Imprinting apparatus and article manufacturing method

Abstract

To provide a position detection technique utilizing a moire pattern, advantageous for high accuracy position detection.SOLUTION: A position detection device comprises: an acquisition unit configured to acquire an image of a moire pattern generated by an overlap of a first diffraction grating having a lattice pattern arranged in a first direction and a second diffraction grating having a lattice pattern arranged with a pitch different from a pitch of the first diffraction grating and in the first direction; and a processing unit configured to analyze a period of a luminance distribution of the acquired moire pattern image, and calculate a measured phase value of the luminance distribution based on the result of the period analysis to calculate a relative positional relation between the first diffraction grating and the second diffraction grating based on the measured phase value. The processing unit determines a phase shift amount for setting the measured phase value without a predetermined range including discontinuous parts of the phase, and shifts the measured phase value by the determined phase shift amount to determine the relative positional relation based on the measured phase value subjected to the phase shift.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to stomach The present invention relates to an imprinting apparatus and an article manufacturing method. [Background technology]

[0002] Imprint technology is a technology that enables the transfer of fine nanoscale patterns, and is attracting attention as one of the lithography techniques for mass production of devices such as semiconductor devices, liquid crystal display elements, magnetic storage media, etc. In an imprint device using imprint technology, a mold on which a fine pattern is formed is used to form an imprint material on a substrate (silicon wafer or glass substrate).

[0003] The imprinting apparatus forms a pattern of projections and recesses made of the imprinting material on the substrate by contacting the mold with the imprinting material and then separating the mold from the hardened imprinting material. A photocuring method for curing the imprinting material on the substrate by irradiating the imprinting material with light such as ultraviolet light may be used. In this case, the mold is made of a material that transmits light such as ultraviolet light, such as quartz.

[0004] In an imprinting apparatus, when the mold and the imprinting material on the substrate are brought into contact with each other, the mold and the substrate must be accurately aligned. In the current situation where the semiconductor process rule is 100 nm or less, the allowable range of alignment error (positioning error) caused by the apparatus is so strict that it is said to be several nm. For this reason, a die-by-die alignment method is adopted as a method for aligning the mold and the substrate (see Patent Document 1). The die-by-die alignment method is a method for aligning the mold and the substrate by detecting, for example, an alignment mark provided in a shot area and an alignment mark provided in the mold for each shot area on the substrate.

[0005] As a method for aligning a mold and a substrate, there is a method for determining the relative positions between the mold and the substrate based on Moire fringes formed by the diffraction of light with respect to alignment marks on the mold and the substrate (see Patent Document 2). When this method is used, the Moire fringes can generate periodic waveforms with large periods, so that it is possible to determine the relative positions with high accuracy even if the resolution of the detection optical system is low. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2018-61061 A [Patent Document 2] Patent No. 5713961 Summary of the Invention [Problem to be solved by the invention]

[0007] In the mold manufacturing process, the circuit pattern and the alignment mark may be created in separate layers. In this case, when creating the alignment mark using the mold manufacturing equipment, the positional relationship between the circuit pattern and the alignment mark may be misaligned depending on the alignment accuracy of the mold manufacturing equipment, as in the mold in Figure 11(b).

[0008] When there is no misalignment between the circuit pattern and the alignment marks, as in the mold in Figure 11(a), the circuit pattern can be transferred without misalignment by aligning the alignment marks on the substrate and the mold. However, when there is a misalignment between the circuit pattern and the alignment marks, as in the mold in Figure 11(b), there will be a misalignment between the circuit patterns when the alignment marks on the substrate and the mold are aligned. Misalignment between the circuit patterns can also occur when aligning a substrate transferred using a mold with a misalignment between the circuit pattern and the alignment marks with a mold such as the one in Figure 11(a).

[0009] Therefore, if there is a misalignment between the circuit pattern and the alignment marks on the mold or substrate, it is necessary to imprint so that there is no misalignment between the circuit patterns, not between the alignment marks, as in the imprinted state in Figure 11(b). Therefore, it is necessary to determine targets for the relative positions between the alignment marks on the substrate side and the mold side.

[0010] Next, consider the case where the relative position between alignment marks is obtained from the moiré fringes. In this case, the target relative position may be a position corresponding to the vicinity of the timing when the phase (unit: radian) of the moiré fringes switches from the maximum value to the minimum value (the pitch shifts). Also, due to manufacturing errors in the alignment marks, distortion may occur in the waveform of the moiré fringes. As a result, an error of several nm may occur between the moiré fringes. Therefore, while the phase is continuous, the error is small enough to be ignored, but an error of several nm may occur in the phase before and after the pitch shift.

[0011] Therefore, when the relative position between alignment marks is determined from the phase of the moiré fringes, depending on the target relative position, an error of several nm in the overlay of the circuit patterns may occur due to pitch deviation.

[0012] The present invention provides a technique that is advantageous for improving the accuracy of position detection using moire. [Means for solving the problem]

[0013] According to one aspect of the present invention, An imprinting apparatus that forms a pattern on a substrate by bringing a pattern area of ​​a mold into contact with an imprint material on the substrate, the imprinting apparatus comprising: a position detection device that detects a relative position between the mold and the substrate based on an image obtained by capturing an image of a mold-side mark arranged on the mold and a substrate-side mark arranged on the substrate; and a control unit that controls a position of at least one of the mold and the substrate based on a result of detection by the position detection device, wherein the mold-side mark includes a first diffraction grating having a grating pattern arranged in a first direction, and a first mark for rough alignment, and the substrate-side mark includes a second diffraction grating having a grating pattern arranged in the first direction at a pitch different from that of the first diffraction grating, and a second mark for rough alignment, the position detection device detects a moire image generated by overlapping of the first diffraction grating and the second diffraction grating from the image, performs a periodic analysis of a luminance distribution of the detected moire, calculates a phase measurement value of the luminance distribution based on a result of the periodic analysis, and calculates the relative position based on the phase measurement value. the processing unit performs coarse position detection between the mold and the substrate based on an image of the first mark and an image of the second mark in the image, determines a phase shift amount for making the obtained phase measurement value a value outside a predetermined range including a phase discontinuity, performs a phase shift to shift the obtained phase measurement value by the determined phase shift amount, and obtains the relative position based on the phase measurement value after the phase shift; the control unit performs coarse alignment between the mold and the substrate based on a result of the coarse position detection, and after the coarse alignment, performs fine alignment between the mold and the substrate by correcting the relative position between the mold and the substrate according to a drawing error between a pattern of the mold and the mold-side mark obtained in advance based on the phase measurement value after the phase shift, and then brings the pattern area of ​​the mold into contact with the imprint material on the substrate; and the position detection device images the mold-side mark and the substrate-side mark in a state in which the pattern area of ​​the mold and the imprint material on the substrate are in contact with each other. is provided. Effect of the Invention

[0014] According to the present invention, it is possible to provide a technique that is advantageous for improving the accuracy of position detection using moire. [Brief description of the drawings]

