Imprinting apparatus and article manufacturing method

Abstract

To provide an advantageous technique for improving an alignment accuracy.SOLUTION: An imprint device includes: an irradiation part that performs a first light irradiation for partially hardening an imprint material on a substrate and a second light irradiation for deforming the substrate; and a control part that controls the irradiation part. The control part switches the first light irradiation and the second light irradiation on the basis of an elastic performance of the imprint material and a deformation amount of the substrate in an alignment step of performing an alignment of a mold and the substrate.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] There is an imprinting apparatus that forms a pattern made of a cured product of the imprinting material on a substrate by contacting a mold with the imprinting material on the substrate and curing the imprinting material. Patent Document 1 describes a step of irradiating light onto at least a part of the imprinting material on the substrate during alignment to improve the alignment accuracy between the mold and the substrate, thereby increasing the viscoelasticity of the imprinting material (pre-exposure step). Patent Document 2 describes a step of heating the patterning area of ​​the substrate so as to reduce the difference in shape between the patterning area of ​​the mold and the patterning area of ​​the substrate (heating step). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-058735 A [Patent Document 2] JP 2013-102132 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the alignment step, it is possible to carry out the above-mentioned preliminary exposure step and heating step in sequence.

[0005] However, if the viscoelasticity of the imprint material is maximized in the pre-exposure step, the bonding strength between the substrate and the mold will be increased, which may make it difficult to deform the pattern area of ​​the substrate as desired in the subsequent heating step, making it difficult to achieve the desired alignment accuracy.

[0006] The present invention provides an advantageous technique for improving alignment accuracy. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided an imprinting apparatus that aligns a substrate and a mold with the imprinting material on the substrate in a state where the mold is in contact with the imprinting material, and then hardens the imprinting material by light irradiation, the imprinting apparatus comprising: a light irradiation unit that performs a first light irradiation for partially hardening the imprinting material and a second light irradiation for deforming the substrate; a measuring device that measures a vibration amount of the substrate or a substrate stage that holds and transports the substrate; a control unit for controlling the light irradiation unit, wherein the control unit performs the following in the alignment: corresponding to the vibration amount Viscoelasticity of the imprint material To and switching between the first light irradiation and the second light irradiation is performed based on the detected light. Effect of the Invention

[0008] According to the present invention, it is possible to provide an advantageous technique for improving alignment accuracy. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the configuration of an imprint apparatus. [Diagram 2] FIG. 2 is a diagram showing an example of the configuration of a light source unit. [Diagram 3] FIG. 1 is a diagram for explaining a conventional imprint process. [Figure 4] 5A to 5C are views for explaining an imprint process in the embodiment. [Diagram 5] 6 is a diagram showing the relationship between the viscoelasticity of an imprint material and the vibration amount of a substrate stage. [Figure 6] 5A and 5B are diagrams for explaining a method of measuring an alignment mark by a detector. [Figure 7] 6A to 6C are diagrams showing changes in viscoelasticity of an imprint material during a preliminary exposure process. [Figure 8] 6A to 6C are diagrams showing changes in the amount of thermal deformation of a pattern formation region of a substrate during a heating process. [Figure 9] 5A to 5C are views for explaining an imprint process in the embodiment. [Figure 10] 5A to 5C are views for explaining an imprint process in the embodiment. [Figure 11] 1A to 1C are diagrams illustrating a method for manufacturing an article according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] 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.

[0011] First Embodiment 1 shows the configuration of an imprint apparatus 1 in one embodiment. The imprint apparatus 1 performs an imprint process, thereby forming a pattern made of a cured product of the imprint material IM on a substrate S. The imprint process can include a contact step, an alignment step, and a curing step. The contact step is a step of bringing the imprint material IM on the substrate S into contact with the mold M. The alignment step is a step of aligning the substrate S with the mold M after the contact step. The curing step is a step of curing the imprint material IM by light irradiation after the alignment step.

[0012] The imprint material is a photocurable composition that is cured by irradiation with light. The photocurable composition 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 may be arranged on the substrate in the form of droplets, or in the form of islands or films formed by connecting a plurality of droplets. The viscosity of the imprint material (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, and resins. If necessary, a member made of a material different from 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.

[0013] 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 S 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. Alignment of the substrate S or a region thereof with the mold M or a region thereof may include control of the position and / or attitude of at least one of the substrate S and the mold M. Furthermore, alignment may include control for correcting or changing the shape of at least one of the substrate S and the mold M.

[0014] The imprint apparatus 1 may include a substrate driving mechanism SD that holds and drives the substrate S, a base frame BF that supports the substrate driving mechanism SD, and a mold driving mechanism MD that holds and drives the mold M. The substrate driving mechanism SD and the mold driving mechanism MD constitute a driving mechanism DRV that drives at least one of the substrate driving mechanism SD and the mold driving mechanism MD so as to adjust the relative position between the substrate S and the mold M. The adjustment of the relative position by the driving mechanism DRV includes driving for contact of the mold M with the imprint material IM on the substrate S, and for separation of the mold M from the hardened imprint material IM (pattern of the cured product).

