Detection device, lithography device, and article manufacturing method

Abstract

To provide a technique of detecting a relative position of a first object and a second object at high detection accuracy.SOLUTION: A detection device detects a relative position of a first mark and a second mark respectively provided for a first object and a second object arranged in a superposing manner. The detection device includes: an illumination system configured to illuminate the first and second marks with illumination light having no polarization; and a detection system including an imaging device and configured to form an image with diffraction light from the first and second marks illuminated by the illumination system on an imaging surface of the imaging device. The first and second marks are configured to be capable of forming, on the imaging surface, optical information showing a relative position in a first direction or a second direction orthogonal to the first direction. A pupil surface of the detection system includes a shading body BP including a first shading part BP1 crossing an optical axis of the detection system in a direction parallel to a third direction (x direction) and a second shading part BP2 crossing the optical axis of the detection system in a direction parallel to a fourth direction (y direction). The third direction is a direction conjugate to the first direction. The fourth direction is a direction conjugate to the second direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a detection apparatus, a lithographic apparatus and a method for manufacturing an article. [Background technology]

[0002] In an imprinting apparatus, a pattern made of the cured product of the imprinting material is formed by bringing a mold into contact with an imprinting material arranged on a substrate and curing the imprinting material. In such an imprinting apparatus, it is important to accurately align the substrate and the mold. Patent Document 1 describes a technique for aligning the substrate and the mold using a mark made of a diffraction grating provided on the substrate and a mark made of a diffraction grating provided on the mold. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2008-522412 Summary of the Invention [Problem to be solved by the invention]

[0004] When a mark is illuminated, light reflected from the edge that is the boundary between the mark and the area outside the mark enters the imaging element as noise light, which can reduce the detection accuracy of the mark. In particular, when the area of ​​the mark is reduced, the effect of noise light on the image formed by the light for detecting position information from the mark increases, and the decrease in detection accuracy can become significant.

[0005] An object of the present invention is to provide an advantageous technique for detecting the relative positions of a first mark and a second mark provided on a first object and a second object, respectively, with high detection accuracy. [Means for solving the problem]

[0006] One aspect of the present invention relates to a detection device that detects relative positions of a first mark and a second mark provided on a first object and a second object, respectively, that are arranged one on top of the other, the detection device comprising: an illumination system that illuminates the first mark and the second mark with unpolarized illumination light; and a detection system including an image sensor that forms an image of diffracted light from the first mark and the second mark illuminated by the illumination system on an image sensor surface, the first mark and the second mark being configured to be able to form optical information on the image sensor that indicates the relative positions in a first direction or a second direction perpendicular to the first direction, the pupil plane of the detection system being provided with a light shielding body that includes a first light shielding portion that crosses the optical axis of the detection system in a direction parallel to a third direction and a second light shielding portion that crosses the optical axis of the detection system in a direction parallel to a fourth direction, the third direction being a direction conjugate to the first direction, and the fourth direction being a direction conjugate to the second direction. Effect of the Invention

[0007] According to the present invention, there is provided an advantageous technique for detecting the relative positions of a first mark and a second mark provided on a first object and a second object, respectively, with high detection accuracy. [Brief description of the drawings]

[0008] [Figure 1] 4A shows the light intensity distribution of light incident on the pupil plane of the detection system and the light intensity distribution at the exit of the pupil plane of the illumination system in the first embodiment, and FIG. 4B shows a light blocking body arranged on the pupil plane of the detection system. [Diagram 2] FIG. 1 illustrates an imprint apparatus as an example of a lithography apparatus. [Diagram 3] FIG. 1 is a diagram illustrating the configuration of a detection device according to a first embodiment. [Figure 4] FIG. [Diagram 5] FIG. 1 is a diagram illustrating a diffraction grating that generates moiré fringes. [Figure 6] FIG. 1 is a diagram illustrating a diffraction grating that generates moiré fringes. [Figure 7] FIG. 4 is a diagram illustrating an example of a mark arrangement within a field of view. [Figure 8]11A and 11B are diagrams illustrating examples of scattered light due to a pattern edge. [Figure 9] 13A shows the light intensity distribution of light incident on the pupil plane of a detection system and the light intensity distribution at the exit of the pupil plane of an illumination system in the second embodiment, and FIG. 13B shows a light blocking body disposed on the pupil plane of the detection system. [Figure 10] FIG. 13 is a diagram illustrating the configuration of a detection device according to a second embodiment. [Figure 11] FIG. 13 is a diagram illustrating the configuration of a discharge device according to a modified example of the second embodiment. [Figure 12] FIG. 13 is a diagram illustrating the configuration of a detection device according to a third embodiment. [Figure 13] 1 is a diagram illustrating a method for manufacturing an article. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0010] FIG. 2 shows the configuration of an imprinting apparatus 1 as an example of a lithography apparatus that transfers a pattern of an original to a substrate. The imprinting apparatus 1 is used in the manufacture of devices such as semiconductor devices, and forms a pattern made of a cured product of the imprinting material 9 on the substrate 8, which is a processing target, by using a mold 7 to mold an uncured imprinting material 9 on the substrate 8. The pattern formation process in which the imprinting apparatus 1 forms a pattern on the substrate 8 may include a contacting step, a filling and alignment step, a curing step, and a separating step. In the contacting step, the imprinting material 9 on the shot region of the substrate 8 is brought into contact with the pattern region 7a of the mold 7. In the filling and alignment step, the imprinting material 9 is filled into the space defined by the substrate 8 and the pattern region 7a, and the shot region of the substrate 8 is aligned with the pattern region 7a of the mold 7. The shot region is an area where a pattern is formed by one pattern formation process, in other words, an area where the pattern region 7a of the mold 7 is transferred by one pattern formation process.

[0011] As the imprint material, a curable composition (sometimes called an uncured resin) that is cured by applying energy for curing is used. As the energy for curing, electromagnetic waves, heat, etc. can be used. The electromagnetic waves can be, for example, light having a wavelength selected from the range of 10 nm to 1 mm, such as infrared rays, visible light, and ultraviolet rays. The curable composition can be a composition that is cured by irradiation with light or by heating. Among these, the photocurable composition that is cured by irradiation with light contains at least a polymerizable compound and a photopolymerization initiator, and may further contain a non-polymerizable compound or a solvent as necessary. The non-polymerizable compound is at least one selected from the group consisting of a sensitizer, a hydrogen donor, an internal mold release agent, a surfactant, an antioxidant, and a polymer component. The imprint material can be arranged on the substrate in the form of droplets, or in the form of islands or a film formed by connecting a plurality of droplets. The imprint material may also be supplied in the form of a film on the substrate by a spin coater or a slit coater. The viscosity of the imprint material (viscosity at 25°C) may be, for example, 1 mPa·s or more and 100 mPa·s or less. Examples of materials that can be used for the substrate include glass, ceramics, metals, semiconductors (Si, GaN, SiC, etc.), and resins. If necessary, a member made of a material different from that of the substrate may be provided on the surface of the substrate. The substrate is, for example, a silicon wafer, a compound semiconductor wafer, or quartz glass. Below, an example in which a photocurable composition is used as the imprint material will be described, but this is not intended to limit the type of imprint material.