[0015] [Figure 1] 5A and 5B are diagrams for explaining pitch deviations of phase measurement values. [Diagram 2] FIG. 1 is a diagram showing the configuration of an imprint apparatus. [Diagram 3] FIG. 2 is a diagram showing an example of the configuration of a detector. [Figure 4] FIG. 13 is a diagram showing another example of the configuration of a detector. [Diagram 5] 5 is a diagram illustrating an example of the relationship between the pupil intensity distribution of an illumination optical system and the numerical aperture of a detection optical system. [Figure 6] 1A to 1C are diagrams for explaining the principle of detecting the relative positions between diffraction gratings using moire. [Figure 7] 1A to 1C are diagrams showing examples of marks for detecting relative positions in two directions, X and Y. [Figure 8] FIG. 13 is a diagram illustrating an example of an arrangement of a plurality of marks. [Figure 9] 5A and 5B are diagrams for explaining pitch deviations of phase measurement values. [Figure 10] 1A and 1B are diagrams for explaining a π phase shift caused by inversion of light and dark in a moire pattern. [Figure 11] 13A and 13B are diagrams illustrating the results of imprinting using a mold in which a circuit pattern and alignment marks are created in separate layers. [Figure 12] 1A to 1C are diagrams illustrating a method for manufacturing an article. [Figure 13] FIG. 13 is a diagram illustrating the appearance of Moiré fringes when the relative position of the mold and substrate is changed little by little. [Figure 14] 1A to 1C are diagrams illustrating the advantages of a configuration using two moiré fringes. [Figure 15] 6 is a flowchart showing a processing procedure performed by the imprint apparatus in a process for determining the amount of misalignment between a circuit pattern on a mold and an alignment mark. [Figure 16] 11 is a flowchart showing a processing procedure performed by an external measurement device in a process for determining the amount of misalignment between a circuit pattern on a mold and an alignment mark. [Figure 17] 11 is a flowchart showing a process for setting parameters of an imprint apparatus. [Figure 18] 1 is a flowchart showing an imprint process during semiconductor manufacturing. [Figure 19] 1 is a flowchart showing an imprint process during semiconductor manufacturing. [Figure 20] 1 is a flowchart showing an imprint process during semiconductor manufacturing. [Figure 21] 1 is a flowchart showing an imprint process during semiconductor manufacturing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] 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.

[0017] 2 shows the configuration of an imprint apparatus 1 according to one embodiment of the present invention. The imprint apparatus 1 brings a pattern area 7a of a mold 7 into contact with an imprint material 9 arranged on a shot area of ​​a substrate 8, and hardens the imprint material to form a pattern made of the hardened imprint material 9 on the shot area.

[0018] 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 viscosity of the imprint material (at 25° C.) can be, for example, 1 mPa·s to 100 mPa·s. Examples of the material of the substrate include glass, ceramics, metals, semiconductors, 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 may be, for example, a silicon wafer, a compound semiconductor wafer, or quartz glass.

[0019] 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, Y-axis, and Z-axis, and the attitude is information that can be specified by the values ​​of the θX-axis, θY-axis, and θZ-axis. Positioning means controlling the position and / or attitude. The alignment may include controlling the position and / or the attitude of at least one of the substrate 8 and the mold 7 .

[0020] The imprinting apparatus 1 may include a curing unit 2, a detector 3, a mold driving mechanism 4, a substrate driving mechanism 5, a dispenser (imprinting material supply unit) 6, and a control unit 15. After a contact step of bringing the imprinting material 9 on the substrate 8 into contact with the mold 7, the curing unit 2 irradiates the imprinting material with energy for curing the imprinting material, thereby curing the imprinting material. The curing unit 2 may be, for example, a light source that generates light for curing the imprinting material. The light source may be, for example, a high-pressure mercury lamp, various excimer lamps, an excimer laser, or a light-emitting diode. The mold 7 has a pattern region 7a, and a pattern is formed in the pattern region 7a by recesses. In a state in which the imprinting material 9 on the substrate 8 and the pattern region 7a of the mold 7 are in contact with each other, the imprinting material 9 may be filled into the recesses of the pattern region 7a. The mold 7 may be made of a material that transmits light for curing the imprinting material 9, such as quartz.

[0021] The substrate driving mechanism 5 can be configured to hold the substrate 8 and drive the substrate 8 about a plurality of axes (for example, three axes of the X-axis, the Y-axis, and the θZ-axis, preferably six axes of the X-axis, the Y-axis, the Z-axis, the θX-axis, the θY-axis, and the θZ-axis). The mold driving mechanism 4 can be configured to hold the mold 7 and drive the mold 7 about a plurality of axes (for example, three axes of the Z-axis, the θX-axis, and the θY-axis, preferably six axes of the X-axis, the Y-axis, the Z-axis, the θX-axis, the θY-axis, and the θZ-axis). The substrate driving mechanism 5 and the mold driving mechanism 4 constitute a driving mechanism that drives at least one of the substrate 8 and the mold 7 so that the relative positions of the substrate 8 and the mold 7 are adjusted. The adjustment of the relative positions by the driving mechanism includes driving for contact of the mold 7 with the imprint material on the substrate 8 and separation of the mold 7 from the cured imprint material (pattern of the cured product).

[0022] In order to detect the relative position between the shot area of ​​the substrate 8 and the mold 7, the detector 3 (position detection device) detects the relative positions of the substrate-side mark 11 arranged in the shot area of ​​the substrate 8 and the mold-side mark 10 arranged in the mold 7 as position information. Here, the substrate-side mark 11 and the mold-side mark 10 constitute a detection target for position information. The substrate-side mark 11 and the mold-side mark 10 may include, for example, a mark for forming a moiré fringe. In this case, the relative positions of the substrate-side mark 11 and the mold-side mark 10 may be detected by the detector 3 as position information of the detection target based on the moiré fringe. Alternatively, the substrate-side mark 11 and the mold-side mark 10 may constitute a box-in-box. In this case, the positions of the substrate-side mark 11 and the mold-side mark 10 may be detected by the detector 3 as position information of the detection target.

[0023] The detector 3 includes an optical system for observing the mark, and the optical axis of the optical system can be disposed perpendicular to the surface of the substrate 8. The detector 3 can be driven by a driving mechanism for positioning in the X and Y directions according to the position of the mark to be detected. The detector 3 may also be driven in the Z direction for focus adjustment, and may include an optical system for focus adjustment.

[0024] Based on the position information detected by the detector 3, the control unit 15 controls at least one of the substrate driving mechanism 5 and the mold driving mechanism 4 so that the shot area of ​​the substrate 8 and the mold 7 are aligned. The imprint apparatus 1 may include a deformation mechanism that deforms the mold 7 to match the shape of the shot area of ​​the substrate 8 with the shape of the pattern area 7a of the mold 7. In this case, the control unit 15 can detect a shape difference between the shot area and the pattern area 7a based on the multiple pieces of position information detected by the detector 3, and control the deformation mechanism based on this shape difference.

[0025] The dispenser 6 places the imprint material 9 on the shot area of ​​the substrate 8. The dispenser 6 can be configured to eject the imprint material 9 at a timing according to a drop recipe while the substrate 8 is being driven by the substrate driving mechanism 5. The drop recipe is information (map) that indicates the placement of the imprint material 9 in the shot area. The dispenser 6 may be provided outside the imprint apparatus 1. In this case, the substrate 8 can be provided to the imprint apparatus 1 with the imprint material 9 placed on the substrate 8 by the dispenser 6.