[0015] The substrate driving mechanism SD may include a substrate holder SH that holds the substrate S, a substrate stage SS that supports the substrate holder SH, and a substrate driving actuator SM that drives the substrate stage SS to drive the substrate S. The substrate driving mechanism SD may be configured to drive the substrate S about multiple axes (e.g., three axes, the X-axis, the Y-axis, and the θZ-axis, and preferably six axes, the X-axis, the Y-axis, the Z-axis, the θX-axis, the θY-axis, and the θZ-axis). The position and attitude of the substrate S may be controlled based on the results of measuring the position and attitude of the substrate S by a measuring instrument 29.

[0016] The mold driving mechanism MD may include a mold holding part MH that holds the mold M, and a mold driving actuator MM that drives the mold M by driving the mold holding part MH. The mold holding part MH may include a mold deformation mechanism that deforms the mold M. The mold deformation mechanism may deform the mold M, for example, by applying a force to the side of the mold M. The mold driving mechanism MD may be configured to drive the mold M about a plurality of axes (for example, three axes of the Z axis, the θX axis, and the θY axis, and 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 M has a pattern area in which a pattern to be transferred to the imprint material IM on the substrate S by the imprint process is formed. The mold driving mechanism MD may include a pressure regulator PC that deforms (the pattern area PR of) the mold M into a convex shape toward the substrate S or flattens it by adjusting the pressure of the space SP on the back side (opposite side to the pattern area PR) of the mold M. With the mold M deformed into a convex shape toward the substrate S, contact between the imprint material IM on the substrate S and the pattern area PR is initiated, and then the pressure regulator PC can adjust the pressure in the space SP so that the contact area between the imprint material IM and the pattern area PR gradually expands.

[0017] The imprint apparatus 1 may include a dispenser 5 that supplies, applies or places the imprint material IM on the substrate S. However, the imprint material IM may be supplied, applied or placed on the substrate S in an apparatus external to the imprint apparatus 1.

[0018] The imprint apparatus 1 may include a light source (curing light source) 2 for irradiating the imprint material IM between the substrate S and the mold M (pattern region PR) with light 9 (curing light) for curing the imprint material IM in the curing step, onto an optical path LP. The optical path LP is an optical path that leads to the substrate S via the mold M and the imprint material IM. The imprint apparatus 1 may further include a detector 12 for detecting the relative positions of the alignment marks provided on the substrate S and the alignment marks provided on the mold M. The detector 12 may illuminate the alignment marks provided on the substrate S and the alignment marks provided on the mold M with detection light 15, and capture images formed by these alignment marks. The detection light 15 is also understood as light irradiated onto the optical path LP.

[0019] The imprint apparatus 1 may further include an imaging unit 6 for detecting the contact state between the imprint material IM on the substrate S and (the pattern area PR of) the mold M, or the filling state of the imprint material IM in the space between the substrate S and (the pattern area PR of) the mold M. The imaging unit 6 may also be used to detect foreign matter between the substrate S and the mold M. The imaging unit 6 may illuminate a layered structure consisting of the substrate S, the imprint material IM, and the mold M with observation light 18, and capture an image formed by this layered structure. The observation light 18 may also be understood as light irradiated to the optical path LP.

[0020] The imprint apparatus 1 may further include a light source unit 20 (light irradiation section) that irradiates the light path LP with modulated light 21. As described later, the light source unit 20 includes a spatial light modulator, and irradiates the light path LP with modulated light 21, which is light modulated by the spatial light modulator. The modulated light 21 may include a first modulated light that partially hardens the imprint material IM and a second modulated light that deforms the substrate S for alignment between the substrate S and the mold M. It is preferable that when the first modulated light is irradiated to the light path LP, the second modulated light is not irradiated to the light path LP, and when the second modulated light is irradiated to the light path LP, the first modulated light is not irradiated to the light path LP. However, both the first modulated light and the second modulated light may be irradiated to the light path LP as long as the period during which the modulated light 21 is irradiated to the light path LP is sufficiently short. The first modulated light and the second modulated light are lights having wavelength ranges that do not overlap with each other. Alternatively, the first modulated light and the second modulated light may be lights having peaks at different wavelengths.

[0021] The first modulated light has a wavelength that hardens the imprint material IM, in other words, a wavelength that increases the viscosity (viscoelasticity) of the imprint material IM. The first modulated light can be light modulated to increase the viscosity of the imprint material IM at any point in the pattern formation region of the substrate S, thereby increasing the bonding strength between the substrate S and the mold M by the imprint material IM. Such irradiation of the first modulated light (first light irradiation) can be called vibration-controlled exposure, and is performed in the alignment process to improve alignment accuracy. In a state in which the bonding strength between the substrate S and the mold M by the imprint material IM is weak (before irradiation of the first modulated light), the substrate S and the mold M can vibrate individually due to disturbances, etc. (i.e., the relative vibration between the substrate S and the mold M is large). By partially increasing the viscosity of the imprint material IM by irradiating the imprint material IM with the first modulated light and increasing the bonding strength between the substrate S and the mold M, the relative vibration between the substrate S and the mold M can be reduced and the convergence of the alignment can be improved. In one example, increasing the viscosity (viscoelasticity) of the imprint material IM by irradiating it with the first modulated light so that the magnitude of the shear force generated by the relative movement between the substrate S and the mold M is within the range of 0.5 to 1.0 N is effective in improving the convergence of the alignment.

