optical axis of condenser lens group 13. Optical axis AX2 is the optical axis of light-sending-side second lens group 15 and light-sending-side first lens group 17. Optical axis AX2 coincides with the axis obtained by reflecting optical axis AX1 about the normal to the surface of diffraction grating plate 14, which passes through the point where the surface of diffraction grating plate 14 intersects with optical axis AX1.

[0022] The configuration of the detection light splitting member 16 will now be described with reference to Figs. 4 and 5. Fig. 4 is a diagram showing an example of the configuration of the detection light splitting member 16 according to this embodiment. Fig. 4 is a perspective view showing the detection light splitting member 16. Fig. 5 is a diagram showing the detection light splitting member 16 as viewed from the light-sending-side first lens group 17 side. The optical axis AX2 and Y axis shown in Figs. 4 and 5 indicate the same directions as the optical axis AX2 and Y axis shown in Figs. 1 to 3, respectively. The z1 axis shown in Figs. 4 and 5 indicates a direction perpendicular to the optical axis AX2 and Y axis.

[0023] The detection light splitting member 16 is composed of a front group and a rear group arranged closer to the test surface WA than the front group. The front group is composed of three phase adjustment members arranged side by side in the Y-axis direction, which intersects with the X-axis direction. In this embodiment, the phase adjustment members are, for example, prisms. As shown in the figure, the front group is composed of prisms 16a, 16b, and 16c. The rear group is composed of prism 16d.

[0024] Prism 16a, prism 16b, and prism 16c are arranged at approximately the same position in the direction of optical axis AX2 and in contact with each other in the Y direction. The boundary where prism 16a and prism 16b meet, and the boundary where prism 16b and prism 16c meet, are each on a plane that passes through the optical axis AX2 and is parallel to the z1 axis. Prism 16a is arranged close to pupil plane TP and on the +Y side of the optical axis AX2. Prism 16c is arranged close to pupil plane TP and on the -Y side of the optical axis AX2. Prism 16b is arranged between prisms 16a and 16c and close to pupil plane TP, straddling both the -Y and +Y sides of the optical axis AX2.

[0025] The thicknesses of prisms 16a, 16b, and 16c in the direction of optical axis AX2 vary differently depending on the position of z1. Accordingly, the +1st-order diffracted light DP1 and the −1st-order diffracted light DM1 incident on detection light splitting member 16 are split in the Y direction into three detection lights: first detection light DL1, second detection light DL2, and third detection light DL3. Therefore, detection light splitting member 16 splits the incident light to generate first detection light DL1, second detection light DL2, and third detection light DL3.

[0026] The thickness of the prism 16d in the direction of the optical axis AX2 varies depending on the position z1. The prism 16d deflects the traveling directions of the first detection light DL1, the second detection light DL2, and the third detection light DL3 by a small angle in the direction z1.

[0027] Here, the prism 16a has an incident surface 160a onto which light is incident and an exit surface 161a from which the first detection light DL1 is emitted. The prism 16b has an incident surface 160b onto which light is incident and an exit surface 161b from which the second detection light DL2 is emitted. The prism 16c has an incident surface 160c onto which light is incident and an exit surface 161c from which the third detection light DL3 is emitted. In other words, the three phase adjustment members have an incident surface onto which light is incident and an exit surface from which multiple detection light beams are emitted. The prism 16d has a rear group incident surface 160d onto which the first detection light DL1 emitted from the exit surface 161a, the second detection light DL2 emitted from the exit surface 161b, and the third detection light DL3 emitted from the exit surface 161c are incident. That is, the rear group has a rear group entrance surface 160d onto which the plurality of detection light beams emitted from the exit surface of the front group from which the plurality of detection light beams are emitted are incident.

[0028] In one example of this embodiment, the angle of incident surface 160a or exit surface 161a relative to rear group incident surface 160d, the angle of incident surface 160b or exit surface 161b relative to rear group incident surface 160d, and the angle of incident surface 160c or exit surface 161c relative to rear group incident surface 160d are different from one another. That is, the angles of the incident surfaces or exit surfaces relative to rear group incident surface 160d are different for each of the three phase adjustment members.

[0029] In one example of this embodiment, the angle between incident surface 160a and exit surface 161a, the angle between incident surface 160b and exit surface 161b, and the angle between incident surface 160c and exit surface 161c are different from one another. That is, the angles formed by the incident surface and the exit surface are different for each of the three phase adjustment members.

[0030] In one example of this embodiment, the angles of the exit surface 161a of the prism 16a and the exit surface 161c of the prism 16c relative to the rear group entrance surface 160d are variable, i.e., the angles of the entrance surfaces of two of the three phase adjustment members relative to the rear group entrance surface 160d are variable. In order to fine-tune the phase of the fringes formed on the test surface WA, which will be described later, it is preferable that the angles of the exit surfaces 161a, 161b, and 161c with respect to a plane perpendicular to the X-axis, and the angle of the rear group entrance surface 160d with respect to a plane perpendicular to the X-axis, are approximately the same. Furthermore, the angle of exit surface 161b of prism 16b relative to rear group entrance surface 160d may be variable. The angles of exit surfaces 161a, 161b, and 161c relative to rear group entrance surface 160d do not have to be variable.

[0031] Note that prisms 16a, 16b, and 16c may not be three separate prisms, but may be an integrated prism whose entrance or exit surface has a different shape on the +Y side and the -Y side of optical axis AX2.

[0032] As long as the detection light splitting member 16 splits the incident light to generate the first detection light DL1, the second detection light DL2, and the third detection light DL3, the shapes and arrangements of the three phase adjustment members may be any of those described above.

[0033] The front group may be composed of prism 16d, and the rear group may be composed of prisms 16a, 16b, and 16c. However, as in this embodiment, the detection light splitting member 16 is composed of a front group and a rear group that is arranged closer to the test surface WA than the front group, and the front group is composed of three phase adjustment members arranged side by side in the Y-axis direction, which can prevent the light beams stopped down by the diaphragm 161 from spreading at the pupil plane TP or from being vignetted by the diaphragm 161.

[0034] Note that a segmented mirror consisting of multiple non-parallel reflective surfaces may be used instead of the detection light splitting member 16. In this case, the reflective mirror may be divided into three parts in the Y direction, and two of the parts may be tilt-adjustable in the X direction. However, this type of mirror has high sensitivity and is likely to generate heat due to light irradiation. Therefore, to achieve high accuracy, it is preferable to use the detection light splitting member 16 as in this embodiment.

[0035] The first detection light DL1, the second detection light DL2, and the third detection light DL3 are collected by the light-sending first lens group 17, reflected by the mirror 18, and irradiated onto the test surface WA. As a result, the first detection light DL1, the second detection light DL2, and the third detection light DL3 form an irradiation area IA on the test surface WA. The first detection light DL1, the second detection light DL2, and the third detection light DL3 are light that pass through positions on the pupil plane TP that are shifted from one another in the Y direction. Therefore, as shown in FIG. 3, the incident directions of the first detection light DL1, the second detection light DL2, and the third detection light DL3 on the test surface WA are generally parallel to the +X direction but are shifted from one another in the Y direction.

[0036] 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 the optical axis AX2 with respect to the normal to the reflecting surface of the mirror 18. Note that the incident angle θ may be less than 80 degrees or equal to or greater than 90 degrees.