[0026] The control unit 15 controls the curing unit 2, the detector 3, the mold driving mechanism 4, the substrate driving mechanism 5, and the dispenser 6. The control unit 15 can be configured, for example, by a PLD (abbreviation of Programmable Logic Device) such as an FPGA (abbreviation of Field Programmable Gate Array), or an ASIC (abbreviation of Application Specific Integrated Circuit), or a general-purpose computer with a program embedded therein, or a combination of all or part of these. The control unit 15 can include a memory for storing programs and data.

[0027] The imprint process by the imprint apparatus 1 will now be described. First, a substrate 8 is transported by a substrate transport mechanism (not shown) to a substrate holding section (not shown) of the substrate driving mechanism 5, and is held by the substrate holding section. Next, under the control of the control section 15, the substrate 8 is driven by the substrate driving mechanism 5 so that a shot area (hereinafter simply referred to as "shot area") of a pattern formation target (imprint target) is positioned under the dispenser 6. While the substrate 8 is being driven by the substrate driving mechanism 5, the dispenser 6 places an imprint material 9 on the shot area.

[0028] Next, under the control of the control unit 15, the substrate 8 is driven by the substrate driving mechanism 5 so that the shot area is positioned under the mold 7. Next, under the control of the control unit 15, at least one of the mold driving mechanism 4 and the substrate driving mechanism 5 is operated so that the imprint material 9 on the shot area and the pattern area 7a of the mold 7 come into contact with each other.

[0029] Next, under the control of the control unit 15, the detector 3 detects position information (relative position) between the shot area of ​​the substrate 8 and the pattern area 7a of the mold 7, and the shot area and the pattern area 7a are aligned based on this position information. The alignment of the shot area and the pattern area 7a can be performed by at least one of the substrate driving mechanism 5 and the mold driving mechanism 4. At this time, the mold 7 may be deformed by a deformation mechanism based on the shape difference between the shot area and the pattern area 7a.

[0030] Next, under the control of the control unit 15, energy for curing is irradiated from the curing unit 2 to the imprint material 9 via the mold 7, and the imprint material 9 is cured. As a result, a pattern made of the cured product of the imprint material 9 is formed on the shot area. Next, under the control of the control unit 15, at least one of the mold driving mechanism 4 and the substrate driving mechanism 5 is operated so that the cured product of the imprint material 9 on the shot area is separated from the pattern area 7a of the mold 7.

[0031] The configuration of the detector 3 will be described below by way of example. FIG. 3 shows an example of the configuration of the detector 3. The detector 3 may include a detection optical system 21 and an illumination optical system 22. The detection optical system 21 and the illumination optical system 22 may be configured to share a part. The illumination optical system 22 guides illumination light from a light source 23 onto the same optical axis as the detection optical system 21 by an optical element such as a prism 24, and illuminates the mold side marks 10 and 11 with the illumination light. The light source 23 may include at least one of, for example, a halogen lamp, an LED, a semiconductor laser (LD), a high-pressure mercury lamp, a metal halide lamp, and a supercontinuum light source. As the illumination light, light having a wavelength that does not harden the imprint material 9 may be used.

[0032] The prism 24 may be disposed on or near a common pupil plane of the detection optical system 21 and the illumination optical system 22. The mold-side mark 10 and the substrate-side mark 11 may each be configured with a diffraction grating. The detection optical system 21 causes the diffracted light from each of the mold-side mark 10 and the substrate-side mark 11 illuminated by the illumination optical system 22 to interfere with each other, forming a moiré fringe (interference fringe) on the imaging surface of the imaging element 25. The imaging element 25 may be, for example, a CCD or CMOS image sensor. The processing unit 26 acquires and processes image data captured by the imaging element 25. The processing unit 26 is, for example, a part of the control unit 15, acquires information on the image captured by the imaging element 25, and calculates the relative positions of the mold-side mark 10 and the substrate-side mark 11 based on the image. The processing unit 26 may include a memory for storing programs and data.

[0033] Furthermore, since moiré fringes are formed by diffracted light from mold-side mark 10 of mold 7 and diffracted light from substrate-side mark 11 of substrate 8, the amount of light of the moiré fringes may depend on the diffraction efficiency of mold 7 and substrate 8. In particular, since the diffraction efficiency changes periodically with changes in wavelength, there are wavelengths at which moiré fringes can be detected efficiently and wavelengths at which moiré fringes are difficult to detect. Light with wavelengths at which moiré fringes are difficult to detect may become noise.

[0034] The prism 24 has a bonding surface, and a reflective film 24a for reflecting light from the peripheral portion of the pupil plane of the illumination optical system 22 may be provided on the bonding surface. The reflective film 24a also functions as an aperture stop that determines the size of the pupil of the detection optical system 21 (or the detection NA: NAo). The prism 24 may be a half prism having a semi-transparent film on the bonding surface. Alternatively, instead of a prism, a plate-shaped optical element having a reflective film formed on its surface may be used. Alternatively, a configuration may be used in which the peripheral portion of the prism 24 in FIG. 3 is a transmitting portion and the central portion is a reflecting portion, and the position of the light source 23 and the position of the image sensor 25 are interchanged.

[0035] The position where the prism 24 is disposed does not necessarily have to be on or near a common pupil plane of the detection optical system 21 and the illumination optical system 22. For example, as illustrated in Fig. 4, the detection optical system 21 and the illumination optical system 22 may have individual aperture stops 27, 28 on their respective pupil planes. The prism 24 may be, for example, a half prism having a semi-transparent film on the bonding surface.

[0036] The light source 23 can be a semiconductor laser, but is not limited to a semiconductor laser and may include an LED, or may include a lamp such as a halogen lamp, a metal halide lamp, a high-pressure mercury lamp, or a sodium lamp.

[0037] In order to generate illumination light including a plurality of wavelengths, the light source 23 may include a lamp light source that generates light in a wide wavelength band, a long wavelength cut filter that blocks the long wavelength side of the light generated by the lamp light source, and a short wavelength cut filter that blocks the short wavelength side of the light generated by the lamp light source. Here, the long wavelength cut filter and the short wavelength cut filter may be filters whose transmission bands change continuously depending on the position of incidence of light.

[0038] 5 illustrates the relationship between the pupil intensity distribution (IL1 to IL4) of the illumination optical system 22 of the detector 3 and the numerical aperture NAo of the detection optical system 21. The pupil intensity distribution of the illumination optical system 22 may include a first pole IL1, a second pole IL2, a third pole IL3, and a fourth pole IL4. The illumination optical system 22 may illuminate the mold-side mark 10 and the substrate-side mark 11 with light incident perpendicularly to the direction in which the patterns of the mold-side mark 10 and the substrate-side mark 11 are arranged in the XY plane, and light incident parallel to the direction. A reflective film 24a functioning as an aperture stop is disposed on the pupil plane of the illumination optical system 22 to block unnecessary light, thereby forming multiple poles (i.e., the first pole IL1 to the fourth pole IL4) from one light source 23.

[0039] Below, with reference to Figures 6(a) to (d), we will explain the principle of the generation of moiré fringes due to diffracted light from the mold-side mark 10 and the substrate-side mark 11, and detection of the relative position between the mold-side mark 10 (mold 7) and the substrate-side mark 11 (shot area of ​​substrate 8) using the moiré fringes.