[0022] The second modulated light may be light modulated so that a light intensity distribution (illuminance distribution) that deforms the substrate S, more specifically, the pattern formation region (shot region) of the substrate S, into a target shape is formed on the substrate S. Irradiation of the substrate S with the second modulated light (second light irradiation) forms a temperature distribution on the substrate S, and this temperature distribution deforms the pattern formation region of the substrate S so as to approach the target shape. When alignment between the pattern formation region of the substrate S and the pattern region PR of the mold M is completed, a curing step (a step in which the curing light source 2 irradiates the imprint material IM with curing light and hardens the imprint material IM) is performed. The second modulated light is light having a wavelength that does not harden the imprint material IM.

[0023] The optical axes of the curing light source 2, the detector 12, the imaging section 6, and the light source unit 20 share the optical path LP. To achieve this, a synthesis mirror 22 and dichroic mirrors 23 and 24 are provided. The synthesis mirror 22 transmits the observation light 18 and reflects the modulated light 21. The dichroic mirror 23 transmits the observation light 18 and the modulated light 21 and reflects the detection light 15. The dichroic mirror 24 transmits the observation light 18, the modulated light 21, and the detection light 15 and reflects the curing light 9.

[0024] The imprint apparatus 1 may further include a control unit 7 that controls the above-mentioned substrate driving mechanism SD, mold driving mechanism MD, pressure regulator PC, dispenser 5, measuring instrument 29, curing light source 2, detector 12, imaging unit 6, light source unit 20, etc. The control unit 7 may be configured, for example, by a PLD (abbreviation for Programmable Logic Device) such as an FPGA (abbreviation for Field Programmable Gate Array), an ASIC (abbreviation for Application Specific Integrated Circuit), a general-purpose or dedicated computer with a built-in program, or a combination of all or part of these.

[0025] 2 shows a configuration example of the light source unit 20. The light source unit 20 may include a first light source 121 that generates a first light having a first wavelength range for generating a first modulated light, and a second light source 122 that generates a second light having a second wavelength range for generating a second modulated light. The light source unit 20 may also include a DMD (digital mirror device) 133 as a spatial light modulator that generates a first modulated light obtained by modulating the first light and a second modulated light obtained by modulating the second light. The light source unit 20 may also include an optical system (125, 126, 111, 132) that causes the first light from the first light source 121 and the second light from the second light source 122 to be incident on the DMD 133 as a spatial light modulator.

[0026] In one example, the light source unit 20 may be configured by connecting an illumination section 120 and a modulation section 130 with an optical fiber 110. The illumination section 120 may include a first light source 121, a second light source 122, a first controller 123, a second controller 124, and mirrors 125 and 126. The optical path of the first light generated by the first light source 121 and the optical path of the second light generated by the second light source 122 are made common by the mirrors 125 and 126, and are connected to an input section 111 of the optical fiber 110. An output section 112 of the optical fiber 110 is connected to the modulation section 130.

[0027] The first controller 123 controls the first light source 121 according to a command from the control unit 7. The control of the first light source 121 may include control of turning on and off the first light source 121. The control of the first light source 121 may further include control of the intensity of the first light generated by the first light source 121. For example, the first controller 123 may include a constant current circuit that supplies the first light source 121 with a current having a current value according to a command value from the control unit 7. Alternatively, the first controller 123 may include a drive circuit that drives the first light source 121 according to the command value, and a photoelectric conversion sensor that receives a part of the first light generated by the first light source 121, and may have a configuration that feeds back an output of the photoelectric conversion sensor to the drive circuit.

[0028] The second controller 124 controls the second light source 122 according to a command from the control unit 7. The control of the second light source 122 may include control of turning on and off the second light source 122. The control of the second light source 122 may further include control of the intensity of the second light generated by the second light source 122. For example, the second controller 124 may include a constant current circuit that supplies a current having a current value according to a command value from the control unit 7 to the second light source 122. Alternatively, the second controller 124 may include a drive circuit that drives the second light source 122 according to the command value, and a photoelectric conversion sensor that receives a part of the second light generated by the second light source 122, and may have a configuration that feeds back an output of the photoelectric conversion sensor to the drive circuit.

[0029] The control unit 7 can individually control the first light source 121 and the second light source 122. For example, the control unit 7 can control the first light source 121 and the second light source 122 so that when one of the first light source 121 and the second light source 122 is turned on, the other is turned off. From another perspective, a configuration can be adopted in which when one of the first light from the first light source 121 and the second light from the second light source 122 is incident on the spatial light modulator (DMD 133), the other of the first light and the second light is not incident on the spatial light modulator. This can be realized, for example, by the control of the first and second light sources 121 and 122 by the first and second controllers 123 and 124, or by a mechanism that selectively blocks one of the first light and the second light.