[0012] In this specification and the accompanying drawings, directions are shown in an XYZ coordinate system in which the direction parallel to the surface of the substrate 8 is the XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are the X direction, Y direction, and Z direction, respectively, and the rotation around the X-axis, the Y axis, and the Z axis are θX, θY, and θZ, respectively. Control or drive regarding the X-axis, Y-axis, and Z-axis means control or drive regarding the direction parallel to the X-axis, the direction parallel to the Y axis, and the direction parallel to the Z axis, respectively. Furthermore, control or drive regarding the θX-axis, θY-axis, and θZ-axis means control or drive regarding the rotation around an axis parallel to the X-axis, the rotation around an axis parallel to the Y axis, and the rotation around an axis parallel to the Z axis, respectively. Furthermore, the position is information that can be specified based on the coordinates of the X-axis, the Y-axis, and the Z axis, and the orientation is information that can be specified by the values ​​of the θX-axis, the θY-axis, and the θZ axis. Positioning means controlling the position and / or the orientation. The alignment (positioning) may include controlling the position and / or attitude of at least one of the substrate 8 and the mold 7 so that an alignment error (overlay error) between the shot area of ​​the substrate 8 and the pattern area of ​​the mold 7 is reduced. The alignment may also include control for correcting or changing the shape of at least one of the shot area of ​​the substrate 8 and the pattern area of ​​the mold 7. The contact step and the separation step may be performed by driving the mold 7 by the mold driving mechanism 4, but may also be performed by driving the substrate 8 by the substrate driving mechanism 5. Alternatively, the contact step and the separation step may be performed by driving the mold 7 by the mold driving mechanism 4 and driving the substrate 8 by the substrate driving mechanism 5.

[0013] The imprinting apparatus 1 may include a curing unit 2, a detection unit 3, a mold driving mechanism 4, a substrate driving mechanism 5, and a control unit C. The imprinting apparatus 1 may further include an application unit 6. After a contact step in which the imprinting material 9 on the substrate 8 is brought into contact with the mold 7, the curing unit 2 irradiates the imprinting material 9 with light such as ultraviolet light as curing energy to cure the imprinting material 9. The curing unit 2 may include, for example, a light source and a plurality of optical elements for uniformly irradiating the light emitted from the light source in a predetermined shape onto the pattern region 7a of the mold 7, which is the irradiated surface. In particular, it is desirable that the irradiation area (irradiation range) of the light by the curing unit 2 is approximately the same as the surface area of ​​the pattern region 7a or slightly larger than the area of ​​the pattern region 7a. This is because the irradiation area is minimized to prevent the mold 7 or the substrate 8 from expanding due to heat caused by irradiation, causing misalignment or distortion in the pattern transferred to the imprinting material 9. In addition, this is also to prevent abnormal operation of the coating unit 6 caused by light reflected by the substrate 8 or the like reaching the coating unit 6 and curing the imprint material 9 remaining in the discharge section of the coating unit 6. Here, as the light source, for example, a high-pressure mercury lamp, various excimer lamps, an excimer laser, or a light-emitting diode can be used. The light source can be appropriately selected depending on the characteristics of the imprint material 9, which is the light-receiving body.

[0014] FIG. 3 shows an example of the configuration of the detection device 3. The detection device 3 is configured to optically detect or measure the relative position between a mold mark (first mark) 10 arranged on a mold (first object) 7 and a board mark (second mark) 11 arranged on a board (second object) 8. The mold mark 10 and the board mark 11 are configured to be able to form optical information indicating the relative position in the X direction (first direction) or the Y direction (second direction) on an imaging plane of an imaging element 25 described later. The detection device 3 may include an illumination system 22 and a detection system 21. A part of the illumination system 22 and a part of the detection system 21 may be shared. The illumination system 22 includes a light source 23, generates illumination light using light from the light source 23, and illuminates the measurement object (first mark, second mark) with this illumination light. This illumination light may be unpolarized light. By using unpolarized illumination light, an optical image having higher brightness can be formed on the imaging plane than when polarized light is used. The detection system 21 detects the relative positions of a mold mark (first mark) 10 and a substrate mark (second mark) 11 as the measurement object by detecting light from the measurement object illuminated with the illumination light.

[0015] The optical axis of the detection device 3 at the positions of the substrate 8 and the mold 7 is perpendicular to the upper surface of the substrate 8 and the lower surface of the mold 7 (pattern region 7a), i.e., parallel to the Z axis. The detection device 3 can be configured to be driven in the X and Y directions by a driving mechanism (not shown) in accordance with the positions of the mold mark 10 and the substrate mark 11. The detection device 3 may be configured to be driven in the Z direction to focus the detection system 21 on the position of the mold mark 10 or the substrate mark 11. The detection device 3 may include an optical element or optical system for focusing. Based on the relative positions of the mold mark 10 and the substrate mark 11 detected or measured using the detection device 3, the positioning of the substrate 8 by the substrate driving mechanism 5 and the correction of the shape and magnification of the pattern region 7a by the correction mechanism (not shown) can be controlled. The correction mechanism is mounted on the mold driving mechanism 4 and can adjust the shape and magnification of the pattern region 7a of the mold 7 by deforming the mold 7. The mold mark 10 and the substrate mark 11 will be described in detail later.

[0016] The mold driving mechanism 4 may include a mold chuck (not shown) that holds the mold 7 by vacuum suction force or electrostatic suction, and a mold driving unit (not shown) that drives the mold 7 by driving the mold chuck. The mold driving mechanism 4 may also include the above-mentioned correction mechanism. The mold driving unit may be configured to drive the mold chuck or the mold 7 about the Z axis, for example. The mold driving unit may further be configured to drive the mold chuck or the mold 7 about at least one of the θX axis, the θY axis, the θZ axis, the X axis, and the Y axis.

[0017] The substrate driving mechanism 5 may include a substrate chuck that holds the substrate 8 by vacuum suction force, electrostatic force, or the like, and a substrate driving unit (not shown) that drives the substrate chuck to drive the substrate 8. The substrate driving unit may be configured to drive the substrate chuck or the substrate 8 about the X-axis, Y-axis, and θZ-axis, for example. The substrate driving unit may further be configured to drive the substrate chuck or the substrate 8 about at least one of the θX-axis, θY-axis, and Z-axis.

[0018] The applicator (dispenser) 6 applies or places uncured imprint material 9 on the substrate 8. The applicator 6 may be located outside the housing of the imprint apparatus 1, in which case the applicator 6 may be understood to be not a component of the imprint apparatus 1.

[0019] The mold 7 has a pattern such as a circuit pattern to be transferred to the substrate 8 (the imprint material 9 thereon) in its pattern region 7a. The mold 7 may be made of a material that transmits light as curing energy, such as quartz. The substrate 8 may be, for example, a semiconductor substrate such as a single crystal silicon substrate, or a substrate having at least one layer on a semiconductor substrate.

[0020] The control unit C may be configured to control the curing unit 2, the detection device 3, the mold driving mechanism 4, the substrate driving mechanism 5, and the application unit 6. The control unit C may be configured, for example, by a field programmable gate array (FPGA), a computer with a built-in program, or a combination of all or part of these. The FPGA may include a programmable logic device (PLD) or an application specific integrated circuit (ASIC). The control unit C includes a memory and a processor, and may operate based on an arithmetic expression, a parameter, and a computer program stored (saved) in the memory to define the operation and function of the imprint apparatus 1. At least a part of the function of the detection device 3, for example, a function of processing an image captured by the image sensor 25, may be provided by a module incorporated in the control unit C, and in that case, the module of the control unit C may be understood as a part of the detection device 3.

[0021] Here, we will explain the imprint process or pattern formation process executed by the imprint apparatus 1. First, a substrate 8 is transported by a substrate transport mechanism (not shown) to a substrate chuck of a substrate driving mechanism 5, and fixed to the substrate chuck. Next, the substrate 8 is driven by the substrate driving mechanism 5 so that the shot area of ​​the substrate 8 moves to a coating position by the coating unit 6. Thereafter, the coating unit 6 applies, arranges or supplies an imprint material 9 to the shot area (imprint area) of the substrate (coating step).

[0022] Next, the substrate 8 is driven by the substrate driving mechanism 5 so that the shot region in which the imprint material 9 is arranged is located directly below the pattern region 7a of the mold 7. Next, for example, the mold 7 is lowered by the mold driving mechanism 4 to bring the imprint material 9 on the substrate 8 into contact with the pattern region 7a of the mold 7 (contact step). As a result, the imprint material 9 is filled into the space between the substrate 8 and the pattern region 7a of the mold 7 (including the recess of the pattern region 7a) (filling step). In addition, for a plurality of mark pairs each consisting of a mold mark 10 and a substrate mark 11, the relative positions of the mold mark 10 and the substrate mark 11 are detected or measured by the detection device 3. Then, based on the result, the pattern region 7a and the shot region of the substrate 8 are aligned (alignment step). At this time, the shape of the pattern region 7a of the mold 7 may be corrected by a correction mechanism. In addition, the shape of the shot region of the substrate 8 may be corrected by a heating mechanism (not shown).