[0040] In this embodiment, the mold-side mark 10 arranged on the mold 7 has a first diffraction grating including a grating pattern arranged in, for example, the X direction (first direction). In addition, the substrate-side mark 11 arranged on the substrate 8 has a second diffraction grating including a grating pattern arranged in the first direction at a pitch (the period at which the grating pattern is formed) different from that of the first diffraction grating. The processing unit 26 can function as an acquisition unit that acquires an image of a moire pattern generated by overlapping the first diffraction grating and the second diffraction grating. The processing unit 26 performs a period analysis of the luminance distribution of the acquired moire image, obtains a phase measurement value of the luminance distribution based on the result of the period analysis, and obtains the relative position of the first diffraction grating and the second diffraction grating based on the phase measurement value.

[0041] As shown in Fig. 6(a) and (b), the diffraction grating 31 (first diffraction grating) provided on the mold 7 as the mold-side mark 10 and the diffraction grating 32 (second diffraction grating) provided on the substrate 8 as the substrate-side mark 11 have slightly different pattern (grating) periods in the detection direction. When two diffraction gratings with different grating periods are overlapped, a moiré pattern having a period reflecting the difference in period between the diffraction gratings appears due to interference of the diffracted light from each of the two diffraction gratings. Since the phase of the moiré pattern changes depending on the relative positions of the diffraction gratings, the relative positions of the mold-side mark 10 and the substrate-side mark 11, i.e., the relative positions of the mold 7 and the substrate 8 (shot area) can be obtained by detecting the moiré pattern.

[0042] Specifically, when the diffraction gratings 31 and 32, which have slightly different periods, are overlapped, the diffracted light from each of the diffraction gratings 31 and 32 overlap, and moiré fringes having a period reflecting the difference in period are generated as illustrated in FIG. 6(c). The positions (phases) of the light and dark of the moiré fringes change depending on the relative positions of the diffraction gratings 31 and 32. For example, when one of the diffraction gratings 31 and 32 is shifted in the X direction, the moiré fringes illustrated in FIG. 6(c) may change as illustrated in FIG. 6(d). The moiré fringes amplify the amount of misalignment between the diffraction gratings 31 and 32 and occur as fringes with a large period, so that even if the resolution of the detection optical system 21 is low, the relative positions of the diffraction gratings 31 and 32 can be detected with high accuracy. The magnification at which the amount of misalignment is increased is defined as the moiré magnification.

[0043] When detecting the diffraction gratings 31 and 32 in a bright field in order to detect the moiré fringes (illuminating the diffraction gratings 31 and 32 from the vertical direction and detecting the diffracted light diffracted in the vertical direction by the diffraction gratings 31 and 32), the detection optical system 21 also detects the zeroth order light from the diffraction gratings 31 and 32. The zeroth order light reduces the contrast of the moiré fringes. Therefore, it is desirable for the detector 3 to have a dark field configuration that does not detect the zeroth order light (i.e. illuminating the diffraction gratings 31 and 32 with oblique incidence).

[0044] In order to detect moiré fringes even in a dark field configuration, one of the diffraction gratings 31 and 32 can be a checkerboard-shaped diffraction grating as shown in Fig. 7(a) and the other diffraction grating can be a diffraction grating as shown in Fig. 7(b). The diffraction grating shown in Fig. 7(b) includes a pattern that is periodically arranged in the detection direction and a pattern that is periodically arranged in a direction perpendicular to the detection direction.

[0045] 5, 7(a) and 7(b), light from the first pole IL1 and the second pole IL2 enters the diffraction grating and is diffracted in the Y direction and also in the X direction by the checkerboard diffraction grating. Furthermore, the light diffracted in the X direction by the diffraction gratings with slightly different periods enters the detection area (NAo) on the pupil of the detection optical system 21 with relative position information in the X direction and is detected by the image sensor 25. Using this, the relative positions of the two diffraction gratings can be obtained.

[0046] FIG. 8 shows a schematic diagram of marks observed when the mold 7 and the substrate 8 are superimposed. The range 53 of the outer frame is a range that can be observed at one time by the detector 3. The range 53 includes a first mark 51a-1 for rough alignment on the mold side and a second mark 52a-1 for rough alignment on the substrate side. The processing unit 26 performs rough position detection between the mold and the substrate based on the image of the first mark 51a-1 and the image of the second mark 52a-1 in the image. The control unit 15 can perform rough alignment between the mold and the substrate based on the result of the rough position detection. After the rough alignment, the control unit 15 can perform fine alignment between the mold and the substrate as described below.

[0047] For example, the processing unit 26 can obtain the relative positional deviation D1 between the shot area of ​​the mold 7 and the substrate 8 based on the geometric center positions of the first mark 51a-1 for rough alignment on the mold side and the second mark 52a-1 for rough alignment on the substrate side. The first mark 51a-1 on the mold side and the second mark 52a-1 on the substrate side can be made small, which allows rough alignment using marks with small occupied areas. Here, an intensity ratio occurs in the image of the mark detected due to the difference in reflectance between the first mark 51a-1 on the mold side and the second mark 52a-1 on the substrate side. If the intensity ratio is large, the image of the mark with high intensity is saturated and a detection error occurs. Therefore, it is necessary to suppress the intensity ratio of the image of the mark.

[0048] Next, the moiré fringes formed by the mark 51a-2 of the mold 7 and the mark 52a-2 of the substrate 8 will be described. The mark 51a-2 and the mark 52a-2 are composed of a first diffraction grating and a second diffraction grating having a periodic pattern shown in FIG. 7(c) or (d), and since the periods in the measurement direction are slightly different from each other, when they are superimposed, moiré fringes are formed in the Y direction. In addition, the shift direction of the moiré fringes when the relative position is changed differs depending on the difference between the period of the mark 51a-2 and the period of the mark 52a-2. For example, if the period of the mark 51a-2 of the mold 7 is slightly larger than the period of the mark 52a-2 of the substrate 8, when the substrate 8 shifts relatively in the +Y direction, the phase of the moiré fringes also shifts in the +Y direction. Conversely, if the period of the mark 51a-2 of the mold 7 is slightly smaller than the period of the mark 52a-2 of the substrate 8, when the substrate 8 shifts relatively in the +Y direction, the phase of the moiré fringes shifts in the -Y direction.

[0049] Next, the moiré fringes formed by the mark 51a-2' of the mold 7 and the mark 52a-2' of the substrate 8 will be described. The mark 51a-2' (third diffraction grating) of the mold 7 and the mark 52a-2' (fourth diffraction grating) of the substrate 8 are obtained by switching the periods of the measurement direction of the mark 51a-2 of the mold 7 and the mark 52a-2 of the substrate 8. Therefore, when the relative positions change, the positions of the moiré fringes on the left side and the moiré fringes on the right side change in the opposite directions. For example, Figures 13(a) to (j) show an example of the change in the moiré fringes when the relative positions of the mold 7 and the substrate 8 are changed little by little. When the relative positions are shifted little by little from Figure 13(a), the same moiré fringes are repeatedly displayed as in Figure 13(j).