[0030] Here, an example of wavelength allocation for the curing light 9, the detection light 15, the observation light 18, and the modulated light 21 (first modulated light, second modulated light) will be described. The curing light 9 is light that cures the imprint material IM, and in one example, may have any wavelength range within the range of 300 nm to 380 nm, but may have a wavelength range of 300 nm or less. The detection light 15 is light for detecting an alignment mark, and in one example, has a wavelength range of 550 nm to 750 nm. The observation light 18 is light for observing the contact state between the imprint material IM and the mold M, and the filling state of the imprint material IM in the space between the substrate S and the mold M, etc. The observation light 18 may have a wavelength range selected from, for example, a wavelength range of 400 nm to 480 nm that does not overlap with the wavelength ranges of the curing light 9 and the detection light 15. The modulated light 21 includes a first modulated light having a wavelength range that cures the imprint material IM, and a second modulated light having a wavelength range that does not cure the imprint material IM.

[0031] The modulated light 21 may be selected from the same wavelength range as the observation light 18, for example, a wavelength range of 400 nm to 480 nm, so as not to overlap with the wavelength ranges of the curing light 9 and the detection light 15. The first modulated light is generated by the modulation section 130 (DMD 133) modulating the first light generated by the first light source 121. The second modulated light is generated by the modulation section 130 (DMD 133) modulating the second light generated by the second light source 122. The wavelengths of the first light generated by the first light source 121 and the second light generated by the second light source 122 can be determined from the upper limit of the wavelength range in which the imprint material IM is cured. For example, if the upper limit of the wavelength range in which the imprint material IM is cured is 440 nm, the wavelength of the first light generated by the first light source 121 can be set to about 410 nm, and the wavelength of the second light generated by the second light source 122 can be set to about 460 nm. The first light source 121 and the second light source 122 are preferably light sources that generate single-wavelength light with a narrow wavelength width, and are suitably, for example, laser diodes. Laser diodes are advantageous in that they can be switched on and off at high speed.

[0032] The light transmitted to the modulation unit 130 via the optical fiber 110 is incident on the DMD 133 as a spatial light modulator via the optical system 132. The optical system 132 may include, for example, a condensing optical system and an illumination system (for example, a microlens array) that homogenizes the light from the condensing optical system and illuminates the DMD 133. The DMD 133 includes a plurality of micromirrors (not shown) that reflect light, and an actuator that drives each of the plurality of micromirrors. Each actuator controls the corresponding micromirror to an angle of −12 degrees (ON state) or +12 degrees (OFF state) with respect to the array surface of the plurality of micromirrors according to a command from the control unit 7. The light reflected by the micromirror in the ON state forms an image on the substrate S as modulated light via an optical system 134 (projection optical system) that makes the DMD 133 and the substrate S in a conjugate relationship with the optical system. The light reflected by the micromirror in the OFF state is reflected in a direction that does not reach the substrate S. The area (maximum irradiation area) projected onto the substrate S when all the micromirrors are turned on is larger than the size of the maximum pattern formation area of ​​the substrate S. Instead of the DMD 133, another spatial light modulator, for example, a liquid crystal display (LCD), may be used.

[0033] The optical system constituting the modulation unit 130 needs to transmit both the first light (first modulated light) having a wavelength that cures the imprint material IM and the second light (second modulated light) having a wavelength that does not cure the imprint material IM. In addition, in a typical DMD, the maximum light intensity that can be irradiated onto the micromirror array decreases at wavelengths of 420 nm or less, and further, the maximum light intensity that can be irradiated onto the micromirror array drops drastically to about 1 / 1000 at around 400 nm, which is the boundary between ultraviolet light and visible light. Therefore, it is desirable to use a laser diode or the like with a short wavelength width to bring the wavelength of the first light source 121 and the wavelength of the second light source 122 close to the upper limit of the wavelength range in which the imprint material IM cures.

[0034] The control unit 7 may generate control data for controlling switching between the ON state and the OFF state of each micromirror of the DMD 133, based on, for example, data on the light intensity distribution (illuminance distribution) to be formed on the surface of the substrate S. The light intensity distribution data may include, for example, information on the time for which each micromirror is to be in the ON state and information on the time for which each micromirror is to be in the OFF state. The more micromirrors that are in the ON state and the longer the ON state is, the greater the amount of exposure light that can be applied to the pattern formation region of the substrate S.

[0035] The control unit 7 may include a memory that stores light intensity distribution data for modulating the first light to generate the first modulated light and light intensity distribution data for modulating the second light to generate the second modulated light. The light intensity distribution data for modulating the first light to generate the first modulated light may include light intensity distribution data for increasing the viscosity of the imprint material IM at an arbitrary location in the pattern formation region of the substrate S to increase the bonding force between the substrate S and the mold M via the imprint material IM.