[0037] FIG. 6(a) is a diagram showing detection light incident on the test surface WA. FIG. 6(b) is a diagram showing an illumination area IA on the test surface WA. FIG. 6(c) is a diagram showing the light intensity distribution in the X-axis direction of the illumination area IA. The solid line shows the light intensity distribution IDL1 of the first detection light DL1. The dashed-dotted line shows the light intensity distribution IDL2 of the second detection light DL2. The dashed line shows the light intensity distribution IDL3 of the third detection light DL3. The detection area DA shown in FIG. 6 will be described later.

[0038] The first detection light DL1, the second detection light DL2, and the third detection light DL3 each consist of two diffracted lights: a +1st-order diffracted light DP1 and a −1st-order diffracted light DM1. Accordingly, the light intensity distributions IDL1, IDL2, and IDL3 each form interference fringes formed by the two diffracted lights. Therefore, as shown in FIG. 6(c), the light intensity distributions IDL1, IDL2, and IDL3 are all intensity-modulated by a sine function (sin function) having a predetermined period FX and amplitude in the X direction. In this embodiment, the amplitude of the sine function modulating the light intensity distributions IDL1, IDL2, and IDL3 is equal to the period FX in the X direction. The first fringe FR1, the second fringe FR2, and the third fringe FR3 shown in FIG. 6(b) are formed on the test surface WA according to the light intensity distributions IDL1, IDL2, and IDL3, respectively, which correspond to the phases of the sinusoidal functions.

[0039] As described above, the first detection light DL1, the second detection light DL2, and the third detection light DL3 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 distributions IDL1, IDL2, and IDL3 are shifted by 1 / 3 of 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, the second detection light DL2, and the third detection light DL3 are irradiated onto the irradiation area IA on the test surface WA in a superimposed manner, i.e., almost overlapping manner. In other words, the first detection light DL1, the second detection light DL2, and the third detection light DL3 are irradiated onto the test surface WA at an oblique incidence from a direction having a directional component in the +X direction, overlapping each other, to form an irradiation area IA on the test surface WA. In Figure 6(b), the first fringe FR1, the second fringe FR2, and the third fringe FR3 are shown shifted in position in the Y-axis direction, but in reality the first fringe FR1, the second fringe FR2, and the third fringe FR3 are almost overlapping in the Y-axis direction.

[0040] Therefore, in the irradiation area IA, the sum of the light intensity of the first detection light DL1, the light intensity of the second detection light DL2, and the light intensity of the third detection light DL3 is constant at any position in the X-axis direction. In other words, the light intensity distributions IDL1, IDL2, and IDL3 are complementary in the X direction. Moreover, the light intensity distribution IDL1, the light intensity distribution IDL2, and the light intensity distribution IDL3 are all constant within a predetermined range in the Y direction. The X direction in the plane of the test surface WA is an example of a first direction.

[0041] The reason for locating the detection beam splitting member 16 near the pupil plane TP is to split the +1st-order diffracted light DP1 and the −1st-order diffracted light DM1 into the first detection beam DL1, the second detection beam DL2, and the third detection beam DL3 according to the incident direction on the test surface WA, regardless of the incident position on the test surface WA. Therefore, the position near the pupil plane TP where the detection beam splitting member 16 is located does not necessarily have to be a 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 or forward along the optical axis AX2 as long as it can split the light beam into the first detection beam DL1, the second detection beam DL2, and the third detection beam DL3 according to the incident direction on the test surface WA. This also applies to the other pupil planes described below.

[0042] As described above, the light-sending optical system (light-sending side second lens group 15 and light-sending side first lens group 17) irradiates the test surface WA with multiple detection lights (first detection light DL1, second detection light DL2, and third detection light DL3) that are 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 (X direction) so as to be superimposed on the test surface WA.

[0043] 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, and the light-receiving side second lens group 21, and then enters the incident surface 22a of the light-receiving prism 22. A slit SL is provided on the incident surface 22a of the light-receiving prism 22. The optical axis AX5 is the optical axis of the light-receiving side first lens group 20 and the light-receiving side second lens group 21. The optical axis AX5 is obtained by reflecting the optical axis AX4 about the normal to the reflecting surface of the mirror 19.

[0044] The mirror 19, the first light-receiving lens group 20, and the second light-receiving lens group 21 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.

[0045] FIG. 7 is a view of the incident surface 22a of the light-receiving prism 22 as viewed from the direction normal to the incident surface 22a. A slit SL is formed on the incident surface 22a at or near the intersection with the optical axis AX2. The slit SL has multiple openings. The multiple openings are arranged at equal intervals along the x2 direction within the incident surface 22a. Each of the multiple openings is rectangular in shape. Note that, as an example, the number of openings is 320, but in FIG. 7, the number of openings is shown as fewer than the actual number to avoid complexity. The portion of the incident surface 22a other than the slit SL is formed with a light-shielding portion OF covered with a light-shielding film.

[0046] The incident surface 22a 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 21. 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 22a. The x2 axis, which is an in-plane direction of the incident surface 22a, 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 22a. The z2 axis is an axis perpendicular to the Y axis and the x2 axis.

[0047] The incident surface 22a is an example of a first conjugate surface that is optically conjugate with the test surface WA. The light-receiving-side first lens group 20 and the light-receiving-side second lens group 21 are an example of a first light-receiving optical system that forms the first conjugate surface. The x2 direction is an example of a second direction corresponding to the first direction (X direction). The slit SL is an example of an aperture member that is arranged on the first conjugate surface (incident surface 22a) and has a plurality of apertures arranged side by side in the second direction (x2 direction) corresponding to the first direction (X direction).

[0048] The slit SL selectively transmits only the light of the first detection light DL1, the second detection light DL2, and the third detection light DL3 reflected from a portion of the illumination area IA on the test surface WA formed on the incident surface 22a that is in an imaging relationship with the slit SL. Therefore, the portion of the illumination area IA on the test surface WA that is in an imaging relationship with the slit SL on the incident surface 22a via the light-receiving-side first lens group 20 and the light-receiving-side second lens group 21 may be interpreted as the detection area DA, as shown in Figures 6(b) and 6(c). In other words, only the light of the first detection light DL1, the second detection light DL2, and the third detection light DL3 reflected from the detection area DA on the test surface WA is transmitted through the slit SL.

[0049] The width of each of the openings constituting the slit SL in the x2 direction is width Swx, and the width in the Y direction is width Swy. Meanwhile, as shown in FIG. 6(b), 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 22a by the light-receiving-side first lens group 20 and the light-receiving-side second lens group 21 matches the ratio of the width Swx to the width Dwx and the ratio of the width Swy to the width Dwy. As an example, the width Swx is 0.03 mm, and the width Swy is 0.05 mm.

[0050] In order to collect the reflected light from the large detection area DA with a width Dwx onto the slit SL having multiple openings with a narrow width Swx, a cylindrical lens 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 21. 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.

[0051] The first detection light DL1, second detection light DL2, and third detection light DL3 that have passed through the slit SL are deflected by a predetermined angle due to the refraction action of the light-receiving prism 22, and then exit the light-receiving prism 22 and enter the front lens group 23 of the relay optical system (front lens group 23, rear lens group 26). The optical axis AX6 is the optical axis of the front lens group 23 and rear lens group 26 of the relay optical system.