[0050] 8, a shift in the X direction is detected using the moire fringes formed by the mark 51a-3 of the mold 7 and the mark 52a-3 of the substrate 8, and the moire fringes formed by the mark 51a-3' of the mold 7 and the mark 52a-3' of the substrate 8. The principle is the same as the detection of a shift in the Y direction using the moire fringes formed by the mark 51a-2 of the mold 7 and the mark 52a-2 of the substrate 8, and the moire fringes formed by the mark 51a-2' of the mold 7 and the mark 52a-2' of the substrate 8 in FIG.

[0051] For each moiré fringe, the phase can be calculated by using arctan after performing a discrete Fourier transform including a fast Fourier transform. Specifically, if the frequency is ω, the frequency function F(ω) obtained by the discrete Fourier transform is composed of a real part and an imaginary part, and is expressed as follows:

[0052] F(ω) = Real F(ω) + i Imaginary F(ω) Here, i represents an imaginary number.

[0053] The phase of F(ω) is then calculated using the following equation:

[0054] arctan (Imaginary F(ω) / Real F(ω))

[0055] For example, in the cases of (a) to (j) in FIG. 13, since the moiré fringes are waveforms of one period, the phase of the moiré fringes can be found by the following equation.

[0056] arctan (Imaginary F(1) / Real F(1))

[0057] In this way, the phase of the left moiré fringes and the phase of the right moiré fringes can be calculated. If the calculated phases are Phase A and Phase B, respectively, the two moiré fringes change in opposite directions, so the phase measurement value P can be expressed by the following equation.

[0058] Phase measurement value P: (Phase A - Phase B) / 2

[0059] If the state in Figure 13(e) is just before the pitch shifts, phase A will be about +π, phase B will be about -π, and the phase measurement value P will be about π. In the cases of Figures 13(a) and 13(j), phase A will be about 0, phase B will be about 0, and the phase measurement value P will be about 0.

[0060] In this embodiment, two moiré fringes are used, but only one moiré fringe may be used. Here, the advantages of using two moiré fringes will be described with reference to FIG. 14. FIG. 14(a) illustrates an example of a configuration using only one moiré fringe. Here, the moiré fringes are arranged without deviation from the central position 54 of the image processing. In contrast, FIG. 14(b) illustrates an example in which the moiré fringes are deviated from the central position 54 of the image processing. If the moiré fringes are deviated from the central position 54 of the image processing as in FIG. 14(b), a measurement error will occur. For example, Phase measurement value P in Fig. 14(a): phase of the moiré fringes, Phase measurement value P in FIG. 14(b): phase of the moiré fringes + deviation from the center position 54 of the image processing, As such, a measurement error occurs between the phase measurement value P in FIG. 14(a) and the phase measurement value P in FIG. 14(b).

[0061] On the other hand, when two moiré fringes are used as in Figure 14(c), Phase measurement value P in FIG. 14(c): {(phase A + deviation from the central position 54 of image processing) - (phase B + deviation from the central position 54 of image processing)} / 2 = (Phase A - Phase B) / 2 This makes it possible to cancel out any deviation from the central position 54 of the image processing. In this way, the configuration using two moire fringes is advantageous in that it is robust against deviation from the central position 54 of the image processing.

[0062] In addition, for the length L0 of one period of the moiré fringes in Figure 8, L: L0 × Moire magnification By so doing, it is possible to obtain the length L of one period of the moiré fringes converted into the device coordinate system.

[0063] The measured value D2 of the moiré fringes can be calculated from the product of the length L and the measured phase value P. Since the range of phase A and phase B can only be from -π to +π, the range of D2 can also only be from -L / 2 to +L / 2, as shown in FIG. 9(a). Therefore, if the phase measured value P is shifted so much that it does not fall within the range from -π to +π, in other words, if there is a pitch shift, it is not possible to determine how many periods of pitch there is from only the phases A and B of the moiré fringes. In this case, the relative positional shift between the mold 7 and the substrate 8 cannot be calculated correctly.

[0064] Also, without using the phase measurement value P, Moire fringe measurement D2A: length L × phase A, Moire fringe measurement value D2B: length L × phase B It is also possible to obtain the measured value D2 of the moiré fringes by calculating (D2A-D2B) / 2. Considering the phase shift processing described later, it is preferable to use the measured value D2 of the moiré fringes in this method.

[0065] 8, it is possible to determine the number of periods of the pitch deviation from the value obtained by converting the relative positional deviation D1 between the mold-side mark 51a-1 and the substrate-side mark 52a-1 into the device coordinate system and the length L. Therefore, if both the moire fringes and the marks for rough alignment such as the mold-side mark 51a-1 and the substrate-side mark 52a-1 are used, Relative positional deviation between the mold 7 and the substrate 8: Pitch deviation period × L + D2 By doing so, the relative positional deviation between the mold 7 and the shot area of ​​the substrate 8 can be calculated with high accuracy. For example, if there is a deviation of −1 period pitch, Relative positional deviation between the mold 7 and the substrate 8: -L + D2 It becomes.

[0066] However, as in position 41 in FIG. 1(a), when phases A and B are near +π or -π (the positional misalignment between the mold and the substrate is near L / 2 or -L / 2), the phases A and B fluctuate by 2π depending on whether or not there is a pitch misalignment, and the phase measurement value P can also fluctuate by 2π. If phases A and B fluctuate by 2π, the measurement value D2 of the moiré fringes can also fluctuate by L. In this case, if the moiré fringes are ideal cosine waves, there is no problem, but because there is a manufacturing error in the alignment marks of the mold and the substrate, the moiré fringes become asymmetric cosine waves when viewed with an accuracy of several nm. Therefore, as shown in FIG. 9(b), for example, when the phase of the moiré fringes during curing is near +π or -π, the alignment result between the mold and the substrate fluctuates by about several nm depending on whether or not there is a pitch misalignment.

[0067] Therefore, in this embodiment, the processing unit 26 determines a phase shift amount for making the obtained phase measurement value a value outside a predetermined range including the phase discontinuity that causes the pitch shift. The processing unit 26 then performs a phase shift on the obtained phase measurement value by the determined phase shift amount, and determines the relative position based on the phase-shifted phase measurement value.

[0068] When phases A and B are within a predetermined range including a phase discontinuity (phases A and B are near the phase where the pitch is shifted), processing unit 26, for example, adds π to phase A and subtracts π from phase B. In this way, the phase where the pitch is shifted can be shifted by the absolute amount π.

[0069] When phase shifted with respect to phases A and B, Phase A': Phase A + phase shift amount (+π), Phase B': Phase B + phase shift amount (-π) If phases A' and B' are outside the range of -π to +π, 2nπ (n is an integer) is added so that phases A' and B' are within the range of -π to +π. Then, a measured value D2A' of the moiré fringes is found from phase A'. Also, a measured value D2B' of the moiré fringes is found from phase B'.

[0070] After that, taking into consideration pulling back half of L (the amount of phase shift of π), the measured value D2 of the moiré fringes is calculated by the following formula.

[0071] D2: (D2A'-D2B') / 2 - L / 2

[0072] This cancels out the phase shift amount, and makes it possible to determine the relative positional shift D2 between the mold 7 and the substrate 8 while avoiding the risk of pitch deviation. Therefore, where there is a possibility that the phase may vary by 2π, as in position 41 in Fig. 1(a), by shifting the phase and adding L (phase equivalent to 2π), it is possible to make D2 continuous, as in position 42 in Fig. 1(b).