[0036] The configuration in which the modulation section 130 is shared by the first light source 121 and the second light source 122 is advantageous for miniaturizing the modulation section 130 or the light source unit 20, thereby simplifying the structure of the imprint apparatus 1. This makes it easy to arrange the modulation section 130 near the optical path LP. The configuration in which the illumination section 120 and the modulation section 130 are separated from each other is advantageous for arranging the illumination section 120, which serves as a heat source, at a position far from the optical path LP of the imprint apparatus 1. However, the illumination section 120 and the modulation section 130 may be arranged in close proximity without using the optical fiber 110. Alternatively, the illumination section 120 may be incorporated into the modulation section 130. In addition, the first light source 121 and the modulation section 130 may be connected by a first optical fiber, and the second light source 122 and the modulation section 130 may be connected by a second optical fiber. In this case, the optical path of the first light emitted from the first optical fiber and the optical path of the second light emitted from the second optical fiber may be combined.

[0037] FIG. 3 shows a conventional operation example of the light source unit 20 in the imprint process executed by the imprint apparatus 1. The imprint process may include a contact step of bringing the imprint material IM on the substrate S into contact with the mold M, and an alignment step of aligning the substrate S and the mold M after the contact step. The imprint process may further include a curing step of curing the imprint material IM after the alignment step, and a separation step of separating the mold M from the cured imprint material IM. The contact step is a step of bringing the imprint material IM on the substrate S into contact with (the pattern region PR of) the mold M by the driving mechanism DRV. This contact step may be a period that starts, for example, when the imprint material IM on the substrate S starts to come into contact with the pattern region PR of the mold M that has been deformed into a convex shape, and ends when the entire area of ​​the pattern region PR is flattened. The imprint process includes a driving step, which is a step associated with the contact step, of bringing the imprint material IM on the substrate S and the mold M closer to each other by the driving mechanism DRV. In FIG. 3, the timing of each step in the imprint process is shown along the time axis.

[0038] In the alignment process, at least one of the substrate S and the mold M is driven by the drive mechanism DRV so that the pattern formation region of the substrate S and the pattern region PR of the mold M are aligned based on the results detected by the detector 12. Also, in the alignment process, the mold M can be deformed by the mold drive mechanism so that the pattern formation region of the substrate S and the pattern region PR of the mold M are aligned based on the results detected by the detector 12. Also, in the alignment process, a heating process described below can be executed so that the pattern formation region of the substrate S and the pattern region PR of the mold M are aligned based on the results detected by the detector 12.

[0039] The filling step proceeds in parallel with the alignment step. In the filling step, the imprint material IM between the substrate S and the pattern region PR of the mold M is filled into the recesses constituting the pattern of the pattern region PR, and the gaps existing between the substrate S and the pattern region PR of the mold M disappear. In one example, the filling step can start prior to the alignment step. FIG. 3 further shows the timing of the light modulation by the DMD 133 of the light source unit 20. The light modulation by the DMD 133 is performed in different modes in the preliminary exposure step A and the heating step B. In the preliminary exposure step A, the first modulated light generated by modulating the first light, which is light in a wavelength range that hardens the imprint material IM, is irradiated onto the optical path LP. In the preliminary exposure step A, the viscosity of the imprint material IM at a predetermined location in the pattern formation region of the substrate S is increased (vibration-damping exposure). The viscosity of the imprint material IM is partially increased, thereby increasing the bonding force between the substrate S and the mold M. This reduces the relative vibration between the substrate S and the mold M. In the heating step B, the second modulated light generated by modulating the second light, which is light in a wavelength range that does not harden the imprint material IM, is irradiated onto the optical path LP. The period (timing, length of time) of the preliminary exposure step A is appropriately determined so as to obtain a desired degree of vibration reduction. In the heating step B, in order to align the pattern formation region of the substrate S with the pattern region PR of the mold M, the substrate S is heated by irradiating the pattern formation region of the substrate S with the second modulated light, and the pattern formation region of the substrate S is deformed. The period (timing, length of time) of the heating step B can be determined so that the pattern formation region of the substrate S has a target shape at the time when the imprint material IM is hardened by the curing light 9 from the curing light source 2 in the hardening step.

[0040] If the viscoelasticity of the imprint material IM is maximized in the preliminary exposure process A, the bonding force between the substrate S and the mold M will become excessively strong, which may result in the deformation of the pattern formation area of ​​the substrate S not being as desired in the subsequent heating process B.

[0041] FIG. 3 shows an example of the change in viscoelasticity of the imprint material IM in the pre-exposure process A. In this example, it is assumed that the viscoelasticity of the imprint material IM is maximized in the pre-exposure process A. FIG. 3 further shows an example of the change in the amount of thermal deformation of the pattern formation region of the substrate S in the heating process B. In this example, it is shown that the actual amount of thermal deformation of the pattern formation region of the substrate S is only about 50% of the target amount of thermal deformation. As a result, accurate alignment of the pattern formation region of the substrate S with the pattern region PR of the mold M is hindered.