[0023] At the stage where the filling and alignment steps are completed, the curing unit 2 irradiates the imprint material 9 with light through the mold 7, and the imprint material 9 is cured (curing step). At this time, the detection device 3 can be driven to retract so as not to block the light path of the curing unit 2. Next, the mold 7 is raised by the mold driving mechanism 4, thereby separating the mold 7 from the cured imprint material 9 on the substrate 8 (separation step).

[0024] The imprint apparatus 1 includes a detection device 3, and can be understood as an example of a lithography apparatus that aligns an original (or a pattern area) with a substrate (or a shot area) based on the output of the detection device 3 and transfers the pattern of the original to the substrate. The imprint apparatus 1 aligns a mold 7 (first object or original) provided with a mold mark 10 (first mark) with a substrate 8 (second object) provided with a substrate mark 11 (second mark) based on the output of the detection device 3.

[0025] The detection device 3 will be described in detail below with reference to FIG. 3. As described above, the detection device 3 includes an illumination system 22 and a detection system 21, and a part of the illumination system 22 and a part of the detection system 21 can be shared. The illumination system 22 guides illumination light generated by light from a light source 23 via a prism 24 or the like to a common optical axis, and illuminates the mold mark 10 and the substrate mark 11. The light source 23 can include at least one of a halogen lamp, an LED, a semiconductor laser (LD), a high-pressure mercury lamp, a metal halide lamp, a supercontinuum light source, and an LDLS (Laser-Driven Light Source) light source. The wavelength of the illumination light generated by the light source 23 is selected so as not to harden the imprint material 9.

[0026] The prism 24 is shared by the illumination system 22 and the detection system 21, and may be disposed on or near a pupil plane Pill of the illumination system 22, or on or near a pupil plane Pdet of the detection system 21. The mold mark 10 and the substrate mark 11 may include marks formed of diffraction gratings. The detection system 21 may form an optical image of interference light (interference fringes or moire fringes) generated by interference between diffracted lights diffracted by the mold mark 10 and the substrate mark 11 illuminated by the illumination system 22, on the imaging plane of the imaging element 25. The imaging element 25 may be formed of, for example, a CCD sensor or a CMOS sensor.

[0027] The prism 24 may have a surface (bonding surface) where two members are bonded together as a reflecting surface RS, and may have a reflecting film 24a on the bonding surface. The prism 24 may be replaced with a plate-shaped optical element having a reflecting film 24a on its surface. The position where the prism 24 is disposed may not be the illumination system 22 or the pupil plane Pill or Pdet of the detection system 21, or near either of them. An illumination aperture stop 27 may be disposed on the pupil plane Pill of the illumination system 22. A detection aperture stop 26 may be disposed on the pupil plane Pdet of the detection system 21. The illumination aperture stop 27 defines the light intensity distribution on the pupil plane Pill of the illumination system 22. The illumination stop 27 may be an optional component, and illumination light parallel to the optical axis may be formed by defining the area of ​​the reflecting film 24a.

[0028] FIG. 4 shows the light intensity distribution on the pupil plane Pill of the illumination system 22 of the detection device 3 in the comparative example, and the numerical aperture NA O A detection aperture stop that defines is shown superimposed. The x-axis and y-axis are conjugate axes to the X-axis and Y-axis, respectively. When there is no mirror between the pupil plane and the mold / substrate that bends the optical axis, the x-axis and the X-axis are parallel. When there is a mirror between the pupil plane and the mold / substrate that bends the optical axis, the X-axis and the Y-axis mapped to the pupil plane by the mirror coincide with the x-axis and the y-axis, respectively. The light intensity distribution on the pupil plane Pill of the illumination system 22 includes a first pole IL1, a second pole IL2, a third pole IL3, and a fourth pole IL4. Illumination by a light intensity distribution having such poles IL1 to IL4 can be understood as oblique incidence illumination. The light from the illuminated marks 10 and 11 is incident on the detection system 21 through the numerical aperture NA. O The light is incident on the imaging surface of the image sensor 25 through the aperture of the aperture stop that defines the

[0029] FIG. 5 is a diagram showing an example of a mark (diffraction grating) that generates moiré fringes. Hereinafter, with reference to FIGS. 5(a) to 5(d), the principle of the generation of moiré fringes by diffracted light from the mold mark 10 and the substrate mark 11, and the detection of the relative positions of the mold mark 10 and the substrate mark 11 using the moiré fringes will be described. The diffraction grating (first diffraction grating) 41 provided on the mold 7 as the mold mark 10 and the diffraction grating (second diffraction grating) 42 provided on the substrate 8 as the substrate mark 11 have slightly different periods in the measurement direction. When two diffraction gratings with different periods are overlapped, a pattern having a period reflecting the period difference between the diffraction gratings, so-called moiré fringes (moiré), appears due to interference between the diffracted lights from the two diffraction gratings. In this case, the phase of the moiré fringes changes depending on the relative positions of the diffraction gratings, so that the relative positions of the mold mark 10 and the substrate mark 11, that is, the relative positions of the mold 7 and the substrate 8 can be obtained by detecting the moiré fringes.

[0030] Specifically, when the diffraction gratings 41 and 42, which have slightly different periods, are overlapped, the diffracted light from the diffraction gratings 41 and 42 overlap, and as shown in FIG. 5(c), a moire fringe having a period reflecting the difference in period is generated. The position of light and dark in the moire fringe (phase of the fringe) changes depending on the relative positions of the diffraction gratings 41 and 42. For example, when one of the diffraction gratings 41 and 42 is shifted in the X direction, the moire fringe shown in FIG. 5(c) changes to the moire fringe shown in FIG. 5(d). The moire fringe magnifies the actual positional deviation between the diffraction gratings 41 and 42 and occurs as a fringe with a large period, so that the relative positions of the diffraction gratings 41 and 42 can be detected with high accuracy even if the resolution of the detection system 21 is low.

[0031] In the comparative example, when the diffraction gratings 41 and 42 are detected in a bright field to detect the moiré fringes, the detection system 21 also detects the zeroth order light from the diffraction gratings 41 and 42. The case where the diffraction gratings 41 and 42 are detected in a bright field can include the case where the diffraction gratings 41 and 42 are illuminated from the vertical direction and diffracted light diffracted in the vertical direction by the diffraction gratings 41 and 42 is detected. Since the zeroth order light reduces the contrast of the moiré fringes, in the comparative example, the detection system 21 has a configuration that does not detect the zeroth order light (a dark field configuration), that is, a configuration that illuminates the diffraction gratings 41 and 42 with oblique incidence.

[0032] Fig. 6 is a diagram showing another example of a mark (diffraction grating) that generates moiré fringes. In the example of Fig. 6, one of the diffraction gratings 41 and 42 is a checkerboard-shaped diffraction grating as shown in Fig. 6(a), and the other diffraction grating is a diffraction grating as shown in Fig. 6(b). The diffraction grating shown in Fig. 6(b) includes a pattern that is periodically arranged in the measurement direction (first direction) and a pattern that is periodically arranged in a direction perpendicular to the measurement direction (second direction).

[0033] In the configurations of Fig. 4 (comparative example), Fig. 6(a) and Fig. 6(b), the light from the first pole IL1 and the second pole IL2 is irradiated onto the diffraction grating and diffracted in the Y direction by the checkerboard diffraction grating, and is also diffracted in the X direction. Furthermore, the light diffracted in the X direction by the diffraction gratings with slightly different periods passes through the detection area (NAo) on the pupil plane Pdet of the detection system 21 with relative position information in the X direction, enters the imaging plane of the image sensor 25, and is detected by the image sensor 25. Using this, the relative positions of the two diffraction gratings 41 and 42 can be obtained.