[0073] Therefore, D2: (D2A'- D2B') / 2 - L / 2+L year, Relative positional deviation between the mold 7 and the substrate 8: Pitch deviation period × L + D2 1(b), D2 becomes continuous near position 42. This makes it possible to obtain the relative positional deviation between the mold 7 and the shot area of ​​the substrate 8 with high accuracy. Therefore, it is possible to prevent a decrease in the alignment accuracy between the mold and the substrate.

[0074] The amount of phase shift allows the most leeway in terms of positive and negative when the phase is shifted by π from the point where the phase switches, as in the above example, but other values ​​are also acceptable. Note that no phase shift and a phase shift with a phase shift amount of 0 are synonymous.

[0075] Also, the light and dark of the moiré fringes in FIG. 10(a) may be inverted and converted into moiré fringes as shown in FIG. 10(b) before calculating phases A' and B'. Inverting the light and dark of the moiré in this way can achieve a π phase shift in the phase measurement value. This makes it possible to make the phase continuous even if the positional deviation between the mold 7 and the substrate 8 during curing is around L / 2. This makes it possible to prevent a decrease in the alignment accuracy between the mold 7 and the substrate 8 due to pitch deviation.

[0076] However, it is necessary to judge whether or not to perform a π phase shift for phases A and B, or whether or not to invert the brightness of the moiré fringes. In order to make such a judgment, it is also necessary to know whether phases A and B at the target position during curing are near the boundary of the pitch deviation.

[0077] The process of acquiring the amount of misalignment between the circuit pattern on the mold and the alignment mark will be described with reference to Figures 15 and 16. Figure 15 is a flowchart of the imprint process for adjustment performed in the imprint apparatus 1, and Figure 16 is a flowchart of the substrate measurement process for adjustment performed in an external measuring device (not shown) in this process.

[0078] 15 is executed by the control unit 15 in the imprint apparatus 1. In step S1, the control unit 15 controls a mold transport mechanism (not shown) and a substrate transport mechanism (not shown) so that the mold 7 and the substrate 8 are carried into the imprint apparatus 1. In step S2, the control unit 15 controls the substrate driving mechanism 5 and the dispenser 6 to supply (place) the imprint material onto the shot area of ​​the substrate 8.

[0079] In step S3, the control unit 15 (processing unit 26) acquires images by capturing images of the mold side mark 10 of the mold 7 and the substrate side mark 11 of the substrate 8 (in the shot area thereof) by the imaging element 25. The control unit 15 (processing unit 26) processes the acquired images to determine the relative positional deviation amount between the alignment marks of the mold 7 and the substrate 8 (rough position detection). Regarding this relative positional deviation amount, not only the XY deviation but also the rotational deviation, the magnification deviation, and other higher-order component deviations may be calculated using multiple pieces of position information detected by the detector 3.

[0080] In step S4, based on the relative positional deviation amount calculated in step S3, the control unit 15 controls the driving mechanism (at least one of the mold driving mechanism and the substrate driving mechanism 5) so as to align the mold 7 with the shot area of ​​the substrate 8. In step 5, the control unit 15 controls the driving mechanism so as to bring the imprint material on the shot area of ​​the substrate 8 into contact with the mold 7 (rough alignment).

[0081] In step S6, the control unit 15 (processing unit 26) causes the image sensor 25 to capture images of the alignment substrate side mark 11 in the shot area of ​​the substrate 8 and the alignment mold side mark 10 of the mold 7 while the mold 7 is in contact with the imprint material on the substrate 8. In step S7, the processing unit 26 performs processing such as a discrete Fourier transform on the image (alignment mark image) obtained by imaging, and obtains phases A and B of two moiré fringes as shown in FIG.

[0082] In step S8, the processing unit 26 first obtains a measurement value D2 of the moiré fringes from the phases A and B. Since the alignment mold side mark 10 of the mold 7 and the alignment substrate side mark 11 of the substrate 8 have already been aligned in step S4 with little deviation, pitch deviation does not usually occur at the time of step S8. Therefore, the measurement value D2 of the moiré fringes is the relative position deviation amount between the mold and the substrate. However, the mold may be misaligned when contacted. Therefore, the processing unit 26 determines how many periods of pitch deviation there are from the value obtained by converting the relative position deviation D1 between the mold side mark 51a-1 and the substrate side mark 52a-1 into the device coordinate system and the length L. Thereafter, the processing unit 26 calculates the pitch deviation period × L + D2 to obtain the relative position deviation between the mold 7 and the substrate 8. In steps S6 to S8, it is also possible to calculate the relative position deviation between the mold 7 and the substrate 8 by steps equivalent to steps S106 to S112 described later.

[0083] In step S9, the control unit 15 controls the driving mechanism to align the mold 7 and the substrate 8 based on the relative positional deviation obtained in step S8 (precise alignment). At this time, it is preferable to align the mold 7 and the substrate 8 so that the relative positional deviation between them is zero.

[0084] In step S10, the control unit 15 controls the curing unit 2 to cure the imprint material. In step S11, the imprint material and Type 7 In step S12, the control unit 15 controls the substrate transport mechanism so that the substrate 8 is transported out of the imprint apparatus 1.

[0085] Although the above procedure is for one shot area, steps S1 to S11 may be repeatedly executed for each of a plurality of shot areas.

[0086] Next, the procedure of FIG. 16 (substrate measurement process (for adjustment)) is performed. In step S21, the substrate 8 processed according to the procedure of FIG. 15 is carried into the external measuring device. In step S22, the external measuring device measures the mark for the external measuring device on the substrate 8, and the alignment error is calculated. The alignment error can be, for example, an average of the alignment errors of the respective multiple shot areas on the substrate 8. In step S23, the control unit 15 of the imprint apparatus 1 acquires the alignment error obtained in step S22, and stores this alignment error in memory as the drawing error E of the mold 7, which is the amount of deviation between the circuit pattern and the alignment mark on the mold 7. In step S24, the substrate 8 is carried out from the external measuring device. By the above process, the drawing error E between the pattern of the mold 7 and the mold side mark 10 is obtained in advance.

[0087] 17(a) shows a diagram illustrating a process for setting parameters of the imprint apparatus. In step S100, the control unit 15 (processing unit 26) sets the alignment error read from the memory as a drawing error E in the imprint apparatus parameters during semiconductor manufacturing.

[0088] 18 and 19 show an example of the procedure of the imprint process during semiconductor manufacturing by the imprint apparatus 1. In step S101, the control unit 15 controls a mold transport mechanism (not shown) and a substrate transport mechanism (not shown) so that the mold 7 and the substrate 8 are carried into the imprint apparatus 1. In step S102, the control unit 15 controls the substrate driving mechanism 5 and the dispenser 6 to place the imprint material on the shot area of ​​the substrate 8.

[0089] In step S103, the control unit 15 (processing unit 26) acquires an alignment mark image by capturing images of the mold side mark 10 of the mold 7 and the substrate side mark 11 of the substrate 8 (in the shot area thereof) using the imaging element 25. The control unit 15 (processing unit 26) processes the acquired alignment mark image to determine the relative positional deviation amount between the alignment marks of the mold 7 and the substrate 8 (coarse position detection). Regarding this relative positional deviation amount, not only the XY deviation but also rotational deviation, magnification deviation, and other higher-order component deviations may be calculated using multiple pieces of position information detected by the detector 3.