[0052] The first detection light DL1, second detection light DL2, and third detection light DL3 are diffracted when passing through a slit SL having multiple openings with a relatively narrow width Swx in the X2 direction, causing their propagation direction to expand in the Z direction. Therefore, the first detection light DL1, second detection light DL2, and third detection light DL3 cannot clearly distinguish between the +1st-order diffracted light DP1 and the −1st-order diffracted light DM1. Therefore, in FIG. 2, the light after passing through the slit SL is shown as the first detection light DL1. In addition, in FIG. 2 viewed from the −Y direction, the second detection light DL2 and third detection light DL3 are not shown because they overlap with the first detection light DL1.

[0053] A pupil splitting prism 24 and a light-splitting prism 25 are arranged on a pupil plane RP2 relative to the entrance surface 22a formed by the front lens group 23. Here, the pupil plane RP2 is a plane where multiple light rays that are emitted in the same direction from different positions on the entrance surface 22a converge at approximately one point. Details of the pupil splitting prism 24 and the light-splitting prism 25 will be described later.

[0054] The first detection light DL1, second detection light DL2, and third detection light DL3 emitted from the spectral prism 25 are incident on the polarizing beam splitter 27 via the rear lens group 26 of the relay optical system. The polarizing beam splitter 27 is arranged closer to the test surface WA than the light-receiving surfaces (light-receiving surfaces 29a and 29b), and splits the incident light into a P-polarized component and an S-polarized component different from the P-polarized component. The polarizing beam splitter 27 is, for example, a prism.

[0055] Of the first detection light DL1, second detection light DL2, and third detection light DL3, the P-polarized light component travels straight through polarizing beam splitter 27 and forms an image of the P-polarized light component of slit SL on light-receiving surface 29a of photodetector 28a. On the other hand, of the first detection light DL1, second detection light DL2, and third detection light DL3, the S-polarized light component is reflected by polarizing beam splitter 27 and forms an image of the S-polarized light component of slit SL on light-receiving surface 29b of photodetector 28b. Therefore, photodetector RS receives the P-polarized light component and the S-polarized light component separated from the multiple detection lights by polarizing beam splitter 27 at different positions on its light-receiving surface (light-receiving surface 29a, light-receiving surface 29b).

[0056] In other words, the light receiving section RS receives multiple detection lights (first detection light DL1, second detection light DL2, and third detection light DL3) that have passed through the openings provided in the slit SL at different positions on the light receiving surface (light receiving surface 29a or light receiving surface 29b). The relay optical system consisting of the front lens group 23 and the rear lens group 26 is an example of a second light-receiving optical system that forms a second conjugate plane that is optically conjugate with the first conjugate plane. The surface on which the light-receiving surface 29a or the light-receiving surface 29b is disposed is an example of the second conjugate plane. That is, the light-receiving surface 29a of the light-detecting unit 28a is disposed on the second conjugate plane. The light-receiving surface 29b of the light-detecting unit 28b is disposed on the second conjugate plane.

[0057] The slit SL is formed on the entrance surface 22a of the light-receiving prism 22, 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 22 changes in the Z direction, so that this tilt of the image plane is corrected. In other words, the light-receiving prism 22 can also be considered as an image plane tilt correction member. The direction of rotation of the polarizing beam splitter 27 around the optical axis AX6 is set so that the P-polarized light and S-polarized light relative to the polarization separation surface 27a of the polarizing beam splitter 27 coincide with the P-polarized light and S-polarized light relative to the test surface WA.

[0058] Photoelectric conversion signals of the detected light received by light-receiving surface 29a of photodetector 28a and light-receiving surface 29b of photodetector 28b and photoelectrically converted are output from photodetector 28a and photodetector 28b, respectively, and input to calculation unit PU. The calculation unit PU is, for example, a computer device equipped with a CPU and memory. The details of the light detecting units 28a and 28b, and the images of the slits SL formed on the light receiving surfaces 29a and 29b thereof will be described later.

[0059] Fig. 8 is a diagram showing an example of pupil splitting prism 24 and spectral prism 25. For ease of understanding, Fig. 8 shows optical axis AX6 parallel to the X axis, similar to Figs. 2 and 3. Fig. 8(a) shows a cross-sectional view in the XZ plane passing through optical axis AX6 of pupil splitting prism 24 and spectral prism 25, and Fig. 8(b) shows a cross-sectional view in the XY plane passing through optical axis AX6 of pupil splitting prism 24 and spectral prism 25.

[0060] The pupil dividing prism 24 is made up of a first prism 241, a second prism 242, and a third prism 243, which are arranged along the Y axis. The first prism 241 is a prism formed by two triangular prisms, a first block 2411 and a second block 2412, which are arranged with their hypotenuses facing each other. The second prism 242 is a single prism. The third prism 243 is a prism formed by two triangular prisms, a fifth block 2431 and a sixth block 2432, which are arranged with their hypotenuses facing each other. Note that in FIG. 8(a), the first prism 241, the second prism 242, and the third prism 243 overlap each other.

[0061] The incident surfaces of the first block 2411, the third block 2421, and the fifth block 2431 are planes perpendicular to the optical axis AX6. The exit surfaces of the second block 2412, the fourth block 2422, and the sixth block 2432 are planes perpendicular to the optical axis AX6. The first block 2411 and the second block 2412 are preferably formed of materials having mutually different refractive indices. The fifth block 2431 and the sixth block 2432 are preferably formed of materials having mutually different refractive indices. Furthermore, the first block 2411 and the second block 2412 are preferably optical members (achromatic) cemented together so that chromatic aberration is corrected. The fifth block 2431 and the sixth block 2432 are preferably optical members cemented together so that chromatic aberration is corrected.

[0062] The first detection light DL1 is refracted at the boundary surface between the first block 2411 and the second block 2412, and is emitted from the first prism 241. The second detection light DL2 is emitted from the second prism 242. The third detection light DL3 is refracted at the boundary surface between the fifth block 2431 and the sixth block 2432, and is emitted from the second prism 242.

[0063] The light-splitting prism 25 arranged on the exit side is a prism formed by placing two triangular prisms, a seventh block 251 and an eighth block 252, with their hypotenuses facing each other. The seventh block 251 and the eighth block 252 are preferably made of materials with mutually different refractive indices.

[0064] The first detection light DL1 emitted from the first prism 241 is first split in the Y direction by being refracted at different angles depending on its wavelength at the incident surface of the seventh block 251. Next, the light split in the Y direction at the incident surface is split in the Y direction by being refracted at different angles depending on its wavelength at the boundary surface between the seventh block 251 and the eighth block 252. The light split in the Y direction at the boundary surface is further split in the Y direction by being refracted at different angles depending on its wavelength at the exit surface of the eighth block 252. As a result, the first detection light DL1 emitted from the first prism 241 is split in the Y direction by the spectroscopic prism 25, and is output from the spectroscopic prism 25 as detection light DL1a, detection light DL1b, and detection light DL1c. Similarly, the second detection light DL2 emitted from the second prism 242 is first split in the Y direction by being refracted at different angles depending on its wavelength at the incident surface of the seventh block 251. Next, the light split in the Y direction at the incident surface is split in the Y direction by being refracted at different angles depending on its wavelength at the boundary surface between the seventh block 251 and the eighth block 252. The light split in the Y direction at the boundary surface is further split in the Y direction by being refracted at different angles depending on its wavelength at the exit surface of the eighth block 252. As a result, the second detection light DL2 emitted from the second prism 242 is split in the Y direction by the spectroscopic prism 25, and is output from the spectroscopic prism 25 as detection light DL2a, detection light DL2b, and detection light DL2c. Similarly, the third detection light DL3 emitted from the second prism 242 is first split in the Y direction by being refracted at different angles depending on its wavelength at the incident surface of the seventh block 251. Next, the light split in the Y direction at the incident surface is split in the Y direction by being refracted at different angles depending on its wavelength at the boundary surface between the seventh block 251 and the eighth block 252. The light split in the Y direction at the boundary surface is further split in the Y direction by being refracted at different angles depending on its wavelength at the exit surface of the eighth block 252. As a result, the third detection light DL3 emitted from the third prism 243 is split in the Y direction by the spectroscopic prism 25, and is output from the spectroscopic prism 25 as detection light DL3a, detection light DL3b, and detection light DL3c.