[0034] In the combination of the configuration of Fig. 4 (comparative example) and the diffraction gratings shown in Fig. 6(a) and Fig. 6(b), the light from the third pole IL3 and the fourth pole IL4 is not used to detect the relative position of the diffraction grating. On the other hand, when detecting the relative position of the diffraction gratings shown in Fig. 6(c) and Fig. 6(d), the light from the third pole IL3 and the fourth pole IL4 is used to detect the relative position of the diffraction grating, and the light from the first pole IL1 and the second pole IL2 is not used to detect the relative position of the diffraction grating. In addition, when the pair of diffraction gratings shown in Fig. 6(a) and Fig. 6(b) and the pair of diffraction gratings shown in Fig. 6(c) and Fig. 6(d) are arranged in the same field of view of the detection system 21 to simultaneously detect the relative positions in two directions, the pupil intensity distribution shown in Fig. 4 is useful.

[0035] Here, the marks observed within one field of view will be described in detail. FIG. 7 is a diagram showing a schematic representation of an image detected by the imaging element 25 when the mold 7 and the substrate 8 are superimposed. The outer frame range 73 indicates a range that can be observed at one time by the detection device 3. The mold mark 10 described above includes a rough inspection mark 71a-1 and diffraction gratings 71a-2 and 71a-2' as precision inspection marks, and the substrate mark 11 described above includes a rough inspection mark 72a-1 and diffraction gratings 72a-2 and 72a-2' as precision inspection marks. The relative positional deviation between the mold 7 and the substrate 8 can be obtained from the detection result by the detection device 3 based on the geometric center positions of the rough inspection mark 71a-1 and the rough inspection mark 72a-1. The difference between the design values ​​of the rough inspection mark 71a-1 and the rough inspection mark 72a-1 with respect to the measurement value D1 is the relative positional deviation. This mark enables rough alignment.

[0036] Next, the moiré fringes formed by overlapping the diffraction gratings 71a-2 and 72a-2 will be described. The diffraction gratings 71a-2 and 72a-2 are configured with a periodic pattern shown in FIG. 6(c) or (d), and since the periods in the measurement direction are slightly different, when these are overlapped, moiré fringes are formed in which the light intensity changes in the Y direction. The difference in the periods between the diffraction gratings 71a-2 and 72a-2 causes the shift direction of the moiré fringes to differ when the relative positions are changed. For example, when the period of the diffraction grating 71a-2 is slightly larger than the period of the diffraction grating 72a-2, if the substrate 8 shifts relatively in the +Y direction, the moiré fringes also shift in the +Y direction. On the other hand, when the period of the diffraction grating 71a-2 is slightly smaller than the period of the diffraction grating 72a-2, if the substrate 8 shifts relatively in the +Y direction, the moiré fringes shift in the -Y direction.

[0037] Another moiré fringe is formed by the diffraction grating 71a-2' and the diffraction grating 72a-2'. The relationship between the periods of the diffraction gratings 71a-2 and 72a-2 is opposite to the relationship between the periods of the diffraction gratings 71a-2' and 72a-2'. Therefore, when the relative positions change, the positions of the two measured moiré fringes change in opposite directions. If the periodic marks on the mold side and the substrate side that generate the moiré fringes are misaligned by one period, the misalignment of one period cannot be detected according to the principle of moiré fringe detection. Therefore, using the rough inspection marks 71a-1 and 72a-1, it can be confirmed that there is no relative misalignment of one period between the mold 7 and the substrate 8. The rough inspection marks 71a-1 and 72a-1 may be marks that generate a moiré signal if the pitch does not cause a position error of one period between the diffraction gratings of the mold 7 and the diffraction gratings of the substrate 8.

[0038] Since the rough inspection mark 71a-1 of the mold 7 and the rough inspection mark 72a-1 of the substrate 8 may be made of different materials, the light intensity detected by the image sensor 25 may differ depending on the wavelength. Therefore, it is preferable that the illumination system 22 is configured to be able to change the wavelength of the illumination light. This can be realized, for example, by configuring the light source 23 to generate light having a corresponding wavelength range and providing a filter that selectively transmits light of any wavelength within the wavelength range. Alternatively, a plurality of light sources that generate light of different wavelengths may be provided, and a light source selected from them may be made to emit light. By making the wavelength of the illumination light changeable, the ratio of the light intensity of the image of the rough inspection mark 71a-1 to the light intensity of the image of the rough inspection mark 72a-1 can be adjusted. In addition, making the wavelength of the illumination light changeable is also effective for adjusting the light intensity of the moire fringes formed by the diffraction gratings 71a-2, 71a-2', 72a-2, and 72a-2'.

[0039] When the mold mark 10 and the substrate mark 11 are irradiated with illumination light, the illumination light may be scattered at the edges (hereinafter, pattern edges) of the diffraction gratings 71a-2, 71a-2', 72a-2, and 72a-2'. For example, the pattern edge is the boundary between the entire diffraction grating 71a-2 and its outside in the case of the diffraction grating 71a-2. If the signal strength of the moire fringes is weak due to factors such as the step amount and / or constituent materials of the diffraction gratings 71a-2, 71a-2', 72a-2, and 72a-2, an error may occur in the detection result due to scattered light. For this reason, it is desirable to reduce the effect of scattered light at the pattern edges (i.e., the scattered light entering the image sensor 25).

[0040] FIG. 8 shows the light intensity distribution of light incident on the pupil plane Pdet of the detection system 21 in the comparative example and the light intensity distribution at the exit of the pupil plane Pill of the illumination system 22, superimposed on each other. Although FIG. 5 shows IL1 to IL4, FIG. 8 shows only IL1 and IL3 for simplification. Scattered light due to the pattern edge is also generated by IL2 and IL4. The scattered light that may be generated by illumination with the illumination light from IL1 in FIG. 8 will be described. The illumination light from IL1 is irradiated onto the mold mark 10 and the substrate mark 11. The specular reflected light generated by this is irradiated outside the aperture PD of the detection aperture stop 26 of the detection system 21, and is blocked by the detection aperture stop 26. Therefore, such specular reflected light is not detected by the image sensor 25. The illumination light irradiated onto the pattern edge parallel to the X direction is scattered in the Y direction by the pattern edge, generating primary reflected light N1(1) and secondary reflected light N1(2) based on the specular reflected light N1(0) of the illumination light from IL1. When the scattered light passes through the aperture PD of the detection aperture stop 26 and enters the image sensor 25, it is detected by the image sensor 25. As a result, noise components are superimposed on the image of the moiré fringes. Similarly, for IL3, the specularly reflected light from the mold mark 10 and the substrate mark 11 is blocked by the detection aperture stop 26. However, the illumination light irradiated on the pattern edge parallel to the Y direction is scattered in the X direction by the pattern edge, generating primary reflected light N3(1) and secondary reflected light N3(2) based on the specularly reflected light N3(0) of the illumination light from IL3. As a result, the scattered light from the four sides of the pattern edge is imaged on the imaging surface of the image sensor 25 and is superimposed on the image captured by the image sensor 25.

[0041] Specific effects on the detection of moiré fringes include the following. When light from an edge parallel to the Y direction is superimposed on a moiré fringe image whose measurement direction is in the X direction, the light increases the amount of light near the edge of the moiré fringe image, and the amount of light of the moiré fringes may change asymmetrically. This may cause errors when detecting the position of the moiré fringe image. Also, when light from an edge parallel to the X direction is superimposed on a moiré fringe whose measurement direction is in the X direction, the light adds a bias to the moiré fringe image. This reduces the contrast when detecting the moiré fringes, leading to a deterioration in detection reproducibility. Therefore, blocking the light from the pattern edge at the pupil plane Pdet of the detection system 21 leads to improved detection performance.