[0090] In step S104, the control unit 15 controls the driving mechanism (at least one of the mold driving mechanism and the substrate driving mechanism 5) to align the mold 7 with the shot area of ​​the substrate 8 based on the relative positional deviation amount calculated in step S103 (rough alignment).

[0091] In step S105, the control unit 15 controls the drive mechanism so that the relative position between the mold 7 and the shot area is shifted (corrected) from the state aligned in step S103 in accordance with the drawing error E set as an imprint apparatus parameter. Thereafter, the control unit 15 controls the drive mechanism so that the imprint material on the shot area of ​​the substrate 8 comes into contact with the mold 7.

[0092] In step S106, the control unit 15 (processing unit 26) causes the image sensor 25 to capture images of the alignment substrate side mark 11 in the shot area of ​​the substrate 8 and the alignment mold side mark 10 of the mold 7 while the mold 7 is in contact with the imprint material on the substrate 8. In step S107, the processing unit 26 performs processing such as a discrete Fourier transform on the image obtained by capturing the image (alignment mark image) to obtain phases A and B (phase measurement values) of the two moiré fringes.

[0093] In step S108, the processing unit 26 determines whether the phases A and B obtained in step S106 are near the pitch shift of π+2nπ (n is an integer) (a predetermined range including a phase discontinuity). If the phases A and B are near the pitch shift, the process proceeds to step S109, and if not, the process proceeds to step S110.

[0094] In step S109, the processing unit 26 determines the amount of phase shift to, for example, π. In step S110, since phases A and B are not in the vicinity of a pitch shift, the processing unit 26 determines the amount of phase shift to 0. In steps S108, S109, and S110, the differences between the target phase and phases A and B may be obtained as the amount of phase shift.

[0095] In step S111, processing unit 26 uses phases A and B and the determined phase shift amount to obtain phases A' and B'. For example, if the phase shift amount is determined to be π, processing unit 26 calculates phase A+π and phase B-π. If the calculation result is not within the range of -π to +π, -2nπ (n is an integer) is further added to bring it into the range of -π to +π. The results obtained by such calculation are set as phases A' and B'.

[0096] In steps S109 and S111, if the phases A and B are in the vicinity of a pitch shift, the phases A' and B' may be obtained by performing a discrete Fourier transform after inverting the brightness of the moiré fringes as shown in Fig. 10. When the brightness of the moiré fringes is inverted, the amount of phase shift is π.

[0097] In step S112, the processing unit 26 first calculates a measurement value D2 of the moiré fringes from the phases A' and B'. Next, the processing unit 26 determines how many periods of pitch shift there are from a value obtained by converting the relative positional shift D1 between the mold-side mark 51a-1 and the substrate-side mark 52a-1 into the device coordinate system and the length L. Thereafter, the processing unit 26 calculates the pitch shift period × L + D2, and adds the phase shift amount × L to the calculation result to calculate the amount of relative positional shift between the mold 7 and the substrate 8.

[0098] In step S113, the control unit 15 controls the driving mechanism to perform alignment (precise alignment) so that the amount of relative positional deviation between the mold 7 and the substrate 8 obtained in step S112 becomes equal to the drawing error E. By this alignment, the circuit pattern of the mold 7 and the circuit pattern of the substrate 8 can be aligned with high precision.

[0099] In step S114, the control unit 15 controls the curing unit 2 to harden the imprint material. In step S115, the control unit 15 controls the drive mechanism to separate the imprint material and the substrate 8. In step S116, the control unit 15 determines whether the imprint process has been completed for all shot areas. If the imprint process has not been completed for all shot areas, the process returns to step S102, and the imprint process is performed for the next shot area. If the imprint process has been completed for all shot areas, the process proceeds to step S117. In step S117, the control unit 15 controls the substrate transport mechanism to transport the substrate 8 out of the imprint apparatus 1.

[0100] (Modification) FIG. 17(b) shows a diagram illustrating a process for setting imprint apparatus parameters according to a modified example. In step S200, the control unit 15 (processing unit 26) sets the alignment error read from the memory as a writing error E as an imprint apparatus parameter during semiconductor manufacturing. Next, in step S201, the processing unit 26 sets the amount of phase shift as an imprint apparatus parameter based on the writing error E and the length L. For example, the phase of the writing error is set as (Drawing error E / length L) * 2π The processing unit 26 then checks whether the phase of the drawing error E is in the vicinity of π+2nπ (n is an integer) where the phase shifts by the pitch (a predetermined range including a discontinuous portion of the phase). If the phase of the drawing error E is in the vicinity of the pitch shift, the processing unit 26 determines, for example, +π as the phase shift amount. If the phase of the drawing error E is not in the vicinity of the pitch shift, the processing unit 26 determines the phase shift amount as 0. Here, the difference between the target phase and the phase of the drawing error E may be obtained as the phase shift amount. The processing unit 26 sets the phase shift amount thus obtained as an imprint apparatus parameter.

[0101] 20 and 21 show an example of a procedure for an imprint process during semiconductor manufacturing using the imprint apparatus 1 according to a modified example. In step S202, the control unit 15 controls a mold transport mechanism (not shown) and a substrate transport mechanism (not shown) so that the mold 7 and the substrate 8 are carried into the imprint apparatus 1. In step S203, the control unit 15 controls the substrate driving mechanism 5 and the dispenser 6 to place the imprint material on the shot area of ​​the substrate 8.

[0102] In step S204, the control unit 15 (processing unit 26) acquires an alignment mark image by capturing images of the mold side mark 10 of the mold 7 and the substrate side mark 11 of the substrate 8 (in the shot area thereof) by the imaging element 25. The control unit 15 (processing unit 26) processes the acquired alignment mark image to determine the relative positional deviation amount between the alignment marks of the mold 7 and the substrate 8 (coarse position detection). Regarding this relative positional deviation amount, not only the XY deviation but also the rotational deviation, the magnification deviation, and other higher-order component deviations may be calculated using multiple pieces of position information detected by the detector 3.

[0103] In step S205, the control unit 15 controls the driving mechanism (at least one of the mold driving mechanism and the substrate driving mechanism 5) to align the mold 7 with the shot area of ​​the substrate 8 based on the relative positional deviation amount calculated in step S204 (rough alignment).

[0104] In step S206, the control unit 15 controls the drive mechanism so that the relative position between the mold 7 and the shot area is shifted by the writing error E set as an imprint apparatus parameter from the state aligned in step S205. Thereafter, the control unit 15 controls the drive mechanism so that the imprint material on the shot area of ​​the substrate 8 and the mold 7 come into contact with each other.

[0105] In step S207, the control unit 15 (processing unit 26) causes the image sensor 25 to capture images of the alignment substrate side mark 11 in the shot area of ​​the substrate 8 and the alignment mold side mark 10 of the mold 7 while the mold 7 is in contact with the imprint material on the substrate 8. In step S208, the processing unit 26 performs processing such as a discrete Fourier transform on the image obtained by capturing the image (alignment mark image) to obtain phases A and B of the two moiré fringes.