[0065] In FIG. 8(b), in order to avoid the drawing becoming complicated, each light is shown as being separated only at the boundary surface between the seventh block 251 and the eighth block 252. Furthermore, the light separating prism 25 may be formed by a single prism having different refractive powers depending on the wavelength.

[0066] Pupil splitting prism 24 is disposed on pupil plane RP2. Therefore, as shown in Fig. 3, light incident on the +Y side of optical axis AX6 is first detection light DL1, light incident near optical axis AX6 is second detection light DL2, and light incident on the -Y side of optical axis AX6 is third detection light DL3. 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.

[0067] As described above, the plurality of detection lights irradiated onto the test surface WA by the light transmitting unit each contain a plurality of different wavelengths. The light receiving unit has a spectroscopic element that splits each of the plurality of detection lights according to wavelength and directs them to different positions on the light receiving surface (light receiving surface 29a or light receiving surface 29b). The spectroscopic prism 25 is an example of such a spectroscopic element. Furthermore, pupil splitting prism 24 is an example of a light separating member that causes multiple detection lights incident on the light receiving section of the light receiving unit to be incident at different positions on the light receiving surface (light receiving surface 29a or light receiving surface 29b).

[0068] 9 is a diagram showing an image of the P-polarized component of the slit SL formed on the light-receiving surface 29a. In FIG. 9, 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 22a. That is, an arbitrary region along the x2 direction of the incident surface 22a 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 22a, 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. Please note that in Figure 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 a direction tilted at a predetermined angle from the Z axis for the sake of convenience.

[0069] The x3 direction on the light receiving surface 29a is an example of a fourth direction corresponding to the first direction (X direction) on the light receiving surface 29a. The Y direction on the light receiving surface 29a is an example of a fifth direction intersecting with the fourth direction. Therefore, the light separation direction by the light separating prism 25 is the fifth direction (Y direction).

[0070] Due to the separation and deflection of the detection light by the pupil splitting prism 24 and the spectral prism 25, the different wavelength components of the first detection light DL1, the second detection light DL2, and the third detection light DL3 are directed to different positions on the light receiving surface 29a, and multiple images of the slit SL (IM1a to IM1c, IM2a to IM2c, and IM3a to IM3c) are formed on the light receiving surface 29a. Images IM1a to IM1c, images IM2a to IM2c, and images IM3a to IM3c formed on the light receiving surface 29a at intervals in the Y direction are respectively images formed by the first detection light DL1, the second detection light DL2, and the third detection light DL3, which are mutually deflected by a small angle in the Y direction by the pupil splitting prism 24 and the spectral prism 25.

[0071] 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. 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. Image IM3a is an image formed by light of a first wavelength in the third detection light DL3, image IM3b is an image formed by light of a second wavelength in the third detection light DL3, and image IM3c is an image formed by light of a third wavelength in the third detection light DL3.

[0072] In Figure 9, for ease of understanding, the first detection light DL1, the second detection light DL2, and the third detection light DL3 contain light of three different wavelengths, and therefore there are three images IM1a to IM1c based on the first detection light DL1, three images IM2a to IM2c based on the second detection light DL2, and three images IM3a to IM3c based on the third detection light DL3. However, the wavelengths of light contained in the first detection light DL1, the second detection light DL2, and the third detection light DL3 are not limited to three discrete wavelengths, and may contain four or more different discrete wavelengths. In this case, the number of images IM1a-IM1c due to the first detection light DL1, the number of images IM2a-IM2c due to the second detection light DL2, and the number of images IM3a-IM3c due to the third detection light DL3 will each be four or more. Furthermore, the wavelengths of the light contained in the first detection light DL1, the second detection light DL2, and the third detection light DL3 are not limited to a plurality of discrete wavelengths, but may be a plurality of discrete or continuous wavelength bands.

[0073] The light receiving surface 29a photoelectrically converts the light quantities of these images IM1a-IM1c, IM2a-IM2c, and IM3a-IM3c, 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 encompasses one of the images IM1a-IM1c, IM2a-IM2c, and IM3a-IM3c. Each photoelectric conversion unit receives the corresponding image IM1a-IM1c, IM2a-IM2c, and IM3a-IM3c, and photoelectrically converts the light quantities and outputs the converted light quantities.

[0074] 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.

[0075] 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, the second detection light DL2, and the third detection light DL3 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, the second detection light DL2, and the third detection light DL3. By narrowing the Y-direction width of each of the multiple images IM1a to IM1c, IM2a to IM2c, and IM3a to IM3c on the light receiving surfaces 29a and 29b, the first detection light DL1, the second detection light DL2, and the third detection light DL3 can be dispersed and received with even higher precision.

[0076] 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 slit SL formed on the light receiving surface 29b is similar to the image of the P-polarized component of the slit SL formed on the light receiving surface 29a described above, and therefore a description thereof will be omitted.

[0077] The measurement principle of the surface position detecting apparatus 100 according to the first embodiment will be described below. As described above, the first detection light DL1, the second detection light DL2, and the third detection light DL3 are irradiated onto the test surface WA, forming the light intensity distributions IDL1, IDL2, and IDL3 shown in FIG. 6(c). The first detection light DL1, the second detection light DL2, and the third detection light DL3 are all 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, IDL2, and IDL3 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, IDL2, and IDL3 shift in the −X direction.

[0078] On the other hand, the detection area DA shown in FIG. 6(c) is an area where the first detection light DL1, second detection light DL2, and third detection light DL3 reflected from the detection area DA pass through the slit SL on the incident surface 22a of the light-receiving prism 22. That is, the detection area DA is in an imaging relationship with the slit SL via the light-receiving-side first lens group 20 and the light-receiving-side second lens group 21. However, because the optical axis AX5 of the light-receiving-side first lens group 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 detection area DA and the light intensity distributions IDL1, IDL2, and IDL3 shown in FIG. 6(c) changes.

[0079] The light intensity of each of the images IM1a-IM1c of the slit 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 of the images IM2a-IM2c of the slit 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. Furthermore, the light intensity of each of the images IM3a-IM3c of the slit SL formed by the third detection light DL3 on the light receiving surface 29a is proportional to the sum of the light intensity of the third detection light DL3 within the detection area DA. Therefore, the light intensity of each of the images IM1a-IM1c, IM2a-IM2c, and IM3a-IM3c varies with the change in the position of the test surface WA in the Z direction. It should be noted that, unlike conventional surface position detection devices, even if the position of the test surface WA in the Z direction changes, the positions of the images IM1a to IM1c, IM2a to IM2c, and IM3a to IM3c on the light-receiving surface 29a do not change.