[0042] FIG. 1(a) shows the light intensity distribution of light incident on the pupil plane Pdet of the detection system 21 in the first embodiment and the light intensity distribution at the exit of the pupil plane Pill of the illumination system 22, superimposed on each other. The light intensity distribution at the exit of the pupil plane Pill of the illumination system 22 includes poles IL1 and IL3. The pole IL1 is disposed on the y-axis, and the pole IL3 is disposed on the x-axis. The mold mark 10 and the substrate mark 11 are illuminated with the illumination light from the pole IL1, thereby generating diffracted light D1(+1) and D1(-1). The diffracted light D1(+1) and D1(-1) pass through the aperture PD of the pupil plane Pdet of the detection system 21 and are incident on the imaging plane of the image sensor 25. The diffracted light D1(+1) and D1(-1) form an optical image of a moiré fringe on the imaging plane of the image sensor 25. Here, the combination of the mold mark 10 and the substrate mark 11 may be a combination of a checkerboard-shaped diffraction grating pattern and a one-dimensional diffraction grating pattern as shown in Figs. 6(a) and (b). The diffracted light of the illumination light illuminating the marks 10 and 11 is diffracted in the X and Y directions. For example, the pitch in the X direction of the diffraction grating pattern in Fig. 6(a) is P1, the pitch in the Y direction is P3, and the pitch in the X direction in Fig. 6(b) is P2. Here, for convenience of explanation, P1>P2 is assumed, but those skilled in the art will understand that diffracted light can be obtained even if the sizes are reversed. Also, here, the mold mark 10 is assumed to be a one-dimensional diffraction grating pattern, and the substrate mark 11 is assumed to be a checkerboard-shaped diffraction grating pattern, but the opposite is also possible. The diffraction angle θ of the first-order diffracted light (angle with respect to the direction parallel to the optical axis) can generally be expressed as follows:

[0043] θx1=arcsin(λ / P1), θx2=arcsin(λ / P2) Here, λ is the wavelength of the illumination light. Diffracted light from the diffraction grating occurs in both positive and negative directions. Therefore, the light diffracted by both the mold mark 10 and the substrate mark 11 that form the moire fringes is diffracted in the X direction with four diffraction angles (θx1+θx2, θx1-θx2, -θx1+θx2, -θx1-θx2). If diffracted light with diffraction angles of θx1+θx2 and -θx1-θx2 is used, the NA of the detection system 21 needs to be enlarged, and the period of the interference fringes becomes fine, so that the detection accuracy cannot be improved even if it is detected. Therefore, diffracted light with diffraction angles θx1-θx2 and -θx1+θx2, which are small diffraction angles, is detected. The angle of the diffracted light in the X direction with respect to the optical axis can be expressed as -θx1+θx2 in the case of D1(+1) shown in FIG. 1(a) and as θx1-θx2 in the case of D2(-1). 1(a), the coordinate in the x direction D1(+1) can be expressed as f×tan(-θx1+θx2), and D1(-1) can be expressed as f×tan(θx1-θx2), where f is the focal length of the lens group arranged between the detection aperture stop 26 of the detection system 21 and the diffraction grating (alignment mark).

[0044] Next, we will explain the diffracted light that diffracts in the Y direction with respect to the optical axis. Since the checkerboard-shaped diffraction grating shown in Fig. 6(a) also has a period in the Y direction, the diffracted light from the diffraction grating in Fig. 6(a) diffracts in both the X and Y directions. Since the pitch in the Y direction is P3, the diffraction angle of the diffracted light can be expressed by the following equation.

[0045] θy=arcsin(λ / P3) In FIG. 1(a), the specular reflection of the illumination light from the pole IL1 is reflected in the Y direction at a position symmetrical to the illumination light with the X axis as the axis of symmetry. In other words, if the incident angle of the illumination light from the pole IL1 on the XY plane is θILy, the position of the illumination light on the detection aperture stop 26 (pupil plane Pdet) is expressed as f×tan(θILy). The specular reflection light is at a position of f×tan(-θILy). The first-order diffracted light from the checkerboard diffraction grating is diffracted at an angle of θy with respect to the specular reflection light. In other words, in FIG. 1(a), the specular reflection of the illumination light from the pole IL1 (f×tan(-θILy)) plus the shift amount of the diffracted light by the angle θy, f×tan(θy), is the position of the diffracted light in the Y direction on the pupil plane Pdet. By adjusting the pitch P3 in the Y direction, the diffraction can be made to the positions D1(+1) and D1(-1) shown in FIG. 1(a). D1(+1) and D1(-1) form interference fringes (moire fringes) whose intensity changes in the X direction on the imaging surface of the imaging element 25, and these are detected by the imaging element 25.

[0046] The pole IL3 is the pole IL1 rotated 90 degrees clockwise, and diffracted light is generated by illuminating the diffraction gratings in Figures 6(c) and (d), and a moire fringe whose intensity changes in the Y direction can be formed. The moire fringes in the X and Y directions may have the same pitch, or may have different pitches considering the pattern area in which the marks are arranged. In the example of Figure 1(a), the light intensity distribution formed at the exit of the pupil plane Pill of the illumination system 22 is composed of the poles IL1 and IL3, and is a light intensity distribution that is asymmetric with respect to the optical axis.

[0047] FIG. 1(b) shows an example of the detection aperture stop 26 arranged on the pupil plane Pdet of the detection system 21. The white parts are apertures, and the black parts are light shielding bodies. As described above with reference to FIG. 8, the scattered light from the pattern edge is distributed on the x-axis and y-axis of the detection aperture stop 26 (pupil plane Pdet). In order to block the unnecessary scattered light, a light shielding body BP having a light shielding part that blocks light is arranged on the x-axis and y-axis of the detection aperture stop 26. This makes it possible to block the scattered light from the pattern edge. The light shielding body BP may include a first light shielding part BP1 that crosses the optical axis of the detection system 21 in a direction parallel to the x-direction (third direction) and a second light shielding part BP2 that crosses the optical axis of the detection system 21 in a direction parallel to the y-direction (fourth direction). The first light shielding part BP1 may be arranged to extend over the entire diameter in the x-direction of the pupil plane Pdet of the detection system 21. The second light blocking part BP2 can be arranged to extend across the entire diameter of the pupil plane Pdet of the detection system 21 in the y direction.

[0048] Here, the x direction (third direction) parallel to the x axis is a direction conjugate to the X direction (first direction) parallel to the X axis, and the y direction (fourth direction) parallel to the y axis is a direction conjugate to the Y direction (second direction) parallel to the Y axis. In the detection system 21, the x direction and the X direction are conjugate to each other, meaning that the x direction and the X direction are the same direction when there is no reflecting surface between the mold 7 / substrate 8 and the pupil plane Pdet of the detection system 21 that bends the optical axis of the detection system 21. In the detection system 21, the x direction and the X direction are conjugate to each other, meaning that when there is a reflecting surface between the mold 7 / substrate 8 and the pupil plane Pdet of the detection system 21 that bends the optical axis, the X direction mapped to the pupil plane Pdet by the reflecting surface coincides with the x direction. When the reflecting surface exists, the x direction and the X direction may or may not coincide with each other. The same applies to the conjugation of the y direction and the Y direction.

[0049] The above description also applies to the x and y directions on the pupil plane Pill of the illumination system 22. That is, the x direction (fifth direction) parallel to the x axis on the pupil plane Pill is a direction conjugate to the X direction (first direction) parallel to the X axis, and the y direction (sixth direction) parallel to the y axis on the pupil plane Pill is a direction conjugate to the Y direction (second direction) parallel to the Y axis. In the illumination system 22, the x direction and the X direction are conjugate to each other when there is no reflective surface between the mold 7 / substrate 8 and the pupil plane Pill of the illumination system 22 that bends the optical axis of the illumination system 22. In the illumination system 22, the x direction and the X direction are conjugate to each other when there is a reflective surface between the mold 7 / substrate 8 and the pupil plane Pill of the illumination system 22 that bends the optical axis, and the X direction is conjugate to each other when there is a reflective surface between the mold 7 / substrate 8 and the pupil plane Pill of the illumination system 22 that bends the optical axis, and the X direction is conjugate to each other when there is a reflective surface between the mold 7 / substrate 8 and the pupil plane Pill of the illumination system 22 that bends the optical axis. When the reflecting surface exists, the x direction may or may not coincide with the X direction. The same applies to the conjugate of the y direction and the Y direction.