[0042] 4 shows an example of an imprint process in the embodiment. In the present embodiment, as described above, the light source unit 20 (light irradiation section) can perform a first light irradiation for partially curing the imprint material and a second light irradiation for deforming the substrate. In the present embodiment, the control section 7 switches between the first light irradiation and the second light irradiation based on the viscoelasticity of the imprint material IM and the deformation amount of the substrate S in the alignment step.

[0043] As shown in FIG. 4, in the alignment process, the preliminary exposure process A is performed. The first modulated light is irradiated by performing the preliminary exposure process A, and the viscoelasticity of the imprint material IM gradually increases. In the preliminary exposure process A, the control unit 7 monitors the state of the viscoelasticity of the imprint material IM. As described above, the first modulated light irradiated in the preliminary exposure process A increases the viscoelasticity of the imprint material IM in the pattern formation region of the substrate S, and reduces the relative vibration between the substrate S and the mold M. The higher the viscoelasticity, the smaller the vibration amount of the substrate S. FIG. 5 shows an example of the relationship between the viscoelasticity of the imprint material IM and the vibration amount of the substrate S. The control unit 7 can calculate the viscoelasticity of the imprint material IM based on the result of measurement by the measuring device 29 that measures the position (vibration amount) of the substrate S or the substrate stage SS that holds and transports the substrate S, and the relationship obtained in advance as shown in FIG. 5. Alternatively, the control unit 7 can calculate the viscoelasticity of the imprint material IM based on an image of the laminated structure of the substrate S, the imprint material IM, and the mold M obtained by imaging by the imaging unit 6.

[0044] In the preliminary exposure process A, a threshold value Sa (first threshold value) of the viscoelasticity of the imprint material IM is set as a criterion for terminating the preliminary exposure process A. The threshold value Sa is set, for example, to a value of the viscoelasticity when the binding force between the substrate S and the mold M is relatively weak, just before the viscoelasticity of the imprint material IM is maximized. The control unit 7 terminates the preliminary exposure process A and starts the heating process B at the timing when the viscoelasticity of the imprint material IM obtained by monitoring exceeds the threshold value Sa. That is, the control unit 7 switches from the first light irradiation to the second light irradiation in response to the viscoelasticity of the imprint material obtained during the execution of the first light irradiation exceeding the threshold value. The second modulated light is irradiated by the execution of the heating process B, and the thermal deformation amount of the pattern formation region of the substrate S gradually increases. In the heating process B, the control unit 7 monitors the state of the thermal deformation amount of the pattern formation region of the substrate S. The control unit 7 calculates the thermal deformation amount of the pattern formation region of the substrate S based on the measurement result by the detector 12 that detects the relative position between the alignment mark provided on the substrate S and the alignment mark provided on the mold M.

[0045] FIG. 6(a) shows an example in which alignment marks are provided at the corresponding four corners of the pattern formation region of the mold M and the substrate S. FIG. 6(b) shows that the detector 12 detects the alignment marks provided on the substrate S and the alignment marks provided on the mold M. When the pattern formation region of the substrate S is thermally deformed in the magnification direction by the execution of the heating step B, the state of FIG. 6(c) can be detected. When the pattern formation region of the substrate S is thermally deformed in the shift direction by the execution of the heating step B, the state of FIG. 6(d) can be detected. Although FIG. 6(c) and FIG. 6(d) show an example in which thermal deformation in the Y direction is measured, thermal deformation in the X direction is also measured at the same time. Based on these results, the amount of thermal deformation of the pattern formation region can be calculated.

[0046] In the heating step B, a threshold value Sb (second threshold value) of the amount of thermal deformation of the pattern formation region of the substrate S is set as a criterion for terminating the heating step B. The threshold value Sb can be set to, for example, 90% of the maximum deformation amount. The control unit 7 terminates the heating step B and starts the preliminary exposure step A again at the timing when the amount of thermal deformation of the pattern formation region of the substrate S exceeds the threshold value Sb. That is, the control unit 7 switches from the second light irradiation to the first light irradiation in response to the amount of deformation of the substrate obtained during the execution of the second light irradiation exceeding the threshold value Sb.

[0047] The viscoelasticity of the imprint material is maximized in the pre-exposure process A that is executed again. Since the heating process B is turned off during this pre-exposure process, the amount of thermal deformation of the substrate S can be reduced.

[0048] After the viscoelasticity of the imprint material is increased to its maximum in the second pre-exposure process A, the pre-exposure process A is completed and the heating process B is carried out again. Since the viscoelasticity of the imprint material has been increased to its maximum at the time of switching from the pre-exposure process A to the heating process B, the amount of thermal deformation of the pattern formation region of the substrate S is smaller than the target amount of deformation, but the error in the amount of thermal deformation finally generated can be kept to a minimum.