[0080] Here, referring again to FIG. 6(c), a method for calculating the position of the test surface WA in the Z direction from the light intensity distributions IDL1, IDL2, and IDL3 on the test surface WA will be described. As shown in FIG. 6(c), on the test surface WA, multiple detection lights are intensity-modulated in the X direction by sinusoidal functions with the same period. The multiple detection lights include first detection light DL1, second detection light DL2, and third detection light DL3, whose sinusoidal functions have mutually different phases in the X direction. The phases of the sinusoidal functions of the first detection light DL1, second detection light DL2, and third detection light DL3 in the X direction differ from one another by 2 / 3·π, where π is the ratio of the circumference of a circle to its diameter.

[0081] Therefore, the light intensity distributions IDL1, IDL2, and IDL3 all have signal intensities expressed by the following equations (1), (2), and (3), which have the same amplitude as the period FZ and are shifted in phase by one-third of the period FZ relative to the position in the Z-axis direction on the test surface WA. Note that in equations (1), (2), and (3), the light intensity distributions IDL1, IDL2, and IDL3 each have a signal intensity I A (Z,λ,x2), I B (Z,λ,x2), and IC It is shown as (Z,λ,x2).

[0082]

number

[0083]

number

[0084]

number

[0085] In equations (1), (2), and (3), R(λ, x2) represents the reflectance of the test surface WA, and φ(Z, λ, x2) represents the phase of the intensity modulation of the light intensity distribution IDL2, which changes depending on the height of the test surface WA in the Z direction. The amplitude of the signal intensity is calculated by multiplying R(λ, x2) by the constant a. As mentioned above, the phase shift α between the first detected light DL1 and the second detected light DL2, and the phase shift α between the second detected light DL2 and the third detected light DL3 are each 2 / 3·π. Therefore, for each wavelength, polarization, and multiple openings that make up the slit SL, the signal intensity I A (Z,λ,x2), I B (Z,λ,x2), and I C Three signal intensities (light amounts) of (Z, λ, x2) are measured.

[0086] The calculation unit PU calculates the reflectance R(λ, x2) and the phase φ(Z, λ, x2) from the signal intensities expressed by equations (1), (2), and (3) by calculations based on equations (4) and (5).

[0087]

number

[0088]

number

[0089] In calibration of the exposure apparatus, the highly precisely controlled stage ST is moved in the Z direction to measure the phase. In other words, the phase is scanned in the Z direction. This allows a linear relationship between the fringe phase φ and the position of the stage ST in the Z direction to be calculated in advance. The calculation unit PU calculates the position of the stage ST in the Z direction based on this linear relationship from the phase φ calculated based on equation (5).

[0090] As described above, the surface position detection device 100 according to this embodiment is a surface position detection device that determines position information of the test surface WA along an axis that intersects with the test surface WA, and includes a light sending unit TS and a light receiving unit RS. The light-sending unit TS has a light-sending optical system (in this embodiment, light-sending-side second lens group 15 and light-sending-side first lens group 17). The light-sending optical system (in this embodiment, light-sending-side second lens group 15 and light-sending-side first lens group 17) irradiates the test surface WA with a plurality of detection lights (in this embodiment, first detection light DL1, second detection light DL2, and third detection light DL3) that are intensity-modulated in a first direction (in this embodiment, X direction) within the test surface WA at oblique incidence from a direction having a directional component in the first direction (in this embodiment, X direction) so as to be superimposed on the test surface WA. The light receiving unit RS has a first light receiving optical system (in this embodiment, a light receiving side first lens group 20 and a light receiving side second lens group 21), an aperture member (in this embodiment, a slit SL), a second light receiving optical system (in this embodiment, a relay optical system consisting of a front lens group 23 and a rear lens group 26), and a light detecting unit (in this embodiment, light detecting unit 28a or light detecting unit 28b). The first light receiving optical system (in this embodiment, the light receiving side first lens group 20 and the light receiving side second lens group 21) forms a first conjugate surface (in this embodiment, the incident surface 22a) that is optically conjugate with the test surface WA. The aperture member (in this embodiment, the slit SL) is arranged on the first conjugate plane (in this embodiment, the incident surface 22a) and has a plurality of apertures arranged side by side in a second direction (in this embodiment, the x2 direction) corresponding to the first direction (in this embodiment, the X direction). The second light receiving optical system (in this embodiment, a relay optical system consisting of the front lens group 23 and the rear lens group 26) forms a second conjugate surface that is optically conjugate with the first conjugate surface (in this embodiment, the incident surface 22a). The light detecting section (in this embodiment, the light detecting section 28a or the light detecting section 28b) has a light receiving surface (in this embodiment, the light receiving surface 29a or the light receiving surface 29b) disposed on the second conjugate plane. The light receiving unit RS receives multiple detection lights (in this embodiment, the first detection light DL1, the second detection light DL2, and the third detection light DL3) that have passed through the opening at different positions on the light receiving surface (in this embodiment, the light receiving surface 29a or the light receiving surface 29b).

[0091] With this configuration, the surface position detecting device 100 according to this embodiment can easily perform chromatic aberration correction while ensuring a predetermined or larger field of view in the first direction (X direction).

[0092] Among semiconductor exposure tools, there is a well-known exposure tool that measures the position of the surface of a substrate (wafer) all at once. Such exposure tools require a wide measurement field that covers the diameter of the substrate. Therefore, an optical system that supports broad wavelengths and has a wide measurement field (e.g., 300 mm or more) with high-precision aberration correction is required. To ensure a measurement field of 300 mm or more, a transmission optical system is more suitable than a reflection optical system in terms of lens design and manufacturing tolerances. However, with transmission optical systems, chromatic aberration correction becomes an issue. Furthermore, as the wavelength band used approaches the short wavelength side, the types of glass that can be used become more limited, making this issue of chromatic aberration correction even more pronounced.

[0093] In the surface position detection device 100 according to the present embodiment, a plurality of openings arranged side by side in the second direction (in this embodiment, the x2 direction) corresponding to the first direction (in this embodiment, the X direction) enable both ensuring a wide measurement field of view (for example, 300 mm or more) in the first direction and overcoming the problem of chromatic aberration correction.

[0094] Here, in the surface position detection device 100 according to the present embodiment, as shown in FIG. 6, the detection region DA on the inspection surface WA is a region where images of a plurality of openings constituting the slit SL are arranged in parallel in the X direction. On the other hand, when the detection region on the inspection surface is a single rectangle extending in the X direction, the length of the long side of the rectangle is, for example, 320 mm. In that case, it is necessary to suppress aberration with high precision in all measurement regions (for example, -160 mm < X < 160 mm) and in all wavelength ranges. When the detection region is a single rectangle extending in the X direction, for example, a transmission optical system may be essential in the objective lens unit. However, when using the ultraviolet region, only quartz or fluorite can be used as the material of the objective lens. Therefore, when the detection region is a single rectangle extending in the X direction, there is a problem that the degree of freedom in selecting the glass material used as the objective lens is small and chromatic aberration correction is difficult.