[0050] It is preferable that the width (width in the y direction) NAbp1 of the first light-shielding part BP1 is equal to or larger than the width (width in the x direction) NA_IL1 of the pole IL1. In other words, it is preferable that NAbp1≧NA_IL1. This allows the first light-shielding part BP1 to block scattered light of the illumination light from any position within the pole IL1. In other words, unnecessary light from the mold mark 10 (diffraction grating) and the substrate mark 11 (diffraction grating) illuminated with the illumination light that does not contain optical information indicating their relative positions can be blocked by both the first light-shielding part BP1 and the second light-shielding part BP2.

[0051] The pupil plane Pdet of the detection system 21 has a light-transmitting region AP in an area where the light shielding body BP is not disposed. It is preferable that the diffracted light from the mold mark 10 (diffraction grating) and the substrate mark 11 (diffraction grating) illuminated with the illumination light passes through the light-transmitting region AP to form optical information indicating the relative positions of the mold 7 and the substrate 8 on the imaging plane of the imaging element 25.

[0052] Specifically, it is preferable that diffracted light D1(+1) and D1(-1) that form moiré fringes on the imaging surface of the imaging element 25 pass through the light-transmitting region AP. Therefore, the light shielding body BP, mold mark 10 (diffraction grating), and substrate mark 11 (diffraction grating) can be designed so that D1(+1) and D1(-1) do not enter the light shielding body BP. First, for simplicity, consider the case where D1(+1) and D1(-1) do not have widths.

[0053] The positions of D1(+1) and D1(-1) are expressed by f×tan(-θx1+θx2) and f×tan(θx1-θx2) on the pupil plane Pdet of the detection system 21. That is, in order for the diffracted light D1(+1) and D1(-1) to pass through the light transmitting region AP in the x direction, the light shielding body BP, the mold mark 10 (diffraction grating), and the substrate mark 11 (diffraction grating) can be designed to satisfy formula (1).

[0054] |f×tan(-θx1+θx2)|≧NAbp1 / 2 ...Equation (1) Furthermore, with respect to the y direction, the light shielding body BP, the mold mark 10 (diffraction grating), and the substrate mark 11 (diffraction grating) can be designed so as to satisfy the formula (2).

[0055] |f×tan(-θILy)+f×tan(θy)|≧NAbp3 / 2 ...Equation (2) Here, |f×tan(-θILy)+f×tan(θy)| has two solutions, one on the negative side and one on the positive side in the y direction. If there is a light transmission area AP near the specular reflection of the illumination light from the pole IL1 (the negative side in the y direction) on the pupil plane Pdet of the detection system 21, it may cause noise. In addition, a finer pitch of the diffraction grating allows a larger number of pitches of the diffraction grating to fit within a given area, so the spread of the angular distribution of the diffracted light is reduced. Therefore, it is preferable that |f×tan(-θILy)+f×tan(θy)| is on the opposite side of the specular reflection of the illumination light from the pole IL1, that is, on the positive side in the y direction.

[0056] For the central ray of the illumination light, by satisfying formulas (1) and (2), the diffracted light that forms the moire fringes is not blocked by the light blocking body BP and can be detected by the image sensor 25. However, the pole IL1 has a width NA_IL1, and the number of pitches of the diffraction grating is finite. Taking these into consideration, formulas (1) and (2) are expanded to formulas (3) and (4).

[0057] |f×tan(-θx1+θx2)|≧NAbp1 / 2+diffracted light width / 2 ...Equation (3) |f×tan(-θILy)+f×tan(θy)|≧NAbp3 / 2+diffracted light width / 2 ...Equation (4) By satisfying equations (3) and (4), all of the diffracted light from the mold mark 10 (diffraction grating) and the substrate mark 11 (diffraction grating) illuminated by the illumination light passes through the light-transmitting area AP and is incident on the imaging surface of the image sensor 25.

[0058] 9(a) shows the light intensity distribution of light incident on the pupil plane Pdet of the detection system 21 in the modified example of the first embodiment and the light intensity distribution at the exit of the pupil plane Pill of the illumination system 22, superimposed on each other. As shown in FIG. 9(a), in the modified example, the light intensity distribution at the exit of the pupil plane Pill of the illumination system 22 has poles IL1, IL2, IL3, and IL4. The light intensity distribution having the poles IL1, IL2, IL3, and IL4 is a light intensity distribution symmetrical with respect to the optical axis. The poles IL1 and IL2 are located at two different points on the y-axis, and the poles IL3 and IL4 are located at two different points on the x-axis. The number of poles is not limited to four, and may be another number (e.g., eight).

[0059] Fig. 9(b) shows the shape of the detection aperture stop 26. The white parts are apertures and the black parts are light shielding bodies. Similar to the light shielding body BP shown in Fig. 1(b), the light shielding body BP shown in Fig. 9(b) has first light shielding parts BP1 and BP2 that block light on the x-axis and y-axis, respectively, of the detection aperture stop 26. The light shielding body BP blocks scattered light from the pattern edge.

[0060] In the configuration example of Fig. 1(a), the arrangement of the poles IL1 and IL3 is not symmetrical with respect to the optical axis. Therefore, a detection error may occur due to a position error of the image plane in the optical axis direction. On the other hand, if the poles IL1, IL2, IL3, and IL4 are arranged symmetrically with respect to the optical axis as in the configuration example of Fig. 9(a), the detection error can be made insensitive to a position error of the image plane in the optical axis direction.

[0061] The diffracted light from the illumination light from the poles IL1 and IL3 in FIG. 9(a) is the same as the diffracted light from the illumination light from the poles IL1 and IL3 in FIG. 1(a). The poles IL1 and IL2 are symmetrical with respect to the x-axis. The illumination light from the pole IL2 is irradiated onto the mold mark 10 (diffraction grating) and the substrate mark 11 (diffraction grating), and the diffracted light diffracted by each mark is shown as D2(+1) and D2(-1). Since the poles IL1 and IL2 are symmetrical with respect to the x-axis, D1(+1), D1(-1), D2(+1), and D2(-1) are incident on the pupil plane Pdet of the detection system 21 at positions symmetrical with respect to the x-axis. D1(+1), D1(-1), 2(+1), and D2(-1) form moiré fringes whose intensity changes in the X-direction.

[0062] The poles IL3 and IL4 are obtained by rotating the poles IL1 and IL2 by 90 degrees clockwise. The diffraction grating for Y-direction measurement illuminated by the illumination light from the poles IL3 and IL4 generates diffracted light D3(+1), D3(-1), D4(+1), and D4(-1) (not shown). D3(+1), D3(-1), D4(+1), and D4(-1) are diffracted to positions rotated 90 degrees around the optical axis from D1(+1), D1(-1), D2(+1), and D2(-1). Moire fringes whose intensity changes in the y-direction are formed by D3(+1), D3(-1), D4(+1), and D4(-1).

[0063] Hereinafter, the detection device 3 of the second embodiment will be described with reference to FIG. 10. The matters not mentioned as the second embodiment may follow the first embodiment. FIG. 10 shows the configuration of the detection device 3 of the second embodiment. The position detection device 3 of the second embodiment includes a first detection system 21 and a second detection system 50. A part of the first detection system 21 and a part of the second detection system 50 may be shared. Furthermore, a part of the first detection system 21, a part of the second detection system 50, and a part of the illumination system 22 may be shared. The first detection system 21 includes a first imaging element 25, and the second detection system 50 includes a second imaging element 51. As described in detail in the first embodiment, the first detection system 21 is configured to detect moire fringes formed by a diffraction grating that is a precision inspection mark. The second detection system 50 is configured to detect a pitch deviation, that is, to detect a rough inspection mark.