[0049] <Second embodiment> 7 shows an example of the change in viscoelasticity of the imprint material IM with respect to the elapsed time in the preliminary exposure process A. If such a relationship is known, the timing Ta at which the viscoelasticity reaches the threshold value Sa can be obtained in advance based on the relationship. In this case, as shown in FIG. 9, the preliminary exposure process A may be terminated and the process may move to the heating process B when the timing Ta has elapsed since the preliminary exposure process A was started. In this way, in the second embodiment, the control unit 7 switches from the first light irradiation to the second light irradiation in the alignment process based on the duration of the first light irradiation.

[0050] 8 shows an example of the change in the amount of thermal deformation of the pattern formation region of the substrate S with respect to the elapsed time in the heating step B. If such a relationship is known, the timing Tb at which the amount of thermal deformation reaches the threshold value Sb can be obtained in advance based on the relationship. In this case, as shown in FIG. 9, the heating step B may be ended at the point in time when the timing Tb has elapsed since the start of the heating step B, and the process may proceed to the second preliminary exposure step A. Thus, in the second embodiment, the control unit 7 switches from the second light irradiation to the first light irradiation in the alignment step based on the duration of the second light irradiation.

[0051] <Third embodiment> The number of times that the switching between the preliminary exposure process A and the heating process B, that is, the switching between the first light irradiation and the second light irradiation, is repeated is not limited to a specific number. The control unit 7 can repeat the switching between the preliminary exposure process A and the heating process B multiple times in the alignment process. FIG. 10 shows a process diagram in which the preliminary exposure process A and the heating process B are repeated three or more times. Also, as shown in FIG. 10, the heating process B may be performed before the preliminary exposure process A. Furthermore, for the viscoelasticity threshold Sa (first threshold) and the thermal deformation amount threshold Sb (second threshold), independent values ​​may be set for each switching between the preliminary exposure process A and the heating process B. For example, thresholds Sa1, Sa2, ..., SaN may be set for each switching from the preliminary exposure process A to the heating process B, and thresholds Sb1, Sb2, ..., SbM may be set for each switching from the heating process B to the preliminary exposure process A (N, M are any natural numbers). Based on these thresholds, the switching between the preliminary exposure process A and the heating process B may be performed.

[0052] <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.

[0053] 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.

[0054] Next, a method for manufacturing an article will be described with reference to Fig. 11. In step SA, 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 a plurality of droplets of the imprint material 3z are applied onto the substrate is shown.

[0055] In step SB, the imprinting mold 4z is placed facing the imprinting material 3z on the substrate with the side on which the concave-convex pattern is formed. In step SC, 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 hardening, the imprinting material 3z hardens.

[0056] In step SD, after the imprint material 3z is cured, the mold 4z and the substrate 1z are separated to form a pattern of the cured product of the imprint material 3z 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.

[0057] In step SE, 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, 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.

[0058] The disclosure of the present specification includes at least the following imprint apparatus and article manufacturing method. (Item 1) An imprinting apparatus for performing an imprinting process including an alignment step of aligning a substrate and a mold in a state where the mold is brought into contact with an imprinting material on the substrate, and a curing step of curing the imprinting material by light irradiation after the alignment step, a light irradiation unit that performs a first light irradiation for partially curing the imprint material and a second light irradiation for deforming the substrate; A control unit that controls the light irradiation unit; having the control unit switches between the first light irradiation and the second light irradiation based on the viscoelasticity of the imprint material and the deformation amount of the substrate in the alignment process. 1. An imprint apparatus comprising: (Item 2) The imprint apparatus of item 1, characterized in that, during the alignment process, the control unit switches from the first light irradiation to the second light irradiation in response to the viscoelasticity obtained during execution of the first light irradiation exceeding a first threshold value. (Item 3) The imprint apparatus described in item 2, characterized in that, in the alignment process, the control unit switches from the second light irradiation to the first light irradiation in response to the amount of deformation obtained during execution of the second light irradiation exceeding a second threshold value. (Item 4) 4. The imprint apparatus according to item 3, wherein the control unit repeats the switching a plurality of times in the alignment process. (Item 5) 5. The imprint apparatus of item 4, wherein independent values ​​are set for the first threshold value and the second threshold value for each switching. (Item 6) a measuring device that measures a vibration amount of the substrate or a substrate stage that holds and transports the substrate, The control unit calculates the viscoelasticity based on the vibration amount obtained by the measurement by the measuring instrument. 6. The imprinting apparatus according to any one of items 1 to 5, (Item 7) An imaging unit that images the imprint material on the substrate, The control unit calculates the viscoelasticity based on an image of the imprint material obtained by imaging by the imaging unit. 6. The imprinting apparatus according to any one of items 1 to 5, (Item 8) a detector for detecting a relative position between the mark provided on the substrate and the mark provided on the mold; The control unit calculates the deformation amount based on the relative position detected by the detector. 8. The imprinting apparatus according to any one of items 1 to 7, (Item 9) An imprinting apparatus for performing an imprinting process including an alignment step of aligning a substrate and a mold in a state where the mold is brought into contact with an imprinting material on the substrate, and a curing step of curing the imprinting material by light irradiation after the alignment step, a light irradiation unit that performs a first light irradiation for partially curing the imprint material and a second light irradiation for deforming the substrate; A control unit that controls the light irradiation unit; having the control unit switches from the first light irradiation to the second light irradiation based on a duration of the first light irradiation in the alignment process, and switches from the second light irradiation to the first light irradiation based on a duration of the second light irradiation. 1. An imprint apparatus comprising: (Item 10) The light irradiation unit includes: a first light source that generates a first light that partially cures the imprint material; a second light source that generates a second light that deforms the substrate for the alignment; a spatial light modulator that generates a first modulated light obtained by modulating the first light and a second modulated light obtained by modulating the second light; 10. The imprinting apparatus according to any one of items 1 to 9, comprising: (Item 11) 11. The imprinting apparatus of item 10, wherein the spatial light modulator includes a digital mirror device. (Item 12) Forming a pattern on a substrate by the imprint apparatus according to any one of items 1 to 10; processing the substrate on which the pattern is formed; and manufacturing an article from the substrate.