[0095] In contrast, in the surface position detection device 100 according to the present embodiment, it is sufficient that aberration is suppressed in the measurement region corresponding to the width Swx of the plurality of openings constituting the slit SL and in the wavelength range of about the spectral resolution (for example, about -10 nm < λ < 10 nm). Since the difficulty of chromatic aberration correction is considered to be considerably reduced compared to the case where the detection region is a single rectangle extending in the X direction, chromatic aberration correction is considered to be possible even in the ultraviolet region. As described above, in the surface position detection device 100 according to the present embodiment, since the position in the Z direction can be measured at each wavelength, the chromatic aberration of the optical system can be corrected by software for each wavelength.

[0096] Furthermore, in the surface position detection device 100 according to this embodiment, on the test surface WA, the multiple detection lights are intensity-modulated in a first direction (in this embodiment, the X direction) by a sine wave function of the same period, and the multiple detection lights include a first detection light DL1, a second detection light DL2, and a third detection light DL3 whose phases in the first direction (in this embodiment, the X direction) of the sine wave function are different from each other. Furthermore, the phases of the sine wave functions of the first detection light DL1, the second detection light DL2, and the third detection light DL3 differ from one another by 2 / 3·π, where π is the circular constant.

[0097] With this configuration, the surface position detection device 100 according to this embodiment can measure the light intensity information of three fringes whose phases are shifted by 2 / 3·π on the light receiving surface (light receiving surface 29a or light receiving surface 29b), and can therefore calculate the phase information of the fringes regardless of the position of the test surface WA in the Z direction. Therefore, it is possible to measure the position of the test surface WA in the Z direction based on triangulation using the fringe phase information.

[0098] Furthermore, in the surface position detecting device 100 according to this embodiment, the light sending unit TS includes a detection light splitting member 16. The detection light splitting member 16 splits incident light to generate a first detection light DL1, a second detection light DL2, and a third detection light DL3.

[0099] With this configuration, the surface position detecting device 100 according to this embodiment can split incident light to generate the first detection light DL1, the second detection light DL2, and the third detection light DL3.

[0100] In the surface position detecting device 100 according to this embodiment, the detection light splitting member 16 is made up of a front group and a rear group that is arranged closer to the test surface WA than the front group. The front group is made up of three phase adjustment members (in this embodiment, prisms 16a, 16b, and 16c) that are arranged side by side in a direction (in this embodiment, Y direction) that intersects with the first direction (in this embodiment, X direction).

[0101] With this configuration, in the surface position detecting device 100 according to this embodiment, the phase of the fringes can be shifted in each of the pupils divided into three in a direction (Y direction in this embodiment) intersecting with the first direction (X direction in this embodiment) in the process of the fringes passing through the pupil plane TP of the light sending optical system. Furthermore, with this configuration, it is possible to prevent the light rays stopped down by the diaphragm 161 from spreading at the pupil plane TP or from being vignetted by the diaphragm 161, compared to when the front group is made up of one prism and the rear group is made up of three prisms.

[0102] Furthermore, in the surface position detecting device 100 according to this embodiment, the light receiving unit RS is disposed closer to the test surface WA than the light receiving surfaces (light receiving surfaces 29a and 29b in this embodiment), and has a polarizing beam splitter 27 that separates the incident light into light of a first polarized component and light of a second polarized component different from the first polarized component. The light receiving unit RS receives the first polarized component and the second polarized component, into which the multiple detection lights are separated by the polarizing beam splitter 27, at different positions on the light receiving surface (light receiving surfaces 29a and 29b in this embodiment).

[0103] With this configuration, the surface position detecting device 100 according to this embodiment can measure the position in the Z direction for each wavelength and each polarization, and therefore the chromatic aberration of the optical system can be corrected by software for each wavelength and each polarization.

[0104] (Configuration for forming white, high-contrast fringes) 6(b), fringes (first fringe FR1, second fringe FR2, and third fringe FR3) are formed on the test surface WA according to the light intensity distribution. A configuration for forming white, high-contrast fringes on the test surface WA will be described.

[0105] In order to form white, high-contrast fringes on the test surface WA, it is necessary to allow only two diffracted lights, the +1st-order diffracted light DP1 and the −1st-order diffracted light DM1, from the diffraction grating plate 14 to be incident on the pupil plane TP, which is the pupil of the objective lens (light-sending-side second lens group 15, light-sending-side first lens group 17). The condition of allowing only two diffracted lights, the +1st-order diffracted light DP1 and the −1st-order diffracted light DM1, to be incident on the pupil plane TP is satisfied for all wavelengths.

[0106] Here, the larger the illumination sigma, the higher the light intensity, but if the illumination sigma is increased, it becomes difficult to make only the +1st-order diffracted light DP1 and the -1st-order diffracted light DM1 incident on the pupil plane TP for all wavelengths. Note that the illumination sigma is the ratio of the numerical aperture (NA) of the illumination system to the numerical aperture of the imaging lens. Furthermore, although the wider the wavelength band, the smaller the Z measurement error due to the process wafer, if the wavelength band is widened, it becomes difficult to make only the +1st-order diffracted light DP1 and the −1st-order diffracted light DM1 incident on the pupil plane TP for all wavelengths.

[0107] 10 shows an example of the configuration of the light introducing portion end surface 120 of the light introducing portion 12. The light introducing portion end surface 120 is the end surface of the light introducing portion 12, and light is emitted from the light introducing portion end surface 120. A light sending side opening 121 is provided on the light introducing portion end surface 120. The light sending side opening 121 is an opening through which light supplied from the light source 10 is emitted. Therefore, the light introducing portion 12 has the light sending side opening 121, which is an opening through which light supplied from the light source 10 is emitted.

[0108] The light introducing portion end face 120 and the diaphragm 161 are positioned optically conjugate. The width Lwx of the light sending side opening 121 is used as the shape of the illumination sigma. Therefore, the light sending side opening 121 is positioned optically conjugate with the diaphragm 161. The width Lwx of the light sending side opening 121 in the x4 direction corresponding to the X direction is a predetermined value. The predetermined value is a value at which the width Lwx of the light sending side opening 121 becomes the illumination sigma. The x4 direction is an example of a third direction corresponding to the first direction.

[0109] By positioning the light-sending side opening 121 and the diaphragm 161 optically conjugately and setting the width Lwx of the light-sending side opening 121 in the x4 direction corresponding to the X direction to a value according to the illumination sigma, all of the light emitted from the light-introducing part end face 120 can be effectively utilized. A light pipe may be attached to the light introducing end surface 120. By attaching a light pipe to the light introducing end surface 120, unevenness of the strands can be averaged out.

[0110] As described above, the aperture stop 161 blocks the zeroth-order diffracted light and the third-order and higher diffracted light generated by the diffraction grating 14a. FIG. 11 shows the X-direction passing position of the diffracted light generated by the diffraction grating 14a on the pupil plane TP versus wavelength. In FIG. 11, the range in the X direction corresponds to the effective diameter of the light-sending-side second lens group 15 relative to the numerical aperture. As described above, the diffraction grating 14a selectively generates +1st-order diffracted light DP1 and −1st-order diffracted light DM1. The diffraction grating 14a has a pattern that minimizes the generation of +2nd-order diffracted light and −2nd-order diffracted light.