[0064] The illumination system 22 and the first detection system 21 can be configured in the same manner as in the first embodiment. This makes it possible to detect with high accuracy the moire fringes formed by the diffraction grating as illustrated in Fig. 6. For the detection of the rough inspection mark by the second detection system 50, it is advantageous for the illumination system 22 to perform, for example, quadrupole illumination as illustrated in Fig. 9(a).

[0065] In order to detect moire fringes with high accuracy, it is desirable to set the imaging magnification from the mold mark 10 / substrate mark 11 to the imaging element 25 to a high magnification. On the other hand, since it is sufficient for the second detection system 50 that detects the rough inspection mark to measure the pitch deviation of the diffraction grating, the effect on accuracy is small even if the imaging magnification from the mold mark 10 / substrate mark 11 to the imaging element 51 is reduced. By reducing the imaging magnification from the mold mark 10 / substrate mark 11 to the imaging element 51, the measurement field of view can be widened. Therefore, even if there is a large deviation in the positions of the mold 7 and the substrate 8, there is an advantage that the position measurement can be performed without searching because a wide range can be observed. As described above, in the second embodiment, the magnification of the first detection system 21 and the magnification of the second detection system 50 can be made different from each other by providing the first detection system 21 and the second detection system 50 by branching the optical path.

[0066] As a modified example, a detection aperture stop may be disposed after the optical path of the first detection system 21 and the optical path of the second detection system 50 are branched. This makes it possible to reduce light that becomes noise. As exemplified in FIG. 11, a first detection aperture stop 26a may be disposed in the optical path between the mold mark 10 / substrate mark 11 and the image sensor 25. Also, a second detection aperture stop 26b may be disposed in the optical path between the mold mark 10 / substrate mark 11 and the image sensor 51. The first detection aperture stop 26a and the second detection aperture stop 26b may have different shapes or characteristics.

[0067] In this modification, the first detection system 21 may detect moiré fringes whose intensity varies in the X direction, and the second detection system 50 may detect moiré fringes whose intensity varies in the Y direction. In this case, it is preferable to improve and adopt the detection aperture stop of FIG. 1(b). In the detection aperture stop of FIG. 1(b), the aperture for detecting moiré fringes whose intensity varies in the X direction is only on the positive side of the y direction, and the aperture for detecting moiré fringes whose intensity varies in the Y direction is only on the positive side of the x direction. Therefore, the detection aperture stop 26a for detecting moiré fringes whose intensity varies in the X direction may be configured so that the negative side of the y direction in FIG. 1(b) is entirely a light-shielding portion. In addition, the output aperture stop 26b for detecting moiré fringes whose intensity varies in the Y direction may be configured so that the negative side of the x direction in FIG. 1(b) is entirely a light-shielding portion. This can further reduce light that becomes noise. The shape of the detection aperture stop is not limited to these.

[0068] Hereinafter, the detection device 3 of the third embodiment will be described with reference to FIG. 12. Note that matters not mentioned as the third embodiment may follow the first or second embodiment. In the third embodiment, the illumination aperture stop 27 arranged on the pupil plane Pill of the illumination system 22 is a pinhole plate having a pinhole. Thereby, the illumination light is composed of a light beam that passes only through the optical axis of the illumination system 22 and its vicinity on the pupil plane Pill of the illumination system 22. The reflection film 24a may be configured to reflect such a light beam and illuminate the mold mark 10 / substrate mark 11. Note that the illumination stop 27 may be an optional component, and illumination light parallel to the optical axis may be formed by defining the area of ​​the reflection film 24a. The detection aperture stop 26 arranged on the pupil plane Pdet of the detection system 21 may follow the first or second embodiment.

[0069] Next, an article manufacturing method using an imprinting apparatus typified by the above-mentioned embodiment will be described. The article may be, for example, a semiconductor device, a display device, or a MEMS. The article manufacturing method may include a transfer step of transferring a pattern of an original to a substrate using a lithography apparatus or an imprinting apparatus, and a processing step of processing the substrate so that an article can be obtained from the substrate that has undergone the transfer step. The transfer step may include, for example, a contact step of bringing the imprinting material 9 on the shot region of the substrate 8 into contact with the mold 7. The transfer step may also include a measurement step of measuring the relative position between the shot region of the substrate 8 (or the substrate mark) and the mold 7. The transfer step may also include an alignment step of aligning the shot region of the substrate 8 and the mold 7 based on the result of the measurement step. The transfer step may also include a curing step of curing the imprinting material 9 on the substrate 8, and a separation step of separating the imprinting material 9 from the mold 7. As a result, a pattern made of a cured product of the imprinting material 9 is formed or transferred onto the substrate 8. The processing steps may include, for example, etching, resist stripping, dicing, bonding, packaging, and the like.

[0070] The pattern of the cured product formed by using the imprinting apparatus is used permanently on at least a part of various articles, or temporarily when manufacturing various articles. The articles include electric circuit elements, optical elements, MEMS, recording elements, sensors, and molds. Examples of the electric circuit elements include volatile or non-volatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensors, and FPGA. Examples of the molds include molds for imprinting.

[0071] The pattern of the cured product is used as it is as at least a part of a component of the article, or is used temporarily as a resist mask, which is removed after etching or ion implantation in a substrate processing step.

[0072] Next, an article manufacturing method will be described, in which a pattern is formed on a substrate by an imprinting device, the substrate on which the pattern is formed is processed, and an article is manufactured from the processed substrate. As shown in Fig. 13(a), a substrate 1z such as a silicon wafer having a workpiece 2z such as an insulator formed on its surface is prepared, and then an imprinting material 3z is applied to the surface of the workpiece 2z by an inkjet method or the like. Here, a state in which the imprinting material 3z in the form of multiple droplets is applied onto the substrate is shown.

[0073] As shown in Fig. 13(b), the imprinting mold 4z is placed so that the side on which the concave-convex pattern is formed faces the imprinting material 3z on the substrate. As shown in Fig. 13(c), the substrate 1z to which the imprinting material 3z has been applied is brought into contact with the mold 4z, and pressure is applied. The imprinting material 3z fills the gap between the mold 4z and the workpiece 2z. When light is irradiated through the mold 4z in this state as energy for curing, the imprinting material 3z is cured.

[0074] 13(d), after the imprint material 3z is cured, the mold 4z and the substrate 1z are separated, and a pattern of the cured product of the imprint material 3z is formed on the substrate 1z. In this cured product pattern, the recesses of the mold correspond to the protrusions of the cured product, and the protrusions of the mold correspond to the recesses of the cured product, i.e., the recessed and protruding patterns of the mold 4z are transferred to the imprint material 3z.

[0075] As shown in Fig. 13(e), when etching is performed using the pattern of the cured material as an etching-resistant mask, the portion of the surface of the workpiece 2z where there is no cured material or where only a thin layer remains is removed, forming a groove 5z. As shown in Fig. 13(f), when the pattern of the cured material is removed, an article having grooves 5z formed on the surface of the workpiece 2z can be obtained. Here, the pattern of the cured material is removed, but it may be used as an interlayer insulating film included in a semiconductor element or the like, that is, a component of an article, without being removed after processing.