[0059] 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]

[0060] 1: imprint device, 20: light source unit, M: mold, S: substrate, IM: imprint material, 121: first light source, 122: second light source, 133: DMD, 130: modulation section

Claims

1. 1. An imprinting apparatus that aligns a substrate and a mold in a state where the mold is brought into contact with an imprinting material on a substrate, and then cures the imprinting material by light irradiation, a light irradiation unit that performs a first light irradiation for partially curing the imprint material and a second light irradiation for deforming the substrate; a measuring device that measures a vibration amount of the substrate or a substrate stage that holds and transports the substrate; A control unit that controls the light irradiation unit; having the control unit switches between the first light irradiation and the second light irradiation based on a viscoelasticity of the imprint material corresponding to the vibration amount during the alignment.

1. An imprint apparatus comprising:

2. 2. The imprint apparatus of claim 1, wherein the control unit switches from the first light irradiation to the second light irradiation in response to the viscoelasticity obtained during execution of the first light irradiation exceeding a first threshold during the alignment.

3. The imprint apparatus according to claim 2, characterized in that the control unit switches from the second light irradiation to the first light irradiation in response to a deformation amount of the substrate obtained during execution of the second light irradiation during the alignment exceeding a second threshold value.

4. The imprint apparatus according to claim 3 , wherein the control unit performs the switching a plurality of times during the alignment.

5. The imprint apparatus according to claim 4 , wherein the first threshold value and the second threshold value are set for each switching.

6. Further comprising a detector for detecting a relative position between a mark provided on the substrate and a mark provided on the mold; The control unit calculates the deformation amount based on the relative position detected by the detector. The imprint apparatus according to claim 3 .

7. An imprinting apparatus for aligning a substrate and a mold in a state where the mold is brought into contact with an imprinting material on the substrate, and then curing the imprinting material by light irradiation, comprising: a light irradiation unit that performs a first light irradiation for partially curing the imprint material and a second light irradiation for deforming the substrate; An imaging unit that images the imprint material; A control unit that controls the light irradiation unit; having the control unit, during the alignment, switches between the first light irradiation and the second light irradiation based on a viscoelasticity of the imprint material obtained from an image of the imprint material captured by the imaging unit.

1. An imprint apparatus comprising:

8. The imprinting apparatus of claim 7, characterized in that the control unit switches from the first light irradiation to the second light irradiation in response to the viscoelasticity obtained during execution of the first light irradiation exceeding a first threshold value during the alignment.

9. The imprint apparatus of claim 8, characterized in that the control unit switches from the second light irradiation to the first light irradiation in response to the amount of deformation of the substrate obtained during execution of the second light irradiation during the alignment exceeding a second threshold value.

10. The imprinting apparatus of claim 9, characterized in that the control unit performs the switching multiple times during the alignment.

11. An imprinting apparatus as described in Claim 10, characterized in that the first threshold value and the second threshold value are set for each switching.

12. a detector for detecting a relative position between the mark provided on the substrate and the mark provided on the mold; The control unit calculates the deformation amount based on the relative position detected by the detector. The imprint apparatus according to claim 9 .

13. The light irradiation unit includes: A first light source that generates a first light that partially cures the imprint material; a second light source generating a second light for deforming the substrate for the alignment; a spatial light modulator that generates a first modulated light obtained by modulating the first light and a second modulated light obtained by modulating the second light; The imprinting apparatus according to claim 1 ,

14. The imprinting apparatus of claim 13 , wherein the spatial light modulator comprises a digital mirror device.

15. The light irradiation unit is A first light source that generates a first light that partially cures the imprint material; a second light source generating a second light for deforming the substrate for the alignment; a spatial light modulator that generates a first modulated light obtained by modulating the first light and a second modulated light obtained by modulating the second light; The imprinting apparatus according to claim 7 , comprising:

16. The imprinting apparatus described in Claim 15, characterized in that the spatial light modulator includes a digital mirror device.

17. A step of forming a pattern on a substrate by an imprinting apparatus according to any one of claims 1 to 16; processing the substrate on which the pattern is formed; and manufacturing an article from the substrate.

Images