[0111] As shown in Figure 11, the passing positions of the diffracted light are asymmetric in the X direction. This is because light is obliquely incident on the diffraction grating plate 14 from a direction having a directional component in the X direction. Comparing -1st-order diffracted light DM1 and 1st-order diffracted light DP1, the distributions of passing positions in the X direction are different. The -1st-order diffracted light DM1 passes through a range RM in the X direction, whereas the 1st-order diffracted light DP1 passes through a range RP in the X direction. As shown in the figure, the range RM is longer than the range RP. Furthermore, when the −3rd-order diffracted light DM3 and the +3rd-order diffracted light DP3 are compared, the distribution of their passing positions in the X direction is different. The −3rd-order diffracted light DM3 is hardly included in the range of the effective diameter for the numerical aperture of the light-sending-side second lens group 15. The +3rd-order diffracted light DP3 is only slightly included in this range.

[0112] 12 shows the position in the X direction on the pupil plane TP of the diffracted light generated by the diffraction grating 14a, relative to the wavelength, on which the light-blocking region defined by the diaphragm 161 is superimposed. Also, FIG. 13 shows the light-blocking region in the direction seen from the light-sending-side second lens group 15 toward the detection light splitting member 16. In order for the aperture 161 to block third-order or higher diffracted light, the aperture 161 has light-blocking regions arranged asymmetrically in the X direction. As shown in Fig. 12, the -3rd-order diffracted light DM3 and the +3rd-order diffracted light DP3 are blocked by the light-blocking regions of the aperture 161. In the aperture 161, the light-blocking region on the +3rd-order diffracted light DP3 side is wider than the light-blocking region on the -3rd-order diffracted light DM3 side. This light-blocking region is particularly effective in blocking the +3rd-order diffracted light DP3.

[0113] The wavelength band of the detection light is a range in which the long wavelength limit wavelength (approximately 0.8 μm) is shorter than twice the short wavelength limit wavelength (approximately 0.4 μm), as shown in Fig. 11. In other words, the longest wavelength among the wavelengths of the detection light is shorter than twice the shortest wavelength among the wavelengths of the detection light.

[0114] Furthermore, in this embodiment, in order to form white, high-contrast fringes on the test surface WA, the order of the optical system arrangement of the light guide 11, diffraction grating plate 14, aperture 161, and detection light splitting member 16 is, from the upstream side, light guide 11, diffraction grating plate 14, aperture 161, and detection light splitting member 16.

[0115] In this embodiment, the light intensity distribution IDL1 of the first detection light DL1, the light intensity distribution IDL2 of the second detection light DL2, and the light intensity distribution IDL3 of the third detection light DL3 irradiated onto the test surface WA are sinusoidal functions of X, and therefore the calculation unit PU calculates the phase φ(Z) based on equation (5) which includes an arctangent function.

[0116] However, if the light intensity distributions IDL1, IDL2, and IDL3 are functions other than sine wave functions, the calculation unit PU may calculate the phase φ(Z) based on the inverse function of the other functions. Therefore, the light intensity distribution IDL1 of the first detection light DL1, the light intensity distribution IDL2 of the second detection light DL2, and the light intensity distribution IDL3 of the third detection light DL3 that are irradiated onto the test surface WA are not limited to sine wave functions with respect to X, and may be other functions.

[0117] However, at least in the portion corresponding to the detection area DA, the light intensity distributions IDL1, IDL2, and IDL3 must be smooth. If the light intensity distributions IDL1, IDL2, and IDL3 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, the signal intensity I A (Z), I B (Z), and I C This is because it becomes difficult to calculate the phase φ(Z) with high accuracy from (Z). In addition, "smooth" may be defined as a function having a continuous differential coefficient (derivative) within a certain interval (i.e., not bending). "Light intensity distributions IDL1 and IDL2" being smooth in the portion corresponding to the detection area DA means, for example, that when the light intensity distributions IDL1, IDL2, and IDL3 are fitted with a certain function, the fitted function has a continuous differential coefficient in the portion corresponding to the detection area DA.

[0118] In addition, if the light intensity distributions IDL1, IDL2, and IDL3 are sinusoidal functions as described above, the calculation unit PU can calculate the phase φ(Z) using a general inverse sine function, thereby simplifying the configuration of the calculation unit PU.

[0119] 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.

[0120] (Exposure Apparatus According to Second Embodiment) 14 is a schematic diagram showing an example of the configuration of an exposure apparatus 200 according to this embodiment. The exposure apparatus 200 according to this embodiment is an exposure apparatus for exposing and transferring an exposure pattern onto a photoresist (resist) PR formed on the surface of a semiconductor wafer or a substrate for a display device (hereinafter collectively referred to as "substrate") WF. The exposure apparatus 200 is equipped with the surface position detection apparatus 100 according to the first embodiment described above. The surface position detection apparatus 100 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. In the XYZ coordinate system of FIG. 14, the direction parallel to the optical axis AXP of the projection optical system 57 is the Z-axis direction.

[0121] The substrate WF loaded 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, causing the surface position detection device 100 to detect Z-direction position information at 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, which are held integrally with the surface position detection device 100, via the positions of reference mirrors 60a and 60b. Furthermore, the position of the substrate stage 59 in the XY directions is measured by interferometer 62 via the position of reference mirror 60b. Interferometers 63a and 64b are an example of a first position measurement unit.

[0122] 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 to the control device 70 as signal S2. Information regarding the X- and Y-direction position of the substrate stage 59 is transmitted to the control device 70 as signal S3. Map data is created within the control device 70 based on signals S2 and S3. The map data represents information regarding the Z-direction position relative to the X- and Y-direction positions of the surface of the substrate WF.

[0123] 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 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.

[0124] The position of the substrate stage 59 in the Z direction during exposure is measured by interferometers 58a and 58b, which are held integrally with the projection optical system 57, via the positions of reference mirrors 60a and 60b, and transmitted as signal S1 to the control device 70. The position of the 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 the control device 70. Interferometers 58a and 58b are an example of a second position measurement unit.

[0125] 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.

[0126] 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.

[0127] 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 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.

[0128] The exposure apparatus 200 according to the second embodiment is equipped with the surface position detecting apparatus 100 according to the first embodiment as an apparatus for detecting the position in the Z direction of the surface of the substrate WF on which the resist PR has been formed. With this configuration, it is possible to minimize measurement errors caused by the reflectance distribution on the surface of the substrate WF and measure the surface position of the surface of the substrate WF with high accuracy. As a result, the exposure apparatus according to the second embodiment can align the surface of the substrate WF on which the resist PR has been formed with respect to the projection optical system 57 with high accuracy, and ultimately perform good projection exposure.

[0129] (Substrate Processing System According to Third Embodiment) 15 is a schematic diagram showing an example of the configuration of a substrate processing line including a substrate processing system 300 according to this embodiment. The substrate processing system 300 includes the surface position detecting apparatus 100 according to the first embodiment, the exposure apparatus 200 according to the second embodiment, and a data holding device 110.

[0130] 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.

[0131] 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 also 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.

[0132] In the substrate processing system 300 according to this 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.

[0133] The substrate WF exposed by the exposure apparatus 200 is transported by the transport mechanism 103 to the coater developer 104, which develops the resist PR on the substrate WF. 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.

[0134] The substrate processing system 300 according to the present embodiment described above includes 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 detecting device 100, but the present invention is not limited to this. The data holding device 110 may be built into the surface position detecting 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, in which the surface position detecting device 100 and the exposure apparatus 200 are installed, and is connected to the surface position detecting device 100 and the exposure apparatus 200 via a network.