[0106] In step S209, the processing unit 26 obtains phases A' and B' using the phases A and B obtained in step S208 and the phase shift amount set in step S201. For example, if the phase shift amount is set to π, the processing unit 26 calculates phase A+π and phase B-π. If the calculation result is not within the range of -π to +π, -2nπ (n is an integer) is further added so that it falls within the range of -π to +π. The results obtained by such calculation are set as phases A' and B'. In steps S208 and S209, if the phase shift amount set in step S201 is π, the phases A' and B' may be obtained by inverting the brightness of the moiré fringes and then performing a discrete Fourier transform.

[0107] In step S210, the processing unit 26 first calculates a measurement value D2 of the moiré fringes from the phases A' and B'. Next, the processing unit 26 determines how many periods of pitch shift there are from a value obtained by converting the relative positional shift D1 between the mold-side mark 51a-1 and the substrate-side mark 52a-1 into the device coordinate system and the length L. Thereafter, the processing unit 26 calculates the pitch shift period × L + D2, and adds the phase shift amount × L to the calculation result to calculate the amount of relative positional shift between the mold 7 and the substrate 8.

[0108] In step S211, the control unit 15 controls the driving mechanism to perform alignment (precise alignment) so that the amount of relative positional deviation between the mold 7 and the substrate 8 obtained in step S210 becomes equal to the drawing error E. By this alignment, the circuit pattern of the mold 7 and the circuit pattern of the substrate 8 can be aligned with high precision.

[0109] In step S212, the control unit 115 controls the curing unit 2 to cure the imprint material. In step S213, the imprint material and Type 7 In step S214, the control unit 15 determines whether imprint processing has been completed for all shot areas. If imprint processing has not been completed for all shot areas, the process returns to step S203, and imprint processing is performed for the next shot area. If imprint processing has been completed for all shot areas, the process proceeds to step S215. In step S215, the control unit 15 controls the substrate transport mechanism to transport the substrate 8 out of the imprint apparatus 1.

[0110] 15, S102 in Fig. 18, and S203 in Fig. 20, the imprint material may be supplied to the substrate before the substrate is carried into the imprint apparatus 1. In addition, in the above-described embodiment, the calculation process using the phase shift is one example, and if the results match even when the sign is inverted or the calculation order is changed, it falls within the scope of the present invention.

[0111] <Embodiment of the article manufacturing method> 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.

[0112] 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.

[0113] Next, a method for manufacturing an article will be described. In step SA of Fig. 12, a substrate 1z such as a silicon substrate having a workpiece 2z such as an insulator formed on its surface is prepared, and then an imprint material 3z is applied to the surface of the workpiece 2z by an inkjet method or the like. Here, a state in which the imprint material 3z in the form of multiple droplets is applied onto the substrate is shown.

[0114] In step SB of Fig. 12, the mold 4z for imprinting is placed with the side on which the concave-convex pattern is formed facing the imprint material 3z on the substrate. In step SC of Fig. 12, the substrate 1z to which the imprint material 3z has been applied is brought into contact with the mold 4z, and pressure is applied. The imprint 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 imprint material 3z is cured.

[0115] 12, 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.

[0116] In step SE of Fig. 12, etching is performed using the pattern of the cured material as an etching-resistant mask, and the portions of the surface of the workpiece 2z where there is no cured material or where only a thin layer remains are removed to form grooves 5z. In step SF of Fig. 12, the pattern of the cured material is removed to obtain an article in which grooves 5z are formed on the surface of the workpiece 2z. 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.

[0117] 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]

[0118] 1: imprint device, 2: curing unit, 3: detector, 4: mold driving mechanism, 5: substrate driving mechanism, 6: dispenser, 7: mold, 8: substrate, 9: imprint material, 10: mark, 11: mark, 15: control unit

Claims

1. 1. An imprinting apparatus for contacting a pattern area of ​​a mold with an imprint material on a substrate to form a pattern on the substrate, comprising: a position detection device that detects a relative position between the mold and the substrate based on an image obtained by capturing an image of a mold side mark arranged on the mold and a substrate side mark arranged on the substrate; a control unit that controls a position of at least one of the mold and the substrate based on a result of detection by the position detection device; Equipped with the mold side mark includes a first diffraction grating having a grating pattern arranged in a first direction and a first mark for coarse alignment; the substrate-side mark includes a second diffraction grating having a grating pattern arranged in the first direction at a pitch different from that of the first diffraction grating, and a second mark for coarse alignment; the position detection device includes a processing unit that detects, from the image, a moire image generated by overlapping the first diffraction grating and the second diffraction grating, performs a periodic analysis of a luminance distribution of the detected moire, obtains a phase measurement value of the luminance distribution based on a result of the periodic analysis, and obtains the relative position based on the phase measurement value; The processing unit includes: performing rough position detection between the mold and the substrate based on an image of the first mark and an image of the second mark in the image; determining a phase shift amount for making the obtained phase measurement value a value outside a predetermined range including a phase discontinuity; performing a phase shift for shifting the obtained phase measurement value by the determined phase shift amount, and determining the relative position based on the phase shifted phase measurement value; The control unit is performing rough alignment between the mold and the substrate based on a result of the rough position detection; After the coarse alignment, a relative position between the mold and the substrate is corrected according to a drawing error between the pattern of the mold and the mold side mark obtained in advance based on the phase measurement value after the phase shift, thereby performing a precise alignment between the mold and the substrate, and then contacting the pattern area of ​​the mold with the imprint material on the substrate; the position detection device captures images of the mold-side mark and the substrate-side mark in a state in which the pattern area of ​​the mold and the imprint material on the substrate are in contact with each other; 1. An imprint apparatus comprising:

2. 2. The imprint apparatus according to claim 1, wherein the processing unit determines the amount of phase shift to be π when the obtained phase measurement value is within the predetermined range, and determines the amount of phase shift to be 0 when the obtained phase measurement value is outside the predetermined range.

3. The imprint apparatus according to claim 2 , wherein when the phase shift amount is determined to be π, the processing unit realizes a π phase shift of the phase measurement value by inverting light and dark of the moire.

4. 4. The imprint apparatus according to claim 1, wherein the control unit performs the precision alignment so that the relative position calculated based on the phase measurement value to which the phase has been shifted by the processing unit is equal to the drawing error.

5. the mold side mark further includes a third diffraction grating having a grating pattern arranged in the first direction at the same pitch as the second diffraction grating, the substrate-side mark further includes a fourth diffraction grating having a grating pattern arranged in the first direction at the same pitch as the first diffraction grating, the processing unit detects, from the image, a first moire image generated by overlapping the first diffraction grating and the second diffraction grating, and a second moire image generated by overlapping the third diffraction grating and the fourth diffraction grating, obtains a first phase measurement value of a luminance distribution of the first moire and a second phase measurement value of a luminance distribution of the second moire, and obtains the phase measurement value based on a difference between the first phase measurement value and the second phase measurement value.

5. The imprint apparatus according to claim 1, wherein the imprint apparatus is a liquid crystal display.

6. The imprint apparatus according to claim 5 , wherein the processing unit performs the phase shift by adding the phase shift amount to the first phase measurement value and subtracting the phase shift amount from the second phase measurement value.

7. forming a pattern on a substrate by the imprint apparatus according to claim 1; A step of processing the substrate on which the pattern is formed; and manufacturing an article from the substrate on which the processing has been performed.

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