[0076] The disclosure herein includes the following detection apparatus, lithography apparatus and article manufacturing methods. (Item 1) A detection device that detects a relative position between a first mark and a second mark provided on a first object and a second object, respectively, which are arranged one on top of the other, comprising: an illumination system that illuminates the first mark and the second mark with unpolarized illumination light; a detection system including an image sensor for forming an image of diffracted light from the first mark and the second mark illuminated by the illumination system on an image sensor of the image sensor, the first mark and the second mark are configured to be capable of forming optical information indicating the relative positions in a first direction or a second direction perpendicular to the first direction on the imaging surface; a light shielding body including a first light shielding portion intersecting an optical axis of the detection system in a direction parallel to a third direction and a second light shielding portion intersecting the optical axis of the detection system in a direction parallel to a fourth direction is provided on a pupil plane of the detection system; The third direction is a direction conjugate to the first direction, and the fourth direction is a direction conjugate to the second direction. A detection device comprising: (Item 2) unnecessary light, which does not contain information indicating the relative positions, among the light from the first mark and the second mark illuminated with the illumination light is blocked by both the first light-shielding part and the second light-shielding part. 2. The detection device according to item 1, (Item 3) the illumination system is configured to obliquely illuminate the first mark and the second mark with the illumination light; 3. The detection device according to item 1 or 2. (Item 4) a light intensity distribution at an exit of a pupil plane of the illumination system is asymmetric with respect to an optical axis of the illumination system; 4. The detection device according to item 3, (Item 5) the light intensity distribution at the exit of the pupil plane of the illumination system is symmetrical with respect to the optical axis of the illumination system; 4. The detection device according to item 3, (Item 6) the illumination system and the detection system share a prism; the pupil plane of the illumination system is disposed between a light source and the prism, and the illumination light illuminates the first mark and the second mark after being reflected by the prism. 6. The detection device according to any one of items 1 to 5, (Item 7) the diffracted light from the first mark and the second mark passes through the prism and is incident on the imaging surface; the pupil plane of the detection system is disposed between the prism and the imaging plane. 7. The detection device according to item 6, (Item 8) the first light-shielding portion extends over an entire diameter of a pupil plane of the detection system in the third direction, the second light-shielding portion extends over an entire diameter in the fourth direction of a pupil plane of the detection system; 8. The detection device according to any one of items 1 to 7, (Item 9) the pupil plane of the detection system has a light transmitting area in an area where the light blocking body is not disposed, diffracted light from the first mark and the second mark illuminated with the illumination light passes through the light transmitting region to form the optical information indicating the relative position on the imaging plane. 9. The detection device according to any one of items 1 to 8, (Item 10) a first-order diffracted light from the first mark and the second mark illuminated with the illumination light passes through the light transmitting region, and forms the optical information indicating the relative position on the imaging plane; 10. The detection device according to item 9, (Item 11) a second detection system including a second imaging element having a second imaging surface; The first object is further provided with a third mark, and the second object is further provided with a fourth mark; the second detection system forms an image on the second imaging plane of the second imaging element using light from the third mark and the fourth mark illuminated by the illumination system; 11. The detection device according to any one of items 1 to 10, (Item 12) A part of the detection system and a part of the second detection system are shared. 12. The detection device according to item 11, (Item 13) the magnification of the detection system and the magnification of the second detection system are different from each other; 13. The detection device according to item 11 or 12. (Item 14) a first aperture stop is disposed on a pupil plane of the detection system, and a second aperture stop is disposed on a pupil plane of the second detection system; 14. The detection device according to any one of items 11 to 13, (Item 15) The illumination system is capable of changing the wavelength of the illumination light. 15. The detection device according to any one of items 1 to 14, (Item 16) A lithography apparatus for transferring a pattern of an original onto a substrate, comprising: A detection device according to any one of items 1 to 15, A lithography apparatus configured to perform alignment between the original as the first object on which the first mark is provided and the substrate as the second object on which the second mark is provided, based on an output of the detection device. (Item 17) Item 17. A lithographic apparatus according to item 16, configured as an imprint apparatus. (Item 18) A transfer step of transferring a pattern of a master to a substrate using the lithography apparatus according to item 17; a processing step of processing the substrate so as to obtain an article from the substrate that has been subjected to the transfer step; A method for manufacturing an article, comprising:

[0077] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0078] 1: imprint device, 2: detection device, 7: mold (first object), 8: substrate (second object), 10: mold mark (first mark), 11: substrate mark (second mark), 21: detection system, 22: illumination system, 25: imaging element

Claims

A detection device for detecting the relative positions of a first mark and a second mark respectively provided on a first object and a second object, comprising: An illumination system for illuminating the first mark and the second mark with unpolarized illumination light; A detection system including an imaging element, for forming diffracted light from the first mark and the second mark illuminated by the illumination system on the imaging surface of the imaging element. The detection device is characterized in that: The first mark and the second mark are configured to be able to form optical information indicating the relative position in a first direction or a second direction orthogonal to the first direction on the imaging surface; On the pupil plane of the detection system, a light-shielding body is provided, which includes a first light-shielding portion extending in a direction parallel to a third direction passing through the optical axis of the detection system, and a second light-shielding portion extending in a direction parallel to a fourth direction passing through the optical axis of the detection system; The axis in the third direction is conjugate to the axis in the first direction, and the axis in the fourth direction is conjugate to the axis in the second direction; The detection device is characterized by the above. Claim 2 Among the light from the first mark and the second mark illuminated by the illumination light, unnecessary light not including information indicating the relative position is blocked by both the first light-shielding portion and the second light-shielding portion. The detection device according to claim 1, characterized by the above. Claim 3 The illumination system is configured to obliquely incident-illuminate the first mark and the second mark with the illumination light. The detection device according to claim 1, characterized by the above. Claim 4 The light intensity distribution at the exit of the pupil plane of the illumination system is asymmetric with respect to the optical axis of the illumination system. The detection device according to claim 3, characterized by the above. Claim 5 The light intensity distribution at the exit of the pupil plane of the illumination system is symmetric with respect to the optical axis of the illumination system. The detection device according to claim 3, characterized by the above. Claim 6 The illumination system and the detection system share a prism; The pupil plane of the illumination system is disposed between a light source and the prism, and the illumination light illuminates the first mark and the second mark after being reflected by the prism. The detection device according to claim 1, characterized by the above. Claim 7 Diffracted light from the first mark and the second mark enters the imaging surface after passing through the prism; The pupil plane of the detection system is disposed between the prism and the imaging surface. The detection device according to claim 6, characterized by the above. Claim 8 The first light-shielding part extends over the entire diameter of the pupil plane of the detection system in the third direction. The second light-shielding part extends over the entire diameter of the pupil plane of the detection system in the fourth direction. The detection device according to claim 1, characterized in that.

9. The pupil plane of the detection system has a light transmission region in a region where the light-shielding body is not arranged. The diffracted light from the first mark and the second mark illuminated by the illumination light passes through the light transmission region to form the optical information indicating the relative position on the imaging surface. The detection device according to claim 1, characterized in that.

10. The first-order diffracted light from the first mark and the second mark illuminated by the illumination light passes through the light transmission region to form the optical information indicating the relative position on the imaging surface. The detection device according to claim 9, characterized in that.

11. The detection device further includes a second detection system including a second imaging device having a second imaging surface. The first object is further provided with a third mark, and the second object is further provided with a fourth mark. The second detection system forms an image of the light from the third mark and the fourth mark illuminated by the illumination system on the second imaging surface of the second imaging device. The detection device according to claim 1, characterized in that.

12. A part of the detection system and a part of the second detection system are shared. The detection device according to claim 11, characterized in that.

13. The magnification of the detection system and the magnification of the second detection system are different from each other. The detection device according to claim 11, characterized in that.

14. A first aperture stop is arranged on the pupil plane of the detection system, and a second aperture stop is arranged on the pupil plane of the second detection system. The detection device according to claim 11, characterized in that.

15. The illumination system can change the wavelength of the illumination light. The detection device according to claim 1, characterized in that.

16. A lithography apparatus for transferring a pattern of a master onto a substrate, comprising the detection device according to any one of claims 1 to 15, characterized in that the alignment between the master as the first object provided with the first mark and the substrate as the second object provided with the second mark is performed based on the output of the detection device.

17. The lithography apparatus according to claim 16, characterized in that it is configured as an imprint apparatus.

18. A transfer step of transferring a pattern of a master onto a substrate using the lithography apparatus according to claim 17, A processing step of processing the substrate so as to obtain an article from the substrate that has undergone the transfer step, An article manufacturing method characterized by including these steps.

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