[0135] The substrate processing system according to this embodiment is a substrate processing system 300 for processing a substrate WF, and includes a first stage (stage ST in this embodiment) on which the substrate WF is placed, a measurement device having a surface position detection device 100 according to the first embodiment described above that measures the positions of multiple points on the surface of the substrate WF in a direction intersecting the surface (Z direction), and a second stage (substrate stage 59 in this embodiment) 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 (substrate stage 59 in this embodiment).The exposure apparatus 200 performs exposure while changing the position of the substrate WF in the direction intersecting the surface, using at least the measurement results from the measurement device. 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.

[0136] (Device manufacturing method according to the fourth embodiment) A device manufacturing method according to this embodiment will be described with reference to Figure 16. The device manufacturing method according to this embodiment is a method for manufacturing a device using the exposure apparatus 200 according to the second embodiment or the substrate processing system 300 according to the third embodiment described above. Therefore, please refer to the above descriptions for details of the operation of the exposure apparatus 200 according to the second embodiment and the substrate processing system 300 according to the third embodiment.

[0137] 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 according to the second embodiment or the substrate processing system 300 according to the third embodiment described above.

[0138] 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.

[0139] 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.

[0140] 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 relating to the second 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.

[0141] 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 locations on the surface of the resist PR formed on the surface of the substrate WF in a direction intersecting the surface using a substrate processing system 300 according to the third embodiment. Then, the 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 locations, 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.

[0142] One embodiment of the present invention has been described in detail above with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes and the like are possible within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0143] 100... surface position detection device, TS... light transmitting section, RS... light receiving section, 15... light transmitting side second lens group, 17... light transmitting side first lens group, 20... light receiving side first lens group, 21... light receiving side second lens group, SL... slit, 23... front side lens group, 26... rear side lens group, 28a... light detecting section, 28b... light detecting section, WA... test surface, 22a... incident surface, 29a, 29b... light receiving surface, DL1... first detected light, DL2... second detected light, DL3... third detected light

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 including a light sending optical system that irradiates the test surface with a plurality of detection lights that are intensity-modulated in a first direction within the test surface at an oblique incidence from a direction having a directional component in the first direction, in a superimposed manner; a first light-receiving optical system that forms a first conjugate plane that is optically conjugate with the test surface; an aperture member that is disposed on the first conjugate plane and has a plurality of apertures that are arranged side by side in a second direction corresponding to the first direction; a second light-receiving optical system that forms a second conjugate plane that is optically conjugate with the first conjugate plane; and a light-receiving unit that has a light-receiving surface that is disposed on the second conjugate plane, and receives the plurality of detection light beams that have passed through the apertures at different positions on the light-receiving surface; A surface position detection device comprising:

2. On the test surface, the plurality of detection lights are intensity-modulated in the first direction by sinusoidal functions having the same period, the plurality of detection lights include first detection light, second detection light, and third detection light, the phases of the sine wave functions in the first direction of which are different from each other; 2. The surface position detection device according to claim 1.

3. the phases of the sine wave functions of the first detection light, the second detection light, and the third detection light differ from one another by 2 / 3·π, where π is the constant of a circle's circumference; 3. The surface position detection device according to claim 2.

4. the light sending unit includes a detection light splitting member that splits incident light to generate the first detection light, the second detection light, and the third detection light; 3. The surface position detection device according to claim 2.

5. the detection light splitting member comprises a front group and a rear group disposed closer to the test surface than the front group, the front group is composed of three phase adjustment members arranged side by side in a direction intersecting the first direction, 5. The surface position detection device according to claim 4.

6. the three phase adjustment members each have an incident surface onto which light is incident and an exit surface from which the plurality of detection light beams exit, the rear group has a rear group entrance surface onto which the plurality of detection light beams emitted from the exit surface are incident, the angles of the entrance surfaces of two of the three phase adjustment members relative to the rear group entrance surface are variable; 6. The surface position detection device according to claim 5.

7. the three phase adjustment members each have an incident surface onto which light is incident and an exit surface from which the plurality of detection light beams exit, the rear group has a rear group entrance surface onto which the plurality of detection light beams emitted from the exit surface are incident, the angles of the entrance surface or the exit surface with respect to the rear group entrance surface are different for each of the three phase adjustment members; 6. The surface position detection device according to claim 5.

8. the three phase adjustment members each have an incident surface onto which light is incident and an exit surface from which the plurality of detection light beams are emitted, and an angle formed between the incident surface and the exit surface differs from one another among the three phase adjustment members; 6. The surface position detection device according to claim 5.

9. The phase adjusting member is a prism.

6. The surface position detection device according to claim 5.

10. The light sending unit includes a light introducing unit to which light is supplied from a light source; a diffraction grating disposed in an optical path between the light introducing portion and the detection light dividing member, the diffraction grating selectively generates +1st-order diffracted light and −1st-order diffracted light; 10. The surface position detecting device according to claim 4.

11. the light sending unit includes a diaphragm that blocks zero-order diffracted light and third-order or higher diffracted light generated by the diffraction grating. The surface position detection device according to claim 10.

12. light is incident on the diffraction grating at an oblique incidence angle from a direction having a directional component in the first direction, the diaphragm has light-blocking regions arranged asymmetrically with respect to the first direction; The surface position detection device according to claim 11.

13. the light introducing section includes a light sending side opening section that is an opening through which light supplied from the light source is emitted, the light-sending-side opening is located at a position optically conjugate with the diaphragm, and has a width in a third direction corresponding to the first direction of the diaphragm that is a predetermined value; The surface position detection device according to claim 11.

14. the detection light splitting member is disposed in close proximity to the diaphragm; The surface position detection device according to claim 11.

15. the longest wavelength of the plurality of wavelengths of the detection light is shorter than twice the shortest wavelength of the plurality of wavelengths of the detection light; The surface position detection device according to claim 11.

16. the light receiving unit is disposed closer to the test surface than the light receiving surface, and has a polarizing beam splitter that separates incident light into light of a first polarized component and light of a second polarized component different from the first polarized component, and receives the first polarized component and the second polarized component separated by the polarizing beam splitter at different positions on the light receiving surface. The surface position detection device according to any one of claims 1 to 9.

17. the light receiving unit has a light separating member that causes the plurality of detection lights incident on the light receiving unit to be incident on different positions on the light receiving surface, The surface position detection device according to any one of claims 1 to 9.

18. 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 has 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; 18. The surface position detection device according to claim 17.

19. a spectral direction of the spectral member is a fifth direction intersecting a fourth direction corresponding to the first direction on the light receiving surface; 19. The surface position detection device according to claim 18.

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

21. 21. The exposure apparatus according to claim 20, a first position measurement unit that measures the 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:

22. forming a resist on a surface of a substrate; Detecting the position of the surface of the resist formed on the surface of the substrate using the exposure apparatus according to claim 20, and setting the surface of the resist at a predetermined position in the optical axis direction of the projection optical system to expose 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:

23. 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 9, 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.

24. forming a resist on a surface of a substrate; using the substrate processing system according to claim 23, detecting positions of a plurality of points on the surface of the resist formed on the surface of the substrate in a direction intersecting with the surface, and exposing an exposure pattern while changing positions of the surface of the resist in a direction intersecting with 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:

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